China Animal Husbandry & Veterinary Medicine ›› 2011, Vol. 38 ›› Issue (9): 130-134.

• 遗传繁育 • Previous Articles     Next Articles

Study on Detecting Shape of Lactation Curve of Cattle Based on Wood Model by ML and REML

WANG Rui-jun1, WANG Ya-chun2, WU Hong-jun3, CUI Jiu-hui3, WANG Dong-sheng3, ZHAO Jian-hu3, ZHANG Wen-guang4, LI Jin-quan1   

  1. 1. Inner Mongolia Agricaltural University, Hohhot 010018, China;2. China Agricultural University, Beijing 100193, China;3. Agriculture and Animal Husbandry Administration Bureau of Hailaer in Inner Mongolia Autonomous Region, Hailaer 021012, China;4. Key Laboratry of Animal Genetic Breeding and Reproduction, Inner Mongolia Agricaltural University, Hohhot 010018, China
  • Received:2011-02-24 Revised:1900-01-01 Online:2011-09-20 Published:2011-09-20

Abstract: Estimated the different statistical models of Inner Mongolia Sanhe cattle’s lactating curve which was based on mis-classification γ function (Wood model) by maximum likelihood method (ML), then test the differences by likelihood ratio(LR). As a result, model Ⅲ was significantly better than the model Ⅱ and Ⅰ(P<0.01). Estimated the model Ⅲ by REML, there were siginicantly differences of milk yield in initial stage under different pari, year, seas and herd(P<0.05). The growth rate of diraly milk yield had significantly difference with the test days(t), natural logarithm of the test days(t'), interaction of the pari and test days, interaction of the pari and natural logarithm of the test days. Milk yield in initial stage has positive or negative correlation with the slope rate coefficient of t and t' (P<0.01).

Key words: Inner Mongolia Sanhe cattle; lactation curve; Wood model; ML; REML

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