Animal Nutrition Notes PDF

Animal Nutrition Notes: Part 2 Lec 4 Carbohydrates Carbohydrates contain ratio of 1 carbon : 2 hydrogen : 1 oxygen Carbohydrates are important for animal nutrition because o Contributes over 70% of the ration dry matter ▪ NDF 28 to 34%...

Animal Nutrition Notes: Part 2 Lec 4 Carbohydrates Carbohydrates contain ratio of 1 carbon : 2 hydrogen : 1 oxygen Carbohydrates are important for animal nutrition because o Contributes over 70% of the ration dry matter ▪ NDF 28 to 34% ▪ starch 22 to 29% ▪ sugar 5 to 7% o Main source of energy as volatile fatty acids (VFA) o Impacts rumen fermentation o Impacts dry matter intake Locations of carbohydrates in plant o Cell wall: fibers include cellulose, lignin, and hemicellulose o Cell content: sugar, starch, pectins ADF (Acid detergent fiber) = cellulose + lignin NDF (neutral detergent fiber) = cellulose + lignin + hemicellulose NDF = ADF + hemicellulose Lignin is undigested fiber (ziro digestability), provides plant rigidity Cell wall is lower in digestibility and higher in fiber Cell contents are Higher in digestibility and lower in fiber Carbohydrates digestibility: pectins > sugars > starch > hemicellulose > cellulose > lignin Fate of carbohydrates o NDF is fermented in the rumen to acetate and butyrate o Starch and sugars are fermented in the rumen to propionate Feed stuff could have all different types of carbohydrates Carbohydrates fermentation rate in the rumen from fast to low fermentation rate o Wheat, barley, oat, corn, sorghum o Steam flaked, high moisture, dry ground, dry rolled, dry whole Corn energy content differs based on corm processing: o Order from high to low energy content: Finely ground > floury > steam flaked > high moisture > ground > cracked Grain particle screens evaluate the particle size distribution Roles of sugar in animal nutrition o Improve rumen fermentation o Capture ammonia in the rumen o Increase feed intake due to improved palatability o Improve fiber digestibility 1 Lec 5 Lipids Lipids contain ratio of 6 carbon : 12 hydrogen : 1 oxygen Lipids include fats and oils Fats are solid at room temperature such as tallow or grease Oils are liquid at room temperatures such as oils of corn, cottonseed, or soy Triglyceride: Consists of one glycerol and three fatty acids molecules Fatty acids are grouped based on saturation to o Saturated fatty acid does NOT contain double bonds such as stearic acid and palmitic acid o Unsaturated fatty acid contains one or more double bonds such as oleic acid, linoleic acid, and linolenic acid Fatty acids are grouped based on length to o Short chain length ( 6 to 14 carbons linked) o Long chain length (16 to 22 carbons linked) Dairy cattle prefer saturated and long chain fatty acids Unsaturated fatty acids are partially hydrogenated by rumen bacteria to detoxify Fats are not a source of energy for rumen microbes The energy content in fats is 2.25 times higher than carbohydrates or protein due to the higher carbon (source of energy) in fats Plants store oils as triglycerides Lipase enzyme in the small intestine breakdown triglycerides, releasing fatty acids and glycerol apart to be absorbed in the small intestine to enter the blood Fatty acids and glycerol in blood travel to the liver to be used as energy sources Mammary gland uses fatty acids as a source of milk fat Excess fatty acids travels to the body fat and deposited as triglyceride fat or liver What is NEFA? o NEFA is non-esterified fatty acids o Release from fat reserves as a back back-up energy source o If NEFA are too high in the blood, the liver clears the NEFA by converting NEF into ketone bodies or stored in the liver as liver triglycerides, leading to fatty liver disease What are PUFAs? o PUFAs are polyunsaturated fatty acids o Impact the synthesis of hormones o Improve fertility o Sources: fish oil, flax seed, corn oil, soy oil, and rumen protected PUFAs Fats are measure in the lab through ether extraction or NIR (near infrared spectrophotometry) 2  Benefits of fats in animal ration o Concentrated source of energy o Reduce dustiness in the ration o Increase energy intake o Improve fertility o Reduce energy deficiency diseases such as ketosis Limitation of fats in animal ration o Expensive