影响奶牛产犊间隔的因素分析

对江苏省徐州市某奶牛场约800头荷斯坦奶牛1998到1999年产犊间隔与产犊季节、产奶量、产犊胎次、犊牛初生重、犊牛性别等基础资料进行统计分析,结果表明:产犊季节对产犊间隔有极显著的影响(P<0.01);奶牛的产奶量对产犊间隔也有极显著的影响(P<0.01);产犊胎次、犊牛初生重及犊牛性别对产犊间隔无显著影响(P>0.05)。     

影响奶牛产犊间隔因素的分析

经对徐州市某奶牛场约800头荷斯坦奶牛1998到1999年产犊间隔与产犊季节、产奶量、产犊胎次、犊牛初生重、犊牛性别等基础资料进行分析，结果表明：产犊季节对产犊间隔有极显著的影响（P＜0.01）；奶牛的产奶量对产犊间隔也有极显著的影响（P＜0.01）；产犊胎次、犊牛初生重及犊牛性别对产犊间隔无显著影响（P＞0.05）。     

规模化奶牛场奶牛胎衣不下原因探究

近几年,规模化万头牧场全面兴起,单产不断提升,然而奶牛胎衣不下常有发生,本文旨在查明分娩奶牛胎衣不下的发病原因及规律,为防治奶牛胎衣不下制定有效的综合防治措施提供数据参考。本研究通过流行病学调查,对2022年11月—2023年10月一年间分娩的2 936头荷斯坦奶牛从分娩胎次、胎儿性别、单双胎、胎儿出生体重、产犊难易度等生产实际状况进行调查与统计,分析其与分娩母牛胎衣不下的关系。结果显示,二胎次奶牛产后胎衣不下的发病率最低,初次分娩的奶牛产后胎衣不下发病率高达24.41%,发病率最高;产公犊的奶牛胎衣不下发病率显著高于产母犊的奶牛（P<0.05）;产双胞胎的奶牛胎衣不下发病率显著高于产单胎的奶牛（P<0.05）;犊牛初生重<30kg时,奶牛胎衣不下发病率高于其他体重群体;在胎天数<260d的分娩奶牛胎衣不下发病率显著高于其他分娩奶牛（P<0.05）;自然分娩奶牛胎衣不下发病率显著低于助产奶牛（P<0.05）。综上,分娩胎次为二胎时,奶牛胎衣不下发病率最低,头胎发病率最高;产公牛犊,母畜怀有双胎,胎儿出生体重<30 kg、>36 kg,早产...     

影响奶牛产犊间隔的因素分析

对江苏省徐州市某奶牛场约800头荷斯坦奶牛1998到1999年产犊间隔与产犊季节、产奶量、产犊胎次、犊牛初生重、犊牛性别等基础资料进行统计分析,结果表明产犊季节对产犊间隔有极显著的影响(P＜0.01);奶牛的产奶量对产犊间隔也有极显著的影响(P＜0.01);产犊胎次、犊牛初生重及犊牛性别对产犊间隔无显著影响(P＞0.05).     

胎次、犊牛性别和初生重及产犊季节对奶牛繁殖性能的影响

为研究不同胎次、犊牛性别和初生重以及产犊季节对繁殖性能的影响,为奶牛的科学配种与产后护理提供参考,本研究测定了120头荷斯坦奶牛产后第一次发情、配种时间、胎衣排出时间、子宫粘液评分及直肠检查评分等繁殖性能指标,并与奶牛的胎次、犊牛性别和初生重以及产犊季节进行相关性分析。结果表明,4胎及以上奶牛的产后第一次发情时间比前3胎要迟10~18d,其产后子宫粘液评分低0.59~0.79分,直肠检查评分低0.53~0.85分(P0.05);产母犊的奶牛第一次发情时间比产公犊的早3.15d,当犊牛初生重大于45kg时奶牛胎衣排出时间最长(17h);冬季奶牛产后第一次发情时间比其它季节早10~12d(P0.05)。研究认为,不同胎次、犊牛性别和初生重以及产犊季节对奶牛产后的第一次发情时间、胎衣排出时间、子宫粘液和直肠检查评分有显著影响。     

江苏地区荷斯坦犊牛初生重影响因素分析

为探索影响犊牛初生重的因素,收集了江苏省某奶牛场2021年度正常健康产犊的荷斯坦牛产犊记录共6 515条。分析不同出生季节、胎次、母牛BCS、在胎天数对初生重的影响。结果表明：夏季出生的犊牛体重最高;头胎牛产的犊牛初生重最低;产母犊群体中,BCS4分及以上的牛所产犊牛初生重显著高于3分牛只（P<0.05）;随着在胎天数的增加,犊牛初生重显著增加（P<0.05）。初生重与在胎天数和母牛BCS呈极显著正相关（P<0.01）。     

