Effect of restricted suckling on milk yield,composition and flow,udder health,and postpartum anoestrus in grazing Holstein cows

The effect of restricted suckling on milk yield and composition, udder health, and postpartum anoestrus in dairy cows in pasture-based systems, was studied in 32 Holstein multiparous cows and their calves. At calving, each cow–calf pair was randomly assigned to one of two treatments: restricted suckling (RS) of the cows by her own or another calf, twice daily for 30 min or artificial rearing (AR) of the calves with milk obtained from the bulk tank, offered twice a day in buckets. Treatments were applied until week 8 after calving. The diet of the cows consisted of direct grazing in improved pastures, corn silage and a commercial concentrate which was offered at milking. Milk production and composition, udder health, body condition score of the cows, body weight and milk intake of the calves were measured weekly, and the first postpartum ovulation was determined three times a week by ovarian ultrasonography. Cows with RS management had a lower machine-milked milk yield (17.9 vs. 24.8 kg/d), a lower fat percentage (3.21 vs. 4.11%) and 4% fat-corrected milk yield (16.2 vs. 25.7 kg/d), and also a lower average milk flow (1.35 vs. 1.76 kg/min) than cows in the AR treatment. There was no effect of treatment on milk protein percentage or udder health as measured by milk electrical conductivity. The interval from calving to first postpartum ovulation was shorter in the AR cows than in the RS cows (18.5 vs. 21.8 days). The RS calves consumed more milk (7.2 vs. 5.4 kg/d), gained more body weight (0.813 vs. 0.656 kg/d), and had a higher body weight at weaning (84.3 vs. 73.3 kg) than AR calves. Restricted suckling of grazing dairy cows had a negative effect on machine-milked milk yield, fat percentage and 4% fat-corrected milk yield, but had no effect on udder health or on improved weight gain and body weight at weaning of the calves.     

母猪日粮中添加低聚壳聚糖对哺乳仔猪生长、抗氧化能力和免疫功能的影响

本试验旨在探讨母猪日粮中添加低聚壳聚糖对哺乳仔猪生长、血液生化指标、抗氧化能力及免疫功能的影响。选用24头胎次、体重和预产期相近的健康大白猪母猪,随机分为3组,每组8个重复,每个重复1头母猪。对照组饲喂基础日粮,Ⅰ、Ⅱ组饲喂分别添加50和100 g/t低聚壳聚糖的基础日粮,试验从母猪妊娠第85天开始至分娩后第21天时结束。结果显示：①Ⅱ组哺乳仔猪腹泻率显著低于对照组和Ⅰ组（P < 0.05）,Ⅰ组与对照组差异不显著（P > 0.05）;与对照组相比,Ⅰ、Ⅱ组仔猪21日龄体重显著提高（P < 0.05）。②Ⅰ组仔猪血浆乳酸脱氢酶（LDH）活性和甘油三酯（TG）浓度,Ⅱ组α-淀粉酶（α-AMY）、LDH活性和低密度脂蛋白（LDL）浓度均显著低于对照组（P < 0.05）。③Ⅱ组哺乳仔猪血清超氧化物歧化酶（SOD）活性,皮质醇、白介素-10（IL-10）、白介素-1β（IL-1β）、肿瘤坏死因子α（TNF-α）和干扰素-γ（IFN-γ）含量均显著高于对照组和Ⅰ组（P < 0.05）,而丙二醛（MDA）浓度显著低于对照组（P < 0.05）。④低聚壳聚糖组母猪初乳中免疫球蛋白G（IgG）、IgA和IgM含量均显著高于对照组（P < 0.05）;Ⅰ组仔猪血清IgG和IgA含量、Ⅱ组仔猪血清IgA含量均显著高于对照组（P < 0.05）。综上所述,母猪日粮中添加一定量的低聚壳聚糖能够提高哺乳仔猪的抗氧化能力、增强机体免疫能力、降低腹泻率,从而提高哺乳仔猪生长性能。     

仔猪苏氨酸营养需要量的研究

为研究早期断奶仔猪苏氨酸需要量,用大白仔猪进行了生长———代谢实验（体重７～２０ｋｇ）和大长北仔猪饲养实验（体重６～１０～２０ｋｇ）,其结果为：①为获得最大日增重和最好饲料报酬,７～２０ｋｇ体重大白仔猪日粮总苏氨酸（ＴＴＨＲ）和可消化苏氨酸（ＤＴＨＲ）适宜含量分别为０．７５％、０．６１％;大长北仔猪分别为０．７５％、０．６４％（６～１０ｋｇ体重）和０．６２％、０．５３％（１０～２０ｋｇ体重）。此ＴＴＨＲ水平相当于美国ＮＲＣ（１９８８）标准相应阶段推荐量的１１０％。②以玉米、豆粕、花生粕为主要原料的５～２０ｋｇ体重仔猪日粮,适宜的必需氨基酸比例（总氨基酸为基础）估计为：赖／含硫／苏／色＝１００：６５：６５：２０。以此必需氨基酸模式配制仔猪日粮,可取得较好的饲养效果,氮沉积和血清尿素氮（ＳＵＮ）浓度较低。③随着日粮苏氨酸水平由８０％ＮＲＣ（１９８８）推荐量增加到１１０％ＮＲＣ（实验１）和１２０％（实验２）,仔猪ＳＵＮ浓度逐渐下降。ＳＵＮ可以作为评价仔猪日粮氨基酸平衡和苏氨酸含量是否适宜的指标之一。④在本实验条件下,日粮不同苏氨酸浓度并未引起仔猪血清胆固醇（实验１）、白蛋白、球蛋白（实验２）含量的明显差别。在实验     

