HSC Agriculture - Animal Production Notes & Classwork Instructions PDF

HSC AGRICULTURE 1. ANIMAL PRODUCTION HSC AGRICULTURE ANIMAL PRODUCTION CLASS NOTES (detailed)  HSC AGRICULTURE 1. ANIMAL PRODUCTION ANIMAL PRODUCTION Animal nutrition RUMINANT AND MONOGASTRIC DIGEST...

HSC AGRICULTURE 1. ANIMAL PRODUCTION HSC AGRICULTURE ANIMAL PRODUCTION CLASS NOTES (detailed)  HSC AGRICULTURE 1. ANIMAL PRODUCTION ANIMAL PRODUCTION Animal nutrition RUMINANT AND MONOGASTRIC DIGESTION (copy this with big bold dot, it’s the lesson heading) LEARN TO = compare the similarities and differences in the physiology of ruminant and monogastric digestion - Digestion is the physical, chemical and sometimes microbial breakdown of food into a soluble form that the animals can absorb - Two most common systems are the monogastrics and the ruminant digestive systems: Monogastrics (pigs, poultry, horses) – have only one stomach and for digestion these animals depend on the activity of enzymes produced by their own digestive glands Ruminants (sheep, cattle, goats) – have four stomachs including a large rumen. The rumen contains a population of bacteria, protozoa and anaerobic fungi which are responsible for digesting much of the feed including cellulose  HSC AGRICULTURE 1. ANIMAL PRODUCTION Organ Monogastrics Ruminants Mouth Digestion begins in Saliva is free from digestive enzymes but mouth where starch is acts as a chemical pH buffer to keep the broken down physically rumen pH neutral (6 - 7) This enables by chewing and microbes in rumen to survive. Food is chemically by action of physically broken down by chewing saliva (which contains an enzyme which acts on the starch molecule to break it down) Stomach(s) Monogastrics have one Ruminants have four stomachs: stomach. Hydrochloric The rumen is a large muscular acid (HCl) and enzymes fermentation chamber and contains a act on food molecules to large population of microbes (bacteria, break them down to protozoans and anaerobic fungi) smaller molecules – Microbes secrete enzymes which assist carbohydrates are broken in three processes: down into simple sugars i) breakdown of carbs (starch, cellulose, and proteins are broken sugars) into fatty acids down into amino acids ii) synthesis of proteins (making of) iii) synthesis of vitamin B The rumen has moving muscular walls which cause the contents to be churned up and mixed. Food is regularly retuned to mouth for regular chewing The reticulum (2nd stomach) is closely joined to rumen and has a similar function. Together, they are referred to as the Paunch. Reticulum also has a strong muscular wall and internal tissue has a honeycomb pattern on it. Microbes continue to release enzymes here The omasum (3rd stomach) sometimes called ‘the bible’ because of leaf-like partitions that line walls. Omasum removes 60 – 70% of the water from the rumen fluid that enters it The abomasum (4th stomach) is the ‘true stomach’. Here, gastric juices are secreted which contain both enzymes (to digest proteins) as well as the HCl (which kills the microbes that have been washed down from the rumen) These microbes are then digested to release amino acids from their body protein Small Digestion is completed Enzymes are secreted by the small Intestine here and amino acids, intestine. Here the starch, proteins and glucose and lipids (fats) fats are broken down into soluble  HSC AGRICULTURE 1. ANIMAL PRODUCTION are absorbed into the compounds which are absorbed into the blood stream through the blood stream through the villi. Any villi projections that line undigested food resides pass into the the small intestine large intestine Large Water is removed from Further digestion of food occurs in the Intestine food residues. large intestine by bacteria. Water is Undigested food residues removed here from food residues. The are expelled as faeces residues pass into the rectum and are through the anus expelled as faeces through the anus Ruminants advantages: Can digest cellulose effectively Upgrade low quality feeds (i.e. hay) to release volatile fatty acids (VFA) which can be ingested by microbes and also released as an energy source into the blood stream Ruminants can make protein from urea (which contains nitrogen) and other non-protein sources of nitrogen Can produce vitamin B by microbial action Ruminants disadvantages: Ruminant digestive system is inefficient – energy is lost as heat, methane and CO2 Animals have to eat for many hours to meet nutritional requirements Any ingested high quality protein (i.e. young legume pasture) has its nutritional value depressed as energy is wasted converting it into microbial protein Ruminant animals are susceptible to bloat Monogastrics advantages: Spend less time eating Do not suffer from bloat More efficient converting feed to bodyweight (food conversion ratio)/product (meat…) Monogastrics disadvantages: Cannot upgrade low quality feeds or produce vitamins Cannot digest cellulose Ruminant digestion: 1. Carbohydrate digestion – Ruminant diet contains large quantities of carbohydrates (cellulose, sugars and starch) Mature pastures contain mainly cellulose and high concentrate feeds (i.e. cereal grains which are fed in feed lots) contain mainly starch Carbohydrates are digested in the rumen Microbes in the rumen secrete enzymes which digest (break down) complex carbohydrates (i.e. starch) into simple sugars These simple sugars are then taken up and metabolised by microbes in rumen Products released by the microbes are volatile fatty acids (acetic, propionic and butyric acid) as well as methane gas and CO2 These VFAs are absorbed into blood through the rumen wall and carried to the liver VFAs are used as the main energy source by the ruminant animal  HSC AGRICULTURE 1. ANIMAL PRODUCTION If methane builds up in rumen = bloat (rich clover pastures will incline ruminants to bloat) ] 2. Protein digestion Food proteins (i.e. protein in legumes) are broken down into peptides and amino acids by the rumen microbes Some amino acids (protein building blocks) are further broken down into organic acids, ammonia and CO2 At the same time, rumen microbes build microbial protein from amino acids and nitrogenous substances (i.e. ammonia – NH3, and non-protein nitrogen – urea, in the food) When microbes (which have built protein) in the rumen die, they travel through the digestive tract to the abomasum and the small intestine where their cell proteins are broken down to small amino acids which are absorbed into the bloodstream Important feature formation of microbial protein is that rumen microbes are capable of synthesising (making) essential amino acids as well as non-essential amino acids Thus essential amino acids do not have to be supplement/supplied