子宫内膜炎患牛子宫内膜PGR和ESR-1 mRNA的表达特征

为探讨卵巢激素及其子宫内膜受体在奶牛子宫内膜炎中的作用,以产后6～10d健康及患急性化脓性子宫内膜炎的中国荷斯坦奶牛为研究对象,通过ELISA法检测子宫内膜中PGF2a,血清中孕酮和雌二醇浓度,SYBRGreenⅠ荧光定量PCR检测子宫内膜PGR和ESR-1mRNA的表达。结果显示,病牛子宫内膜PGF2α水平为（6.503±0.122）μg/L,血清孕酮为（0.816±0.281）μg/L,血清雌二醇为（35.462±2.523）μg/L,而对照组分别为（14.408±0.285）,（0.543±0.142）,（37.6±1.317）μg/L;子宫内膜炎患牛组PGF2a水平极显著低于对照组（P〈0.01）,孕酮含量显著高于对照组（P〈0.05）,PGF2a与孕酮水平呈显著负相关（r=0.893）,雌二醇含量组间差异不显著。PGR基因的mRNA水平极显著高于对照组（P〈0.01）,而ESR-1基因的mRNA水平低于对照组,且差异极显著（P〈0.01）。上述结果表明,孕酮浓度显著升高及PGR mRNA高表达,可能抑制子宫收缩;ESR-1mRNA低表达使子宫新陈代谢减慢,子宫内膜合成PGF2a功能下降,这些改变有可能促进了产后子宫内膜炎的发生发展。     

奶牛蹄叶炎的病因探究

本文旨在对严重影响奶业健康发展的奶牛蹄叶炎的病因进行探究。在辉山奶牛场阜新市彰武县三场经产奶牛中,挑选临床健康奶牛10头作为对照组;患蹄叶炎奶牛10头作为试验组。采集两组奶牛血液,分别用牛内毒素酶联免疫试剂盒和荧光分光光度法测定血浆中内毒素和组胺的含量。结果显示,试验组血浆内毒素及组胺含量分别比对照组高0.65ng/mL、21.8ng/mL,差异均极显著(P<0.01)。说明患病牛血浆内毒素和组胺含量升高是诱发奶牛蹄叶炎的重要因素。     

EM发酵玉米秸秆和青贮玉米秸秆对奶牛生产性能的对比试验

本试验应用EM发酵玉米秸秆和青贮玉米秸秆饲喂奶牛,以观察两种方法处理的玉米秸秆对奶牛生产性能及经济效益的影响效果。结果表明,用EM发酵的玉米秸秆饲喂奶牛较青贮玉米秸秆饲喂奶牛,每天每头奶牛采食量提高1.03%,平均产奶量提高2.02%,经济效益提高0.13元;EM原液发酵的玉米秸秆和青贮玉米秸秆1∶1混合饲喂奶牛,每天每头奶牛采食量、平均产奶量、经济效益分别比饲喂青贮玉米秸秆的奶牛提高2.85%、2.99%和1.15元。     

A case-control study to identify farm factors affecting fertility of dairy herds: univariate description of factors

Objective To identify farm factors which were associated with reproductive performance in dairy herds in New South Wales.
Procedure A survey was administered by face to face interview to examine the responses of producers drawn from 757 herds, which used the New South Wales Agriculture Department Dairy Herd Improvement scheme. A case-control approach was used to select a total of 126 herds from the first (top group - cases) and fourth quartiles (low group - controls) for intercalving interval.
Results We found that the estimated interval from calving to first mating was significantly different between groups (P = 0.03) and that the groups significantly differed in both their target for interval to first mating (P = 0.02) and their perceived optimum time for first mating (P = 0.04). Other factors associated with a longer intercalving interval included, use of embryo transfer programs (P = 0.08), younger managers (P = 0.02), fewer breedings per day (P = 0.01), a greater number of people detecting heats (P = 0.07), but less hours spent detecting heats while handling the cows (P = 0.11), and a failure to vaccinate bulls for campylobacteriosis (P = 0.14).
Conclusions Managers of herds with poorer reproductive performance did not intend to mate cattle as soon after calving as managers with better reproductive performance, were not as active in seeking veterinary advice on reproduction, and were attempting to treat reproductive diseases and disorders themselves.     

Milk production increase following treatment of Dutch dairy cattle with thiabendazole

Summary

In a trial involving 542 dairy cattle on 28 farms, 276 were treated once with thiabendazole within two days of calving. The treated group showed an average increase in milk yielded over the non‐return group of 229.8 kg during the subsequent lactation.

In the treated group, total milk fat production was increased over that of the controls by 7.4 kg per cow; milk protein was increased by 6.9 kg per cow. All treatment parameter differences were highly significant at the 1% level of probability.     

