Study On The Energy And Protein Requirement Of The Hetian Fowls

The trial studied the effect of the vary dietary energy and protein on the growing performance, slaughter performance, muscular ingredient and nutritional utilization, so determining the optimal energy and protein requirement of Hetian chicken at the different environment temperature and growing stage.Experiment 1. The growing performance: The trial was conducted at the spring-summer and autumn-winter season. The nine diet obtained from L9(34) orthogonal design of three energy levels and three protein levels were fed to pure hetian chicken, which were allotted to four growing stage(0-4weeks, 5-8weeks, 9-12weeks, 13-16weeks). The feeding trial showed that the environmental temperature had an important effect on the energy requirement and feed intake. The effect of the environmental temperature on the energy requirement had a relation with the temperature required by the fowls growing. The fowls needs more energy requirement when the environment temperature was different with the optimal temperature needed by growing fowls.The energy requirement of Hetian fowls is higher at the spring-summer seasons than at the autumn-winter seasons. But the protein requirement had little change. Feed intake had a negative relation with the dietary energy and the environmental temperature . The female had a good feed-gain ratio at high protein treatment for the 0- to 12- weeks period and at low protein treatment for the 13- to 16- weeks period. The dietary protein had little effect on the male feed-gain ratio. The dietary energy and protein had a significant effect on the body weight and daily gain(P<0.05). The fowls of high energy and high protein treatment had a best body weight at spring-summer seasons. But at the autumn-winter seasons, the female had a best body weight at high protein treatment during the whole growing period and low energy treatment for the 0-to 8- weeks period and middle energy treatment for the 9- to 16- weeks period, the male had a best body weight at middle energy treatment during the whole growing period and high protein treatment for the 0- to 8- weeks period andlow protein treatment for the 9- to 16- weeks period. The amount of protein consumed per gram of gain increased with the increase of the dietary protein or the decrease of the dietary energy. The dietary energy and protein has a little effect on the energy consumed per gram of gain.Experiment 2. The slaughter performance: The dietary energy and protein has a significant effect on the PAF and PLM and PLBWM of male(P<0.05), but has little effect on the female slaughter performance and male intermuscular fat pad and subcutaneous fat pad(P>0.05). Increasing the dietary protein increased the PAF and PLM and PLBWM. Increasing the dietary energy reduced the PAF and increased PLM and PLBWM. The intermuscular fat pad and subcutaneous fat pad of male were higher 7.8%, 7.45% than that of female respectively. The female abdominal fat percentage was higher 43.3% than male's.Experiment 3. The muscular ingredient: Increasing the dietary protein reduced the muscular fat and increased the muscular moisture and unsaturated fatty acid and essential fatty acid. Increasing the dietary energy increased the muscular moisture and saturated fatty acid and reduced muscular unsaturated fatty acid and essential fatty acid and IMP. The dietary energy has little effect on the muscular protein. The muscular total free amino acid and essential amino acid and taste amino acid increased with the increasing dietary energy and protein.Experiment 4. The metabolic trial. The middle dietary energy maximize the ARE% and ARN% for 0- to 8- weeks periods. The ARE% and ARN% increased with the increase of the dietary energy for 9- to 16- weeks periods. Increasing the dietary can result in the decrease of the ARE% and ARN%. The ARE% had a negative correlation with feed:gain ratios and intermuscular fat, and had a positive correlation with the PAF and subcutaneous fat pad. The PAF and subcutaneous fat pad had a positive relation with ARN% for 0- to 12- weeks per...