source of energy o Reduce feed intake o Reduce fiber digestion Fat content in animal ration is 5% Fat content in calves milk replacers is 15 – 20% Lactating cows over 30 kg of milk require extra fat in the ration If the added fat negatively impacts rumen fermentation, milk fat test can drop. If the added fat contains higher levels of PUFA, milk fat test can drop If the added fat is correctly fed, milk fat could increase 3 Lec 6 Proteins and Amino Acids The importance of protein o Build lean tissue, hormones and enzymes, and replace cells o Impacts feed intake o Both the rumen microbes and dairy cattle need protein for nitrogen and amino acids o Needed to produce milk protein Sources of nitrogen used by rumen microbes o Peptides (short chain of amino acids) o Amino acids o Ammonia Crude or total protein o Calculated by measuring the amount of nitrogen by Kjeldahl lab procedure or NIR o Protein is 16% nitrogen o Easy to measure in the lab o % protein content of a feed = Nitrogen% x 6.25 Amino acids o Building blocks of protein o Consist of carbon, oxygen, hydrogen, and NITROGEN o Contain an amino group (NH2) and acid group (COOH) on each end of an amino acid o The peptide bonds link amino acids together to form a peptide Unavailable protein o Represents the protein that is not digested and appears in the feces o Factors that increase unavailable protein are ▪ Stage of feed maturity ▪ feed processing ▪ heating Metabolizable protein o Represents the protein available for animal use after digestion and rumen fermentation o Sources of metabolizable protein ▪ Microbial protein ▪ Rumen undegraded protein o Difficult to measure in the lab, requires rumen model Rumen degradable protein (RDP) o Represents the protein degraded in the rumen by microbes o Breaks down to ammonia, amino acids, and peptides o Rumen microbes capture convert RDP into microbial protein 4  Soluble protein o Represents protein rapidly degraded in the rumen to ammonia o Such as urea and ammonia Rumen undegradable protein (RUP) o Represents protein that is not degraded in the rumen NPN or Non-protein nitrogen o Represents nitrogen not in the form of an amino acid o Sources are urea, ammonium phosphate, and biuret o Ruminants can use NPN as rumen microbes convert the NPN to high quality microbial protein Sources of amino acids to ruminants o Rumen microbial protein o RUP o Protected amino acids especially methionine and lysine Microbial protein is important to the ruminants because it provide the optimal amino acid profile MUN (milk urea nitrogen) o reflects the cow’s ability to capture nitrogen as microbial protein o MUN levels > 12 mg/dl reflect lower nitrogen efficiency; levels > 16 mg/dl reduce fertility. o Evaluate the level of protein, type of protein (RDP and RUP), amount and type of carbohydrate (sugar and starch), and rumen health 5 Lec 7 Role of Vitamins Classification of vitamins o Fat Soluble Vitamins ▪ Measured as international units per animal ▪ Vitamin A, D, E, and K ▪ Vitamin potency drop 5-7% / month when combined with mineral pre- mix ▪ Animals on pasture and/or green chop get adequate vitamins A, D, and E. ▪ Ensiling forages reduces the potency of fat soluble vitamins due to acid conditions. ▪ Hay levels of vitamins decline during storage. ▪ o Water Soluble Vitamins ▪ Measured in mg or grams per day ▪ B vitamins and C Vitamin potency drop 5-7% / month when combined with mineral pre-mix Beta-carotene (Vitamin A precursor) o Function: Improves fertility, increases fiber digestion by rumen microbes, enhances immune response, and controls mastitis o Feeding Strategy for dairy cows: early lactation and during mastitis -prone time B and C-vitamins and choline o Synthesized via rumen microbiota o Choline is a “pseudo pseudo-vitamin” o Ruminal disappearance of unprotected forms is extensive B vitamins o Involved in various metabolisms as enzymes cofactors (activators) o Needed for liver glucose synthesis from propionate o Glucose in dairy cows is needed for ▪ Milk synthesis ▪ Oocyte quality ▪ Immune cells: main Delivery approaches of B vitamins o In the Diet: Best method, should be protected from rumen degradation o Injection: Stressful, impractical and costly Biotin o Function: Improve hooves by reducing heel