影响西门塔尔母牛情期受胎率因素的分析

为探讨影响新疆地区西门塔尔母牛情期受胎率的因素,本试验采用SAS 8.1对影响情期受胎率的配种季节、与配公牛和母牛年龄3个因素进行最小二乘方差分析,各水平间进行Duncan多重比较并分析不同水平对情期受胎率的影响。结果表明,不同配种季节对西门塔尔母牛情期受胎率影响极显著(P<0.01),春季西门塔尔母牛情期受胎率极显著低于夏季、秋季、冬季(P<0.01),冬季情期受胎率最高(64.7%),而春季情期受胎率最低(40.0%);与配公牛对西门塔尔母牛情期受胎率无显著影响(P>0.05);母牛年龄对西门塔尔母牛情期受胎率的影响极显著(P<0.01),随着母牛年龄的逐渐增加情期受胎率有降低的趋势。依据本研究结果,可针对各影响因素合理有效的调控,从而提高母牛的情期受胎率,最终提高牛场经济效益。     

Factors Affecting the First Service Conception Rate of Cows in Smallholder Dairy Farms in Bangladesh

The successful outcome of an insemination is a combination of both male and female fertility‐linked factors. We investigated the first service conception rate of cows at artificial insemination (AI) in the smallholder dairy farms in Bangladesh. Frozen straws were prepared from ejaculates of Bos indicus (n = 7) and Bos indicus × Bos taurus (n = 7) AI bulls. Fertility was determined from 6101 first services in cows that were performed by 18 technicians in four regions between April 2004 and March 2005. Pregnancy was diagnosed by rectal palpation between 60 and 90 days post‐insemination. The Asian version of Artificial Insemination Database Application (AIDA ASIA) was used for bulls‐, cows‐ and AI‐related data recording, and later retrieved for analysis. The mean ± SD number of inseminations performed from individual bulls and their conception rates were 436.0 ± 21.6 and 50.7 ± 1.9%, respectively. Logistic regression demonstrated body condition scores (BCS), heat detection signs, months of AI and their interactions had greatest effects (odds ratios: 1.24–16.65, p < 0.04–0.001) on first service conception rate in cows. Fertility differed (p < 0.02–0.001) between the regions, previous calving months, months of AI, BCS, parity and heat detection signs of cows. Inseminations based on mounting activity (n = 2352), genital discharge (n = 3263) and restlessness and/or other signs (n = 486) yielded a conception rate of 53.6%, 48.8% and 50.1%, respectively (p < 0.05). Conception rate between technicians ranged between 43.4% and 58.6% (p < 0.05). The days interval from calving to first service (overall mean ± SD = 153.4 ± 80.6) had relationship (p < 0.001) with BCS, months of previous calving and parity of the cows. Fertility at AI in smallholder farms can be improved by training farmers on nutrition and reproductive management of the cows.     

影响荷斯坦牛产奶量差的因素分析

产奶量差是奶牛个体同一胎次前后2个泌乳月产奶量的差值,可准确反映产奶量变化情况。为探究影响荷斯坦牛产奶量差的因素,本研究收集整理了江苏省某大型奶牛场2015-2018年55 193头次荷斯坦牛生产性能测定记录,并利用最小二乘法分析胎次、测定年度、产犊季节、泌乳月4个因素对荷斯坦牛产奶量差的影响。结果显示:胎次、测定年度、产犊季节、泌乳月及其交互作用对产奶量和产奶量差均有极显著影响(P<0.01)。其中,不同胎次、测定年度和产犊季节的荷斯坦牛总产奶量在第2个泌乳月增加最快,产奶量差为8.79kg;头胎第6泌乳月、二胎第7泌乳月和三胎及以上第6泌乳月产奶量下降最大,产奶量差分别为-2.86kg、-4.59kg和-6.13kg;2015-2018年4个测定年度中,第10、第6、第7、第6泌乳月产奶量降低最大,产奶量差分别为-2.26kg、-4.98kg、-4.44kg和-3.56kg;春季产犊的荷斯坦牛第4泌乳月、夏季产犊的荷斯坦牛第12泌乳月、秋季产犊的荷斯坦牛第9泌乳月、冬季产犊的荷斯坦牛第6或第7泌乳月产奶量下降最大,产奶量差分别是-4.34kg、-4.71kg、-5.36kg和-5.40kg。此外,产奶量差与泌乳持续力呈极显著正相关(P<0.01),与产犊间隔呈显著正相关(P<0.05),与泌乳天数、高峰奶、乳脂率、蛋白率、305d产奶量呈极显著负相关(P<0.01)。因此,产奶量差作为衡量奶牛产奶量变化的指标之一,可为牧场进行科学饲养管理提供参考。     

