种鸡的磷需要量

种鸡的日粮既要能支持种鸡自身的最佳生产性能 ,又要能为雏鸡的孵化和成活提供必需的养分     

饲喂不同磷水平及不同纤维来源对泌乳奶牛磷利用率的影响

本试验研究饲喂不同磷水平及不同纤维来源对泌乳奶牛磷利用率的影响.试验设4个处理组,2×2因子设计.磷水平为0.32%和0.46%,粗纤维来源为:10%豆皮替代6%苜蓿干草(DM计).各处理日粮均为50%玉米青贮和苜蓿青贮.32头泌乳早期或中期的荷斯坦奶牛饲喂10周.用未消化的酸性洗涤纤维作为指示剂半体内法培养12 d估测粪中排泄磷.试验组平均产奶量为43 kg/d.磷水平为0.32%和0.46%试验组产奶量分别为42.1和44.0kg/d.乳脂率分别为3.68%和4.12%,乳蛋白产量分别为1.240和1.323kg/d.0.32%磷组奶牛磷的摄人量低于NRC估测的需要量(0.37%),伴随着干物质采食量降低1.5 kg/d.粪中排泄磷随日粮磷含量的提高而呈线型提高,依据此方程,将日粮中磷的含量从0.44%降至0.37%,粪中排泄磷可降低12%.用豆皮替代部分苜蓿干草对干物质采食量和产奶量无影响,但可降低粪中磷排泄量,可能是提高了磷的表观消化率.通过降低磷的摄入量和用豆皮替代苜蓿干草的方法可以降低粪中磷排泄量.产奶量为43 kg/d的奶牛磷需要量大于0.32%(鉴于NRC的需要量为0.37%),日粮中用高消化率的非粗料纤维来源替代粗饲料纤维可以适当降低磷的供给量但又能满足营养需要.     

奶牛营养平衡与需要量

随着我国奶牛业的快速发展,奶牛对日粮营养平衡的要求越来越高,而正确理解奶牛的营养需要对制定营养平衡的日粮配方非常重要。本文主要从能量、蛋白质、纤维、矿物质和维生素方面探讨奶牛的适宜营养需要量。     

蛋鸡产蛋期磷需要量的研究进展

磷是动物生长必需的矿物元素,植物原料中的磷70%～80%以植酸磷的形式存在,难以被家禽等单胃动物利用。近几年,随着蛋鸡育种发生变化及植酸酶技术的进步,蛋鸡对磷的需要量以及玉米-豆粕型饲粮中无机磷的添加量可能也发生了变化。本文综述了产蛋期蛋鸡磷需要量方面的研究进展,为磷在蛋鸡上的科学研究和精准应用提供理论参考。     

奶牛维生素E的需要量

维生素E是动物不可缺少的一种营养物质,在畜牧生产特别是奶牛生产中,它作为一种营养添加剂或营养性药物,广泛用于奶业生产、奶牛繁殖和疾病防治中,已成为一种提高生产力如产奶量的有效措施。笔者根据国内外的文献报道,就维生素E的作用、用途、用量等进行简要综述,以为科学利用维生素E提供依据。     

反刍动物磷需要量的重估环境保护要求饲喂给奶牛低于推荐量的低磷日粮

在对现代体大而高产的奶牛日粮磷需要量的最新研究中,欧洲和美国得到了非常相似的结果。美国和欧洲的科学家确定,在目前奶牛的饲养实践中磷的供给是过量的,而且需要量本身可减少。这些最新中国奶牛·2004年第1期的发现给反刍动物饲料生产者提出了一系列的挑战。一月份,在诺丁汉会议上,美国奶牛饲草研究中心、麻省威斯康星大学的LarrySatter教授在会上作了报告,并提出了新的低于全国研究理事会(NRC2001)推荐的奶牛日粮磷需要量,并强调这与最新的研究结果相符。在一研讨会上,国立农业研究院(INRA)、法国营养和饲养生理系的FrancoisMeschy…     

日粮磷水平对泌乳奶牛健康和产奶量的影响

本试验目的是研究2种日粮磷水平对奶牛生产性能的影响.试验日粮磷含量为(以干物质为基础):①接近NRC水平(0.37%);②超过NRC水平(0.57%).试验采用荷斯坦奶牛,饲喂期为泌乳初的165 d,或持续更长的时间,直至人工授精后已确认妊娠60 d.产犊时随机分配奶牛成2组.第1组日粮磷含量为0.37%,供试泌乳奶牛为123头;第2组日粮磷含量为0.57%,供试泌乳奶牛为124头.试验期至少165 d.在泌乳的前3周,奶牛拴系在牛舍内,饲喂2种过渡日粮,该日粮磷水平分别按试验日粮要求配制.然后将奶牛移入散养牛舍,分别饲喂试验日粮.试验结果如下:日粮磷含量为0.37%组和0.57%组的奶产量、乳脂及乳蛋白分别为35.1 kg/d、3.92%及2.90%和34.9 kg/d、3.98%及91%,差异均不显著.泌乳50 d和100 d的血磷含量为:(磷含量为0.37%组)6.1和6.2 mg/dl;(磷含量为0.57%组)6.8和6.9mg/dl.本试验结果表明:日粮磷水平对奶牛产奶量、健康及体况评分均无显著影响.     