in animals diet  HSC AGRICULTURE 1. ANIMAL PRODUCTION HSC Practise: (2020) (2017)  HSC AGRICULTURE 1. ANIMAL PRODUCTION BENEFICIAL RELATIONSHIPS BETWEEN MICROBES AND ANIMALS INCLUDING THE ROLE OF MICROBES IN ANIMAL DIGESTION LEARN TO = describe the relationship between the ruminant and rumen microbes The rumen is a large muscular fermentation chamber and contains a large population of microbes (bacteria, protozoans and anaerobic fungi) Microbes secrete enzymes which assist in three processes: 1. Breakdown of carbs (starch, cellulose, sugars) into fatty acids 2. Synthesis of proteins (making of, e.g. from urea) 3. Synthesis of vitamin B An important feature of the formation of microbial protein is that bacteria in the rumen are capable of synthesising both essential and non-essential amino acids. This means essential amino acids do not have to be supplied in the animal’s diet. Theoretically this means an animal could exist without the consumption of true protein. HSC Practise: (2021)  HSC AGRICULTURE 1. ANIMAL PRODUCTION THE FATE OF ENERGY IN ANIMAL NUTRITION LEARN TO = construct a diagram to illustrate the energy losses associated with digestion and metabolism in animals Only part of total energy in food is available for use by body as losses of energy occur in urine, faeces, gas and heat - Energy requirements of animals are usually considered under two headings: 1. Maintenance Energy Requirements – consists of amount of energy needed to keep animal alive and healthy but does not allow for growth or production. Maintenance energy is directed towards muscular work (walking, breathing etc) and keeping the body warm 2. Production Energy Requirements – additional energy needed for forms of production i.e. growth, pregnancy and lactation. Production energy is directed towards storing chemical energy in the body during growth and supplying chemical energy contained in milk or eggs  HSC AGRICULTURE 1. ANIMAL PRODUCTION MANAGING THE NUTRITIONAL REQUIREMENTS OF MONOGASTRICS AND RUMINANTS IN TERMS OF THEIR DIGESTIVE PHYSIOLOGY LEARN TO = design and explain a ration to meet the nutritional requirements of a selected animal for a particular stage of production - 400kg beef steer - May requires 49.0 MJ energy / day - May requires 12% protein - Sources of energy for cattle: - Cattle can receive nutrients from roughages and concentrates - Grazing cattle survive on roughages (pasture) however feedlot cattle and grazing cattle in drought times can be supplemented with concentrates (grains) - Cattle raised on roughage need to have concentrates introduced slowly into their diet (if concentrates initially exceed 40% of total diet, could result in rapid fermentation of starch leading to accumulation of acid in rumen, causing metabolic disorder known as acidosis or grain poisoning). Microbes in the rumen die - Roughages should make up the bulk of the diet however concentrates are useful in lower quantities to supply energy need for the production of meat - Cattle sent to feedlots are weaned onto a high concentrate diet - Typical feedlot entry weights for steers/heifers = 400-450kg LWT. - The extra energy supplied enables these animals to be ‘finished’ at higher liveweights in a shorter time frame - The energy from grain also promotes marbling of the meat muscle (the laying down of intramuscular fat – it is highly desired in restaurants and export markets, especially Japan) - Questions 25,26,27 P.83  HSC AGRICULTURE 1. ANIMAL PRODUCTION LEARN TO = use nutritional data to determine the suitability of animal feeds in terms of energy and protein requirements for particular production stages for one monogastric and one ruminant Monogastric = Broiler (meat chicken) Starter (chick) Requires 0.26 MJ energy / day Requires 22% protein Finisher (3 months old) Requires 1.17 MJ energy / day Requires 19% protein Q’s Use Table 5.5 Common Horse Feeds 1. How much Lucerne would a Starter chick require per day to meet energy needs? 2. Would lucerne be a suitable total feed? Justify. 3. How much Lucerne would a Finisher chick require per day to meet energy needs? 4. Would lucerne be a suitable total feed? Justify. 5. How much Soybean meal would a Starter chick require per day to meet energy needs? 6. Would Soybean meal be a suitable total feed? Justify. 7. How much Soybean meal would a Finisher chick require per day to meet energy needs? 8. Would Soybean meal be a suitable total feed? Justify. Composition of a Typical Broiler Feed % Wheat 45.0 Sorghum 25.0 Soyabean Meal 12.0 Canola Meal 8.0 Meat & Bone Meal 7.0 Tallow 2.0 Lysine 0.3 Methionine 0.2 Vitamins & Trace Minerals 0.5 TOTAL 100  HSC AGRICULTURE 1. ANIMAL PRODUCTION Ruminant = beef steer 200kg maintenance Requires 27.0 MJ energy / day Requires 9.0% protein 450kg maintenance Requires 49.0 MJ energy / day Requires 9.5% protein POTENTIAL FEED Lucerne hay = 9.2 MJ/kg and 16% protein How many kg of lucerne hay would each class of stock require to meet energy requirements? Would lucerne be a suitable total feed?  HSC AGRICULTURE 1. ANIMAL PRODUCTION Animal growth and development CHANGES IN THE PROPORTION OF MUSCLE, FAT AND BONE DURING THE LIFE OF AN ANIMAL a. compare the proportions of bone, muscle and fat at various stages of development in an animal and relate these to consumer needs - Development of body tissues over time: - Please copy below: An ideal carcase of a beef cattle has: - Minimum bone - Maximum muscle - Optimum fat Fat enhances flavour and stops carcase drying out Older animals have a higher percentage of fat to bone and muscle, have smaller proportions of retail cuts in the loin, ribs and forequarters and have bigger flanks and briskets (cheaper cuts) At the same weight or age, females are generally fatter because they mature faster. Early maturing breeds (e.g. Herefords, Angus, Murray Gray) at the same age have more fat than later maturing animals Muscle and fat scoring – used to grade the quality of an animal Muscle is scored from A (heavy muscle) to E (little muscle) Fat is scored from 1 (lean) to 6 (fat)  HSC AGRICULTURE 1. ANIMAL PRODUCTION Consumers require meat that is: - Of consistent quality - Convenient or easy to cook and prepare - Versatile (different meal ideas) - Inexpensive Market specifications – a description of type of carcase that buyers require For beef cattle, AUS-MEAT is the standard language for market specifications across Australia 1. Live weight – weight of animal before slaughter 2. Fat score – used to rank the fatness of an animal and on cattle, P8 site is the standard site where fat depth is measured on the carcase. This is on the rump of the animal 3. Hot Standard Carcase Weight (HSCW) – the weight of the animal after it has been killed and