TITLE:
Effects of Dietary Energy Density in the Dry Period on the Production Performance and Metabolism of Dairy Cows
AUTHORS:
Yun Wang, Qiuling Hou, Gaozhan Cai, Zhiyong Hu, Kerong Shi, Zhengui Yan, Xueyan Lin, Zhonghua Wang
KEYWORDS:
Dry Period, Dairy Cows, Energy, Production Performance, Biochemical Indicator, Hormone Level
JOURNAL NAME:
Advances in Bioscience and Biotechnology,
Vol.8 No.3,
March
28,
2017
ABSTRACT: Thirty healthy Holstein dairy cows in the dry period were randomly divided into three groups and fed diets with different net energy for lactation (group A: 1.2 Mcal/kg DM, group B: 1.3 Mcal/kg DM, and group C: 1.4 Mcal/kg DM) for 8 weeks prepartum. Thereafter, dairy cows were fed a diet of the same formulation (1.66 Mcal/kg DM) for 12 weeks postpartum. The effects of different dietary energy densities in the dry period on postpartum performance and metabolic parameters of dairy cows were observed. Milk yield was reduced by 14.5% in the low-energy diet group; however, there were no differences in milk composition between the three groups. Postpartum plasma β-hydroxybutyrate, non-esterified fatty acid, growth hormone, and glucagon levels were significantly decreased whereas leptin and neuropeptide levels were elevated in the low-energy diet group. Moreover, body fat mobilization was attenuated, and the decline in postpartum body condition was reduced in the low-energy diet group, thus effectively reducing the postpartum negative energy balance.