饲料中添加烟酸对夏季奶牛产奶性能的影响

试验选取9头泌乳早期处于热应激的荷斯坦牛,采用3×3拉丁方设计,分别饲喂基础日粮(对照组)和在基础日粮中添加5g/d和10g/d烟酸日粮,研究添加烟酸对奶牛生产性能影响。结果表明:添加5g/d和10g/d烟酸可使奶牛产奶量分别提高13.20%和9.39%(P<0.05);而4%标准乳量无显著差异(P>0.05);添加烟酸对乳蛋白和乳脂率无显著影响(P>0.05)。     

Transcutaneous ultrasound over the right flank to diagnose mid- to late-pregnancy in the dairy cow

Objective   To investigate the practical application and image quality of transcutaneous ultrasonography across the right flank for the diagnosis of mid- to late-gestation in cattle.
Procedure   Dairy cows of known pregnancy status were used to establish criteria for the identification of mid- to late-stage pregnancy by transcutaneous ultrasonography. Factors involved in the practical application of transcutaneous ultrasound for routine use in pregnancy diagnosis in dairy cattle were also examined.
Results   Transcutaneous ultrasound, using a 3.5-MHz sector transducer applied over the caudodorsal right flank fold, allowed rapid and detailed visualisation of bovine pregnancy (i.e. fetus, fetal fluids, placentomes and/or fetal membranes) and could be used to establish criteria for the diagnosis of pregnancy. The commonly available cattle holding facilities of the herringbone dairy, rotary herringbone dairy, AI race or crush, and walk-through dairy all allow safe access to the right flank of a dairy or beef cow. However, transcutaneous scanning over the right flank is difficult in modern rotary turnstile dairies.
Conclusion   A 3.5-MHz sector transducer applied over the caudodorsal right flank fold allows detailed visualisation of the bovine fetus in most types of cattle-holding facilities. Further investigation of the sensitivity and specificity of this technique over the entire gestation period and its possible use in ageing of the bovine fetus is merited.     

沈阳市某乳业公司奶牛钙、磷、β-胡萝卜素盈缺状况检查

对沈阳市某乳业公司七个奶牛场牛群血中钙、磷、β-胡萝卜素含量进行抽检，从全群3，000多头成母牛中共抽检350头奶牛，其中包括84头高产奶牛、77头干奶牛、92头产后牛和97头有病牛。结果表明：全群牛血中钙、磷的平均含量偏低，血钙的最高值、平均值和最低值分别为3．32mmol／l、2．26 0．44mmol／l和1．53mmol／l，血磷的最高值、平均值和最低值分别为2．71mmol／l、1．72 0．51mmol／l和0．84mmol／l；血中钙、磷比例不当，其最大值、平均值和最小值分别为3．96：1．0、1．70：1．0和0．645：1．0：血中钙、磷含量乘积偏低，其最高值、平均值和最低值分别为63．74、48．20和24．50；血中β-胡萝卜素含量不足，其最高值、平均值和最低值分别为657μg／100ml、278．69 201.78μg／100ml和52μg／100ml，其中高产牛血中含量相对较高。     

Comparison of transcutaneous ultrasound over the right flank with transrectal ultrasound for pregnancy diagnosis in the dairy cow