dressed. Dressing involves removing inedible parts like hooves, skin and internal organs 4. Dressing percentage – affected by time of last feed before slaughter, liveweight and fatness level, stress level, sex and breed  HSC AGRICULTURE 1. ANIMAL PRODUCTION Factors affecting carcass composition: - Breed: Carcasses of dairy cattle are leaner (less fat) than those of beef cattle - Sex: Females have a greater proportion of fat and a lower proportion of muscle than males. - Nutrition: If growth is restricted by nutrition, fat is most affected, then muscle. Bone growth is rarely affected  HSC AGRICULTURE 1. ANIMAL PRODUCTION MANAGEMENT PRACTICES TO OPTIMISE GROWTH AND DEVELOPMENT a. evaluate management techniques available to farmers to manipulate growth and development including use of hormone growth promotants (HGPs), feed additives and genetics - As a young animal gets older two changes occur: 1. It increases in size and weight – growth 2. The proportions of various parts of its body change – development - Growth has a marked effect on - Time of selling an animal - Feed requirements - Type of carcase produced - Fast growth rates are desirable so that animals reach slaughter weight as quickly as possible - Fast growth rates will result from animals that have high food conversion efficiencies - Fast growth rates result in faster stock turnover - Most animals have an S-shaped curve with an initial period of limited growth, followed by rapid weight gain before maturity and then weight and height stabilises HORMONE GROWTH PROMOTANTS (HGP’s) Growth promotants have been used in recent years to increase growth in farm animals. These compounds are similar to sex hormones, and are often called anabolic steroids. Growth promotants will only be profitable when feed supplies are plentiful. In steers the promotant (Ralgro) is a pellet which is implanted under the skin behind the ear. Small amounts of steroid are released gradually over a 2 month period. They reduce the chance of there being drug residues in the meat, the treated animal needs to be withheld from slaughter for sufficient time to enable the carcass levels of synthetic hormone to decrease. Many countries ban the import of meat that has been treated with anabolic steroids.  HSC AGRICULTURE 1. ANIMAL PRODUCTION - According to Food Standards (ANZ) HGPs have been used safely in Australia for 30 years and are used on approx 40% of Australian cattle. This is estimated to add $210m to the industry annually. Negative consumer sentiment towards use of these promotants have resulted from studies showing residues in meat. Many people fear these residues, if eaten, will have adverse effects on the consumer – hormone imbalances, premature puberty in children, increased cancer risks. GENETICS Crossbreeding: mating of two (or more) different breeds. Advantages include a large genetic pool, offspring inherit the best qualities of both breeds, offspring often show additional vigour (hybrid vigour or heterosis) and are more productive than either parent. FEED ADDITIVES Farmers feed young animals high levels of protein and energy to ensure growth is maximised. It is also important to include fats, vitamins and minerals as part of a balanced diet. As animals mature, the producer can modify the quantities of protein and energy in rations when growth begins to slow. Higher levels of energy can be fed to animals to increase the deposits of intermuscular and intramuscular fat. This may assist in meeting marketing requirements for animal products or to ensure that animals are in adequate condition for breeding.  HSC AGRICULTURE 1. ANIMAL PRODUCTION Animal reproduction and genetics THE ROLE OF HORMONES IN THE REGULATION OF ANIMAL REPRODUCTION AND BEHAVIOUR a. describe how hormones regulate reproduction and behaviour in animals including testosterone, oestrogen, progesterone, prostaglandin, follicle stimulating hormone and luteinising hormone [Read from textbook P.99 initially & individually] * CORRECTION! P.97 is the start in BOB interface - Oestrus largely determined by a hormone called oestrogen – oestrus is the period of sexual receptivity - During or shortly after oestrus (heat) ovulation occurs – the releasing of an ovum from the ovary into the upper part of the uterine tube - Essential that if an animals ova are to be fertilised then joining/AI must take place during oestrus - Farmers must become familiar with their animals behaviour to recognise when oestrus occurs - Behaviour i.e. restless, more active, bellowing, mounting other cows, stand to be ridden. If her flanks are muddy (from other cows attempting to mount her) and her vulva is moist, swollen and discharging clear mucous then she is on heat - The pituitary gland (located at base of brain) and the ovaries (back end of animal in her reproductive organs section. 2 ovaries, one on each side of the uterus, situated in lower abdomen) secrete hormones - Oestrus and ovulation are brought about by a series of steps: i) The pituitary gland releases FSH (follicle stimulating hormone) which travels in blood stream to ovaries. FSH stimulates growth of Graafian follicle ii) Oestrogen levels in blood increase until pituitary reduces FSH and increase LH (luteinising hormone) iii) LH secreted by pituitary causes follicle to rupture and ovum to be released and if the animal is inseminated, the ovum may be fertilised. Ruptured follicle forms a corpus luteum iv) Corpus luteum secretes progesterone and oestrogen – if fertilised, production of progesterone continues through pregnancy (progesterone depresses production of FSH and ovarian follicles cannot develop further i.e. when progesterone levels are high, oestrus and ovulation cannot occur) v) In non-pregnant animals corpus luteum persists for up to 16 days. Progesterone decreases and as corpus luteum regresses the pituitary gland releases FSH again continuing cycle - Maintaining healthy, well nourished cattle ensures that cows have the best chance of ovulating regularly and bulls have high sperm counts as well as to meet the demands of growing foetuses  HSC AGRICULTURE 1. ANIMAL PRODUCTION - Behaviour changes occur when an animal is pregnant, largely due to the high levels of progesterone - Progesterone maintains the pregnancy as it stimulates the development of the walls of the uterus which nourished the embryo - Progesterone and oestrogen stimulate the growth of mammary gland in preparation for lactation – necessary for all animals except poultry - Parturition (birth) is brought about by intricate interactions between the foetal, placental and mothers hormones – some parts of these are still not fully understood. It is known that the mothers hormone balance changes, the passage