warts, claw lesions, white line separations, sand cracks, and sole ulcers; increase milk yield o protected biotin increased milk quantity and milk quality (milk fat and milk protein) compared with non-protected biotin 6  Niacin o Increase milk yield, increase milk fat and milk protein o Reduce NEFA and ketosis o Rumen protected niacin is 8 times more potent than unprotected niacin o Reduce heat stress through ▪ Niacin increases blood flow to the exterior of the animal via vasodilation. ▪ Niacin increases sweating rate ▪ Niacin decreases body temperature with increased water intake. o Choline ▪ Increases milk production 7 Lec 8 Minerals Minerals are classified into 2 groups o Macro-minerals ▪ Required in grams per day ▪ Expressed as percent of the ration dry matter ▪ Excesses normally do not cause problems ▪ Na, Cl, Ca, P, K, S, Mg o Micro-minerals ▪ Fed in milligrams per day ▪ Expressed as ppm ▪ Zn, Cu, Co, I, Mn, Fe, Se, and Cr Calcium chloride is a better source of calcium than calcium carbonate due to higher absorption Dicalcium phosphate is a better source of phosphorus than Monocalcium phosphate due to higher absorption Delivery systems for minerals o TMR o Top dress o Free choice o Injected trace minerals Studies showed that injected minerals reduced health problems in dairy cows such as stillbirth, endometritis, and displaced abomasum Inorganic forms of minerals o Sulfate o Carbonate o Nitrate Forms of organic minerals o Metal amino acid complex o Metal amino chelate o Metal proteinate o Metal polysaccharide complex o Hydroxyl ligand Benefits of organic mineral compared with inorganic minerals o better absorption o Less mineral antagonism o Stimulate biological processes 8  Strategies of adding organic minerals to cattle feed o Provide 25 to 30% of the total trace mineral supplemented, whereas the inorganic minerals are 70 – 75% of the total trace mineral supplemented Target cows for organic mineral supplementation o Embryo transfer cows o Environmental stressed cows o Far off, close up, and early lactation cows until cows are pregnant Potassium (K) o Heat stress increases K requirements Magnesium (Mg) o Potassium antagonism o Increases milk fat % Organic selenium (Se) or selenomethionine o Source will be yeast raised on high Se o Increases blood Se levels o overcomes the poor absorption of inorganic Se such as selenite or selenate o Replaces half of the inorganic Se for lactating cows o Replaces 100% of the inorganic Se for lactating cows Organic zinc (Zn) or Zn methionine o Function: Improve immune response, harden hooves, and lower inflammation, improve pregnancy rate, increase milk production, increase milk fat and milk protein, improve udder health 9 Lec 9 Feed additives Benefits of feed additives o Cover up poor management o Profit enhancers Roles of feed additives o Energy balance o Calcium balance o Immune function o Rumen enhancers o Reproduction o Foot health o Protein efficiency o Mycotoxin binders The number 1 influencer when selecting feed additives in the farm is the nutritionist Criteria for evaluating feed additives o Function, level, cost, benefit to cost, strategy, status Monensin o Functions: reduce ketosis and displaced abomasum in transition cows by shifting rumen fermentation and microbial selection. Increase milk production. Control cocci in calves and heifers. o Feeding Strategy: Feed to dry cows (to reduce metabolic disorders) and lactating cow (to improve feed efficiency) while monitoring milk components to evaluate optimal levels of monensin Priority feed additives for lactating cows o 1- Monensin o 2- Silage inoculants o 3- Organic trace minerals (Zn, Se, Cr, & Cu) o 4- Yeast and yeast culture o 5- Sodium bicarb o 6- Biotin Signs of mycotoxins in the feed o Immune suppression o Rumen disorders o Loose fecal discharges o Reduced dry matter intake o Hormonal-like changes (udder development and reduced fertility) 10  Examples of mycotoxins in the feed o Aflatoxin o Zearalenone o DON o T-2 Mycotoxin binders or flaw agents o Clay -based compounds such as bentonite, zeolite, and calcium aluminosilicate are effective with aflatoxin toxins o Yeast cell wall extracts such as MOS and glucomannans are effective with zearalenone, DON, T-2 toxins, DON toxins 11