一年生黑麦草在不同基肥条件下的生物量研究

在不同基肥条件下，测定一年生黑麦草的产草量、根系长度和深度，结果表明：有机肥每667m^2 1200kg＋复合肥每667m^2 100kg作基肥，一年生黑麦草的产草量最高，达到53226．6kg/hm^2，根系最发达。     

日粮中添加铜对高产乳牛泌乳量影响的研究

本研究探索了在奶牛日粮中添加Cu++对其产奶性能的影响.结果表明,在日粮中添加Cu++ 7.6×10-6,牛奶的乳脂率和干物质含量并未降低,牛奶中铜的残留量低于国家规定标准,能使奶牛泌乳量增产7.66%～9.61%,从而增加乳牛业的经济效益.     

甲醛处理豆粕对蛋白质瘤胃降解及活体外瘤胃发酵的影响

通过尼龙袋试验和产气量试验研究甲醛处理大豆粕对瘤胃蛋白质降解率、产气量和活体外瘤胃发酵参数的影响。3个处理分别为对照组、处理Ⅰ和处理Ⅱ,其中处理Ⅰ、处理Ⅱ的甲醛添加量分别占大豆粕粗蛋白质(CP)0.6%和1.2%。研究结果表明:与对照组相比,处理Ⅰ和处理Ⅱ的干物质及蛋白质的降解率及降解速度显著下降(P<0.001),快速降解组分的比例和有效降解率显著下降,慢速降解组分比例显著提高(P<0.001),但两处理组之间干物质降解速度和蛋白质慢速降解组分比例均无显著差异(P>0.05)。与对照组相比,处理Ⅰ与处理Ⅱ的72h产气量和理论最大产气量均显著升高(P<0.001),而产气速度显著降低(P<0.005);甲醛处理对活体外瘤胃72h发酵的pH值、NH3-N浓度没有显著影响(P>0.05),但发酵液中丙酸摩尔比例显著上升(P<0.05),从而导致乙酸/丙酸降低。两个处理组活体外24h发酵液中甲醛浓度分别为0.994μg/mL和0.370μg/mL;而72h发酵液中甲醛浓度分别为0.410μg/mL和0.141μg/mL。本试验结论:甲醛处理能有效降低蛋白质在瘤胃内的降解率,并改善活体外发酵参数,其中甲醛添加量以占0.6%CP的处理更为有效。     

Effects of maize (Zea mays L.) silage feeding on dry matter intake and milk production of dairy buffalo and cattle in Tarai, Nepal

To identify the effects of whole crop maize silage (MS) as a substitute for rice straw (RS) on feed intake and milk production of mid-late lactating buffalo and cattle in Tarai, Nepal, eight Murrah and eight Jersey-Hariana were fed the basal diet, RS ( ad libitum ) with concentrate (0.68% of bodyweight [BW] on a dry matter [DM] basis). A 4 × 4 Latin square design experiment was conducted in each animal species with graded levels of MS substitution for RS (0%, T1; 33%, T2; 67%, T3 and 100%, T4). The MS had higher digestibility and total digestible nutrient (TDN) than RS. The DM intake per BW of the both species was highest in T3. The substitution of MS for RS increased the crude protein intake and the TDN intake in the both species. Although the buffalo showed the highest milking performance in T4, the cattle showed no significant differences in their milking performance among the treatments. The substitution of MS for RS improved the feed intake and milk production in the buffalo. On the other hand, the milk yield was not raised in the cattle, though the feed intake was increased by the substitution.     

A model to assess the use of caecal and faecal inocula to study fermentability of nutrients in rabbit

An in vitro gas production trial was conducted using 10 Hyla rabbits to evaluate the use of caecal and faecal inocula in fermentability studies. Caecal content (CI) and hard faeces (FI) were used as inocula. Six legume and six cereal concentrates were used as substrates. Gas production was recorded 19 times at 2–24 h intervals throughout fermentation (120 h). The fermentation characteristics (degraded organic matter, OMd; potential gas production, A; volatile fatty acid, VFA; ammonia, NH₃) were measured by testing the inoculum and substrate (legumes vs. cereals). The inocula were different (p < 0.01) in OMd (818.2 vs. 799.4 g/kg OM for CI and FI respectively), A (255.0 vs. 267.1 ml/g OM), total VFA (67.3 vs. 53.2 mmol/g OM) and NH₃ content (21.2 vs. 19.8 mmol/l). Moreover, the significant differences in the (acetate + propionate)/butyrate ratio (5.02 vs. 4.09 for CI and FI respectively, p < 0.01) and in the branched chain proportion (isobutyrate + isovaleriate)/total VFA (0.044 vs. 0.031, p < 0.01) indicate that the inocula differed in fermenting legumes or cereals, but the equations for estimating caecal fermentation characteristics from those of faeces showed R² values from 0.673 to 0.975 (p ≤ 0.01). Our results confirm that in vitro fermentation characteristics of faeces were highly related to those of caecal content.     

