Net protein and metabolizable protein requirements for maintenance and growth of early-weaned Dorper crossbred male lambs

Background： Dorper is an important breed for meat purpose and widely used in the livestock industry of the world.However, the protein requirement of Dorper crossbred has not been investigated. The current paper reports the net protein（NP） and metabolizable protein（MP） requirements of Dorper crossbred ram lambs from 20 to 35 kg BW.Methods： Thirty-five Dorper × thin-tailed Han crossbred lambs weaned at approximately 50 d of age（20.3 ± 2.15 kg of BW） were used. Seven lambs of 25 kg BW were slaughtered as the baseline animals at the start of the trial. An intermediate group of seven randomly selected lambs fed ad libitum was slaughtered at 28.6 kg BW. The remaining 21 lambs were randomly divided into three levels of dry matter intake： ad libitum or 70% or 40% of ad libitum intake. Those lambs were slaughtered when the lambs fed ad libitum reached 35 kg BW. Total body N and N retention were measured.Results： The daily NP and MP requirements for maintenance were 1.89 and 4.52 g/kg metabolic shrunk BW（SBW0.75）.The partial efficiency of MP utilization for maintenance was 0.42. The NP requirement for growth ranged from 12.1 to 43.5 g/d, for the lambs gaining 100 to 350 g/d, and the partial efficiency of MP utilization for growth was 0.86.Conclusions： The NP and MP requirements for the maintenance and growth of Dorper crossbred male lambs were lower than the recommendations of American and British nutritional systems.

Effects of Dietary Metabolizable Energy and Crude Protein Levels on Reproductive Performance of Magang Geese

[ Objective] To investigate the effects of different levels of metabolizable energy and crude protein on egg laying performance and hatch- ing efficiency in Magang geese. [Method] The healthy Magang geese at 2 years old were randomly assigned into four groups, group Ⅰ, group Ⅱ, group Ⅲ and control group. They were fed with diets at different levels of metabolizable energy and crude protein, and then their eggs were collect- ed and hatched. During the test, their health was observed, and the egg weight, egg yield and hatching rate were recorded. [ Result] The average egg laying rates and average egg weight were significantly higher in the group Ⅰ, group Ⅱ and group Ⅲ than in the control group. The hatchable egg rates and egg fertilization rates of the group Ⅰ, group Ⅱ and group Ⅲ were also increased, and significance was found between the group Ⅲ and the other group （P 〈 0.05）. The feed costs of the three test groups were lower than that of the control group, and the feed cost was higher in the group Ⅲ than that in the group Ⅰ and Ⅱ. [ Conclusion] The levels of metabolizable energy and crude protein in diet have significant effects on laying performance and hatching efficiency in Magang geese.

Protein requirements of early-weaned Dorper crossbred female lambs

The net protein （NP） and metabolizable protein （MP） requirements of Dorper crossbred female lambs from 20 to 35 kg body weight （BW） were assessed in a comparative slaughter trial. Thirty-five Dorper×thin-tailed Hart crossbred lambs weaned at approximately 50 d of age （（19.1±2.37） kg of BW） were used. Seven randomly selected lambs were slaughtered at the beginning of the trial as baseline group （BL）. An intermediate group of seven randomly selected lambs fed ad libitum （AL） intake was slaughtered when the lambs reached an average BW of 28.6 kg. The remaining 21 lambs were allotted randomly to three levels of dry matter intake： AL or restricted to 70 or 40% of the AL intake. All lambs were slaughtered when the sheep fed AL intake reached 35 kg of BW. Total body N and N retention were determined. The results showed that the maintenance requirements for NP and MP were 1.75 and 3,37 g kg^-1 metabolic shrunk body weight （SBW^0.75）, respectively. The partial efficiency of protein use for maintenance was 0.52. The NP requirements for growth ranged from 10.9 to 42.4 g d^-1 for the lambs gaining 100 to 350 g d^-1 from 20 to 35 kg BW. The partial efficiency of MP for growth was 0.52. In conclusion, the NP and MP requirements for the maintenance and growth of Dorper crossbred female lambs were lower than those reported by AFRC （1993） and NRC （2007） recommendations.

Evaluation of Pomegranate Pomace Using in Situ and Gas Production Techniques

This study was carried out to determine nutritive value of pomegranate pomace using in situ and gas production techniques. In this study, two fistulated wethers （38 ± 1.5 kg） were used in situ method. The gas production was measured at 2, 4, 6, 8, 12, 16, 24, 36 and 48 h and ruminal DM （dry matter） and CP （crude protein） disappearances were measured at 0, 2, 4, 6, 8, 12, 16, 24, 36, 48, 72 and 96 h. DM degradabilities of treated pomegranate pomace at 8 h to 96 h were larger than untreated pomegranate pomacewhich showed significant differences （p 〈 0.05）. CP degradabilities of treated pomegranate pomace at 96 h was 62.38% that showed significant differences （p 〈 0.05）. The metabolizable proteins of treated and untreated pomegranate pomace were 73 and 64.27 g/kg respectively that showed significant differences （p 〈 0.05）. The gas productions of treated and untreated pomegranate pomace at 48 h were 79.91 and 128.75 mL/g DM respectively that showed significant differences （p 〈 0.05）. It was concluded that the pomegranate pomace can be used largely as ruminant feeds.