Hemato-biochemical changes, disease incidence and live weight gain in individual versus group reared calves fed on different levels of milk and skim milk

A 2 × 3 factorial design was used to study the impact of rearing systems, individual (I) versus group (G) and different levels of milk/skim milk feeding (F1, F2 and F3) on hemato‐biochemical profile, disease incidence and average daily gain of crossbred (Bos indicus × Bos taurus) calves. Six calves were taken in each group on the basis of their birth weight and housed in individual (2.20 × 1.16 m²/calf) or in group pens (2.20 × 1.03 m²/calf). After 3 days of colostrum feeding, calves were allocated to one of three different milk feeding schedules: milk fed up to 8 weeks of age (F1), milk up to 4 weeks followed by 50% replacement by skim milk up to 6 weeks and 100% thereafter (F2) and 100% replacement of milk with skim milk after 4 weeks (F3). Calf starter and cereal green fodders were fed ad libitum from the second week of age and continued for 14 weeks. Parameters on health and disease profiles of calves (disease incidence, duration of illness, response to treatment and recovery) and weekly live weight change were recorded. Calf scour predominated (52.8%), followed by joint ill (25.0%) and respiratory infections (19.4%). The disease incidence was greater (P < 0.01) in individually housed calves (94.4 vs. 55.9%). The management of navel ill required longer recovery (7.01 days) followed by joint ill (4.87 days) and respiratory infection (4.86 days). The average daily gain during 0–14 weeks of age was higher (P < 0.01) in group‐housed calves (433 ± 22 vs. 355 ± 31 g), while the effect of feeding was not significant. Blood samples collected at 4, 8 and 14 weeks of age showed some periodic higher concentrations (but within normal range) of plasma urea and total protein in group housed calves on F2 and F3 feeding schedules in response to high protein intake. Other parameters remained non‐significantly different. Thus, group‐housed calves can be reared successfully with comparatively better performance and less illness than individually housed ones under the present health care and housing management system. However, the system should not be used as a substitute for good management, and frequent observations of calves should be an integral part of any successful rearing program.     

利用全基因组高通量SNP标记定位二花脸×沙子岭家系中的断奶体重QTL

 【目的】利用二花脸×沙子岭家系定位影响仔猪45日龄断奶体重的数量性状位点（quantitative trait loci,QTL）并搜寻QTL区间内与表型相关的位置候选基因,为最终鉴别因果基因奠定前期工作基础。【方法】构建二花脸×沙子岭猪F2资源家系,利用Illumina porcine 60k DNA芯片判定F2个体的基因型,对45日龄断奶体重表型进行全基因组连锁分析,定位影响二花脸×沙子岭家系F2家系仔猪45日龄断奶体重的QTL。在Ensemble（EMBL-EBI）和NCBI（National Center for Biotechnology Information）网站基因组数据库中搜寻相应的位置候选基因。【结果】在猪的2号染色体（sus scrofa chromosome 2,SSC2）上定位到了1个5%基因组水平显著的QTL,在猪的5号染色体（sus scrofa chromosome 5,SSC5）和猪的14号染色体（sus scrofa chromosome 14,SSC14）上分别定位到了1个1%基因组水平显著的QTL。在上述3个QTL区域内搜寻到了5个与仔猪45日龄断奶体重相关的候选基因,分别是SSC2上的CYP2R1、COPB1、PDE3B基因和SSC5上的NOP2、GDF3基因。【结论】本研究将影响二花脸×沙子岭家系仔猪45日龄断奶体重的QTL定位于SSC2、SSC5和SSC14,并揭示出5个与仔猪45日龄断奶体重相关的候选基因。     

