Estimation of genetic parameters and Variance components of milk traits in Holstein-Friesian and British-Holstein dairy cows
Çalışmanın amacı Holştayn ve İngiliz Holştayn ineklerinin süt verim özelliklerinin genetik parametrelerini tahmin etmektir. Çalışmada kullanılan veriler İskoçya da süt ineklerinin süt, sağlık ve dölverimi kayıtlarını tutan bir şirketten (LSUK) temin edilmiştir. Bütün düzeltmelerden sonra laktasyon süt verimi, yağ ve proteinin bulunduğu 70931 adet veri kullanılmıştır. Süt, yağ ve proteinin varyans unsurlarının tahmininde ASREML programı kullanılmıştır. Bahsedilen özelliklerin tahmininde tek özellikli bireysel hayvan modeli kullanılmıştır. Ortalama buzağılama yaşı 26-65 ay, ortalama laktasyon uzunluğu da 300-320 gün olarak belirlenmiştir. Bahsedilen özelliklerin kalıtım dereceleri de 0.22 ile 0.52 arasındadır ve Holştaynların bu değerleri İngiliz Holştaynlarından büyüktür. Bir çok özellik için fenotipik korelasyonlar genetik korelasyonlardan daha kuvvetli bulunmuştur. Süt ve yağ arasındaki genetik korelasyon katsayısı 0.38 bulunurken, süt ve protein arasındaki 0.92 olarak belirlenmiştir.
Holştayn frizyan ve ingiliz holştayn sütçü sığırlarında süt özelliklerinin varyans unsurları ve genetik parametrelerinin tahmini
The objectives of this study were to estimate the genetic parameters of milk traits of dairy cows and to examine the associations among these traits in both Holstein-Friesian and British-Holstein. The data used in this study was obtained from (LSUK), an organisation for the recording of milk, health and service parameters of dairy cows in Scotland. The data consisted of information on total lactation milk, fat and protein yield. The final number of production records retained in the production database after all edits was 70931. Variance components and genetic parameters for milk, fat and protein yield were estimated using the ASREML program. Analysis for milk, fat and protein yield was conducted for each of the prepared data sets using a univariate animal model. Mean calving age ranged from 29-65 months. The mean lactation length ranged from 300-320 days. The heritabilities of these traits were ranging from 0.22 to 0.52. The heritabilities of milk, fat and protein yield were higher in Holstein-Friesian than British-Holstein. For most of the traits, phenotypic correlations were larger than the genetic correlations. The results showed that there were moderate-strong positive genetic and phenotypic correlations among the production traits. The genetic correlations ranged from 0.38 between milk and fat yield to 0.92 between milk and protein yield.
___
- 1. Willis MB: Dalton’s Introduction to Practical Animal Breeding. Blackwell Scientific Publications Ltd, Oxford, UK, 1991.
- 2. Djemali M, Berger PG: Yield and reproduction characteristics of Friesian cattle under North African conditions. J Dairy Sci, 75, 3568-3575, 1992.
- 3. Ray DE, Halbach TJ, Armstrong DV: Season and lactation number eff ects on milk production and reproduction of dairy cattle in Arizona. J Dairy Sci, 75, 2976-2983, 1992.
- 4. Ulutas Z, Ap Dewi I, Saatcı M: Six diff erent models on suckler cattle to estimate of genetic parameters and breeding values for pre-weaning and post-weaning weights. Turk J Vet Anim Sci, 25, 179-184, 2001.
- 5. Erdoğan HM, Çitil M, Güneş V, Saatcı M: Dairy cattle farming in Kars District, Turkey. I. Characteristics and production. Turk J Vet Anim Sci, 28, 735-743, 2004.
- 6. Bourdon RM: Understanding Animal Breeding. Prentice-Hall, Inc. USA, 1997.
- 7. Saatcı M, Ap Dewi I, Aksoy AR: Application of REML procedure to estimate the genetic parameters of weekly liveweight in one-to-one sire and dam pedigree recorded Japanese quail. J Anim Breed Genet, 120, 23-28, 2003.
- 8. Pryce JE, Veerkamp RF, Thompson R, Hill GW, Simm G: Genetic aspects of common health disorders and measures of fertility in Holstein Friesian dairy cattle. Anim Sci, 65, 353-360, 1997.
- 9. Hargrove GL, Mbah DA, Rosenberger JL: Genetic and environmental infl uences on milk and milk component production. J Dairy Sci, 64, 1593-1597, 1981.
- 10. Van Vleck LD, Van Dong MC: Genetic (co)variances for milk, fat and protein yield in Holsteins using an animal model. J Dairy Sci, 71, 3040-3046, 1988.
- 11. Campos MS, Wilcox CJ, Becerril CM, Diz A: Genetic parameters for yield and reproductive traits of Holstein and Jersey cattle in Florida. J Dairy Sci, 77, 867-873, 1994.
- 12. Suzuki M, Vleck LD: Heritability and repeatability for milk production traits of Japanese Holsteins from an animal model. J Dairy Sci, 77, 583-588, 1994.
- 13. Gilmour AR, Cullis BR, Welham SJ, Thompson R: ASREML. NSW. Agriculture, Orange, Australia, 1998.
- 14. Hoekstra J, Lugt AW, Werf JHJ, Ouweltjes W: Genetic and phenotypic parameters for milk production and fertility traits in upgraded dairy cattle. Livest Prod Sci, 40, 225-232, 1994.
- 15. Van Dorp TE, Dekkers JCM, Martin SW, Noordhuizen JPTM: Genetic parameters of health disorders, and relationships with 305-day milk yield and conformation traits of registered Holstein cows. J Dairy Sci, 81, 2264-2270, 1998.
- 16. Juga J: Estimation of variances and covariances of milk traits by REML with an individual animal model. Acta Agriculturae Scand Section A, 42, 198-204, 1992.
- 17. Dematawewa CMB, Berger PJ: Genetic and phenotypic parameters for 305-day yield, fertility, and survival in Holsteins. J Dairy Sci, 81, 2700-2709, 1998.
- 18. Kadarmideen HN, Thompson R, Simm G: Linear and threshold model genetic parameters for disease, fertility and milk production in dairy cattle. Anim Sci, 71, 411-419, 2000.
- 19. Butcher DF, Freeman AE: Heritabilities and repeatabilities of milk and milk fat production by lactations. J Dairy Sci, 51, 1387-1391, 1968.