Effects Of Guanidineacetic Acid On Growth Performance,Slaughter Performance And Digestive Metabolism Of Lambs

This experiment was conducted to investigate the effects of dietary supplemented with guanidineacetic acid(GAA)on growth performance,slaughter performance,nutrient apparent digestibility,and rumen fermentation of lambs.Forty-eight 4-months-old Dorper × thin-tailed Han F1 hybrid ram lambs with similar body weight(24.8±1.3kg)were randomly divided into 4 groups to conduct feeding and digestion and memtabolism experiments.Lambs in four groups were fed basic diets and supplemented with 0(control group),300(300GAA group),600(600GAA group),900(900GAA group)mg of GAA per kg of dietary.The results in this experiment showed as follows:1)Campared with control、300GAA、600GAA group,the final weight、ADG and the feed conversion efficiency of 900 GAA group were significantly increased(P<0.05),the ADFI of every group was not significant.2)Compared with control,carcass weight,net meat weight of 900 GAA group were significantly higher(P<0.05).Compared with control,the eye muscle area of 300 GAA,600GAA and900 GAA groups was significantly improved(P<0.05).Compared with control,the length of ileum of300 GAA,600GAA and 900 GAA groups was significantly improved(P<0.05),the ileum’ weight of900 GAA group was significantly improved than control,300 GAA and 600 GAA groups(P<0.05).The content of CP in 600 GAA,900GAA groups was significantly improved than control,300 GAA groups(P<0.05).3)The apparent digestibility of DM,OM,CP and NDF of 900 GAA group were significantly higher than those in control,300 GAA and 600 GAA groups(P<0.05).Compared with other groups,the apparent digestibility of GE,metabolizability of GE of 900 GAA group were significantly higher(P<0.05).Nitrogen deposition increased linearly(P<0.05)in all experimental groups.Campared with control,300 GAA,600GAA groups,apparent digestibility of N in 900 GAA group was significantly improved(P<0.05).Nitrogen deposition rate in 900 GAA group was significantly improved than that in control,300 GAA and 600 GAA groups(P<0.05).4)GAA can significantly decreased the p H of ruminal fluid(P<0.01),and the p H of 600 GAA and 900 GAA groups were significantly lower than control and 300 GAA groups(P<0.01).The content of acetic acid of 300 GAA,600GAA,900 GAA group was significantly improved(P<0.05).The TVFA content of each experimental group increased linearly(P<0.05).The results showed that the content of pectase increased linearly(P<0.01).Carboxymethyl cellulase of 900 GAA group was significantly higher than control,300 GAA groups(P<0.05).Compared with control,the xylanase of600 GAA and 900 GAA groups was significantly improved(P<0.05).The activity of protease in 900 GAA group was significantly higher than control(P<0.05).The number of rumen coccus albicans and rumen bacillus amylophilus of 900 GAA group was significantly improved compared with control and 300 GAA groups(P<0.05).The number of rumen prevotella and methanogens of 900 GAA group was significantly improved than control,300 GAA groups(P<0.05).5).The activities of SOD in 600 GAA,900GAA groups were significantly higher than control,300 GAA groups(P<0.01).Compared with control and 300 GAA groups,the content of MDA in 900 GAA group was significantly lower(P<0.01).With the supplementation of GAA,the activity of GSH-Px in blood increased linearly(P<0.01)and 900 GAA group had higher value than the other three groups(P<0.01).The results indicated that dietary supplementation of GAA can improve the growth performance,slaughter performance,meat quality.It can also improve the digestibility of nutrients,promote energy metabolism and improve rumen fermentation.The optimal dose was 900mg/kg of diet under the condition of this experiment.