DOCSLIB.ORG

Genetic Analyses of South African Terminal Sire Sheep Breeds

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Genetic Analyses of South African Terminal Sire Sheep Breeds GENETIC ANALYSES OF SOUTH AFRICAN TERMINAL SIRE SHEEP BREEDS by Oliver Tendayi Zishiri Thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Agriculture (Animal Sciences) at Stellenbosch University Faculty of AgriSciences Department of Animal Sciences Supervisor: Professor S.W.P. Cloete Co-supervisor: Professor K. Dzama Dr J.J. Olivier Date: March 2009 DECLARATION By submitting this thesis electronically, I declare that the entirety of the work contained is my own, original work, and that I have not previously in its entirety or in part submitted it for obtaining any qualification. Date…………………………………………… Copyright © 2009 Stellenbosch University All rights reserved ii Abstract Genetic analyses of South African terminal sire sheep breeds Candidate : Oliver Tendayi Zishiri Study leader : Professor S.W.P. Cloete Co-study leaders : Professor K. Dzama Dr. J.J. Olivier Department : Animal Sciences Faculty : Agricultural and Forestry Sciences Degree : MSc Agric Fluctuations and a general decline in the ratio between wool and meat prices resulted in marked changes in the South African sheep industry. Commercial producers now exploit other mechanisms such as terminal crossbreeding of Merino-type with meat type breeds or dual-purpose breeds to attain short-term benefits resulting from price fluctuations between wool and mutton without compromising the wool-producing capacities of ewe flocks. Most components of lamb production have low heritability. However, heterosis can be achieved by mating wool-type breeds with specialist meat breed rams. Genetic improvement of livestock depends on defining breeding objectives, estimation of genetic parameters and accurately identifying the right animals to be used for future breeding. Genetic parameters for traits of economic importance in terminal sire sheep breeds that could be used on Merino-type ewes in commercial operations in South Africa had not been published for the national flock apart from a preliminary study having been conducted by Olivier et al. (2004). Selection objectives were poorly defined due to lack of parameter estimates for variance and covariance components. Against this background, this study obtained pedigree information and live weight data from the National Small Stock Improvement Scheme for the Dormer, Ile de France and Merino Landsheep and estimated non-genetic factors and genetic parameters influencing early growth traits. Genetic and phenotypic trends for early growth traits were constructed for the three breeds to monitor genetic progress. Non-genetic factors influencing early growth traits in the Dormer, Ile de France and Merino Landsheep were estimated using data obtained from the National Small Stock Improvement Scheme of South Africa. The original data sets for the Dormer, Ile de France and Merino Landsheep consisted of the following number of records respectively: 52 202, 35 553 and 7 772. However, pre-weaning weights were available for the Ile de France and Merino Landsheep breeds only and post-weaning weights were available only for the Dormer breed. The data sets were complicated to such an extent that smaller data sets had to be generated to analyse for fixed effects. The traits that were analysed were birth weight, pre-weaning weight, weaning weight and post-weaning weight. The fixed effects, identified as having a significant effect (P < 0.01) on early growth traits were sex of lamb, birth type, age of dam, contemporary groups, age at which the trait was recorded and month of birth and year of birth iii in the Merino Landsheep breed. Although some significant interactions were found, they were subsequently ignored owing to their very small effects. In all three breeds, male lambs were significantly (P < 0.001) heavier than female lambs and single-borne lambs were significantly heavier at birth than multiple borne lambs. The age of dam had a significant curvilinear regression on all early growth traits in all three terminal sire sheep breeds. It was concluded from the study that the influence of non-genetic factors on early growth traits should be adjusted for or eliminated statistically in genetic evaluations to get accurate genetic parameter estimations. (Co)variance estimates for birth weight, weaning weight and post-weaning weight were obtained for the Dormer breed using restricted maximum likelihood procedures (REML). Direct heritabilities (h2) in single-trait analyses were 0.21 ± 0.03, 0.23 ± 0.02 and 0.29 ± 0.05 for birth weight, weaning weight and post-weaning weight, respectively. Direct heritabilities of 0.28 ± 0.04, 0.55 ± 0.06 and 0.32 ± 0.02 for birth weight, weaning weight and post-weaning weight respectively were obtained using three-trait analysis. Direct maternal genetic effects (m2) were excluded from the analyses because of the failure to partition maternal effects into maternal genetic and maternal permanent environmental effects (m2 and c2). This culminated as a consequence of poor data and population