影响荷斯坦母犊断奶平均日增重的因素分析

为探究影响荷斯坦母犊断奶平均日增重的因素,利用一般线性模型对江苏某奶牛场2017-2019年7 101条犊牛断奶重数据进行分析,探索母牛不同初产月龄、产犊季节、胎次以及初乳浓度对断奶犊牛平均日增重的影响。结果表明：母牛不同初产月龄、产犊季节、胎次、初乳浓度对断奶母犊平均日增重、初生重以及断奶重均有极显著影响(P<0.01)。其中母牛初产月龄为22月龄及以下时犊牛日增重最高,初产月龄为22～24月龄时断奶体重最高;母牛夏季产犊时犊牛日增重和断奶体重极显著高于其他产犊季节(P<0.01);4胎及以上母牛所产犊牛日增重极显著高于其他胎次(P<0.01);母牛初乳浓度Brix值大于等于30%时日增重极显著低于其它初乳浓度的犊牛(P<0.01);犊牛初生重为32～34 kg时日增重最高。该结果为牧场预测犊牛生长发育状态及饲养管理改进提供了参考。     

胎次、妊娠天数及月份与奶牛产后疾病相关性探析

研究不同胎次、妊娠天数、围产时间、犊牛初生重及月份与奶牛产后疾病的相关性,为降低奶牛产后疾病发病率提供参考。本文调查了宁夏某场2 975头中国荷斯坦牛不同胎次、妊娠天数及月份等对奶牛产后疾病胎衣不下、乳房炎、子宫炎、蹄病及产后瘫痪的影响程度,并进行相关分析。研究结果表明,随着胎次的增加,奶牛胎衣不下、乳房炎、蹄病和产后瘫痪的发病率逐渐增加,但对子宫炎发病率的影响不明显,其中第6胎奶牛的产后发病率最高。5-7月份奶牛产后疾病的发病率最高。妊娠天数和奶牛进入围产圈时间的增加使得产后疾病的发病率降低。犊牛初生重的增加使得奶牛胎衣不下和产后瘫痪的发病率升高。患胎衣不下导致乳房炎和子宫炎发病率增加,患蹄病导致胎衣不下、乳房炎和子宫炎发病率增加,产后瘫痪导致胎衣不下、乳房炎发病率增加。不同胎次、妊娠天数、产犊月份、围产时间和犊牛初生重对奶牛产后胎衣不下、乳房炎、子宫炎、蹄病和产后瘫痪有一定的影响,且产后疾病间相互影响。     

影响荷斯坦牛产犊难易的原因分析

通过研究不同胎次、产犊季节和犊牛初生重、犊牛性别、产犊方式等因素对荷斯坦牛难产程度的影响,旨在降低难产率,帮助牛场制定合理有效的繁殖管理措施。试验收集上海金山奶牛场2018年1~12月产犊难易记录共2 812条,采用GLM模型对影响奶牛难产程度的因素进行分析。结果表明,胎次、产犊季节、犊牛初生重、犊牛性别、产犊方式对难产程度有显著影响(P<0.05),且第二胎奶牛自然分娩比例最高;春季和夏季产犊低难产度所占比例较大;随着犊牛初生重的增加,难产程度逐渐增大;生公犊难产程度越大;双胎生产方式难产度增大。     

影响新疆褐牛产奶量主要因素的相关分析

对乌鲁木齐种牛场562头新疆褐牛1997年至2003年奶牛的产犊间隔、产奶量、产犊季节、产犊胎次、犊牛初生重、犊牛性别、体尺等基础资料进行统计分析,分析研究了上述各因素与产奶量之间的关系.为有计划的开展配种工作和提高奶牛的终生产奶量提供科学依据.结果表明:产犊间隔、产犊季节、胎次、体斜长对产奶量有极显著的影响(P＜0.01);犊牛性别、体高、胸围对产奶量无显著影响(P＞0.05).综合分析认为新疆褐牛适宜的产犊间隔为410d,适宜的产犊季节为秋、冬季.     