through the cervix and the vagina enlarge, continuous contractions of uterine wall force foetus through cervix into vagina and finally through vulva - Prostaglandin is naturally produced by the uterus and terminates the normal cycle when a cow is not pregnant. This allows the cow to return to heat, ovulate and start a new cycle. Prostaglandins will synchronize heat only if cows are cycling; however, they are not effective on all days of the estrous cycle. TASK: Complete Q’s 16-21 (CH6P99) TASK: Complete printed past paper responses on interplay of hormones. TASK: use 12 Agriculture - NESA HSA Examination resources booklet (Canvas) to answer ALL multiple choice questions on ‘hormones’ (Ctrl-f). Record paper Year and Question number (e.g. 2016 Q2). TASK: Copy Figure 6.8 (p.98)  HSC AGRICULTURE 1. ANIMAL PRODUCTION b. explain the interaction between hormones in an animal’s oestrus cycle  HSC AGRICULTURE 1. ANIMAL PRODUCTION FACTORS THAT LIMIT THE FERTILITY OF FARM ANIMALS a. identify the factors that limit fertility of farm animals including genetics, environment, pests and diseases, management and nutrition Factors affecting fertility include: 1. Genetics: - Genetic differences exist between species and between breeds of the same species - A sow can produce eleven piglets/litter compared to a ewe producing typically 1-3/pregnancy or a cow producing 1 calf per year. - Border Leicester’s generally lamb at a higher percentage (twins multiples) than Merinos. - Some animals are infertile because of inherited genetic abnormalities in the anatomy of reproductive or endocrine glands. 2. Nutrition: - Rate of development of reproductive organs and onset of puberty are determined by body weight (more so than age) - Mature females on a low plane of nutrition and below normal body weight will have irregular oestrus cycles, lower ovulation rates and decreased fertility. Offspring of such an animal will be smaller and weaker - Ewes are often given additional feed shortly before and during the joining period – this is called flushing and will increase ovulation rate and fertility (potential number of foetuses) - Feeding animals a high plane of nutrition in later stages of pregnancy increases foetal growth and may result in higher birth weights - Overfeeding may lead to oversized progeny - can lead to dystocia (difficult birth) - A deficiency in vitamin A prevents normal sperm formation and overfeeding/excessive fatness may reduce libido (sexual drive) 3. Climate: - Two main aspects of climate affect reproduction: i) Temperature (determined principally by latitude and altitude) – high temps increase embryonic mortality and reduce birth weights in piglets and lambs – low birth weights produce weak animals and increased chance of death. High temps reduce sperm production and make sperm abnormal. Adequate shelter and water should be provided during joining in summer. Combination of low temps, wet and windy weather may lead to heavy losses of newborns. ii) Day length – breeding season is dependent on day length. Polyoestrous animals (pigs, cattle) do not rely on seasons so much, however, seasonally dependent animals (horses, sheep, goats) are more likely to breed in particular months of the year. The change in the ratio of hours of daylight to hours of darkness controls breeding activity. * Think - how could this be manipulated by farmers? 4. Disease:  HSC AGRICULTURE 1. ANIMAL PRODUCTION - Any disease that affects the health and vitality of animals may reduce reproductive capacity. Diseases may affect reproductive organs themselves i.e. some infections stop production of sperm/ova or prevent the passage of the sperm/ova along the reproductive tract. Other diseases result in a lack of implantation of the embryo or abortion of the foetus during pregnancy. Leptospirosis produces high fever and abortion in cows and Vibriosis results in infertility and abortion in ewes and cows * Task - research vaccine product names for the prevention of aforementioned diseases. 5. Management: - Farmers can improve fecundity and fertility of animals by the following management practices i) Accurately detecting heat when inseminating ii) Selectively culling in order to remove infertile animals iii) Determining the optimum mating time so breeding activity is at its highest iv) Prevent and control diseases and parasites v) Provide animals with adequate nutrition – the relative types/quantities of feed vi) Provide sufficient male animals so that all females are mated * Task - research the recommended ratio for joining of both ewes and cows  HSC AGRICULTURE 1. ANIMAL PRODUCTION REPRODUCTIVE TECHNIQUES a. evaluate management techniques available to farmers to manipulate reproduction in farm animals including artificial insemination, multiple ovulation, flushing, embryo transfer and oestrus synchronisation [Copy Diagram above] 1. ARTIFICIAL INSEMINATION Advantages Relatively inexpensive Increased production - is the main reason for using AI on dairy cattle. AI-bred dairy cattle produce about 10–16 kg more fat and protein per lactation than their naturally-bred herd mates. Disease control By using AI and licensed semen, venereal diseases (i.e. diseases usually spread by the bull during mating) can be eliminated from a herd. Sire availability The wide choice of bulls within each breed allows flexible breeding programs and greatly facilitates crossbreeding. Safety AI allows the elimination of dangerous bulls on the farm. Better records AI requires good records which will aid better management of the herd. Disadvantages Careless bull selection, semen processing, storage and careless use of semen, may result in damage to the health and general production level of the herd. A dirty or careless inseminator may spread disease. Deep uterine insemination of a pregnant cow may result in abortion. There may be some inconvenience in holding cows for service. View semen under microscope prior to AI: https://drive.google.com/file/d/1ZBDZlyQIkVhnvXFH_0UqUsFRkrrzPf69/view? usp=drive_link  HSC AGRICULTURE 1. ANIMAL PRODUCTION [Below - Read Table 2.7 only] 2. MULTIPLE OVULATION - INCREASING OVULATION RATE - Aims to increase the number of multiple births Methods: - Permanent 1. Crossing with other breeds that naturally produce more twins/triplets 2. Select with the flock/herd for animals that have had multiple births or were a twin/triplet - Temporary 1. Inject with Follicle Stimulating hormone (FSH) 2. Specific vaccine that immunizes against their own hormones including progesterone 3. Potential - melatonin implant (Google - Regulin) 3. FLUSHING (Repeated from previous) Ewes are often given additional feed shortly before and during the joining period – this is called flushing and will increase ovulation rate and fertility (potential number of foetuses).  