Quantitative relationships between suckling-induced teat stimulation and the release of prolactin,gastrin, somatostatin,insulin, glucagon and vasoactive intestinal polypeptide in sows

The pituitary hormones prolactin and oxytocin play important roles in the production and ejection of milk. In addition, some gastrointestinal peptides are released in response to suckling. During suckling, the piglets massage the udder of the sow both before and after let-down and the duration of suckling is correlated to the amount of milk produced by the sow. The aim of this study was to investigate whether there is a quantitative relation between the release of prolactin, gastrin, somatostatin, insulin, glucagon and vasoactive intestinal polypeptide (VIP) and the amount of stimulation of the sow's teats by the piglets.Repeated blood samples were drawn from three Swedish Landrace sows during three consecutive nursings by each sow on days 1, 3, 7 and 14 after parturition. The duration of massage by the piglets was noted, as was the number of piglets massaging. Hormone levels were quantified by radioimmunoassay.The releases of prolactin, somatostatin, insulin, glucagon and VIP but not of gastrin were found to be significantly related to the amount of teat massage performed by the piglets during the first 2 weeks of lactation. The release was related to the duration of piglet massage or to the combined effect of duration and the number of piglets massaging but not to the number of piglets massaging per se. The basal level of prolactin was found to decrease during this time.     

乳源性生物活性肽生物学作用及其应用

乳中含有大量不同活性的生物活性肽。这些肽或自然存在于乳中或源于乳蛋白水解后的产物。在乳中已发现自然态存在的活性肽包括ＥＧＦ、ＴＧＦ、ＮＧＦ、ＩＧＦ－Ⅰ、ＩＧＦ－Ⅱ、胰岛素等，其浓度在初乳中一般比较高，而且因新生动物胃肠道蛋白酶的活性较低，乳中还存在着蛋白酶抑制剂，因此这些乳源性生物活性肽在新生幼畜胃肠道中比较稳定。灌（口）服ＥＧＦ、纱或ＩＧＦ－Ⅰ能刺激新生幼仔胃肠道的成熟，推测初乳源生物活性肽在调     

白羽王鸽不同育雏数量的生长情况比较

以贵州省惠水县龙翔鸽业有限公司的白羽王鸽种鸽及其所产仔鸽为研究对象,从3000多对种鸽中随机选取125对,并对其270只仔鸽分别进行生物学特性观察和生长情况测定。结果表明,5～9日龄各组雏鸽处于生长高峰期;自然育雏0～15日龄试验I组和Ⅱ组与对照组在增重方面差异显著（P〈0．05）;15日龄后经人工育肥,试验组与对照组的平均日增重接近（P〉0．05）。表明自然育雏以每窝2只为好,人工哺育以每窝3只为好,可缩短繁殖周期,提高生产效率。     

我国常见典型仔猪日粮系酸力和电解质平衡水平的调查研究

本文旨在对我国常见典型仔猪日粮的系酸力(acid-binding capacity,ABC)和电解质平衡(dietary electro-lyte balance,dEB)进行调研,为合理配制仔猪日粮提供必要参考。选取了6个省份18个有代表性的大型饲料企业断奶仔猪饲料的pH、ABC、Na、K、Cl百分含量状况进行调研,并计算了dEB值。结果表明:断奶仔猪日粮pH、ABC、Na、K、Cl百分含量及dEB值分别为(5.91±0.42)、(37.72±8.64)mmol/100g、(0.32±0.34)%、(0.83±0.27)%、(0.77±0.85)%及(132.58±86.93)mEq/kg DM,不同饲料企业间的各项指标差异很大。     

大尾寒羊哺乳羔羊蛋白质代谢规律的研究

本文采用消化代谢试验、饲养试验和屠宰试验等方法 ,研究大尾寒羊哺乳羔羊蛋白质的代谢规律及需要量。结果表明 ,哺乳羔羊对乳中蛋白质的消化率为 94.6 %,沉积率为 73.3%;全哺乳期和补料期羔羊对粗蛋白维持需要量分别为 3.7和 4.0g kgW～ 0 .75·d ,对可消化蛋白质维持需要分别为 3.5和 3.37g kgW0 .75·d ,对可消化蛋白质的生长需要分别为 0 .196和 0 .2 19gDCP g增重。     

天津地区首次发现猪附红细胞体病的诊治

附红细胞体（Ｅｐｅｒｙｔｈｒｏｚｏａ,附红体）是人畜共患的以病原体附着在红细胞表面和游离在血浆中引起附红细胞体病的病原体。通过涂片镜检可观察到附红体确诊。治疗用血虫净（贝尼尔）和四环素及新砷矾钠明（９１４）、得咪酰（土霉素和增效剂）,治疗实验结果效率分别为１００％、１０．３％、９０％。     

哺乳仔猪血清中IgG的动态变化

选择３２头自然分娩、初生重１ｋｇ～１．５ｋｇ的大白猪×内蒙黑猪杂交Ｆ１代新生仔猪，研究２８ｄ产后期内血清中ＩｇＧ的动态变化。结果表明，仔猪出生后没吃母乳以前血清中的ＩｇＧ甚微（０．１２±０．０５８ｍｇ／ｍｌ），吃完初乳后血清中ＩｇＧ含量迅速升高，到２４ｈ达到峰值（６０．１０±１１．１８ｍｇ／ｍｌ），随后缓慢下降，到２１ｄ（２０．５３±６．４６ｍｇ／ｍｌ），随后又开始上升。