Methods of Heat Detection and Pig Breeding Practices PDF
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Central Luzon State University
Antonio J. Barroga
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This document provides a detailed overview of methods for heat detection, hereditary characteristics, and economic traits crucial for pig breeding. It explains how to improve pig production, including culling and selection of animals. The content also covers evaluation based on physical traits like body conformation, size, and various methods used in pig production.
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ANTONIO J. BARROGA PRO FESSOR VI University Extension Office, Research, Extension, and Training, Central Luzon State Education University Master in Agribusiness Management, Central Luzon State University Bachelor of Science in Agriculture major in Agr...
ANTONIO J. BARROGA PRO FESSOR VI University Extension Office, Research, Extension, and Training, Central Luzon State Education University Master in Agribusiness Management, Central Luzon State University Bachelor of Science in Agriculture major in Agricultural Economics, Central Luzon State University METHODS OF HEAT DETECTION HAUNCH PRESSURE TEST RIDING THE BACK TEST SEMEN ON THE SNOUT TEASER METHOD TAPE RECORDER METHOD PLAYING THE SOUND OF A GRUNTING BOAR Hereditary Characteristics Phenotype (P) – external or observable characteristics of an animal Genotype (G) – genetic make-up of the animal Environment (E) – factors surrounding the animal P=G+E PREGNANCY CYCLE OR GESTATION PERIOD Pregnancy or gestation is the period from fertilization to farrowing time. It ranges from 110-120 days for normal birth and the average is 114 +4days Two Groups of Characteristics Quantitative Characteristics – both the environment and genetics contribute their share. Examples: ADG, FCR, fertility (litter size), carcass quality, etc. Qualitative Characteristics – 100% due to genetics. Environment does not affect the outcome of performance. Example: color of the skin, standing ears, etc. Under the quantitative characteristics we expect more variation in the herd due to the influence of environment and genetics. If the performance of the animal is largely influenced by environment then a particular trait can be improved by managerial interventions. If the performance is due to genes, The contribution of the then improvement genotype to the phenotype is expressed in a factor called through genetics 2 heritability (h ) will be easier. Methods of Improving Production 1.Improvement of environment (feeds, management, health) – Ideal for traits with low heritability such as reproductive traits. 2.Improvement through selection – for traits like feed efficiency, growth and carcass quality. HERITABILITY (h2) – part of the phenotype that is genetically determined which can be expressed in a ratio or percentage. h2 = ranges from 0 to 1 h2 = 0, genotype has no influence on characteristics, only the environment. Example: barrows (castrated), vitamin deficiency, tail dock h2 = 1, characteristics is purely determined by genotype. Example: skin color, sex 2 Range of h : High : 0.5> Medium : 0.15 – 0.3 Low : 0 – 0.15 Selection can also be Selection defined as choosing the parents of the next generation. Natural selection prevails in the wild where selection is known as the “survival of the fittest”. Man learned artificial selection when he started domesticating animals. Economic Traits a. Prolificacy – high reproductive rate and able to wean large litter b. Growth rate – high average daily gain c. Feed efficiency – ideal feed conversion ratio d. Carcass quality – based on consumer preference Physical basis for selection 1. body conformation 2. size 3. body joints 4. feet and legs 5. back 6. free from abnormalities and diseases 7. mammary glands 8. external reproductive organs 9. semen quality 10. libido or masculinity Not Normal Fat Gilt Correct and defective pastern Normal and abnormal front foot Normal and abnormal claws Correct and Improper Pastern Performance basis for selection 1. growth rate 2. feed efficiency 3. carcass quality 4. fertility and prolificacy 5. mothering ability 6. hardiness Methods of Selection 1.Pedigree method – based on record of ancestry or collateral relatives. 2.Independent culling level – selection is based on set standard for each trait. Failure to satisfy one trait warrants the culling of the animal even if the animal performed well in other traits. 3.Tandem method – works well with correlated traits. 4.Selection Index – this method establish a kind of single figure to measure the individual net traits of breeders. Two or more traits are considered at a time. The higher the index, the better the performance we expect. Example: SI = 240 + [(100)(ADG kg)] – [(50)(FCR)] – [(19.7)(BF cm)] Given : ADG = 0.65 kg; FCR = 2.5; and BF = 2.0 cm SI = 240 + [(100)(0.65)] – [(50)(2.5)] – [(19.7)(2.0)] SI = 240 + 65 – 125 – 39.4 SI = 140.6 Culling The removal of unwanted pigs based on farm standard is called culling. It is the opposite of selection and as culling is being intensified the faster is the improvement of the herd. Reasons for culling Age or parity number – reached the maximum productive life of number of litters Reproductive failure repeat breeder, pseudo-pregnancy, abortion Poor mothering ability cannibalistic poor milker low litter size at weaning Diseases brucellosis, leptospirosis, PRRS, etc. Injuries leg problems mammary injuries Most common reasons for culling a.Fertility problems 40% b.Diseases, age etc. 35% c.Leg defects 25% Culling Sows 1.Cull in case of >3 unsuccessful breeding during entire life time of the sow. 2.Cull sows/gilts with leg defects which are not able to carry the weight of pregnancy. 3.Cull sows upon recommendation of the farm manager and farm vet in case of other defects. Culling Sows 3. Cull sows with recurrent mastitis and/or endometritis or insufficient milk and other defects of the udder resulting in high mortality rate in piglets during lactation period. 4. Cull sows which frequently crush piglets. If housing and equipment do not have any influence on the occurrence of crushing. 5. Cull sows with pseudo-pregnancy. Culling Boars 1.Defects of the legs. 2.Inability to mount. 3.Poor semen quality and quantity. 4.Wrong mounting position. 5.Too aggressive (fights female). 6.Old boars (3 years old). Advantages of Artificial Insemination Semen from a range of top-performing tested boars of several breeds is available from AI centres. The genetic influence of good boars can be spread more widely. AI is a safe, cheap method of introducing new genes into pig herds, especially those classified as specific pathogen-free, minimal disease or high health status. Advantages….. There is less risk introducing exotic diseases into Australia with AI than in the importation of live pigs. AI overcomes be size differences between boars and sows. It may be used during temporary shortages of boars from death, lameness or failure to work. Disadvantages Reduced farrowing rate (50%) with frozen semen. Lower than average results with chilled semen stored longer than 72 hours. Disappointing results where AI is poorly timed or done incorrectly.