HSC AGRICULTURE 1. ANIMAL PRODUCTION Extension understanding: if ewes are exposed to green feed (actively growing), flushing with high nutrition feed will have no effect. This is due to the ewe receiving high protein feed from the green pasture, which her body interprets as good seasonal conditions (and therefore opportune time to conceive). 4. EMBRYO TRANSFER The process that involves flushing fertilized embryos from a donor (ewe, cow) and implanting them into a recipient to create a surrogate pregnancy. Benefits: a. Obtain more calves more quickly than natural reproduction, especially from high EBV females b. Frozen embryos stored and used later c. Frozen embryos transported place to place (even between countries) d. Embryos can be split to give 4 or more new embryos e. Embryos can be sexed e.g. dairy industry – only implant female embryos Disadvantages: See Textbook P.104 5. OESTRUS CONTROL / SYNCHRONISATION Two common Oestrus control/synchronisation methods - - Progesterone Treatment - Prostaglandin injection (summarise below)  HSC AGRICULTURE 1. ANIMAL PRODUCTION Consolidation Activity: Complete the HSC Examination questions below. * Note - this is from the HSC EXAM 2001 Q6 (old syllabus, however, for revision purposes this section is very similar to the current syllabus) HSC EXAM 2018 Q24 Complete Q24, with reference to the Maring Guidelines below. Note - ‘answers could include’ means just that - they are possible - but not an exhaustive list.  HSC AGRICULTURE 1. ANIMAL PRODUCTION BREEDING SYSTEMS AND THEIR GENETIC BASIS TO IMPROVE QUALITY AND PRODUCTION OF ANIMALS a. discuss the use of breeding systems in animal production systems including crossbreeding and line breeding benefits - Mating (joining) is quite distinct from the selection of breeding stock - Farmer will decide which animals are placed together - Breeding systems include: 1. Inbreeding: mating of close relatives (brother and sister, father and daughter) Produces a uniform line. Generally illadivsed. 2. Linebreeding: a type of inbreeding based on a single common ancestor (sire or dam) used over several generations of mating. Its value depends on the degree of superiority of the outstanding animal used. Linebreeding will result in a limited genetic pool for the herd and all offspring have similar characteristics and results are predictable. Line breeding has the same problem as inbreeding as undesirable traits can appear 3. Outbreeding: breeding of completely unrelated animals of the same breed. New genes are brought into the herd all the time 4. Crossbreeding: mating of two (or more) different breeds. Advantages include a large genetic pool, offspring potentially inherit the best qualities of both breeds, offspring often show additional vigour (hybrid vigour or heterosis) and are potentially more productive than either parents. Typically ‘terminal’ production (progeny are not retained for breeding). b. outline the role of objective measurement and heritability on the breeding programs of farms, using at least one specific industry program as an example In the cattle industry, Breedplan is a program used to determine the genetic potential of male and female animals within that breed. Measurements are taken (eg live weight at various ages, fat depth) to be consolidated in a database and matched to an animal ID to produce a breeding index. This assists in improving productivity of the beef cattle system. `  HSC AGRICULTURE 1. ANIMAL PRODUCTION Consolidation Activity: 2017 HSC Q24.C  HSC AGRICULTURE 1. ANIMAL PRODUCTION Animal pests and diseases ANIMAL DISEASE a. investigate the complex interaction between the problem organism, the host and the environment for one animal disease Micro-organisms cause disease by entering a host, multiplying and leaving the host. Infection depends on the following: existence of pathogen transfer of pathogen Invasion of host by pathogen Establishment of pathogen in host where host’s barriers are overcome The establishment of disease causing microorganisms is demonstrated by the disease triangle [Copy 10.2, p.146) ADD Disease triangle Key points: symptoms show extent of disruption by disease Spread of Pathogens to new Host View p. 147 of Dynamic Ag & copy the 5x Methods of transmission Resistance and Immunity in Animals Complete Q’s 18,19,20 (p.147)  HSC AGRICULTURE 1. ANIMAL PRODUCTION INTEGRATED PEST MANAGEMENT (IPM) a. research using secondary sources an IPM program for an animal production system Copy Definition: Integrated pest management (IPM) the use of two or more methods to control pests or diseases Summarise the Basic steps involved in the development of any IPM program from p.153 (there are 6x). TASK: Evaluate an IPM program naming the target organism and the animal host. Include at least two methods of control. For each method develop a brief description, advantages, disadvantages and a judgement of this process. b. evaluate an IPM program, naming the target organism and the animal host MASTITIS Cause - bacteria entering the udder. (i.e. Staphylococcus aureus) Can affect one or more quarters of the udder. An infected quarter becomes swollen and sore. Milk contains pus. This disease results in a loss of milk production. The bacterial infection is spread through a herd by: - A lack of cleanliness in the dairy - Dirty milking cups - Muddy yards - Poor milking techniques IPM involves using several strategies to control pests or pathogens Two or more control methods are used together or integrated i.e. chemical control is used in conjunction with genetic and management control IPM aims to keep or maintain pest populations at the lowest level Examples of use of IPM in controlling animal disease: Mastitis i) Management Control: to prevent bacterial infection procedures include: - Spraying iodine on cow’s teats after milking to prevent bacterial infection in teat (bacteria may have been transferred from milking cup) - Washing udders with water (if muddy) before milking cows - Hygienic conditions in dairy shed and holding yards to prevent a build up of faeces that can harbour bacteria. Yard and milking stalls must be regularly washed down - Culling cows that suffer from mastitis infections to minimise the possibility of transferring the infection to other cows  HSC AGRICULTURE 1. ANIMAL PRODUCTION ii) Chemical Control - infected cows are given antibiotics and isolated from other milking cows. Their milk is not combined with rest of milking herd as there is no tolerance to antibiotic residue in milk for sale iii) Quarantine Control - keeping infected animals isolated from the rest of the milking herd  HSC AGRICULTURE 1. ANIMAL PRODUCTION Revision Q’s (2019 Trial)  HSC AGRICULTURE 1. ANIMAL PRODUCTION Animal ethics and welfare ETHICS, WELFARE AND LEGAL ISSUES AND REQUIREMENTS a. illustrate how knowledge and understanding of animals’ physical and behavioural characteristics can assist in the management of a particular animal species (TASK - for the Green and Red sections please do your own summary of the information (this means pick the important parts from each and every paragraph)) Two physical characteristics of cattle and relate this knowledge to better management. These physical characteristics are: vision hearing. Vision Cattle are prey species and have eyes on either side of their head. This enables them to have a wide field of view known as panoramic vision (330°) but only a narrow band of binocular vision where their two eyes work together (25 - 30°). They have a blind spot behind them (30°).  