structures emanating from the loss of genetic links across flocks due to the random entrance and exit of flocks from the recording scheme. Maternal permanent environment was estimated at 0.15 ± 0.02, 0.13 ± 0.02 and 0.20 ± 0.03 for birth weight, weaning weight and post-weaning weight respectively using single-trait analysis. The correlation between direct effects and maternal effects (ram) was excluded from the analyses due the structure of the data. Genetic, phenotypic and environmental correlations between early growth traits were low to moderate. The medium to high heritability estimates for early growth traits obtained in the study led to the conclusion that Dormer sheep can successfully be used in terminal crossbreeding programs to improve meat production characteristics. Direct heritability estimates were 0.31 ± 0.14, 0.09 ± 0.02 and 0.14 ± 0.003 for birth weight, pre-weaning weight and weaning weight respectively using single-trait analysis for the Ile de France breed. Maternal effects were significant for all the traits studied despite the failure to properly partition them into their components due to the loss of genetic linkages across generations emanating from poor data structure. Genetic, phenotypic and environmental correlations were estimated using three-trait analysis and were found to be low to moderate for early growth traits. Direct genetic and maternal permanent environmental ratios were also computed and they did not differ much from the results obtained using single-trait analyses. The reasonable genetic parameter estimates obtained in the study led to the conclusion that the Ile de France can be selected to use as sires in crossbreeding programs. Genetic parameters were estimated for early growth traits in the Merino Landsheep breed. REML estimates of birth weight, pre-weaning weight and weaning weight were obtained using animal models in single-trait analyses. The direct heritability estimate for birth weight was 0.23 ± 0.13 using an animal model with additive direct genetic effects and dam permanent environmental effects as the only random factors. The dam permanent environmental effect for birth weight amounted to 0.10 ± 0.07. Direct heritability for pre-weaning weight was 0.36 ± 0.05 and the dam permanent environmental effect 0.56 ± 0.03. Weaning weight was estimated using an animal iv model that contained direct additive effects and dam permanent environmental effects. The direct heritability estimate for weaning weight was 0.17 ± 0.03. Maternal genetic effects were estimated to be 0.02 ± 0.01. Genetic and phenotypic trends were constructed for early growth traits in the Dormer, Ile de France and Merino Landsheep breeds. The traits that were considered were birth weight, pre-weaning weight, weaning weight and post-weaning weight. However, pre-weaning weights were available for the Ile de France and Merino Landsheep breeds only and post-weaning weights were available only for the Dormer breed. The Dormer exhibited significant improvement in the phenotypic and genetic aspects of early growth traits during the 17 years of evaluation (1990-2007). The average predicted direct breeding values of birth weight decreased by 0.055 % during the evaluation period. The predicted direct breeding value for weaning weight increased by 0.12 % during the 17 year period. Post-weaning weight improved by 0.32 % per annum. The Ile de France registered an increase in the predicted breeding value of birth weight which amounted to 0.025 % per annum. Averaged direct breeding values for pre-weaning weight increased at an annual rate of 0.23 %. and that of weaning weight increased by 1.21 %. In the Merino Landsheep the predicted direct breeding value for birth weights decreased by 0.04 % per annum and pre-weaning and weaning weights increased by 0.36 % and 0.10 % respectively. The trends were obviously biased due to inconsistencies in data structure and very few records available for analysis in this breed. In conclusion, it was evident that the additive genetic variation was available for all the early growth traits in all the three breeds. Although adequate genetic variation for substantial genetic progress was available, only modest rates of progress were attained for all the traits in all three breeds. The only possible exception was weaning weight in the Ile de France breed, which improved at > 1 % per annum. At least all changes were in the desired direction. Breeders should be encouraged to record data consistently, as one of the major shortcomings in the data for all breeds were a lack of continuity in the submission of data to the NSIS. More informative analyses ought to be feasible if this requisite could be met. v Opsomming Genetiese analise van die verskillende Suid-Afrikaanse terminale kruisvaarrasse Kandidaat : Oliver Tendayi Zishiri Studieleier : Professor S.W.P. Cloete Mede- Studieleiers : Professor K. Dzama Dr. J.J. Olivier Departement Veekundige Wetenskappe Fakulteit : Landbou en Bosbou Wetenskappe Graad : M.Sc Landbou Die wisselende en algemene afname in die prysverhouding van wol tot vleis het merkbare veranderinge in die Suid-Afrikaanse skaapbedryf teweeggebring.
