弗莱维赫牛改良贵州本地黄牛的效果研究

[目的]探讨弗莱维赫牛改良贵州本地黄牛的效果。[方法]以弗莱维赫牛为父本,分别与本地黄牛(♀)、西本杂(西门塔尔牛×本地黄牛,♀)杂交,测定其杂交后代的生产性能、屠宰性能及泌乳性能,并与贵州本地黄牛进行比较。[结果]F1弗莱维赫牛(♂)×西门塔尔牛(♂)×本地黄牛(♀)杂交后代的生长性能、屠宰性能及泌乳性能最优,F1弗莱维赫牛(♂)×本地黄牛(♀)杂交后代次之,本地黄牛最差。[结论]以弗莱维赫为父本杂交改良本地黄牛及生产三元杂交牛(弗×西×本),其后代具有明显的杂种优势,能显著提高肉牛养殖的经济效益。     

Empirical Percentile Growth Curves with Z-scores Considering Seasonal Compensatory Growths for Japanese Thoroughbred Horses

Percentile growth curves are often used as a clinical indicator to evaluate variations of children’s growth status. In this study, we propose empirical percentile growth curves using Z-scores adapted for Japanese Thoroughbred horses, with considerations of the seasonal compensatory growth that is a typical characteristic of seasonal breeding animals. We previously developed new growth curve equations for Japanese Thoroughbreds adjusting for compensatory growth. Individual horses and residual effects were included as random effects in the growth curve equation model and their variance components were estimated. Based on the Z-scores of the estimated variance components, empirical percentile growth curves were constructed. A total of 5,594 and 5,680 body weight and age measurements of male and female Thoroughbreds, respectively, and 3,770 withers height and age measurements were used in the analyses. The developed empirical percentile growth curves using Z-scores are computationally feasible and useful for monitoring individual growth parameters of body weight and withers height of young Thoroughbred horses, especially during compensatory growth periods.     

饲养管理对哺乳仔猪成活率与断奶重的影响

将60头八眉猪二元待产母猪随机分成实验组和对照组,每组30头,实验组在预产期前30d在母猪的饲料中添加适量的营养物质,基础喂量为每天每头2kg,每产一头仔猪增加0.25kg,仔猪生出后1～3日龄保温箱的温度控制在30～32℃,4～7日龄为28～30℃,8～28日龄圈舍温度控制在22 ～ 25℃.对照组产前30d在饲料中不添加含蛋白质饲料,每天每头饲喂3.5kg.仔猪出生1～7日龄保温箱的温度控制在28 ～30℃,8～28日龄分娩舍温度控制在20～25℃.结果表明,实验组28日龄成活率和断奶重明显高于对照组,差异均显著（P＜0.05）.     

A Method of Modelling Pig Breeding Schemes

Optimal use of limited resources as nucleus and testing capacity is important when organizing crossbreeding schemes in pigs. This paper introduces a method of modelling pig crossbreeding schemes consisting of nucleus, multiplier and commercial tiers. As an efficient alternative to the gene flow method (Hill, W.G. 1974. Anim. Prod. 18, 117-139), lag, original genetic level and annual genetic improvement for each line and cross are combined into one single evaluation criterion, the average discounted revenues of the breeding scheme. An optimum allocation of nucleus and testing capacity within breeding schemes, as well as an optimum solution between schemes can be found. As an example, the optimization of a four-way crossbreeding scheme is shown. the optimum allocation of nucleus capacity was 35% and 15% in each dam line and sire line, respectively. The corresponding figures for testing capacity were 23% and 27%.     

Potential role of N-carbamoyl glutamate in biosynthesis of arginine and its significance in production of ruminant animals

Arginine （ARG） exerts many beneficial effects on animal body and enhanced angiogenesis, lactogenesis, which finally leads to the improvement in nitrogen （N） metabolism, reproduction, lactation, immunity and growth. Unfortunately, unprotected ARG will be degraded in the rumen and its price is high, thus feeding rumen-protected ARG seems to be uneconomical. Alternatively, N-carbamoyl glutamate （NCG） is structural analogue of N-acetyl glutamate, cofactor of cabamoyl phosphate synthetasel, is lower in rumen degradation compared to ARG. Additionally, rumen epithelial and duodenal cells have potentially utilized the NCG for ureagenesis. Supplementation of NCG to high yielding dairy cows increased plasma concentration of ARG and nitric oxide, decreased the plasma ammonia N and improved lactation performance and N utilization. Supplementation of NCG enhanced pregnancy rates in rats, improved litter size and fetal survival rate, thereby improved the reproductive performance of sows. Oral NCG supplementation increases plasma ARG and somatotropin levels, and increased growth rate and muscle protein synthesis in nursing piglets. The NCG is potential a relatively cheaper source of feed additive to offer vital compensation over oral administration of ARG, resulting in improved ruminant animal health and production. In this article, we reviewed the mechanism of AfiG biosynthesis by NCG and their significance in growth, reproduction, milk production and N utilization in ruminant animals.     