HSC AGRICULTURE 1. ANIMAL PRODUCTION It has also been shown that cattle have slit shaped pupils and weak eye muscles, which inhibits their ability to focus quickly on objects. What does this mean? Cattle can detect sudden movement better than humans but are very slow to focus quickly on close objects, as they need to turn and face the movement and then view with both eyes to calculate distance. This means that they often don’t see gateways if the gates are not directly in front of them within their 25 - 30° of binocular vision. It also means that they frighten easily if handlers suddenly enter their field of vision without warning. Similarly, flapping flags and wind blown objects or papers can catch cattle unaware and frighten them. It also means that cattle need to be given the opportunity to turn, look at the handler and focus. This is important when a handler puts pressure on animals, expecting them to move. Cattle need to be given time to look and then move in the desired direction. Having a blind spot behind them means that cattle will more than likely kick if the handler enters the blind spot too closely or unannounced. It also means that when cattle are being pressured they will turn to face the pressure, e.g. handler or dog, so that they can see what it is that is pressuring them. Generally, animals react to contrast and brightness, causing them to baulk going into shaded areas, yards with different coloured panels and highly reflective surfaces and other areas where there are large contrast in colours. This means that shiny containers lying in yards, clothing hanging on fences and gates or shadows from fences, trees or vehicles can all cause cattle to refuse to move through gateways and along races. Hearing Cattle are very sensitive to high-pitched noises. Handlers yelling, dogs barking, whistles and cracking whips can all increase the heart rate of cattle causing stress. Research has shown that dairy breeds are more sensitive to sound than beef breeds. Calm cattle are always easier to move and handle than agitated and anxious animals. Management strategies that decrease the stress caused to the animals, allow more efficient movement or handling and improve handler safety and reflect an understanding of the physical characteristics of cattle include: Allow cattle time to focus on gateways Allow cattle the opportunity to see the handler or dog that is pressuring them  HSC AGRICULTURE 1. ANIMAL PRODUCTION Avoid coming from the animal’s blind spot directly behind them without warning Remove shiny and reflective objects from yards that may cause them to baulk Remove objects hanging on gate and fence posts that may cause them to baulk Avoid using barking dogs, whistles and whips when working cattle in yards. Some BEHAVIOURAL CHARACTERISTICS of cattle and how an understanding of them can be used to improve handling techniques: Herd instinct Social order Flight zone. Herd instinct As cattle are prey species, they tend to feel most comfortable within the herd, not as individuals isolated from their group. This is particularly noticeable when animals are threatened by a predator or handler, they mob together. This characteristic of cattle assists when the aim is to muster a group grazing in a paddock and bring them into yards or move them to another paddock. But it can also make the job of drafting cattle into smaller groups or splitting herds more difficult. The aim is always to use the group to get them where you want them to go. Isolating individuals should be avoided unless necessary for a particular purpose, specifically the handler should avoid getting between the isolated individual and the herd. Handling isolated cattle can be dangerous as the animal is usually very stressed. It is generally easier to return the individual to the mob, making handling safer for both the animal and handler. Social order Like many species, cattle develop social orders within herds. When herds are moved and individuals from different herds nixed, aggression often occurs until the new order is established. Butting and pushing are signs of aggression. Young bulls often show signs of playfulness but this can develop into more aggressive behaviours as they age and become territorial. Adult bulls often fight, particularly when they are crowded in gateways and yards.  HSC AGRICULTURE 1. ANIMAL PRODUCTION Individual cattle may be picked on by more dominant individuals and may therefore be better suited to life in a group with other individuals that are less aggressive. Care should be taken when yarding groups to limit the chance of individuals being injured and stressed. This stress can adversely affect the animal’s production in particular the quality of the animals’ meat. This is most likely when the cattle are horned. Flight zones Most animals have a flight zone. The ones that don’t are usually stud animals or hand raised school animals that are completely tame. When a handler approaches an animal, the point at which the animal starts to turn and move away is recognised as its flight distance. When this distance is measured right around the animal, the circle is the flight zone. The flight zone is an animal’s personal space. If the handler penetrates the flight zone the animal’s flight or fight sense is triggered. An individual animal’s flight zone will vary depending on how calm it is. The flight zone gets bigger when it becomes excited. This can happen when animals are moved, mixed with unfamiliar individuals, transported, yarded or exposed to a range of stimuli such as dogs, bikes or vehicles. To generate movement of cattle, the handler must penetrate the flight zone. If the animal cannot move away from the handler, it will attempt to run past or even over the handler. When the handler wishes to move cattle, they should move in and out of the animals’ flight zone. It is usually desirable not to keep pressuring animals.  