剩余采食量对不同品种育肥牛生长性能、营养物质表观消化率及血清生化和激素指标的影响OA

This study was conducted to investigate the effects of residual feed intake(RFI)on growth perform-ance,apparent nutrient digestibility and serum biochemical and hormone parameters of different breeds of fin-ishing cattle,and to explore the effects of breed,RFI and their interactions on fattening performance of beef cattle.Twelve healthy Simmental bulls and twelve healthy Holstein dairy bulls with similar body weight were individually housed and fed,with a 7-day adaptation period followed by a 136-day experimental period.The study employed a 2×2 factorial completely randomized design with breed and RFI,divided into 4 groups with 6 cattle in each group:Simmental bulls with low residual feed intake group(XM-L group),Simmental bulls with high residual feed intake(XM-H group),Holstein dairy bulls with low residual feed intake(HS-L group)and Holstein dairy bulls with high residual feed intake group(HS-H group).The results showed as fol-lows:1)the dry matter intake(DMI)and RFI of XM-L group and HS-L group were significantly lower than those of XM-H group and HS-H group(P＜0.05).2)During 620 to 670 kg phase,the apparent digestibility of dry matter(DM),neutral detergent fiber(NDF)and acid detergent fiber(ADF)of HS-L group and HS-H group was significantly lower than that of XM-L group and XM-H group(P＜0.05).During 780 to 830 kg phase,the apparent digestibility of DM,crude protein(CP),NDF and ADF of HS-L group and HS-H group was significantly lower than that of XM-L group and XM-H group(P＜0.05),and the apparent digestibility of CP and NDF of HS-H group was significantly lower than that of HS-L group(P＜0.05).3)During 780 to 830 kg phase,the serum glucose(GLU)content of XM-L group and XM-H group was significantly lower than that of HS-L group and HS-H group(P＜0.05),and the serum GLU content of HS-L group was significantly lower than that of HS-H group(P＜0.05).The serum free fatty acids(FFA)content of XM-H group and HS-H group was significantly lower than that of XM-L group and HS-L group(P＜0.05).4)During 780 to 830 kg phase,the serum insulin(INS)content of XM-L group and XM-H group was significantly lower than that of HS-L group and HS-H group(P＜0.05).The serum leptin(LEP)content of XM-H group and HS-H group was significantly lower than that of XM-L group and HS-L group(P＜0.05).In summary,feeding low RFI fattening cattle can improve feed efficiency and NDF apparent digestibility,it has characteristics of better serum glucose(GLU)utilization efficiency and lipid mobilization degree,and the serum GLU and FFA con-tents may be considered as potential auxiliary indicators for RFI selection.The apparent digestibility of DM,CP,NDF and ADF of Holstein dairy bulls is lower than that of Simmental bulls.Under these experimental con-ditions,the Simmental bulls with low RFI exhibit superior fattening performance.[Chinese Journal of Animal Nutrition,2026,38(4):2698-2708]