饲料中添加不同水平锰对生长育肥猪增重和组织中矿物元素沉积的影响

选用施格×三江白猪杂交一代幼猪25头,随机分成5组(分别为1,2,3,4,5组),每组5头,分圈饲养.在含锰27～31ppm的玉米-豆粕型实用无鱼粉日粮中分别添加锰(以MnSO_4·5H_2O形式)0ppm,20ppm.40ppm,80ppm,160ppm,依次饲喂各组试验猪.应用最优非线性回归方法及通径分析方法探讨了30～90kg阶段生长肥育猪日粮中添加不同水平锰对增重和组织中几种矿物元素(钙、磷、镁、锌、铁、铜)沉积的影响.结果表明,日粮锰在27～191ppm范围内对30～90kg生长育肥猪的生长发育无不良影响.日平均采食量(ADF)变化不显著(P>0.05);第2组(日粮锰含量为47～51ppm)猪的平均日增重(ADG)、饲料效率(G/F)较其他组高(P<0.01或0.05);锰对增重具有直接促进作用(P_1=0.2687),但含量不宜过高(Σrijpy=-1.1470).铜沉积的升高,是引起增重的原因之一(P_7=0.4207,Σrijpyi=0.5286).被毛作为评定锰营养状态的指标是可取的.锰沉积与其他几种矿物元素沉积的关系非常复杂,建立了有关的回归模型.     

Liveweight changes of sheep grazing a range of herbage allowances underPinus radiata agroforestry regimes

A range of improved pasture herbage feed allowances (1 to 5 kg dry matter/head/day) were offered to young sheep, grazing underPinus radiata grown at 0, 50, 100 and 200 stems per hectare. Six trials were conducted, each for 30 days duration between spring 1986 and autumn 1988, at tree age 13–15 years. Mean liveweight gain over all trials for 0 (open pasture), 50, 100 and 200 stems per hectare were 170, 155, 136 and 94 g/sheep/day, respectively. Liveweight gain increased curvilinearly with increasing pasture allowance at all tree stockings and tended to level off above 3 kg green dry matter/head/day. Green matter pasture in vitro digestibility of the green pasture fraction changed little with increasing tree stocking despite changes in pasture composition. Pine needle accumulation under the higher tree stockings depressed the quality of the total feed on offer. Livestock performance under low tree stocking agroforestry regimes can be satisfactory, providing pasture management encourages fresh nutritious feed.     

草原放牧系统持续管理试验研究:试验设计及放牧率对草-畜系统影响分析

在内蒙古典型草原区中国科学院草原生态定位站研究不同放牧率、放牧方式和放牧季节对草原植物和家畜生产的影响。结果表明,地上现存量随着放牧率的增加而降低,但达到峰值的日期提前了。地上生物量与放牧率无明显趋向性变化。家畜增重随着放牧率的增大而下降,公顷总增重与放牧率成二次曲线关系。将放牧率对草原生产力的动态确定为可持续放牧率和改良放牧率。     

放牧强度和草地类型对育肥羔羊生产性能的影响

在华北农牧交错带坝上地区 ,研究放牧强度和草地类型对肥育羔羊生产性能的影响。结果表明 ,在育肥期间 ,放牧强度对育肥羔羊个体增重的影响主要与季节有关。试验结束时 ,供试羔羊体重间差异不显著 (P>0 .0 5) ,但是单位面积家畜生产性能之间差异极显著 (P<0 .0 1 ) ,其中以重牧区畜产品产量最高 ,达 1 92 .53kg/hm2× 1 0 8d,中牧和轻牧区分别为 1 81 .6和 1 1 0 .9kg/hm2 × 1 0 8d。杂花苜蓿—扁穗冰草—新麦草草地对羔羊育肥增重效果最为显著 (P<0 .0 5)。放牧强度和草地类型互作对羔羊的增重差异极显著 (P<0 .0 1 )。不同草地类型适宜的放牧强度各异。羔羊干物质和蛋白质日采食量均随着放牧强度的增加而降低     

