Estimation of Genetic Parameters for Lactation Curve Traits in Holstein Dairy Cows in Iran
محورهای موضوعی : Camelف. سقانژاد 1 , ه. آتشی 2 , م. دادپسند 3 , م.ج. ضمیری 4 , ف. شکری-سنگری 5
1 - Department of Animal Science, Shiraz University, Shiraz, Iran
2 - بخش علوم دامی-دانشکده کشاورزی- دانشگاه شیراز
3 - Department of Animal Science, Shiraz University, Shiraz, Iran
4 - Department of Animal Science, Shiraz University, Shiraz, Iran
5 - Department of Animal Science, Shiraz University, Shiraz, Iran
کلید واژه: lactation curve, Holstein dairy cow, incomplete gamma function,
چکیده مقاله :
The objectives were to estimate (co)variance components and genetic parameters for lactation curve traits in Holstein dairy cows in Iran. The used data were records on Holstein cows collected during January 2003 to December 2012 by the Animal Breeding Center of Iran (Karaj, Iran). In order to describe the lactation curve, an incomplete gamma function was fitted to 691200 test-day records on 96263 lactations, 377696 test-day records on 52168 lactations, and 182143 test-day records on 24951 lactations for the first three parities, respectively. Lactation curve traits that were analyzed included a scaling factor associated with initial yield, the inclining and declining slopes of the curve, peak time, peak yield, 305-d milk yield and a lactation persistency measure derived from the incomplete gamma function. The estimated heritability of lactation curve traits for the first, second and third lactation ranged from 0.012 to 0.29, 0.017 to 0.15, and 0.02 to 0.13, respectively. Genetic correlations among lactation curve traits for the first, second and third lactation ranged from -0.68 to 0.99, -0.84 to 0.98 and -0.90 to 0.94, respectively. The estimated repeatability of lactation curve traits ranged from 0.07 to 0.40. The moderate to large positive genetic correlations of 305-d milk yield with initial yield, peak yield and lactation persistency suggest that one of these traits could be used as a selection criterion to improve all four traits. However, the peak yield and 305-d milk yield were more heritable than lactation were persistency and initial yield.
هدف این پژوهش، برآورد اجزای واریانس و پارامترهای ژنتیکی معیارهای تداوم شیردهی و تولید شیر 100 و 305 روز در گاوهای هلشتاین ایران بود. از رکوردهای روز-آزمون تولید شیر گردآوری شده بین سالهای 1380 تا 1391 به وسیله مرکز اصلاح نژاد دام و بهبود تولیدات دامی کشور، استفاده شد. چهار معیار برای سنجش تداوم شیردهی استفاده شد: 21P: نسبت شیر تولیدی در بخش دوم دوره شیردهی به شیر تولیدی در بخش نخست دوره شیردهی، 31P: نسبت شیر تولیدی در بخش سوم دوره شیردهی به شیر تولیدی در بخش نخست دوره شیردهی، Pw: سنجه تداوم شیردهی حاصل از پارامترهای تابع گامای ناقص و Pj: تفاوت تولید در روزهای 280 و 60 دوره شیردهی. برای هر حیوان در هر دوره شیردهی تولید شیر در 100 روز اول، دوم و سوم و همچنین تولید در روز 60 و 280 و تولید شیر 305 روز با استفاده از پارامترهای تابع گامای ناقص برآورد شد. وراثتپذیریهای برآورد شده برای معیارهای مختلف تداوم شیردهی در زایش اول، دوم و سوم به ترتیب بین 1 تا 6 ، 2 تا 10، و 1 تا 12 درصد بود. همبستگی ژنتیکی بین معیارهای تداوم شیردهی در زایش اول، دوم و سوم به ترتیب 77 تا 98، 65 تا 98 و 58 تا 98 درصد بود. همبستگی ژنتیکی بین معیارهای تداوم شیردهی و تولید شیر 305 روز در زایش اول، دوم و سوم به ترتیب بین 18 تا 63، 32 تا 75 و 41 تا 71 درصد برآورد شد. تکرارپذیری معیارهای تداوم شیردهی و تولید شیر 100 و 305 روز به ترتیب 6 تا 20 درصد، 30 درصد و 40 درصد برآورد شد.
