奶牛饲喂舔砖饲料的效果试验

尿素含氮量 4 4%～ 4 6 % ,作为反刍家畜非蛋白氮的饲料 ,完全可以补充蛋白质饲料的缺乏。尿素被反刍家畜瘤胃微生物利用 ,进而大量繁殖 ,微生物最终成为饲料被畜体消化吸收。尿素从非蛋白氮转化为营养效价很高的菌体蛋白而被利用 ,扩大了蛋白质饲料的来源。利用舔砖的方式饲喂尿素 ,可以解决常规喂尿素存在的诸多问题。为了观测该饲料提高产奶能力 ,降低饲料成本和提高经济效益的水平状况 ,特作本次对比试验。1　试验奶牛的选择和试验方法1 .1　奶牛的选择选择永昌县城关镇两户健康无病的黑白花奶牛 1 2头 ,每户 6头 ,产犊 1 5～ 2个月 ,…     

奶牛糖蜜尿素复合营养舔砖的开发研制及补饲效果试验

在欧美等畜牧业发达国家,使用舔砖已成为牛羊饲养的必要措施,并且该商品的生产在不断地创新和发展。联合国粮农组织(FAO)已将这项投入小、效益大的实用技术推广到亚、非等一些国家,作为反刍动物廉价的补充饲料,并取得了良好的效果。舔砖尤为适用于粗放条件下“低精料长周期”的     

低质饲料补加尿素营养舔砖饲喂生长绵羊效果试验

试验选用８月龄甘肃细毛母羊１９只。随机分成试验组和对照组（Ｐ〉０．０５）。对照组采食基础日粮,试验组采食基础日粮＋营养舔砖饲喂基础日粮组成为麦秸９０％,皮１０％。结果表明,饲水素营养舔砖可以提高生长羊增重,一的３．３８倍,羊毛昼夜生长量可提高２５．９％,显著地高于对照组（Ｐ〈０．０５）。     

高蛋白质副产品饲料饲喂奶牛的营养特性分析

在未来几十年,我国饲料蛋白质资源的缺口将逐步加大。这一问题近几年表现尤为突出。例如,植物蛋白质饲料的“当家”原料—大豆粕因国内需求量大而受国际市场制约,价格起伏不定,2003年达到罕见的超高价位,严重影响了饲料工业持续健康发展。因此,充分了解各种高蛋白质农副产品的营养特性,对迅速发展奶牛业,缓解饲料蛋白质资源紧缺具有重要意义。1植物源的高蛋白质副产品1.1菜籽粕菜籽粕是对油菜籽直接压榨或进行溶剂提取加工除去绝大部分油后得到的饼粕,其芥子油含量不超过2%,风干固体组分中的芥子油甙含量不超过30mmol/g的一种无油固体。其蛋…     

牛羊饲喂糖蜜尿素舔砖好

糖蜜尿素舔砖是牛羊词喂尿素等安全有效的方法。牛羊饲给舔砖，能提高饲料利用率和转化率，节省精料，显著提高增重和母畜的奶量，是一种制做容易，饲喂方便的好方法。     

复合营养舔砖对奶牛产奶量的影响

近年来 ,我区草食家畜饲养量逐步上升 ,特别是山区奶牛、肉羊、肉牛饲养量增长迅速 ,成为广大农牧民增收的一个主要渠道。但是 ,由于均以舍饲为主 ,家畜出现异嗜、厌食和发育不良等症状。有些养殖户盲目补充非蛋白氮和矿物质 ,造成有的家畜发生中毒 ,甚至死亡 ,严重影响了养殖效益和生产积极性。张掖地区畜牧兽医研究所科研人员经过调查研究 ,参考国内外资料和牛羊营养标准 ,研制生产了牛羊复合营养舔砖 (以下简称舔砖 )。为研究本舔砖对奶牛产奶量的影响效果 ,特进行本试验。1　材料与方法1.1　试验材料1.1.1　供试品 :本舔砖是将营养物质…     

尿素饲喂奶牛效果的分析

非蛋白质含氮化合物作为反刍家畜的蛋白质补充饲料，既节省饲料成本，又不影响生产力，是牛奶生产过程中值得推广的一项有利措施。2003年12月21日至30日，在大安市牛羊胚胎移植中心进行了奶牛饲喂尿素的试验，现将试验情况介绍如下：     

尿素饲喂奶牛效果的观察

尿 素 可 以 为 反 刍 家 畜 提 供 瘤 胃 中 微 生 物 合 成营 养 价 值 很 高 的 菌 体 蛋 白 所 需 要 的 氮 源 ,从 而 起 到补充 蛋 白 质 营 养 的 作 用 。 尿 素 一 般 含 氮 量 为 46%,尿 素 中 46%的 氮 如 果 能 被 瘤 胃 微 生 物 合 成 菌 体 蛋白 ,则 1kg 的 尿     

Factors affecting milk urea nitrogen and protein concentrations in Quebec dairy cows

Milk urea nitrogen (MUN), together with percentage milk protein (PROT), are increasingly used as indicators of the protein-energy balance and for monitoring nutrition and diagnosing feeding disorders. The goal of this study was to analyze the effects of parity, milk yield, days in lactation, somatic-cell count, and herd and feeding factors on MUN and PROT. In 10 dairy herds, one milk sample was taken from each of 418 cows, within +/- 2 days of the routine milk-test visit. We used a four-step multiple linear-regression model with backward elimination, including interactions between herd and the different factors. For both dependent variables, there were significant interactions with herd. Herd-specific models were markedly different; however, the daily amount of protein concentrates fed remained (and had a positive coefficient) in seven of 10 herd models for MUN. This factor is easy to record under field conditions and has to be considered in the evaluation of the ration by means of MUN and PROT. Overfeeding of rumen soluble protein can be easily diagnosed and corrected using MUN analyses. The relationships between MUN and PROT in respect of the factors parity, daily milk yield, and days postpartum also vary considerably among herds.     