HSC AGRICULTURE 1. ANIMAL PRODUCTION Groups of cattle will have a collective flight zone. Better cattle management by understanding their behavioural characteristics - To make cattle move forward in a race, the handler should walk in the opposite to direction to the way the cattle are facing. - To make cattle move backwards in a race, the handler should walk in the same direction to the way the cattle are facing. - Basic principles that can be used to help move cattle in open paddocks: o ◦The handler should alternate moving into the collective flight zone and out of the collective flight zone. Alternating pressure is more effective than continuous pressure. o ◦Move in straight lines and do not circle around animals. o ◦Do not chase individual animals as they will move back into the herd. o ◦Work the group point of balance. o ◦Avoid the blind spot behind the animal. o ◦If cattle baulk at an object or shadow, wait for the leader to cross it, then allow the rest of the herd to follow. o ◦Try to keep the animals calm and moving at a walk. o ◦Avoid deep penetration into the group’s flight zone. b. discuss the factors that should be considered when carrying out a particular husbandry practice to reduce the negative welfare impacts to the animal such as use of appropriate equipment, skill of the operator, timing of the animal practice, management of the animals after completion of practice c. discuss one ethical issue relevant to an animal production system such as mulesing, live export, battery egg production, use of farrowing crates Legal, welfare and ethical issues related to mulesing in sheep Legal requirements 1. What limitations are placed on the age of sheep for mulesing? In NSW it is illegal to mules sheep over the age of 12 months, unless under veterinary supervision. 2. What is the ideal age of sheep for mulesing? Ideally mulesing should be carried out at marking time when they are 4-6 weeks old. 3. Is anaesthetic required before mulesing? Anesthetic is only required for the mulesing of sheep after the age of 12 months and the mulesing must be performed by a veterinarian.  HSC AGRICULTURE 1. ANIMAL PRODUCTION 4. Are all sheep breeds mulesed? Only sheep of the Merino breed are mulesed. Other breeds tend to be more plain-bodied and therefore do not have the wrinkles of skin that provide favourable sites for the blowflies to infest. Figures indicate that approximately 70% of all Merino sheep are mulesed. Animal welfare issues 5. Why is mulesing routinely carried out? The blowfly, has been documented, as the most detrimental parasite affecting the Australian sheep and wool industry. Blowflies seek to lay eggs in the damp wool of sheep. The flesh eating maggots that hatch have the potential to cause wounds that can lead to blood loss, septicaemia and death. Mulesing is the surgical removal of skin around the breech and tail area of lambs to reduce the chance of breech and tail fly strike. The resulting skin is tighter and remains more clean and dry than if not mulesed. By removing the skin folds from around the breech and tail area, a potential site for blowflies to lay their eggs is removed, thus drastically reducing the incidences of blowfly strike. An integrated pest management (IPM) approach is required to control blowfly strike. This involves the husbandry activities of tail docking, jetting and routine checking of flocks to locate and treat affected animals, as well as mulesing. Blowflies are usually most active after rain when the temperatures are warm to hot. 6. What are some of the risks to the animal due to mulesing? Because mulesing results in quite a large open wound there is the risk of infection and flystrike. 7. List some practices that help to reduce the stress on animals caused by the operation of mulesing. To reduce the chance of flystrike, the operation should be carried out during periods of low fly numbers, i.e. during the cooler months or dry periods. The wound should be sprayed with an antibacterial fly powder or spray to reduce the chance of infection and deter flies from the wound area. To further reduce the chance of infection, the operation should be carried out with sharp, clean implements. Lambs should be vaccinated to reduce the chance of clostridial infections. Lambs should be marked and mulesed in small groups as this decreases  HSC AGRICULTURE 1. ANIMAL PRODUCTION the amount of time they are separated from their mothers, increases their ability to find their mothers and reduces the amount of time they are left in the yards where they suffer increased risk of infection. No matter what method is used it is important to have a skilled operator carrying out the mulesing. This increases the success rate and the efficiency of the operation. Increased efficiency leads to lambs back with their mothers more quickly and hence less stress on them. 8. Research is being carried out to find alternatives to mulesing. Briefly describe two alternatives that are currently being researched. Much work is being done to select and breed sheep with bare breech and resistance to blowfly maggots. Ideally sheep should be smooth-skinned presenting many less sites that are likely to be struck. Although this alternative to mulesing will take a long period of time to achieve, it is likely to provide the best solution to the problem of flystrike. The Australian Wool Innovation is working on the development of plastic clips that can be applied to wrinkles in the breech. These act in a similar way to elastrator rings used for tail docking and castration, causing the excess skin of the breech area to be shed. The University of Adelaide has identified a protein that kills wool follicles and tightens the skin. Investigations are being carried out to development of an application for automated delivery of the protein into the breech area. Ethical issues 9. While mulesing causes stress to the animals and considerable work for the producer, the advantages of it are obviously seen to outweigh both of these. Write your thoughts about mulesing and how the advantages must be considered against the disadvantages. Make sure you consider: the pain and stress on the animal the reasons for carrying out mulesing possible outcomes if mulesing was not carried out practical alternatives to mulesing the advantages to the producer your background and own personal experiences (these help form your opinions). Researchers (Fell & Shutt, 1988) described the pain associated with mulesing as the greatest acute stressor of all lamb marking procedures. So clearly it should not be a procedure that can be taken lightly. This does not mean that it should not