Effect of dietary near ideal amino acid profile on heat production of lactating sows exposed to thermal neutral and heat stress conditions

作     者：S.Zhang J.S.Johnson N.L.Trottier S.Zhang;J.S.Johnson;N.L.Trottier

作者机构：Department of Animal ScienceMichigan State UniversityEast Lansing 48824USA USDA-ARS Livestock Behavior Research UnitWest Lafayette 47907USA 

出 版 物：《Journal of Animal Science and Biotechnology》 (畜牧与生物技术杂志（英文版）)

年 卷 期：2021年第12卷第2期

页      面：739-754页

核心收录：

学科分类：0710[理学-生物学] 0831[工学-生物医学工程（可授工学、理学、医学学位）] 0832[工学-食品科学与工程（可授工学、农学学位）] 090502[农学-动物营养与饲料科学] 1004[医学-公共卫生与预防医学(可授医学、理学学位)] 0905[农学-畜牧学] 09[农学] 0906[农学-兽医学] 0703[理学-化学] 0836[工学-生物工程] 

基　　金：supported by the USDA-NIFA(award number 2014–67015-21832). 

主　　题：Amino acid Heat stress Lactating sows Low protein diet Total heat production 

摘      要：Background:Reduced protein diet manifested potential to mitigate heat production based on the concept of ideal amino acid profile.The hypothesis of this study was that lactating sows fed a low crude protein(LCP)diet with supplemental amino acid produce less heat compared to those fed a high crude protein(HCP)diet under both thermal neutral(TN)and heat stress(HS)conditions.Methods:Thirty-two lactating sows were allotted to HCP(193 g CP/kg)and LCP(140 g CP/kg)diets under thermal neutral(TN,21±1.5°C)or cycling heat stress(HS,32±1.5°C daytime and 24±1.5°C nighttime)conditions.Diets contained 0.90%SID lysine and 10.8 MJ/kg net energy.Positive pressure indirect calorimeters were used to measure gas exchange in individual sows with litters,and individual piglets on days 4,8,14 and 18.Sow and litter weights were recorded on days 1,10 and 21.Results:Sow total heat production(THP)was calculated by subtracting litter THP from sow+litter THP based on BW0.75.Sow BW and body protein(BP)loss was greater for LCP diet compared to HCP diet in peak lactation(P0.05 and P0.01,respectively)and throughout the entire lactation period(P0.05 and P=0.056,respectively)under HS conditions.Heat-stressed sows fed HCP diet had higher(P0.05)rectal temperature at 13:00(P0.05)and 19:00(P0.01),and higher respiration rate at 07:00(P0.05),13:00(P0.05)and 19:00(P0.05)compared to TN sows fed HCP diet.In sows fed LCP diet,those under HS tended to have higher(P=0.098)rectal temperature at 13:00 and had higher(P0.05)respiration rate at 07:00,13:00 and 19:00 compared to TN sows.The relationship between daily THP and days in lactation of sows fed LCP diet was quadratic(P0.05),with an ascending trend until day 14 and a descending trend from days 14 to 18.Sows fed LCP diet had lower daily THP at day 18(P0.001)compared to those fed the HCP diet under HS conditions.Conclusion:Reduction in THP in sows fed LCP diet was largely associated with THP on day 18 of lactation under HS conditions.Feeding LCP diets alleviated the increased body temperature in sows under HS conditions throughout lactation,which was accompanied by a reduction in respiration rate.Total heat production is associated with days in lactation,in particular under HS conditions with THP appearing to peak between days 14 and 18.