Load more

Recommended publications
  • Sheep Newz #14 Autumn 2019
    Sheep NewZ #14 Autumn 2019 Hello Members, ASSOCIATION NEWS & VIEWS Thanks to all who have supported this issue of “Sheep NewZ”. It would be good to have some more photos/articles From The President each time other than those on the feature breed. I wonder how much money is being spent on bureaucracy in Hope everyone has had a great time over the the wool research, development and promotion sectors? holiday season. The weather was great here There seem to be several companies with great mission in the south over the summer and everyone statements but is anything much actually happening out seemed to be having lots of fun. there? NZ Merino seems to be achieving the most in both Lambs and ewes are bringing record prices this season advertising their product and developing new uses. which is very pleasing. However the same old fiddle plays Some of the Companies and their mission statements are: - the same old tune to try and bring prices down such as the Wool Research Organisation of New Zealand, “To uncertainty of the Brexit deal, Trump, and the Chinese promote, encourage and fund scientific or industry research economy which shows how we can be exposed so quickly. and information transfer that relates to the post harvest wool Hopefully common sense will prevail and our prices stay up industry” Several projects on going from 2013 – results?? at a reasonable level. Wool Industry Research Ltd – a subsidiary of the above “Focus on investment in research which increases the value It is really disappointing to see our farm training institutes and competiveness of commercial NZ wool based activity facing difficult times.
    [Show full text]
  • Romney Sheep Breeders Society Winter Newsletter 2017
    NEWSLETTER Issue 1 Romney Sheep Breeders Society Winter Newsletter 2017 MERRY CHRISTMAS - PHOTO BY JULIE MURRAY IN THIS ISSUE Dinner and flock competition report -Ashford cattle show results- Young Romney Breeders- New members welcome -shopping with Romney wools- Sponsorship- merchandise - Winter lamb recipe- council meeting dates Issue Date Dinner at The George and fflocks were so good but had to Youngs Trophy for the most Flock competition results fcome to the following conclusion done for the society Alex Long Small pedigree flock A gathering of the Romney st 1 Larry Cooke Champion Flock breeders enjoyed an evening nd meal of Lamb with family and 2 Mr & Mrs Rawlinson PH&PE Skinner 3rd Cobtree YFC friends Raffle - Generous gifts from Large pedigree Flock Fine dining and conversation were many supporters and 1st PH&PE Skinner only interluded by a humorous talk sponsors gave dinners a 2nd Claire Langrish by President Howard Bates on his chance to dig deep into 3rd Paul Bolden exploits in the Navy and sheep ttheir pockets and manage Commercial Flock industry, presentation of the Flock tto raise an amazing £460 1st Larry Cooke Competition trophies and the Ram nd Thank you to all who took part 2 L Ramsden sale prize winners and your generosity. Judge Alan Barr reported that it 3rd A Dunlop had been a difficult task as all NEWSLETTER | Issue 1 2 Ashford cattle Show -Romney Carcass classes judged by Nick Results Brown There was an amazing entry this year from the Romney Class 42 Best Romney lambs born Breeders in carcases, wool in 2017 and finished lambs.