复合微生物制剂CMP复合饲料对黑色肉羊补饲增重效果

试验组平均日增重 2 91 .61 g ,对照组平均日增重 1 49.64g ,差异极显著 ( p <0 .0 1 ) ,其它性能试验组也明显优于对照组     

The long-term effects on upland sheep production in the UK of a change to extensive management

Extensification (a reduction in fertilizer inputs and stocking rate of grassland) is seen as one way of increasing the conservation value and of reducing the environmental impact of upland sheep production in the UK, but little is known about the consequences of such a change. This study determines the changes in animal production over ten years following the introduction of four extensive grazing management strategies to perennial ryegrass/white clover pastures at two upland sites. Fertilizer‐free treatments were maintained with sward heights of: 4 cm (treatment 4/4U) or 8 cm (8/8U) during the whole of the grazing year, 4 cm during summer and 8 cm during autumn (4/8U) and 8 cm during summer and 4 cm during autumn (8/4U). A control treatment that received 140 kg N ha^?1 year^?1 was also maintained with a sward surface height of 4 cm (4/4F). Scottish Blackface sheep grazed all treatments. The 4/4F treatment carried the greatest number of animals (3746 grazing days ha^?1 year^?1); the 4/4U and the 8/8U treatments carried 0·73 and 0·43 of this number respectively. The number on the 4/8U treatment was similar to that on the 4/4U while the 8/4U treatment carried 1·41 of that on the 8/8U treatment (0·61 of 4/4F). Mean individual animal performance was greatest on the 8 cm swards and tended to be lowest on the 4/4F treatment. However, the 4/4F treatment produced the greatest live weight of lamb (623 kg ha^?1 year^?1) with the 4/4U producing 0·77, and the 8/8U producing 0·55, of this amount. Although there was year‐to‐year variation in agricultural output, it was concluded that the lower levels of sheep production that result from a change to extensive systems of grazing management can be maintained for at least 10 years.     

Effect of maize grain and herbage allowance on estimated metabolizable energy intake and animal performance in beef cattle finishing systems

This study investigated the effects of levels of supplementation with maize grain and herbage allowance (HA) on grass herbage and maize intake, animal performance and grazing behaviour in two replicated grazing experiments with Angus beef cattle in Argentina. In Experiment 1, the response to increasing HA (2·5, 5·0 and 7·5 kg DM herbage 100 kg^?1 live weight (LW) d^?1 with and without 0·5 kg DM maize grain 100 kg^?1 LW d^?1) was investigated. In Experiment 2, the responses to level of maize grain offered (0, 0·5 and 1·0 kg DM maize grain 100 kg^?1 LW d^?1) at an HA of 2·5 kg DM herbage 100 kg^?1 LW d^?1 and an HA of 5·0 kg 100 kg^?1 LW d^?1 without maize grain were assessed. In Experiment 2, soyabean meal was added to control the crude protein concentration in the diet. Two methods were used for intake estimations: pre‐ and post‐feeding herbage mass difference, and the use of the n‐alkane and ¹³C technique. The latter predicted most accurately the metabolizable energy requirements calculated from live weights and liveweight gain of beef cattle attained in each treatment in both experiments. Increasing HA significantly increased herbage intake and liveweight gain (P < 0·01), and general quadratic relationships between these variables could be fitted across experiments despite differences in animal and pasture characteristics. Increasing the amount of maize grain offered significantly reduced herbage intake and grazing time, but increased liveweight gain and digestibility of the diet. Substitution rate increased with increasing HA in Experiment 1 but was not affected by level of maize supplementation in Experiment 2. These relationships will aid the development of grazing management models for Argentinean conditions.     

Some Arthropods Affecting Man and Livestock in New Zealand

Extract

At present, the standard tuberculin test used in New Zealand is the subcaudal intradermal test using 0·1 ml Commonwealth Serum Laboratories Synthetic Medium tuberculin, animals being classified as positive or negative to the test on the presence or absence of any swelling either visible or palpable at the site of the injection at the 96th hour.