Energy and protein requirements for maintenance of Hu sheep during pregnancy

• Published in: Journal of Integrative Agriculture Vol. 17; no. 1; pp. 173 - 183
• Main Authors: ZHANG, Hao, SUN, Ling-wei, WANG, Zi-yu, MA, Tie-wei, DENG, Ming-tian, WANG, Feng, ZHANG, Yan-li
• Format: Journal Article
• Language: English
• Published: Jiangsu Engineering Technology Research Center of Mutton Sheep & Goat Industry, Nanjing Agricultural University, Nanjing 210095, P.R.China 2018; Laboratory of Metabolic Manipulation of Herbivorous Animal Nutrition, College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, P.R.China; Joint International Research Laboratory of Agriculture & Agri-product Safety, Yangzhou University, Yangzhou 225009, P.R.China%Jiangsu Engineering Technology Research Center of Mutton Sheep & Goat Industry, Nanjing Agricultural University, Nanjing 210095, P.R.China; Elsevier
• Subjects: carbon and nitrogen balance; energy; methane emission; pregnancy; protein; carbon and nitrogen balance; methane emission; protein; pregnancy; energy
• ISSN: 2095-3119; 2352-3425
• DOI: 10.1016/S2095-3119(17)61691-5

This study aimed to determine the effect of stage and level of feed intake on energy metabolism, carbon-nitrogen （C-N） balance, and methane emission to determine energy and protein requirements for maintenance of maternal body including pregnancy tissues during pregnancy using the method of C-N balance. Twenty-one ewes carrying twin fetuses were randomly divided into three groups of seven ewes each in the digestion and respirometry trial at d 40, 100, and 130 of gestation, respectively. Three groups were fed a mixed diet either for ad lib#urn intake, 70 or 50% of the ad libfum intake during pregnancy. The results showed that the apparent digestibility of C and N were increased as feeding levels decreased at each stage of gestation. The daily net energy requirements for maintenance （NEro） were 295.80, 310.09, and 323.59 kJ kg-1 BW0.75 （metabolic body weight） with a partial efficiency of metabolisable energy utilization for maintenance of 0.664, 0.644, and 0.620 at d 40, 100, and 130 of gestation, respectively. The daily net protein requirements for maintenance were 1.99, 2.35, and 2.99 g kg-1 BW0.75 at d 40, 100, and 130 of gestation, respectively. These results for the nutritional requirements of the net energy and protein may help to formulate more balanced diets for Hu sheep during pregnancy.