    [Show full text]
  • Lamb Rearing Performance in Highly Fecund Sheep
    Copyright is owned by the Author of the thesis. Permission is given for a copy to be downloaded by an individual for the purpose of research and private study only. The thesis may not be reproduced elsewhere without the permission of the Author. Lamb Rearing Performance in Highly Fecund Sheep J ulie Marie Everett-Hincks 2004 This thesis is presented in partial fulfillment of the requirements for the degree of Doctor of Philosophy at Massey University, Palmerston North, New Zealand The Massey University Animal Ethics Committee has approved the studies involving animal manipulations I have prepared this thesis and it is a record of my own work. I took the photos of the sheep, unless otherwise specified. Abstract This thesis investigates ewe and lamb behaviour, genetics and environmental effects to determine whether lamb rearing petformancecan be improved in highly fecund heep. The studies were carried out under commercial pastoral farming conditions. High performing sheep farmers were surveyed to identify management and performance practices that differentiate farms with high and low lamb rearing ucces . Farmers agreed that mothering ability was the most important factor affecting lamb urvival and considered lamb survival to be the most important trait affecting fann profit. The survey identified the Coopwotth breed as the predominant breed of high lambing percentage flocks. Heritability estimates were derived for lamb survival (h2= 0. 1 6), ewe maternal behaviour score (h2= 0.05) and litter survival (h2= 0.00) in a Coopworth flock that had been selected fo r improved maternal ability fo r nearly 30 year . Maternal genetic variation in the Coopworth flock was low fo r lamb and maternal traits and suggests that farmers must con ider the environment and management technique to improve lamb survival.
    [Show full text]
  • From Birth to Colostrum: Early Steps Leading to Lamb Survival Raymond Nowak, Pascal Poindron
    From birth to colostrum: early steps leading to lamb survival Raymond Nowak, Pascal Poindron To cite this version: Raymond Nowak, Pascal Poindron. From birth to colostrum: early steps leading to lamb survival. Reproduction Nutrition Development, EDP Sciences, 2006, 46 (4), pp.431-446. 10.1051/rnd:2006023. hal-00900627 HAL Id: hal-00900627 https://hal.archives-ouvertes.fr/hal-00900627 Submitted on 1 Jan 2006 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Reprod. Nutr. Dev. 46 (2006) 431–446 431 c INRA, EDP Sciences, 2006 DOI: 10.1051/rnd:2006023 Review From birth to colostrum: early steps leading to lamb survival Raymond N*, Pascal P Laboratoire de Comportements, Neurobiologie et Adaptation, UMR 6175 CNRS-INRA-Université François Rabelais-Haras Nationaux, Unité de Physiologie de la Reproduction et des Comportements, INRA, 37380 Nouzilly, France Abstract – New-born lambs have limited energy reserves and need a rapid access to colostrum to maintain homeothermy and survive. In addition to energy, colostrum provides immunoglobulins which ensure passive systemic immunity. Therefore, getting early access to the udder is essential for the neonate. The results from the literature reviewed here highlight the importance of the birth site as the location where the mutual bonding between the mother and her young takes place.
    [Show full text]
  • Genetics of Flystrike, Dagginess and Associated Traits in New Zealand Dual-Purpose
    Copyright is owned by the Author of the thesis. Permission is given for a copy to be downloaded by an individual for the purpose of research and private study only. The thesis may not be reproduced elsewhere without the permission of the Author. Genetics of flystrike, dagginess and associated traits in New Zealand dual-purpose sheep A thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Animal Science at Massey University, Palmerston North, New Zealand Natalie Kathleen Pickering 2013 Genetics of flystrike and dagginess in New Zealand dual-purpose sheep “The greatest benefit of dag control or elimination may come from reduced fly strike” V. J. Mackereth (1983), an astute breeder. ii Abstract Abstract Pickering, N. K. (2013). Genetics of flystrike, dagginess and associated traits in New Zealand dual-purpose sheep. PhD thesis, Massey University, Palmerston North, New Zealand. A literature review identified breech bareness, dagginess and fibre traits as potential indirect indicator traits for flystrike. Dagginess (faecal accumulation) had the greatest potential as an indirect indicator, and has been identified as an important trait itself. Therefore flystrike and dagginess were investigated for their associations with fibre and production traits. A genome-wide association study (GWAS) was performed to identify regions under selection and associated with these traits. Finally, a genomic selection (GS) analysis was performed for dagginess and dual-purpose production traits to estimate molecular breeding values (MBVs) and to determine their impact on the New Zealand dual-purpose selection index. Heritability, genetic and phenotypic parameter estimations were performed on a flystrike case-control dataset collected over 2 years.