Objective   Evaluate the sensitivity and specificity of transrectal ultrasound and transcutaneous ultrasonography across the right flank between days 31 and 196 of pregnancy in the dairy cow.
Procedure   Pregnancy status and stage of gestation at date of pregnancy diagnosis by transcutaneous and transrectal ultrasonography were determined for 1570 dairy cattle. Sensitivity and specificity values and probabilities of a correct diagnosis for both techniques were determined and compared. Possible effects of gestational age, herd, method of transcutaneous ultrasound diagnosis, cow age, cow and bull breed, and calf sex on the determination of a correct diagnosis of pregnancy status were evaluated for both techniques.
Results   The overall sensitivity and probability of a correct diagnosis of pregnancy status from days 31 to 196 of gestation were significantly higher when using transrectal ultrasound relative to transcutaneous ultrasound over the right flank. However, the sensitivity of transcutaneous ultrasound changed over the course of pregnancy: it was low (7–8%) before day 84, increased to 89% between days 141 and 154, and was close to 100% thereafter. The specificity of both methods did not differ significantly. Herd and gestational age at date of pregnancy diagnosis were significantly associated with making a correct test result using transcutaneous ultrasound, although only the latter predictor was significantly associated with making a correct test result using transrectal ultrasound.
Conclusion   Transcutaneous ultrasound can not be recommended as an accurate method for early pregnancy diagnosis in the dairy cow, particularly on a whole-herd basis. However, if pregnancy testing is undertaken in mid to late gestation, this technique could provide an accurate and rapid alternative to transrectal ultrasound or manual palpation per rectum.     

奶牛乳房炎的病原菌分离鉴定与药敏试验

对山东济南市 5个奶牛场的 1 65份临床型和 1 4 7份隐性型乳房炎奶样进行了病原菌分离鉴定。临床型未用利福平复合新药奶样 48份 ,细菌检出率为 83 33 % ;用该药 2d内采集的奶样 1 1 7份 ,细菌检出率 60 68%。隐性乳房炎奶样细菌检出率 72 2 9%。用新研制的利福平复合新药对未用该药奶样分离菌 35株和用该药后有代表性的分离菌 40株 ,共 75株临床型分离菌进行药敏试验 ,结果 84%为高度敏感 (63/ 75) ,1 6 %为中度敏感 (1 2 / 75)。鉴定的细菌有葡萄球菌 ,链球菌 ,大肠杆菌 ,棒状杆菌 ,芽孢杆菌等。根据用药后患病奶牛的临床表现和奶样细菌分离情况 ,表明该药对奶牛乳房炎具有显著的治疗效果     

Selenium requirements in grazing dairy cows: a review

ABSTRACT

In New Zealand, the recommended intake of Se for dairy cattle (0.03?mg/kg dry matter (DM)) is lower than in the United Kingdom and Australia (0.1 and 0.04?mg/kg DM, respectively), and much lower than in the United States of America (0.3?mg/kg DM). Advisors in New Zealand often suggest that New Zealand intake recommendations are far too low and that recommendations from the United States of America should be used. This has created confusion as farmers are given very different advice depending on which recommendations their advisor uses. In this review, we assess whether the published evidence supports the existing dietary requirements and associated Se status thresholds, or if change is required. We focus particularly on the evidence-base in cattle fed a primarily pasture-based diet, as it is critical that dietary recommendations are derived from data created using cows fed similar diets. Accordingly, we also consider whether the increased use of fodder crops, especially during the dry period, is likely to have altered the Se requirements of dairy cows in New Zealand. We report that the science behind the dietary requirements for Se is robust, being supported by factorial models validated using New Zealand data, and on-farm experimental studies. Published nutritional data suggest that the increased use of fodder crops is unlikely to have altered the dietary balance of pro- and antioxidant factors in New Zealand dairy cows in a way that would meaningfully affect Se requirements. However, the lack of specific data on the vitamin E and fatty acid content of the crops being fed in New Zealand means that more information is needed to confirm this conclusion. In general, the existing New Zealand recommendations for Se-status thresholds are supported, although studies are still lacking to properly characterise the upper threshold of the marginal range. Nevertheless many studies in New Zealand, of herds with marginal or low adequate Se status (using New Zealand recommendations), have failed to show an effect of Se supplementation on milk production, intramammary infection or reproductive performance, so it is highly unlikely that the upper threshold of the range is much higher than the current recommendation. Proponents of the hypothesis that Se intakes in New Zealand dairy cattle should be increased by at least 10 times the current recommendations are therefore not using the evidence base correctly.     

