山毛豆草粉颗粒料对肉兔的饲用价值评定

为探讨山毛豆(Tephrosia candida)草粉对肉兔的饲用价值,将60只新西兰青年肉兔分为5组,分别添加0％(对照),10％,20％,30％和40％的山毛豆草粉制成全价颗粒饲料,饲喂90 d后测定各组饲料的营养成分及肉兔采食量、日增重、料重比和屠宰性能.结果表明:山毛豆营养生长期粗蛋白含量为17.77％,肉兔对山毛豆中粗蛋白的消化率为78.09％,山毛豆的可消化总养分为56.18％.与对照组相比,添加20％草粉日增重达到20.80 g·d-1(P＜0.01);料重比为4.45∶ 1(P＜0.05)；屠宰率为57.78％(P＜0.01)；单位kg增重平均最低饲料成本差异显著(P＜0.05).因此,添加20％山毛豆草粉制成全价颗粒饲料可显著提高肉兔的生产性能和养殖效益.     

PBL教学法在高校食品专业文献检索课程中的应用研究

分析高校食品专业本科生文献检索课程教学中引进PBL教学模式的必要性及其教学特点,探讨该课程PBL教学模式的基本思路,提出PBL教学法在食品专业文献信息检索课程中应用的优点及在教学中应注意的问题。     

温度、食料条件对白背飞虱种群增长的影响

白背飞虱若虫和全世代发育速率与温度的关系呈逻辑斯谛关系,成虫产卵前期和卵的发育速率与温度的关系呈二次抛物线关系。在18—30℃下,卵孵化率比较稳定,水稻生育期对卵孵化亦无明显影响,孵化率平均为86.96％。若虫存活率、成虫产卵量和内禀增长力受温度和食料条件的影响十分明显,取食分蘖期和拔节期水稻的若虫存活率最高,成虫产卵量和内禀增长力最大。在水稻各生育期,若虫存活率、成虫产卵量和内禀增长力与温度的关系呈抛物线趋势。当温度达到35℃时,各生育期卵孵化率均下降到50％以下,且若虫陆续全部死亡。     

Phenotypes Including Immunocompetence in Scavenging Local Chicken Ecotypes in Tanzania

A study was conducted to determine the variations in physical characters and immunocompetence among scavenging local chicken ecotypes in Tanzania. Eighty-four adult scavenging local chickens from four eco-climatic regions of Tanzania were studied. Measurements of adult body weight, body length, shank length and egg weight and observations of plumage colour and pattern, earlobe colour, skin colour and the shape of the comb were conducted. The antibody response to sheep red blood cells, serum haemolytic complement and the cutaneous response to phytohaemagglutinin-P were assessed. Five ecotypes were identified and named Mbeya, Morogoro-medium, Ching'wekwe, Kuchi and Singamagazi. Singamagazi and Kuchi were significantly heavier, with longer shanks and heavier eggs than the other ecotypes. The average adult body weight for males ranged from 1621 g (Mbeya) to 2915 g (Singamagazi). Average female weights ranged from 1108 g (Morogoro-medium) to 2020 g (Singamagazi). Mean egg weights ranged from 37.65 g (Ching'wekwe) to 45.61 (Singamagazi). The Kuchi had mostly rose and walnut combs, while the other ecotypes were mostly single combed. In each ecotype there were chickens with a high or low antibody response to red blood cells, but there was a significant difference between the ecotypes.     