The usefulness of determining urea levels and the acidity of milk for evaluating protein nutrition in cows

Samples of blood, urine and milk were examined in 94 clinically healthy cows of 10 herds. The average milk samples and the feed ration used in these herds were also examined. The determination of urea concentration and milk acidity was evaluated as to its suitability for the assessment of the protein-glycide ratio and acid-base activity of feed ration. The determination of urea content in an average milk sample was found to be an expeditious procedure. The results of this examination can be used for the evaluation of the protein supply to cows with the same reliability as the determination of serum urea. The passage of urea from serum to milk was proportional. The correlation coefficient for the relation of both parameters was statistically highly significant (r = 0.940). According to the calculated equation of regression line (f2 = 0.734 + 0.669 X f1), the values from 2.94 to 4.10 mmol/l are approximately adequate to the reference range of serum urea from 3.30 to 5.00 mmol/l in milk used in Czechoslovakia. The acidity of milk was found to have a low sensitivity for being used with success for the determination of the acid-base activity of feed ration. The examination of the net acid-base urinary output cannot be replaced by the determination of milk acidity.     

Relationship between milk urea concentration and the fertility of dairy cows

The relationship between milk urea concentration and the fertility of dairy cows was examined in two studies. The first examined the relationship between bulk milk urea concentration and overall herd fertility, using data collected from 250 herds in the UK. There was no relationship either between bulk milk urea concentration and fertility, or between changes in bulk milk urea concentration and fertility. The second study compared the relationship between the milk urea concentration five days after service, and the fertility of individual cows on 11 UK dairy farms. There was no significant difference between the milk urea concentration of the cows that became pregnant and those that did not.     

Relation between milk urea content and nitrogen excretion from lactating cows

Abstract

Thirty-two Chinese Holstein lactating cows were used to investigate the relationship of milk urea nitrogen (MUN) and nitrogen excretion loading to the environment. Cows were fed a similar amount of forage, and concentrates according to milk production. Total collection of urine and faeces were conducted continuously for three days. The milk urea nitrogen was significantly correlated to total nitrogen excretion (R ²=0.70), urinary nitrogen excretion (R ²=0.85), and nitrogen excretion from faeces (R ²=0.22). The following equation was proposed to predict total nitrogen excretion (TNE) (g/d) based on milk urea nitrogen (MUN) (mg/dl): TNE?=?15.46(±1.83)×MUN?+?193.40(±28.79). The results obtained in this study suggested that MUN might be used to predict TNE from lactating cows.     

Effect of lameness on milk yield in dairy cows

OBJECTIVE: To examine the relationship between lameness and milk yield in dairy cows. DESIGN: Cohort study. ANIMALS: 531 dairy cows. PROCEDURE: Cows affected with lameness were classified into 1 of 3 groups on the basis of type of diseases or lesions observed, including interdigital phlegmon (foot rot), papillomatous digital dermatitis (foot warts), or claw lesions. Cows not affected with lameness were classified as healthy. From Dairy Herd Improvement Association records, 305-day mature equivalent milk yield data were collected at the end of lactation or when the cow left the herd. Milk yield was compared between cows affected with lameness and healthy cows. RESULTS: 167 (31%) cows were affected with lameness during lactation. Lame cows had claw lesions (60%), papillomatous digital dermatitis (31%), or interdigital phlegmon (9%). Milk yield in lame cows with interdigital phlegmon (mean, 17,122 lb) was significantly less, compared with healthy cows (19,007 lb). CONCLUSIONS AND CLINICAL RELEVANCE: In this herd, interdigital phlegmon was associated with a 10% decrease in milk production. Lame cows with claw lesions or papillomatous digital dermatitis produced less milk than healthy cows, but the difference was not significant.     

Predicting urinary nitrogen excretion by milk urea nitrogen in lactating Chinese Holstein cows

The objective of this study was to assess the relationship between milk urea nitrogen (MUN, mg/dL) and urinary nitrogen (UN) excretion (UN, g/day) in lactating Chinese Holstein cows. Twelve mature lactating cows were divided into four groups by their days in milk and milk yield and fed four different crude protein levels diets (13.2, 14.1, 15.0 and 16.2%, dry matter (DM) basis) with a similar net energy content. The experiment was conducted according to a multiple 4 × 4 Latin square design. The entire length of the experimental periods was 56 days, each period consisting of 14 days with days 1–9 for adjustment and days 10–14 for the collection of urine and data. The crude protein content had significant effects on the MUN content and UN excretion (P < 0.01), but little effect on milk yield and composition (P > 0.05). There was a close relationship between MUN and UN excretion (P < 0.001). The following equations were established to predict UN (g/day) excretion based on MUN (mg/dL) in the lactating Chinese Holstein cows: UN = 10.07 × MUN + 47.29. The results obtained in this study suggested that MUN could be used as a parameter to estimate UN excretion, while the equations to predict UN based on MUN might be somewhat different due to the differences in breeds of cow.