    [Show full text]
  • 227 Sheep SHEEP DEPARTMENT Kelly Secord
    SHEEP DEPARTMENT Kelly Secord- Superintendent Entry Information: Entries can be made online at livestockexpo.org. Entry Deadline and Fee October 10, 2020 Junior Breeding Sheep Entry Fee: $18.00 Junior Market Lamb Entry Fee: $30.00 Open Show Entry Fee: $20.00 Junior Breeding and Market Showmanship Entry Fee: $10.00 *Pre-Entry required* There will be a $25.00 service charge on all declined credit cards. Sheep Arrival Schedule Junior Breeding Sheep - November 11, 8:00 a.m. thru November 13, 12 Noon Junior Market Lambs/Commercial Ewes - November 11, 8:00 a.m. thru November 12, 12 Noon Open Breeding Sheep - November 11, 8:00 a.m. thru November 14, 4:00 p.m. Release Schedule Junior Sheep: Breeds will be released following completion of each BREED show. (Unless entered in Open show, then must follow open show release) Open Sheep: All breeds released upon completion of each breed's show unless showing in Supreme Selection, Thursday, November 19th. Stalling Information Stalling will be done based on number of entries. Stalling preferences must be put on entrty form to be taken into consideration. Pen size in South Wing A & B is 6x6 or 7X7. Feeders Supply - (502) 583-3867 Show Schedule WEDNESDAY, NOVEMBER 11, 2020 8:00 a.m. Begin Receiving Sheep 12:00 Noon to 5:00 p.m. Breeding Sheep and Showmanship Check-In THURSDAY, NOVEMBER 12, 2020 8:00 a.m. Continue Receiving Sheep 9:00 a.m. to 5:00 p.m. Breeding Sheep and Showmanship Check-In 4:00 p.m. Market Lambs must be in place and weight cards turned in FRIDAY, NOVEMBER 13, 2020 8:00 a.m.
    [Show full text]
  • ACE Appendix
    CBP and Trade Automated Interface Requirements Appendix: PGA August 13, 2021 Pub # 0875-0419 Contents Table of Changes .................................................................................................................................................... 4 PG01 – Agency Program Codes ........................................................................................................................... 18 PG01 – Government Agency Processing Codes ................................................................................................... 22 PG01 – Electronic Image Submitted Codes .......................................................................................................... 26 PG01 – Globally Unique Product Identification Code Qualifiers ........................................................................ 26 PG01 – Correction Indicators* ............................................................................................................................. 26 PG02 – Product Code Qualifiers ........................................................................................................................... 28 PG04 – Units of Measure ...................................................................................................................................... 30 PG05 – Scientific Species Code ........................................................................................................................... 31 PG05 – FWS Wildlife Description Codes ...........................................................................................................