Evaluating Sugarcane Diets for Dairy Cows Using a Digestion Model

To eliminate unnecessary feeding trials, a mechanistic model of sugarcane digestion was used in the search for suitable supplements to improve milk production. Milk production simulated by the model was compared with data observed in four feeding trials published in the tropical literature where crossbred dairy cows were fed sugarcane/urea diets with different types of supplements. The predicted effects of the supplements on the ruminal microbial population, concentrations of ammonia and volatile fatty acids were also compared with the published results in one experiment. The model indicated the nutrient most limiting milk production for the different feeding situations. The addtion of Leucaena to the basal sugarcane/urea improved the availability of amino acids and long-chain fatty acids, with energy becoming the limiting factor. Supplementation with rice bran increased the availability of energy and long-chain fatty acids, but amino acids then became the limiting factor. Supplementation with both Leucaena and rice bran further improved the milk yield, but availability of energy now limited milk production. Supplementation with Leucaena increased milk production more than supplementation with king grass. The main reason for this increase was increased amino acid absorption due to increased microbial outflow. In all feeding situations, the average difference between the predicted milk production and that observed experimentally was 0.57 kg/d (ranging from 0.08 to 1 kg/d).     

Preliminary Epidemiological and Clinical Observations on Shimao Zheng (Fleece-Eating) in Goats and Sheep

Veterinary Research Communications -     

杂交肉牛不同年龄,营养水平的肥育效果研究

利用利木赞与本地牛杂交一代7～8月龄公犊12头，10～11月龄公牛12头，供给日增重0．9千克，1．2千克和1．5千克营养水平的日粮，经120天肥育，结果表明：7～8月龄和10～11月龄高营养水平组平均日增重分别为1．274±0．06千克和1．340±0．15千克；7～8月龄组对不同营养水平敏感，各组间差异极显著（P＜0．01）；产肉性能以高营养水平组最好，屠宰率62．4％，净肉率52．98％，眼肌面积91平方厘米。     

Effects of High-tannin Sorghum and Bentonite on the Performance of Laying Hens

The effects of feeding high-tannin sorghum (HTS) (5% catechin equivalents (CE)) on the performance of laying hens were examined in two experiments. In experiment 1, the effects of including varying levels of HTS in layer diets were investigated. Sixty-three Isabrown hens were randomly assigned to each of the seven diets over a period of 56 days. In experiment 2, the effects of bentonite on the utilization of HTS (3.74% CE) by laying hens were investigated. Forty-five Isabrown hens were randomly assigned to each of five diets over a period of 42 days. In both experiments, weekly measurements were made for feed intake (FI), percent hen-house production (% HHP), egg weight and egg specific gravity (ESG). The results of experiment 1 showed that the different sorghum inclusion levels had no effect (p>0.05) on HHP, egg weight and ESG, while those of experiment 2 showed that maize and LTS diets gave similar weight gain, FI and FE (p>0.05). However, HHP was higher (p<0.05) for the LTS diet than for the other diets. The addition of bentonite of 0.25% or 0.5% to the HTS diet did not improve (p>0.05) layer performance. When all the results were considered together, it was concluded that HTS can be used in layer diets without adverse effects on performance. The use of bentonite to deactivate sorghum tannins is not considered necessary.     

The Effect of Supplementation with Fresh Browse of Ziziphus mauritiana or Combretum aculeatum on Feed Intake,Nitrogen Utilization and Growth of Grazing Range Sheep

The influence of 0, 60 or 120 min access to a grove of either Ziziphus mauritiana (Ziziphus) or Combretum aculeatum (Combretum) on forage intake and on the digestibility, growth and excretion of nutrients was determined using 40 Oudah rams grazing for 7 h/day on poor-quality dry season pasture in the Sahel. The effects of browse species and browsing duration (0, 30, 60 or 120 min) on the ruminal ammonia content were also evaluated using 8 mature fistulated rams. Ziziphus increased both total digestible organic matter and total dry matter intakes per (kg live weight)^0.75 without decreasing herbage intake, whereas 60 or 120 min access to Combretum reduced herbage intake by 6.3% and 4.2%, respectively. The digestibility of the diet decreased (p<0.05) with the duration of access to the groves. Despite the provision of more nitrogen (N) than in the control diet, ruminal NH₃-N decreased 24 h after browsing commenced. The reduced live weight gain of sheep browsing Combretum may indicate more deleterious compounds in Combretum than in Ziziphus. Ziziphus appears to have more potential than Combretum to increase sheep production in low-input crop/livestock systems.