Angeles-Hernandez J.C., Albarran-Portillo B., Gonzalez A.G., Salas N.P. and Gonzalez-Ronquillo M. (2013). Comparison of mathematical models applied to f1 dairy sheep lactations in organic farm and environmental factors affecting lactation curve parameter. Asian-Australasian J. Anim. Sci. 26, 1119-1126.
Atashi H., Moradi-Sharbabak M. and Abdolmohammadi A. (2006). Study of some suggested measures of milk yield persistency and their relationships. Int. J. Agric. Biol. 8, 387-390.
Atashi H., Zamiri M.J. and Sayyadnejad M.B. (2012). Effect of twinning and stillbirth on the shape of lactation curve in Holstein dairy cows of Iran. Arch. Tierz. 55, 226-233.
Boujenane I. and Hilal B. (2012). Genetic and non genetic effects for lactation curve traits in Holstein-Friesian cows. Arch. Tierz. 55, 450-457.
Ferris T.A., Mao L.L. and Anderson C.R. (1985). Selecting for lactation curve and milk yield in dairy cattle. J. Dairy Sci. 68, 1438-1448.
International Committee for Animal Recording. (2011). Standards and guidelines for recording milk and milk constituents. Section 2.1, Pp. 23-56, in International Committee for Animal Recording (ICAR) Rules. Guidelines approved by the General Assembly held in Riga, Riga, Latvia.
Keown J.F., Everett R.W., Empet N.B. and Wadell L.H. (1986). Lactation curves. J. Dairy Sci. 69, 769-781.
Macciotta N.P.P., Dimauro C., Catillo A., Coletta A. and Cappio-Borlino A. (2006). Factors affecting individual lactation curve shape in Italian river buffaloes. Livest. Sci. 104, 33-37.
Macciotta N.P.P., Vicario D. and Cappio-Borlino A. (2005). Detection of different shapes of lactation curve for milk yield in dairy cattle by empirical mathematical models. J. Dairy Sci. 88, 1178-1191.
Meyer K. (2006). WOMBAT–A Program for Mixed Model Analyses by Restricted Maximum Likelihood. User Notes. Animal Genetics and Breeding Unit, Armidale, Australia.
Rao M.K. and Sundaresan D. (1979). Influence of environment and heredity on the shape of lactation curves in Sahiwal cows. J. Agric. Sci. 92, 393-401.
Rekik B. and Gara A.B. (2004). Factors affecting the occurrence of atypical lactations for Holstein-Friesian cows. Livest. Prod. Sci. 87, 245-250.
Rekik B., Gara A.B., Hamouda M.B. and Hammami H. (2003). Fitting lactation curves of dairy cattle in different types of herds in Tunisia. Livest. Prod. Sci. 83, 309-315.
Schmidt G.H. and Van Vleck L.D. (1974). Principles of Dairy Science. Freeman and Company, San Francisco, California.
Shanks R.D., Berger P.J., Freeman A.E. and Dickinson F.N. (1981). Genetic aspects of lactation curves. J. Dairy Sci. 64, 1852-1860.
Tekerli M., Akinci Z., Dogan I. and Akcan A. (2000). Factors affecting the shape of lactation curve of Holstein cows from the Balikrsir province of Turkey. J. Dairy Sci. 83, 1381-1386.
Togashi K. and Lin C.Y. (2003). Modifying the lactation curve to improve lactation milk and persistency. J. Dairy Sci. 86, 1487-1493.
Wood P.D.P. (1967). Algebraic model of the lactation curve in cattle. Nature. 216, 164-165.