奶牛受胎率低的原因及对策

奶牛受胎率是衡量奶牛养殖的一项主要技术指标，是奶牛发展的关键因素。受胎率高低对奶牛群发展，牛奶产量，经济效益等都有直接影响。因此，我们把提高奶牛受胎率作为一项重要工作来抓。结合我县奶牛养殖的实际情况，参考相关资料，找出原因，并提出相应对策。     

甘肃省荷斯坦牛泌乳指数浅析

近年来,我场奶牛年增单产不断提高,奶牛产奶量的提高是否会引起泌乳指数的变化呢？为此,笔者对我场４９年来母牛个体单产的资料数据进行整理分析如下。１　甘肃省黑白花奶牛育种协作组１９８６年对全省８０９５头成母牛生产性能的鉴定资料表明,达到品种登记的成母牛为１５２３头,１～５胎３０５天产奶量４胎略高于５胎,以５胎３０５天泌乳指数为１００,成母牛胎次泌乳指数如表１。２ １９９８年我场５１３头成母牛１～５胎产奶资料分析,各胎次３０５天产奶泌乳指数如表２。２．１　从表２中看出,１～４胎泌乳指数与１９８６年省育…     

提高奶牛受胎率的卵泡和黄体活动调控研究

在夏季和秋季对经产荷斯坦奶牛进行定时排卵-输精程序（TAI）处理并在输精后进行HCG处理（第5d和第10d分别肌注HCG2000IU／头），另于冬季单独对自然发情人工授精母牛进行输精后HCG处理。从各季节HCG处理组及其对照组中抽取部分奶牛，在输精后第0d（输精当天）、7d、14d、和21d分别采血，以测定孕酮和雌二醇水平。所有试验牛在输精后45-60d进行直肠妊娠检查以确定是否受胎。结果显示：夏季TAI＋HCG组、TAI组、对照组母牛输精后的受胎率差异不显著（p〉0．05），分别为26．67％（4／15）、16．67％（2／12）和10．71％（3／28）。秋季TAI＋HCG组、TAI组、对照组情期受胎率差异也不显著（p〉0．05），分别为：55．00％（11／20）、42．11％（8／19）和31．43％（11／35）。冬季HCG组和对照组的受胎率分别为63．16％（12／19）和45．00％（9／20）（P〉0．05）。在夏秋冬三个季节，输精后HCG处理相应显著提高第7d、14d和21d血液中孕酮水平（p〈0．05），但稍稍降低雌二醇水平（p〉0．05），显著降低E2／P比值（p〈0．05）。与受胎率的差异相关，秋冬季各组牛输精后血浆P水平高于（p〉0．05）或（极）显著高于（p〈0．01或p〈0．05）夏季相应组；血浆E2水平则稍高于（p〉0．05）夏季相应组。以上结果说明，TAI单独处理可以将受胎率提高约10～15个百分点；输精后单独HCG处理可以将爱胎率又提高约10-15个百分点，这主要是促进黄体功能的结果，而且提高的幅度在秋冬季要高于夏季。     

饲粮能氮瘤胃释放同步化对泌乳奶牛瘤胃发酵、生产性能及氮平衡的影响

本试验旨在研究饲粮瘤胃能氮释放同步化对泌乳奶牛瘤胃发酵、生产性能及氮平衡的影响.试验采用4×4的拉丁方试验设计,试验动物为4头安装永久性瘤胃瘘管的泌乳中期荷斯坦奶牛,试验处理为4种瘤胃能氮释放同步化指数(SI)不同的等能、等氮饲粮(饲粮Ⅰ,SI=0.95;饲粮Ⅱ,SI =0.90;饲粮Ⅲ,SI =0.83;饲粮Ⅳ,SI...     