Histologic and histochemical study of placentomes in cows after induced labor

The placentomes were extirpated from 16 cows after parturition induced with 750 micrograms cloprostenol or 20 mg dexamethasone on the 277th day of gravidity, on an average, from 9 cows after spontaneous parturition, and from 7 cows after hysterectomy in the eighth month of gravidity. In the cows with induced calving the foetal placenta was not expelled within 12 hours after calving in 68.7% of the cases whereas in the spontaneous parturitions this proportion was only 22.2% of cases. The placentomes obtained immediately after calf expulsion, and then after four and eight hours, were subjected to histological and histochemical examination. In the terminal crypts of the placentome in cross sections obtained from cows which expelled the placenta in time after natural and induced parturitions, the number of binuclear cells of the fetal syncytium and of cells of the dam epithelium (P less than 0.001) was found to be significantly lower than in the cases of afterbirth retention (1.2 and 3.9; 6.4 and 18.5). The cells of the cow's epithelium of the expelled placentae had a higher activity of acid phosphatase and lipids and the foetal syncytium had a higher activity of non-specific esterase. Increased alkaline phosphatase activity was characteristic of the cow's epithelium in the cases of subsequent retention of afterbirth. These findings should be taken into account in efforts for developing new methods of the induction of parturition if the undesired occurrence of afterbirth retention is to be reduced.     

Evaluation of the effects of treating dairy cows with meloxicam at calving on retained fetal membranes risk

Some non-steroidal anti-inflammatory drugs increase the risk of retained fetal membranes. This is the first study to investigate the effects of meloxicam on the risk of retained fetal membranes. Administration of meloxicam to dairy cattle immediately following calving revealed no differences in the incidence of retained fetal membranes between meloxicam-treated and untreated animals. There was no difference between the 2 groups in the incidence of periparturient diseases following calving. Meloxicam can be used on the day of calving in lactating cows without increasing the risk of retained fetal membranes.     

Peripartal changes in serum alkaline phosphatase activity and lactate dehydrogenase activity in dairy cows.

Peripartal serum alkaline phosphatase activity and lactate dehydrogenase activity were measured in 30 dairy cows in order to examine the association between retained fetal membranes and enzyme activity. Daily blood samples were obtained from pregnant cows, starting 15 days before the expected day of calving until eight days after parturition. Sera from 15 cows which retained fetal membranes longer than 24 hours and 15 cows which shed fetal membranes within six hours after parturition were analyzed for alkaline phosphatase and lactate dehydrogenase enzyme activities. Mean alkaline phosphatase enzyme activities ranged from 15.93 to 32.6 U/L in retained and nonretained placenta cows. There was a trend towards higher serum alkaline phosphatase activities in retained placenta cows but the differences were not significant among the groups (P greater than 0.05). Mean lactate dehydrogenase activities ranged from 307.2 to 438.86 U/L in nonretained and retained placenta cows. Lactate dehydrogenase enzyme activities in nonretained and retained placenta cows were similar (P greater than 0.05). The alkaline phosphatase and lactate dehydrogenase enzyme activities peaked at the time of parturition in both groups. However, the differences in alkaline phosphatase and lactate dehydrogenase activities on different days within non-retained and retained placenta cows were significant (P less than 0.05). Results indicate that prepartal changes in alkaline phosphatase and lactate dehydrogenase enzyme activities are not predictive of placental retention postpartum.     

多西环素泡腾片治疗子宫内膜炎和胎衣不下临床效果观察

为探讨多西环素泡腾片对子宫内膜炎和胎衣不下治疗作用,对患病奶牛用多西环素泡腾片进行1～3个疗程的治疗,观察临床效果。结果显示,104例为奶牛子宫内膜炎,治疗后有效率98.77%,治愈率93.27%。126例为奶牛胎衣不下,治疗后有效率98.23%,治愈率95.24%。表明多西环素泡腾片对奶牛子宫内膜炎和胎衣不下有较好的治疗效果。     

Influence of the duration of calving and obstetric assistance on the placental retention index in Holstein dairy cows

The aim of this study is to evaluate the influence of duration of calving and obstetric assistance on retained placenta incidence of high milk production Holstein cows. Experimental groups were determined according to the duration of the expulsive phase of calving: 2 h (n = 16), 2‐4 h (n = 16) and >4 h (n = 12), and additionally allocated in two sub‐groups: spontaneous calving (n = 22) and intervention calving (n = 22). Diagnosis of retained placenta was considered with a threshold of 8 h after the expulsive phase. Cows without obstetric intervention, with labor duration of 2 h, presented reduced time needed for placental release, in comparison to those with obstetric assistance. In the 2–4 h group and >4 h, there was no statistical difference. The 2 h and 2–4 h groups with intervention and the spontaneous >4 h group were considered retained placenta groups. On the other hand, performing obstetric intervention when calving period was superior to 4 h nulled the occurrence of retention of fetal membranes. As a conclusion, obstetric assistance predisposes placental retention to calving with <2 h of duration in dairy cows. Conversely, when calving is more than 4 h, performing fetal extraction has a beneficial influence on preventing retained placenta.     

