Effects of Different Protein Energy Ratios on Fattening Performance,Slaughter Performance and Meat Quality of Pigs

[Objectives]Protein energy ratio refers to the proportional relationship between protein and energy levels in animal diets,i.e.,the grams of crude protein corresponding to every megacalorie of energy,which is generally expressed as CP:ME or CP:DE.This study was conducted to investigate the effects of different diets on fattening and slaughter performance and meat quality traits for"L(Large Yorkshire)×L(Landrace)"crossbred pigs.[Methods]Eighteen piglets of L×L crossbred with similar body weights about 51 kg were selected.The piglets were divided into 3 groups randomly and each group was assigned to 3 replicates with 2 piglets in a replicate.Group A was fed diet Ⅰ (control diet),group B was fed the same diet of group A in the first month of the trial but fed diet Ⅱ in second month,and group C consumed diet Ⅲ.All the pigs were fed in the same feeding condition for two months except the different diets during the trial.One pig in similar body weight from each replicate was slaughtered for the determination of slaughter performance and meat quality traits in the end of the trial.[Results]The average daily feed intake(ADFI)of pigs from group B was only(2.32±0.52)kg and significantly lower than those from group A and group C(P<0.05),but no difference was found in average daily gain(ADG) and feed/gain(P>0.05).Also,no differences occurred in the carcass length,back fat thickness,longissimus muscle (LM) area and dressing percentage(P>0.05).In addition,no differences were found in the meat quality traits of shear force,meat color,pH_(45 min),pH_(24 h) and cooking loss(P>0.05).However,the water-holding capacity of meat from group C was(2.58±0.02)ms and significantly lower than that of(2.80±0.20)ms from group A(P<0.05).Although the contents of glutamic acid and cystine in LM from group B was significantly lower than those from group A and group C(P<0.05),no differences occurred in the contents of other amino acids,the total amino acid and total flavor amino acid among the three groups(P>0.05).However,the inosine monophosphate content of LM from group C was only(331.80±11.53)mg/100 g and significantly lower than those of(361.00±6.36)and(366.37±4.80)mg/100 g from group A and B(P<0.05).Even though no differences were found in the contents of DM and CP in LM among the three groups of pigs,the content of intramuscular fat(IMF)in LM from group B and group C was increased by 45.6%and 46.58%respectively from that of group A(P<0.05),but no difference occurred between group B and C(P>0.05).[Conclusions]DietsⅡ and Ⅲ in this study caused no differences in fattening and slaughter performance of L×L crossbred pigs,but the effects on some meat traits were still significant,especially on the improvement of intramuscular fat in experimental pigs.Therefore,they could improve the meat quality of crossbred pigs to a certain extent.

Effects of Chinese Herbal Medicine Feed Additives on Growth Performance and Dietary Nutrient Metabolism of Black-bone Chickens

[Objectives]To study the effects of Chinese herbal medicine feed additives on the growth performance and dietary nutrient metabolic rate of black-one chickens.[Methods]480 pieces of 1-day-old Donglan Black-bone Chickens were selected and divided into 4 groups,with 6 replicates in each group,with 20 pieces in each replicate.Among them,group A was the control group and was fed the basal diet;the groups B,C,and D were the experimental groups,which were separately supplemented with 0.25%,0.50%and 1.00%of Chinese herbal medicine additives in the basal diet,and the experimental period was 70 d.At the end of the feeding experiment,24 experimental chickens with similar body weight were selected from each group,and the same design of the feeding experiment was used to continue to feed the original diet for the metabolic experiment to determine the nutrient metabolic rate.[Results]Except the 50-70 d stage,the average daily gain(ADG)of group B in other stages was increased by 5.00%-9.15%(P<0.05),and the average body weight of group B at 70 d was also increased by 4.86%(P<0.05);the ADG of group C at 36-49,1-49 and 1-70 d and the average individual weight at 70 d were also higher than that of group A by 5.90%,2.66%,2.68%and 2.57%,respectively(P>0.05);at 36-49 d,the average daily feed intake(ADFI)of group A was higher than that of group B by 6.04%(P<0.01),and was also higher than that of groups C and D by 5.12%and 4.13%(P<0.05),respectively;at 1-49 d,the ADFI of group A was higher than that of group C by 2.86%(P<0.05),and there was no significant difference between the four groups of experimental chickens at each stage(P>0.05);at 22-35 and 1-70 d,the feed to gain ratio(F/G)of group B was 6.32%and 3.41%lower than that of group A(P<0.05),and at 36-49 and 1-49 d,the F/G of group B was even lower;at 36-49 d,the F/G of group C was 10.15%lower than that of group A(P<0.05),and at 1-49 d,it was also lower than that of group A by 5.29%(P<0.01);there was no significant difference between the two groups at other stages.In terms of nutrient metabolism:the three different amounts of this additive have increased the metabolic rate of DM,CP,CF,NFE,CA,Ca,P,TE and other nutrients in the diet to varying degrees,especially the addition of 0.25%and 0.50%had the significant increase.[Conclusions]The addition of 0.25%Chinese herbal medicine additives in the diet can significantly improve the growth performance and main nutrient metabolic rate of Donglan Black-bone Chickens.