影响江苏地区荷斯坦牛体细胞数变化模式的非遗传因素分析

旨在探究江苏地区荷斯坦牛体细胞数变化模式的影响因素。本研究通过对江苏地区12个奶牛场2017—2019年荷斯坦牛253 706条DHI测定日SCC记录进行分析,在划分9种SCC变化模式基础上,利用最小二乘法探究不同牧场规模、胎次、产犊季节、产犊间隔和305天产奶量对荷斯坦牛SCC变化模式的影响。结果表明,SCC模式在各因素不同水平间分布均有极显著差异（P<0.01）。其中,较低-维持模式在5 000头以上的牧场比例最高,较低-感染模式的比例最低;感染-维持模式在1 000头以下的牧场比例最高,较低-维持模式的比例最低。较低-维持模式在1胎牛的比例最高,感染-痊愈模式的比例最低;较低-感染模式在5胎牛的比例最高,较低-维持模式的比例最低。较低-感染模式在春季产犊时奶牛的比例最高,较低-维持模式的比例最低;易感-降低模式在夏季产犊时奶牛的比例最高,较低-感染模式的比例最低。较低-感染模式在产犊间隔为441 d以上的奶牛比例最高,较低-感染模式在产犊间隔为300~400 d的奶牛比例最低。较低-感染模式在305天产奶量为3 000~5 000 kg的奶牛比例最高;较低-维持模式在305天产奶量为9 001~11 000 kg的奶牛比例最高,感染-痊愈模式的比例最低。上述结果表明,不同牧场规模、胎次、产犊季节、产犊间隔和305天产奶量对荷斯坦牛SCC变化模式的分布均有一定影响,该结果为荷斯坦牛隐性乳房炎的预测提供了参考。     

新疆地区荷斯坦干奶牛与泌乳牛四季NH3排放量变化的研究

试验于2011年7月～2012年7月在同一栋牛舍内对20头干奶牛和20头泌乳牛分别进行了四季氨气排放量测定,每个季节根据气象信息所提供的当地气温,分别在季前、季中、季末共选取气温相近的18d,分别对干奶牛（9d）与泌乳牛（9d）进行监测。通过测定不同时间段牛舍内NH3的浓度,把3次实测值进行累加,计算出24h奶牛NH3的排放值。结果表明,四季试验期间干奶牛舍内平均NH3排放量是6．42g／（头·d）,四季泌乳牛舍内平均NH、排放量是10．62g／（头·d）。四季温度的变化对奶牛排放NH3有一定的影响。奶牛NH3的排放量与奶牛的采食量、饲料配方和饲料中CP水平有关,一头体重500kg左右的奶牛一年产生约3．6kg的氨气：     

Analysis of Non-genetic Factors Affecting SCC Change Pattern of Holstein Cows in Jiangsu Province

The objective of this study was to explore the influence factors of SCC change pattern of Holstein cows in Jiangsu. Based on the division of 9 SCC change patterns, 253 706 DHI records of Holstein cows from 2017 to 2019 in 12 dairy farms in Jiangsu province were analyzed, and the least squares model was used to explore the influence of different farm size, parities, calving seasons, calving intervals, and 305-days milk production on SCC change pattern. The results showed that the distribution of SCC patterns at different levels of each factor was significantly different (P<0.01). Among them, the percentage of lower to maintain pattern was the highest, and lower to infection pattern was the lowest for cows in farm with more than 5 000 cows. The percentage of infected to maintain pattern was the highest, and lower to maintain pattern was the lowest for cows in farm with less than 1 000 cows. The percentage of lower to maintain pattern was the highest, and infected to healed pattern was the lowest for cows with parity 1. The percentage of lower to infection pattern was the highest, and lower to maintain pattern was the lower for cows with parity 5. The percentage of lower to infection pattern was the highest, and lower to maintain pattern was the lowest for cows calving in spring. The percentage of susceptible to reduce pattern was the highest, lower to infection pattern was the lowest for cows calving in summer. The percentage of lower to infection pattern was the highest for cows with calving interval more than 441 d, and lowest for cows with calving interval with 300-400 d. The percentage of lower to infection pattern was the highest for cows with 305-days milk production of 3 000-5 000 kg. The percentage of lower to maintain pattern was the highest, and infected to healed pattern was the lowest for cows with 305-days milk production was 9 001-11 000 kg. The results indicate that different farm sizes, parities, calving seasons, calving interval, and levels with 305-days milk production have certain influences on the distribution of the SCC change patterns in Holstein cows. The results provide references for the prediction of subclinical mastitis in Holstein cows.     