A Markovian decision model for beef cattle replacement that considers spring and fall calving

In certain production environments, beef cows are mated during a breeding season that starts in early summer. Cows found not to be pregnant at the end of the breeding season could either be culled or retained and remated the following summer. Alternatively, nonpregnant cows could be mated in the winter. This option would result in having both a spring and a fall calving herd. The purpose of our study was to determine the optimal replacement policy (maximizing long-run average net returns) for a specific production environment by determining for each age of cow, reproductive status (nonpregnant or pregnant), and season of pregnancy checking (spring or fall) whether the cow should be retained to the next breeding season (summer or winter) or be replaced by a pregnant heifer. The problem was formulated as a Markovian decision process and the optimal policy was found by linear programming. The optimal policy was one in which nonpregnant cows were always culled and replaced by heifers in the summer breeding herd, resulting in spring calving only.     

奶牛产后胎衣不下原因调查分析及防治

在奶牛养殖领域有不少牛因为长时间胎衣不下滞留在子宫中造成终身不孕,使奶牛利用年限极大缩短,养殖场淘汰率显著升高。为进一步探明青海省门源县奶牛产后胎衣不下的主要原因,于2020年对门源县养殖的奶牛胎衣不下进行深入调查,并明确了造成胎衣不下的主要原因,提出相应的防治措施。     

Aspects of bacteriology and endocrinology of cows with pyometra and retained fetal membranes

In an effort to clarify the pathogenesis of pyometra, 20 cows with retained fetal membranes and 20 without, but with contemporary calving dates were studied. They were palpated and their uteri were subjected to sample collections for bacteriologic cultural examinations twice weekly for 4 weeks. Blood samples were obtained each day and evaluated for serum progesterone concentration. Three cows without and 3 with retained fetal membranes developed pyometra during the study, resulting in 3 groups designated control (CON), cows with retained fetal membranes (RFM), and cows with pyometra (PYO). Bacterial isolations occurred less frequently in the CON group than in the PYO and RFM groups. Growth patterns of bacteria also varied between groups. Coliform and incidental bacteria disappeared from the uterus of the PYO group by the end of the 3rd week. In contrast, heavy growth of Corynebacterium pyogenes and gram-negative anaerobic bacteria developed during this same period in the PYO group. In cows with pyometra, the significant persistent pathogenic bacteria recovered were C pyogenes and gram-negative anaerobic bacteria, especially Fusobacterium necrophorum and Bacteroides melaninogenicus. Anaerobic bacteria were isolated simultaneously with C pyogenes in most cows of the PYO group, but less often in CON and RFM groups, and highest growth levels were present near the time of ovulation. Clinically, pyometra usually developed about 10 days after observation of concurrent ovulation and high growth levels of C pyogenes and gram-negative anaerobic bacteria. A hypothesis is presented for development of pyometra in the cow.     

Effect of beta-carotin serum concentration on the reproductive performance in dairy cows

The aim of the following investigation was to study the effect of beta-carotin serum concentrations on reproductive performance in dairy cows. Blood samples were collected from 201 cows 3 to 4 weeks antepartum, 1 to 2 weeks postpartum and at the time of insemination. Concentrations of beta-carotin in blood serum were determined via HPLC. The incidence of retained placental fetal membranes, endometritis, ovarian cysts as well as the beginning of the oestrous cycle and various measures of fertility such as first service conception rate, pregnancy index, interval from calving to first insemination, interval from calving to conception, interval from first insemination to conception and expected calving interval were recorded and analysed. The beta-carotin serum concentrations were not related to the incidence of retained placental fetal membranes, endometritis, ovarian cysts or the onset of cyclicity post partum. Cows with lower beta-carotin concentrations partially seemed to have a reduced reproductive performance than cows with higher beta-carotin concentrations. Overall, our results suggest only a minor relationship between the beta-carotin serum concentration and fertility in dairy cows.     

广西荷斯坦奶牛胎衣不下的病因、发病规律及防制措施

奶牛胎衣不下常会引起奶牛子宫内膜炎,降低产奶量,延长产犊周期甚至引起败血症,给奶牛养殖业造成巨大的经济损失。作者针对广西奶牛胎衣不下发生原因、发病规律及综合防制措施进行调查分析,总结一些有效的预防和治疗胎衣不下的措施,旨在为南方地区奶牛业全面降低胎衣不下发病率提供参考资料。