Potential role of N-carbamoyl glutamate in biosynthesis of arginine and its significance in production of ruminant animals

Arginine (ARG) exerts many beneficial effects on animal body and enhanced angiogenesis, lactogenesis, which finally leads to the improvement in nitrogen (N) metabolism, reproduction, lactation, immunity and growth. Unfortunately, unprotected ARG will be degraded in the rumen and its price is high, thus feeding rumen-protected ARG seems to be uneconomical. Alternatively, N-carbamoyl glutamate (NCG) is structural analogue of N-acetyl glutamate, cofactor of cabamoyl phosphate synthetase1, is lower in rumen degradation compared to ARG. Additionally, rumen epithelial and duodenal cells have potentially utilized the NCG for ureagenesis. Supplementation of NCG to high yielding dairy cows increased plasma concentration of ARG and nitric oxide, decreased the plasma ammonia N and improved lactation performance and N utilization. Supplementation of NCG enhanced pregnancy rates in rats, improved litter size and fetal survival rate, thereby improved the reproductive performance of sows. Oral NCG supplementation increases plasma ARG and somatotropin levels, and increased growth rate and muscle protein synthesis in nursing piglets. The NCG is potential a relatively cheaper source of feed additive to offer vital compensation over oral administration of ARG, resulting in improved ruminant animal health and production. In this article, we reviewed the mechanism of ARG biosynthesis by NCG and their significance in growth, reproduction, milk production and N utilization in ruminant animals.     

Improving efficiency of sow productivity： nutrition and health

This reviews research focused to understand the nutrient requirement and balance to meet the needs of fetal growth,mammary growth,and milk production.This summary will handle how feeding strategies can be adjusted according to the nutrient needs for a sow to enhance productivity and health.Most research data used in this summary are based on the studies conducted by the authors between 1996 and 2013.Nutrient requirements of sows are affected by stage of gestation and parity of sows.Dietary antioxidant concentrations need to be re-evaluated for its sufficiency in sow diets especially to prevent excessive oxidative stress during late gestation and lactation.When feeding sows,consideration of phase feeding of gestating sows and parity feeding of lactating sows could enhances production longevity and health of sows.Use of selected nutrients and additives seems to help productivity and health of sows.     

胰岛素、催乳素和孕酮对奶牛乳腺上皮细胞泌乳功能的影响

具有泌乳功能的乳腺上皮细胞系可作为乳腺发育学、乳腺病理学、泌乳生物工程学研究的细胞模型,本研究测定了激素对奶牛乳腺上皮细胞系泌乳功能的影响,为阐述泌乳机制提供工作基础。应用HPLC方法对体外培养奶牛乳腺上皮细胞的酪蛋白和乳糖的分泌情况和细胞培养液中的酪蛋白、乳糖含量进行测定,以确定胰岛素、催乳素和孕酮处理后的奶牛乳腺上皮细胞的泌乳功能。试验结果表明：奶牛乳腺上皮细胞具有酪蛋白和乳糖的分泌能力,在72h内,随着细胞培养时间延长,胰岛素处理组细胞中的酪蛋白和乳糖的升高趋势不明显,孕酮处理组升高趋势较明显,催乳素处理组升高趋势很明显;胰岛素处理组、催乳素处理组和孕酮处理组细胞培养液中酪蛋白升高趋势均很明显,乳糖含量均很高,三组激素比较而言,胰岛素处理组乳糖含量最高。此外,三组激素对乳腺上皮细胞活力影响均很大,在72h之内,总体变化为：催乳素处理组和孕酮处理组细胞活力均升高,胰岛素处理组细胞活力下降。     

Maternal behaviour and performance in first-parity outdoor sows

When sows and their litters are kept outdoors, much of the responsibility for the litter is shifted from the herdsman to the sow compared to when the sows are kept indoors. Therefore, the maternal ability, including maternal behaviour, is believed to be important in outdoor piglet production. The aim of this study was to describe maternal traits in conventionally bred first-parity sows kept outdoors. Nursing behaviour, sow activity, sow body reserves, litter size and piglet growth were studied in 40 first-parity sows during a seven week long lactation. The sows were kept in groups outdoors. Sow activity (lying down or active) and nursing behaviour (nursing frequency, nursing duration and nursing terminator) were recorded on videotapes at four days post partum (pp) and directly observed at four and six weeks pp. Cross suckling was observed at four and six weeks pp. Sows were weighed and measured for backfat depth five days before farrowing, two weeks pp and at weaning seven weeks pp. Piglets were weighed at four days pp, at two weeks pp and at weaning. We concluded that sow nursing behaviour and activity are individual characteristics repeatable within sows' late lactation. Less active sows are more available for suckling. Light and thin sows have an earlier and more progressed weaning process than heavier, fatter sows. A significant positive relation was found between sow appetite in early lactation and piglet growth until weaning. Sow nursing behaviour is not important for piglet growth when sows and piglets are held in groups, piglets have access to sow feed and piglets are weaned as late as at seven weeks of age.