    [Show full text]
  • Breeder's Directory
    The Banner Breeders’ Directory These progressive breeders usually have quality breeding stock for sale at all times. We recommend you contact them or any of our advertisers when making your selection. One year’s listing is only $65 and $35 for additional listings and includes a one year subscription and a free listing on our website! Call today, 309/785-5058 or fax 309/785-5050 and have your flock represented. COLUMBIAS RAMBOUILLETS HEUPEL SUFFOLKS, Marv & HAMPSHIRES Sandy Heupel, “60 Years of Real ALABAMA BRANDT’S COLUMBIAS, Ron & TERRYS SHEEP, Teresa Terry & Linebreeding To Produce The NELSON HAMPS, Rodney & Andrea Brandt, 729 Monroe Andy Edmondson, “Focus on Big-Beautiful-Bold Ones. All Kathy Nelson, “Entire Flock Avenue, Los Banos, CA 93635. Fleeces.” 5135 Ranchita Canyon White Pedigreed with a High QR & RR’s” 13329 Weld County CORRIEDALES Ph. 209/704-1073 (Ron). Email: Road, San Miguel, CA 93451. Ph. Concentration of the “R” Road 74, Eaton, CO 80615. [email protected]. 805/835-9919. Email: teterry@ Factor” 5925 Foxen Canyon Home: 970/454-3775. Cell: 970/ WILDWIND CORRIEDALES, CORMOS live.com. Road, Santa Maria, CA 93454. Ph. 481-9837. Email: nelsheep1@ Grover/Quay, “Top Breeding 805/937-5716. what-wire.com. Selections are Available at the SHROPSHIRES McCABE SUFFOLKS, Lloyd & Farm”, 130 Jones Road, SoCal WOOL SHEEP: Cormos, PREUIT HAMPS & SUFFOLKS, Sheila McCabe, 7933 Jahn Road, Wetumpka, AL 36092. Ph. Corriedales and Romneys, Kyle & Denise Preuit , “We Raise ANDERSON FARMS, Matthew, Dixon, CA 95620. Ph. 707/693- 334/514-0495. Email: egwildwind George Saunders, “Covered Good, Sound Sheep!” 286 E.
    [Show full text]
  • 1968 Henderson: WOOL FOLLICLE and FLEECE CHARACTERS OF
    New Zealand Society of Animal Production online archive This paper is from the New Zealand Society for Animal Production online archive. NZSAP holds a regular An invitation is extended to all those involved in the field of animal production to apply for membership of the New Zealand Society of Animal Production at our website www.nzsap.org.nz View All Proceedings Next Conference Join NZSAP The New Zealand Society of Animal Production in publishing the conference proceedings is engaged in disseminating information, not rendering professional advice or services. The views expressed herein do not necessarily represent the views of the New Zealand Society of Animal Production and the New Zealand Society of Animal Production expressly disclaims any form of liability with respect to anything done or omitted to be done in reliance upon the contents of these proceedings. This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License. You are free to: Share— copy and redistribute the material in any medium or format Under the following terms: Attribution — You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use. NonCommercial — You may not use the material for commercial purposes. NoDerivatives — If you remix, transform, or build upon the material, you may not distribute the modified material. http://creativecommons.org.nz/licences/licences-explained/ WOOL FOLLICLE AND FLEECE CHARACTERS OF F1 AND Fz BORDER LEICESTERxROMNEY SHEEP A. E.
    [Show full text]
  • Genetic Variation and Covariation in Productive Characters of New Zealand Romney Marsh Sheep Alexander Lindsay Rae Iowa State College
    Iowa State University Capstones, Theses and Retrospective Theses and Dissertations Dissertations 1950 Genetic variation and covariation in productive characters of New Zealand Romney Marsh sheep Alexander Lindsay Rae Iowa State College Follow this and additional works at: https://lib.dr.iastate.edu/rtd Part of the Veterinary Pathology and Pathobiology Commons Recommended Citation Rae, Alexander Lindsay, "Genetic variation and covariation in productive characters of New Zealand Romney Marsh sheep" (1950). Retrospective Theses and Dissertations. 14622. https://lib.dr.iastate.edu/rtd/14622 This Dissertation is brought to you for free and open access by the Iowa State University Capstones, Theses and Dissertations at Iowa State University Digital Repository. It has been accepted for inclusion in Retrospective Theses and Dissertations by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. INFORMATION TO USERS This manuscript has been reproduced from the microfilm master. UMI films the text directly from the original or copy submitted. Thus, some thesis and dissertation copies are in typewriter face, while others may be from any type of computer printer. The quality of this reproduction is dependent upon the quality of the copy submitted. Broken or indistinct print, colored or poor quality illustrations and photographs, print bleedthrough, substandard margins, and improper alignment can adversely affect reproduction. In the unlikely event that the author did not send UMI a complete manuscript and there are missing pages, these will be noted. Also, if unauthorized copyright material had to be removed, a note will indicate the deletion. Oversize materials (e.g., maps, drawings, charts) are reproduced by sectioning the original, beginning at the upper left-hand corner and continuing from left to right in equal sections with small overiaps.