Experimental studies on the impact of an increased dose of anionic salts on the metabolism of dairy cows

Summary

This study was initiated to investigate the influence of a daily dose of anionic salts (AS) above the valid upper limit at present on metabolism of dairy cows. Eleven non‐pregnant and non‐lactating Holstein‐Friesian crossbred cows with a permanent rumen cannula were used in a study with a controlled feeding design. The initial daily dose was 2500 meq/day, which resulted in a Dietary Cation Anion Difference (DCAD) of ‐211 meq/kg dry matter. Every seven days, the daily dose was raised by 500 meq. If a cow stopped eating, the application of AS was stopped and these cows were monitored over the next seven days. On day 30 another batch of hay, having the same DCAD but higher concentrations of minerals and energy, was fed. Blood and urine samples were taken to monitor acid‐base balance and calcium concentrations. Acid‐base balance was strongly influenced by AS. Blood pH dropped steadily and reached values around 7.23. Urine pH dropped quickly below 6 and remained at that level regardless of the increased dosage of AS. Net acid base excretion (NABE) fell continuously with the increase of the dosage of AS and reached values below ‐200 mmol/l. Calcium concentrations in the serum were nearly stable, but those in urine increased sharply and remained on an elevated level with increasing doses of AS. A few days before the individual cow's refusal of feed intake, calcium excretion in urine decreased. The majority of cows stopped eating while consuming a diet containing 3500 to 4000 meq AS except two animals who consumed up to 6000 meq/day AS but they received the better hay in the second half of the treatment period. In this time pH in blood increased slowly. NABE remained stable on a low level at ‐100 mmol/l. The results showed that with an increasing amount of AS fed the risk of clinical acidosis increased. The decreasing urine concentrations of calcium indicate a breakdown of the compensation capability of the single cow. Besides the dose of AS fed, the quality of the feed stuff might be another factor concerning the tolerance of cows against AS.     

Genetic and Environmental Correlations Among Female Fertility Traits and Milk Production in Different Parities of Swedish Red and White Dairy Cattle

The main objective of this study was to estimate genetic correlations between fertility and production traits in first, second and third lactations as well as between fertility traits measured in the same way at different ages. The fertility traits studied were: number of inseminations per service period, number of treatments for reproductive disturbances, interval between first and last inseminations, interval between calving and first insemination, and interval between calving and last insemination. Early milk production was measured as the average of the energy-corrected milk yield at the second and third monthly testdays in a lactation. The number of records was approximately 450 000, 350 000, 180 000 and 75 000 in the heifer period, first, second, and third lactations, respectively. A linear, trivariate model that included the effects of herd-year, year, month, age and sire of the cow was applied. To reduce the effect of ongoing selection, 305-days kg protein production in first lactation was included as a variate in all of the analyses. Correlations between the herd-year effects indicated that factors of herd-year level conducive to increased production had a tendency to increase the number of inseminations as well as the number of reproductive treatments, although there was an earlier start and termination of the insemination period. Genetic correlations between fertility traits and production were in the range of 0.2-0.4, all of them unfavourable and higher at later parities. The genetic correlations between fertility traits in the heifer period and the same traits in first lactation were 0.7. Genetic correlations between the first and second lactation varied between 0.7 and 0.9, and between the second and third lactation they were all 0.9 or higher. In conclusion, fertility and production traits need to be selected for simultaneously if fertility is going to be maintained along further genetic improvement on production, and such selection should include fertility results from lactating cows.     

半胱胺盐酸盐对泌乳20～42周奶牛产奶性能和部分免疫指标的影响

采用96头多胎荷斯坦奶牛,试验开始时平均泌乳时间为135d,平均日产奶量35kg。根据试验前1周日平均产奶量(M)将牛群分为4个产量组:第1组M≤30kg(n=24),第2组30kg40kg(n=24)。每组内随机划分半胱胺盐酸盐(Lactonin,LT)试验(Treatment,n=49)与对照(Control,n=47)。试验于平均泌乳期第20周开始,按剂量顺序给试验组奶牛添喂经过包被保护的半胱胺盐酸盐(Lactonin)2000～6000U/d,持续23周。试验1组(n=12)平均奶产量增加18%(P<0.05);4个试验组(n=49)平均乳脂率显著增加(P<0.05),乳蛋白率呈增加的趋势(0.05相似文献   

浅谈云南省奶牛业

阐述了云南省奶牛业的现状,论述了云南奶牛业发展中存在的五个问题,并针对性地提出了云南省奶牛业发展的六条应对措施。总结认为首先应制定发展目标,做好发展规划,其次政府应加强宏观调控,加大对奶牛业的扶持力度,积极开拓市场,可使云南奶牛业迅速发展。     

中药穴位注射对奶牛胎衣不下的疗效观察

奶牛产后胎衣不下对奶牛业造成极大的经济损失。本试验旨在研究一种简便易行、成本低、高效的非手术治疗方法。本试验应用当归及复方丹参注射液经百会穴及交巢穴注射,使胎衣排出率达100%,用药后的当年受孕牛占96.2%。可见,此方法可以有效治疗奶牛产后胎衣不下并能提高奶牛的当年受孕率。