不同播种方式对岷山红三叶草产量的影响

通过在海拔2 450 m的岷县南部高寒阴湿地区进行岷山红三叶Trifolium pratense cv.Minshan干草丰产栽培试验,得到以下结论：条播为岷山红三叶进行干草生产的最佳播种方式,行距以20 cm最为理想,该行距下生长速度快,而且产草量最高。播种当年A组（行距20 cm）鲜草产量比对照组(撒播)高出4 987.5 kg/hm2,是对照组的1.27倍,差异极显著（P＜0.01）;A组鲜草产量比B组（行距40 cm）高101 kg/hm2,差异显著（P<0.05）。生长第2年,A组鲜草产量均高于对照组和B组,是对照组的1.16倍,差异极显著（P＜0.01）,是B组的1.02倍,差异显著（P＜0.05）。不同播种方式对岷山红三叶鲜干比无影响。     

Evaluation of Awassi genotypes for improved milk production in Syria

A performance evaluation, conducted between 2003 and 2005, compared the milk production of three genotypes of Awassi ewes: Turkish (T), Syrian (S) and the F1-cross between the Turkish and Syrian ewes (TS), at the International Center for Agricultural Research in the Dry Areas (ICARDA) experimental farm in Tel Hadya (northern Syria). After weaning, which occurred at 56days, milk yield and milking length were measured weekly during the milking period (n = 381). Milk yield of TS and T ewes were 12% and 30% higher, respectively, than S ewes. Milk yield and milking length of TS ewes reflected additive inheritance and did not differ from the parental genotypes' average (p ≥ 0.199). Culling of low producing ewes in 2003 and 2004 also resulted in increased milk yield. Dams of all genotypes displayed similar weights at birth (p = 0.898) and weaning (p ≥ 0.677). The latter suggests dams of the different genotypes olerated equally the pre-weaning lactation load. Performance tended to improve as ewes aged, with milk yield and milking length peaking at 3years of age (p > 0.05). Ewe lambing weight, birth–weaning ewe weight decline, litter size, and litter weight weaned peaked at 4–5years of age (p ≤ 0.016). With the exception of birth–weaning ewe weight decline, year effects influenced the traits under study (p ≤ 0.035). Excluding litter size, the best performance was in 2005, followed by 2003 and 2004. Milk yield increased with litter size at weaning (b = 18.7; p = 0.024). The lambing–weaning ewe weight decline (3.6kg) and ewe productivity (0.46kg litter weaned weight per kg ewe weight) did not differ between genotypes (p ≥ 0.178). Average litter size was 1.15, with the TS ewes displaying the largest litter size (1.23; p = 0.026). Single lambs were 25% heavier than twins at birth averaging 4.73kg and 3.8kg, respectively. Male lambs were 4% heavier than female lambs at birth (p < 0.0001) and 9.3% heavier at weaning (p < 0.0001). Lamb birth weights, weaning weights and daily weight gains were similar for all genotypes (p ≥ 0.210). The average proportion of fat (5.95%), crude protein (5.19%) and solids non-fat (11.29%) in the milk varied across genotypes where S < TS < T (p ≤ 0.0037). F1 crosses with T increased the productivity of S ewes by 12.2%. It is noteworthy that this occurred under improved feeding and may not be recommended for other conditions. Culling low producing ewes led to a 12.8% increase in milk yield, which could translate into a substantial boost in revenue for farmers rearing traditional sheep flocks in milk producing areas.     

高钙日粮对蛋鸡生产性能及出壳雏体内锌含量的影响

生长期日粮钙>3.11%,可使蛋鸡性成熟期明显延缓,开产日龄推迟;其蛋锌及子代出壳雏血锌和多数组织锌含量明显降低,但胚胎及出壳雏鸡未见畸变.出壳雏血锌含量能反映体内锌状态,可作为其评价指标.产蛋期高钙(6.11%)或低钙(0.83%)日粮均可使产蛋性能及孵化率降低.     

Effect of multi-enzymes in combination with a direct-fed microbial on performance and welfare parameters in broilers under commercial production settings

The objective of this study was to determine the response of broilers to the combination of multi-enzymes and direct-fed microbial (DFM) under commercial production settings. A total of 7,000 1-day-old male broilers (Ross 308) were distributed over 10 pens (700 broilers/pen). Two dietary treatments were tested using complete randomized design, including a control diet and a test diet with addition of multi-enzymes (xylanase, amylase, and protease (XAP)] and DFM (a combination of spores from 3 strains ofBacillus amyloliquefaciens). Pelleted diets were offered ad libitum in 3 phases and water was freely available. During starter and grower phases (0 to 21 d), the enzyme and DFM combination resulted in improved FE (P < 0.05). During the finisher phase, higher feed intake and BW gain (P < 0.05) were observed for the test group. Overall, there were significantly higher feed intake, BW gain, and lower water-to-feed ratio in test group compared to the control group. This was related to improved (P < 0.05) modified production efficiency factor which was calculated based on final BW, survival rate, feeding period, and mortality-weight-corrected FCR. The test group had improved litter quality and a reduced foot-pad lesion score compared to the control. In addition, there was a tendency (P < 0.1) of reducingClostridium perfringens population in cecal digesta and higher lactic acid content in the ileal digesta, when expressed on an as-is basis, in the test group. In this study, we demonstrated that using a multi-enzymes and DFM combination in the diet for broilers can result in improved FE in starter/grower phases and animal welfare parameters, and lead to improved production efficiency under commercial settings.     

氟烷基因对猪生产经济性状的影响

猪应激综合征(Porcine Stress Syndrome,PSS)是受猪染色体上的隐性基因-氟烷基因控制,使得猪只在受到外界环境的刺激时,临床上出现发抖、呼吸急促、呼吸困难、皮肤变紫色、体温上升、肌肉硬化甚至死亡等一系列症状,外界压迫因素越大,对猪只造成的影响越强烈。文中综述氟烷基因对猪生长性能、繁殖性能以及猪肉品质的影响,以期为猪养殖者及实验室检测方面提供参考。