be considered as an operation with obvious advantages. Anyone who has seen the graphic results of a blowfly strike on sheep will be acutely aware of the pain and stress that the option of not mulesing  HSC AGRICULTURE 1. ANIMAL PRODUCTION Merino sheep may result in. So while progress is slow and we edge towards viable alternatives to mulesing, for many, mulesing will remain a necessary evil. If mulesing is to be a part of the management strategies to assist in the control of flystrike then attention needs to be given to reduce the pain and stress caused on each animal that is mulesed. Mulesing should be carried out by skilled operators, using appropriate instruments that are sharp and cleaned. It is important that only those lambs that have wrinkles in the breech area should be mulesed. Each farmer should select animals for breeding that are more plain-bodied and individuals that are excessively wrinkly or are struck more frequently should be culled. Ideally lambs should be mulesed at 4 – 6 weeks of age as research has shown that younger animals recover more quickly than older animals. Lambs should be mulesed in small groups so that they can be returned to their mothers and released onto pastures as quickly as possible. This reduces the time lambs are in dirt yards where the risk of infection is increased. To further reduce the risk of disease, lambs should be vaccinated and the wounds sprayed with antibacterial fly powder or spray. d. investigate animal welfare legislation for a specific farm animal and discuss the implications of the legislation for the relevant production system (www.schools.nsw.edu.au/animalsinschools) Ethics, welfare and legal issues and requirements - Owners and managers are responsible for the health and wellbeing of animals - Behaviour/attitude of managers will determine the welfare in a flock or herd - Managers need to anticipate situations which welfare may be at risk and to recognise early signs of ill-health or distress so preventative action can be taken - Basic requirements of welfare of animals: - A level of nutrition adequate to sustain good health and vigour - Access to sufficient water of suitable quality - Social contact with other animals - Sufficient space to stand, lie down and perform normal behaviour - Protection from predators - Protection from injury and disease with treatment if necessary HSC AGRICULTURE 1. ANIMAL PRODUCTION - Protection from extremes of weather (trees for shade and windbreaks) - Provision of drought relief feed (fodder storage) - Stock handling facilities that do not cause injury and which minimise stress to animals (people and mustering dogs or too many bulls/rams in one paddock)  HSC AGRICULTURE 1. ANIMAL PRODUCTION Experimental analysis and research in plant/animal systems EXPERIMENTAL DESIGN a. design and conduct a simple plant or animal trial using appropriate methodology Task: Design a trial using 12 lambs (Direction - Explain how the lambs are inducted and managed in a feedlot scenario). b. outline the role of a control, randomisation, replication and standardisation of conditions in a simple plant or animal trial Task: Copy terms below 1. Control – having a control allows for the results to be compared to a standard; allows for the assessment of the impact of the change in variables. 2. Randomisation – eliminates bias to promote accuracy in results. For example: dividing a plot into multiple sections and randomly allocating which crop is planted in/density of seeds to eliminate chance of say one variable being trialled on soil that has higher nutrients than the soil the other variables are conducted on. 3. Replication – repetition increases the accuracy of results. In larger sample sizes outliers can be identified and an average collected to produce an accurate result. Trials should be replicated at least 3 times. 4. Standardisation of conditions – entails that all other variables – except for the one that is being tested for – are kept uniform including the environment (as much as possible). This ensures that the trial is fairly conducted and that no variables are given an undesired advantage, which leads to inaccurate results. For example: using the same potting mix, allocating the same amount of water, placing pots in the same place, using the same paddock/paddocks of similar conditions. THE COLLECTION AND ANALYSIS OF DATA a. analyse and interpret agricultural data by calculating a mean, a measure of variability (standard deviation) and a test of significance such as Standard Error Task: copy below, but not table Mean – the average of all the scores; may be distorted by extreme numbers. A measure of variability (standard deviation) – sample standard deviation measures the degree of variance around the mean. It is equal to the  HSC AGRICULTURE 1. ANIMAL PRODUCTION square root of sample variance. For all distributions, approximately 68% lay within one SD either side of the mean; 95% lie within two SDs of the mean and 99.7% lie within three SDs on either side of the mean. For example: the average height is 170cm and the SD is 8cm, then 68% of the population are in the range 170 8cm; 95% are in the range 170 16cm and 99.7% 170 24cm in height. - Sample variance: also measures the degree of spread around the mean (unlike SD, its units are not the same as the original variates). Each score is subtracted from the mean and then squared to counteract the positive and negative signs on either side of the normal curve. The greater the variance the less accurate is the mean in making assumptions about the whole populations. Sample variance for an individual score = (score – mean)2 Total sample variance (S2) = For example: The standard error can be used to determine the significance of the results. If the difference between the two means in an experiment is more than twice the standard error, the results are significant and a recommendation can be made. b. present data in an appropriate form Task: use Data from broiler chicks to model table above CW - Copy table from Canvas into workbook c. propose recommendations based on the interpretation of the results of agricultural experiments Task: interpret your results from the table and propose recommendations for the Trial process (hint - discuss points from Experimental Design)  HSC AGRICULTURE 1. ANIMAL PRODUCTION THE ROLE OF RESEARCH a. outline the impact of research on agricultural production systems Research has had a major influence on agricultural production systems. Either it has improved production in the production system by finding more efficient methods to produce a product, or because it has changed current practices for reasons such as animal welfare, in light of new research findings.