ACTA VETERINARIA ET ZOOTECHNICA SINICA ›› 2014, Vol. 45 ›› Issue (12): 1939-1948.doi: 10.11843/j.issn.0366-6964.2014.12.005

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Study on General Lactation Curve Models and Milk Composition Change Models of Chinese Holstein Cows in the North of China

XIONG Ben-hai,YANG Liang,YANG Qin,PAN Xiao-hua,HAN Ying-dong,PANG Zhi-hong   

  1. (State Key Laboratory of Animal Nutrition,Institute of Animal Science,Chinese Academy of Agricultural Sciences,Beijing 100193,China)
  • Received:2014-04-01 Online:2014-12-23 Published:2014-12-23

Abstract:

 The aim of this study was to reveal the lactation characteristics of Chinese Holstein dairy cows in different parities and to construct models for changes of daily milk yield(DMY) and milk composition percentages(milk fat percentage,MFP;milk protein percentage,MPP;milk lactose percentage,MLP;milk solid percentage,MSP) with the days in milk (DIM).The DHI original datasets (of which:the DHI datasets of first parity was 11 901,the second was 13 474 datasets,the third parities was 13 215 datasets)in the First Lactating Holstein Dairy Farm in Tianjin of the northern China(2008-2010 years 1-3 parities)were collected and Wood model was applied,as well as the differences of indexes mentioned above among parities were analyzed.The results showed that Wood model was extremely fitted with lactation curve for Chinese Holstein cows in parity 1 to 3,and the corresponding models were built.Lactation characteristic parameters such as time to peak yield (tm,d),peak yield (ym,kg•d-1),relative rate of decline at the point halfway between peak yield and end of lactation(r(th)) induced by parameter ab and c indicated that r(th) declines rapidly for cows in the parity 2 and 3,which resulted in their total milk yield reducing.Models for milk fat displayed that average MFP in the second parity of dairy cows(3.93%) was higher than the first parity (3.83%) and the third parity was lowest (3.69%),and average MPP in the second parity of dairy cows(3.24%) was higher than the third parity (3.18%) and the first parity were lowest (3.10%),and average MLP declined with the increase of parities (4.87%,4.84%,4.75% for parity 1,2 and 3,respectively).Average MSP in the second parity of dairy cows(12.54%) was higher than the third parity (12.52%) and the first parity were lowest (12.50%),and the above results indicated that though milk yield in the third parity was lower than the second parity,MSP was not improved as the milk yield decline.Significant differences were observed for DMY,MFP,MPP,MLP and MSP among the 3 parities(P<0.05).In addition,Wood model performed a best fit of DMY,MPP and MSP followed,while the MFP and MLP fitted poorly.In conclusion,Chinese Holstein cows in the second parity have the best milk performance,followed by the primiparous cow,and both milk yield and milk quality like MFP and MPP declined significantly for cows in parity 3.Therefore,it’s urgent for the dairy production to strengthen the management of cows in third parity or higher and to maintain the health and lactation potential of cows.

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