Body phosphorus mobilization and deposition during lactation in dairy cows

Dairy cow bone phosphorus (P) mobilization and deposition and their influence on P requirements were studied over the lactation cycle. Thirty Holsteins received a common diet during the dry period and one of the following three dietary treatments that varied in P percentage during the subsequent lactation (44 weeks): (i) 0.36 throughout (constant P, 0.36‐0.36‐0.36), (ii) 0.36 for 30 weeks then 0.29 for 14 weeks (P changed once, 0.36‐0.36‐0.29), and (iii) 0.43 for 10 weeks, 0.36 for 20 weeks, and 0.29 for 14 weeks (P changed twice, 0.43‐0.36‐0.29). Six P balance studies were conducted during the experiment, including one during the dry period and five along lactation, based on P intake, faecal P, urinary P and milk P, when appropriate. Blood samples were taken during balance to analyse bone formation (osteocalcin) and resorption (pyridinoline) marker concentrations and rib biopsies performed to determine bone P content. Phosphorus balance was negative during weeks ?4 to ?1 relative to lactation for all groups and remained negative for cows fed 0.36% P during weeks 1–5, but showed a positive value for cows that received 0.43% P. The balance was close to zero for all groups at weeks 19–23 and showed a clear retention during weeks 38–42; by the end of lactation, cows re‐stored most of the P mobilized earlier. The pattern in P balance was consistent with changes in blood bone metabolism marker concentrations, rib bone P content, and faecal and urinary P concentrations over the experiment, indicating that cows, irrespective of the dietary P treatments received, mobilized P from bone during the late dry period when fed a low‐Ca diet and early lactation, and re‐stored P in late lactation. This dynamic of P metabolism can have important implications for dietary P requirements and ration formulations.     

牦牛乳及乳制品、犏牛和黑白花奶牛乳的脂肪酸组成分析

用气相色谱 质谱联用仪(GC MS)对牦牛乳、黑白花奶牛乳、犏牛乳及牦牛乳制品（奶油、酥油、曲拉、酸奶）中的脂肪酸组成进行了测定。结果表明,牦牛乳中功能性脂肪酸,如共轭亚油酸（CLA）、亚油酸（LA）、α 亚麻酸（ALA）、γ 亚麻酸（GLA）占总脂肪酸的比重均显著高于犏牛乳和黑白花奶牛乳（P＜0.05）;犏牛乳中ω 6/ω 3 PUFA的比值（1.55）略高于牦牛乳（1.54）,差异不显著（P＞0.05）,但都在最佳膳食平衡比值范围内,黑白花奶牛乳中ω 6/ω 3多不饱和脂肪酸（PUFA）的比值（11.33）超过了推荐最佳比值。加工处理能够改变乳制品脂肪酸的构成,如牦牛乳奶油中检测出原奶中所不含的一种亚油酸（18:2Δ8c,11c）。酥油主要以不饱和脂肪酸（UFA）为主,而曲拉主要以饱和脂肪酸（SFA）为主,牦牛酸奶中没有检测到GLA。     

Effect of maize starch concentration in the diet on starch and cell wall digestion in the dairy cow

An in vivo experiment was performed to determine the effect of level of maize starch in the diet on digestion and site of digestion of organic matter, starch and neutral detergent fibre (NDF). In a repeated change‐over design experiment, three cows fitted with a rumen cannula and T‐piece cannulae in duodenum and ileum received a low‐starch (12% of ration dry matter) and a high‐starch (33% of ration dry matter) diet. Starch level was increased by exchanging dried sugar beet pulp by ground maize. After a 2‐week adaptation period, feed intake, rumen fermentation parameters (in vivo and in situ), intestinal flows, faecal excretion of organic matter, starch and NDF were estimated. When the high‐starch diet was fed, dry matter intake was higher (19.0 kg/day vs. 17.8 kg/day), and total tract digestibility of organic matter, starch and NDF was lower when the low‐starch diet was fed. Maize starch concentration had no significant effect on rumen pH and volatile fatty acid concentration nor on the site of digestion of organic matter and starch and rate of passage of ytterbium‐labelled forage. On the high‐starch diet, an extra 1.3 kg of maize starch was supplied at the duodenum in relation to the low‐starch diet, but only an extra 0.3 kg of starch was digested in the small intestine. Digestion of NDF was only apparent in the rumen and was lower on the high‐starch diet than on the low‐starch diet, mainly attributed to the reduction in sugar beet pulp in the high‐starch diet. It was concluded that without the correction for the reduction in NDF digestion in the rumen, the extra supply of glucogenic (glucose and propionic acid) and ketogenic nutrients (acetic and butyric acid) by supplemented starch will be overestimated. The mechanisms responsible for these effects need to be addressed in feed evaluation.     

乳牛流产胎儿中新孢子虫的鉴定

在血清学调查的基础上，进行了流产胎牛体内新孢子虫的鉴定。取新孢子虫血清抗体阳性乳牛的流产胎牛的脑、心、肺、脾、肝等组织进行病理学检查，经HE染色观察到脑组织中存在类似于新孢子虫包囊样结构，经免疫组织化学染色排除刚地弓形虫包囊的存在，确认该包囊为新孢子虫包囊。同时提取流产胎牛脑组织DNA，应用新孢子虫特异性引物Np6／Np21进行PCR扩增，扩增出的特异性目的争带的序列与新孢子虫标准株Nc-1的gene5序列的一致性为98％。首次证实我国大陆流产胎牛脑组织中存在新孢子虫。