    [Show full text]
  • Major Genes and QTL Influencing Wool Production and Quality: a Review
    Genet. Sel. Evol. 37 (Suppl. 1) (2005) S97–S107 S97 c INRA, EDP Sciences, 2004 DOI: 10.1051/gse:2004028 Major genes and QTL influencing wool production and quality: a review Ian William P∗, Ian Robert F CSIRO Livestock Industries, F.D. McMaster Laboratory, Chiswick Research Centre, Armidale, NSW Australia (Accepted: 5 July 2004) Abstract – The opportunity exists to utilise our knowledge of major genes that influence the economically important traits in wool sheep. Genes with Mendelian inheritance have been identified for many important traits in wool sheep. Of particular importance are genes influencing pigmentation, wool quality and the keratin proteins, the latter of which are important for the morphology of the wool fibre. Gene mapping studies have identified some chromosomal regions associated with variation in wool quality and production traits. The challenge now is to build on this knowledge base in a cost-effective way to deliver molecular tools that facilitate enhanced genetic improvement programs for wool sheep. gene / major gene / QTL / wool production / wool quality 1. INTRODUCTION Whilst the genetic improvement of sheep bred primarily for wool production has been slow relative to other livestock species, this cannot be blamed on the tools available to the breeders and advisor geneticists. In most countries where wool sheep are grown, there is a quite sophisticated wool market and market intelligence, and the important price determinants are well quantified and communicated. This has facilitated the formal definition of breeding objectives for breeders. Of those traits that are important in an economic sense, most are either moderately or highly heritable, and are easy and inexpensive to measure to a level sufficiently precise for animal evaluation.
    [Show full text]
  • Making Every Mating Count June 2013
    MAKING EVERY MATING COUNT JUNE 2013 0800 BEEFLAMB (0800 233 352) | WWW.BEEFLAMBNZ.COM BY FARMERS. FOR FARMERS Revised and edited by: Dr Ken Geenty Former Research & Development Manager NZ Meat and Wool Producer Boards Beef + Lamb New Zealand would like to acknowledge the writers of 200 by 2000 – A Guide to Improved Lambing Percentage, used as the basis of this book. Prof Paul Kenyon, Dr Trevor Cook and Dr Julie Everett-Hincks provided valuable editorial advice. SUMMARY 2 DEFINITIONS 8 SHEEP REPRODUCTIVE CYCLE 9 CHAPTER ONE 10 An overview of lambing performance on farms CHAPTER TWO 18 Weaning to mating CHAPTER THREE 27 Mating and early pregnancy CHAPTER FOUR 45 Mid to late pregnancy CHAPTER FIVE 59 Lambing CONCLUSIONS 74 APPENDIX 75 Appendix one 76 Appendix two 81 Appendix three 85 Appendix four 88 Appendix five 90 Appendix six 91 SUMMARY MAKING EVERY MATING COUNT CHAPTER 1: AN OVERVIEW OF CHAPTER 2: WEANING TO MATING LAMBING PERFORMANCE ON The period from weaning to mating is important for FARMS preparation of ewes and rams for good reproductive performance. Improved lambing percentage makes the biggest contribution to higher profits on sheep farms. This EWE WEIGHT AND CONDITION FOR MATING chapter covers changes in the sheep industry, lambing performance on farms and changes needed to the A good lambing percentage is largely achieved by farm system with improved lambing percentage. early preparation between weaning and the next mating. CHANGES OVER TIME Ewes need to be in good body weight and condition Sheep industry trends during the 1990s and early 2000s (CS3) for high ovulation rates at mating.
    [Show full text]