梅花鹿受胎率主要影响因素分析

为进一步提高梅花鹿受胎率,并形成配套的繁育技术,本试验对影响梅花鹿受胎率因素进行分析。结果表明：优、良、差3种膘情的梅花鹿发情率分别为93．8％,75．0％,4．4％,差异极显著（P〈0．01）;育成梅花鹿发情率为38．2％,经产鹿发情率为67．6％,经过幼鹿培育的育成鹿发情率为55．9％,经产鹿与未经产鹿发情率存在较...     

克拉玛依地区荷斯坦牛超排效果及影响因素的分析

本研究比较了不同年度、季节、超排方法、促卵泡素（FSH）的剂量、超排处理开始时发情周期天数及供体牛年龄对荷斯坦牛超排效果的影响。结果表明，秋季、冬季与夏、春季比较在采卵数和可用胚数方面差异极显著（P〈0．01）。改进方法与常规方法比较采卵数差异极显著（P〈0．01），可用胚数差异显著（P〈0．05），8．0mL、9．4mL、10．0mLFSH剂量之间各项指标均差异显著（P〈0．05）。而超排处理的年度、超排处理开始时发情周期天数及供体牛年龄对荷斯坦牛超排效果影响不显著（P〉0．05）。     

定时输精对奶牛第一情期受胎率的效果分析

[目的]探讨不同月份和精液类型对利用定时输精程序处理奶牛后第一情期受胎率的影响.[方法]选择93头产后60 d以上不发情和产后配1～3次仍未受胎的奶牛,不检查卵巢直接利用激素生源2+1进行同期发情处理.1～3月份处理41头奶牛,6～8月份处理52头;其中,利用性控精液配种58头,常规精液配种35头.[结果]表明:经定时...     

影响奶牛繁殖力的因素

奶牛的繁殖力在生产实践中具有重要的意义,繁殖力的高低不仅影响牛群的增殖,而且影响牛群的产奶水平和牛场的经济效益。影响奶牛繁殖力的因素是多方面的,下面从五个方面给与剖析和介绍。1营养对奶牛供给合理平衡的营养是保证奶牛繁殖力的重要因素,营养对奶牛的发情、配种、受胎起决定性作用,其中以能量和蛋白质对奶牛的繁殖力影响最大,矿物质和维生素也对繁殖力起重要作用。能量、蛋白质、维生素和矿物质缺乏可导致流产、早产和产出发育不完全的小牛。1.1能量能量水平过高过低都会影响奶牛的繁殖力。能量水平长期不足,会导致发情症状不明显…     

影响家畜超数排卵效果的因素

超数排卵(MO,MultipleOvulation)乃是胚胎移植所需胚胎的主要来源。它充分挖掘良种母牛的遗传潜力,向社会提供大量的优质胚胎。本文阐述了国内外超数排卵的发展情况,从不的角度分析了影响超排效果的几个因素。     

应用微卫星DNA标记分析荷斯坦母牛系谱可靠性及影响因素

为了评估当前中国荷斯坦牛群体的系谱准确性,本研究选择15头种公牛及来自21个牛场的2 220头女儿牛,借助牛3号染色体(BTA3)上17个微卫星标记,对女儿-公牛标记基因型是否错配进行分析。结果,按照错配标记数大于等于3个为系谱错误的标准,本研究所涉及的母牛群中系谱错误率为16.62%。经对影响系谱错误的因素分析表明,场效应是主要的影响因素,不同场间系谱错误比例差异较大;由于公牛女儿在各牛场中分布不均匀,导致公牛效应也达到显著。研究结果提示在中国荷斯坦牛群体进行亲子鉴定是亟需和必要的。     

热应激影响荷斯坦奶牛泌乳机制的研究进展

奶牛在极端热环境下会产生热应激反应,导致奶牛泌乳量降低、乳品质下降。本文从热应激诱导乳腺氧化应激及影响机体激素代谢、抑制乳成分合成角度综述了热应激影响奶牛泌乳的机制,并对补饲添加剂缓解热应激的效果进行总结,以期为进一步探究热应激机理及寻求有效、合理的缓解措施提供理论依据。     

奶牛消化道三位体瘘管术的后期护理

奶牛三位体瘘管就是通过手术的办法,将软体硅胶瘘管埋殖于瘤胃、十二指肠前端、回肠末端,用于反刍动物营养教学和研究的永久性瘘管。它具有成本低、使用时间长、效率高等特点。可直接有效地对各种营养物质灌注和取样。目前被广泛应用于反刍动物营养研究领域。中国农业科学院畜牧研究所反刍动物营养研究室2005年3月对4头一岁奶牛成功地实施了消化道三位体瘘管手术。“三位体瘘管术”的后期护理是瘘管牛能否存活的关键。笔者作为试验牛场的兽医,对这四头瘘管牛实施了全程护理。经过60天的护理和观察,四头瘘管牛的创面已痊愈,各项生理体征和饮…     

慢性冷应激对奶牛乳清生化指标及酶活性的影响

为研究慢性冷应激对荷斯坦奶牛乳清生化指标和酶活性的影响。结果显示,随着环境温度的下降,乳清ALB、BUN、P含量呈升高趋势;TP、Ca含量降低;Glu、CHO含量无显著性变化(P>0.05);ALT、AST、ALP和LDH活性下降。表明慢性冷应激可引起奶牛乳清中某些生化指标和酶活性的变化。     

First Service Pregnancy Rates Following Post‐AI Use of hCG in Ovsynch and Heatsynch Programmes in Lactating Dairy Cows

Lactating dairy cows (n = 667) at random stages of the oestrous cycle were assigned to either ovsynch (O, n = 228), heatsynch (H, n = 252) or control (C, n = 187) groups. Cows in O and H groups received 100 μg of GnRH agonist, i.m. (day 0) starting at 44 ± 3 days in milk (DIM), and 500 μg of cloprostenol, i.m. (day 7). In O group, cows received 100 μg of GnRH (day 9) and were artificially inseminated without oestrus detection 16–20 h later. In H group, cows received 1 mg oestradiol benzoate (EB) i.m., 24 h after the cloprostenol injection and were artificially inseminated without oestrus detection 48–52 h after the EB injection. Cows in C group were inseminated at natural oestrus. On the day of artificial insemination (AI), cows in all groups were assigned to subgroups as follows: human Chorionic Gonadotrophin (O‐hCG) (n = 112), O‐saline (n = 116), H‐hCG (n = 123), H‐saline (n = 129), C‐hCG (n = 94) and C‐saline (n = 93) subgroups. Cows in hCG and saline subgroups received 3000 IU hCG i.m. and or 10 ml saline at day 5 post‐AI (day 15), respectively. Pregnancy status was assessed by palpation per rectum at days 40 to 45 after AI. The logistic regression model using just main effects of season (summer and winter), parity (primiparous and pluriparous), method₁ (O, H and C) and method₂ (hCG and saline) showed that all factors, except method₁, were significant. Significant effects of season (p < 0.01), hCG and parity (p < 0.01), and a trend of parity and season (p < 0.1) were detected. A clear negative effect of warm period on first service pregnancy rate was noted (p < 0.01). The pregnancy rate was the lowest in the H protocol during warm period (p < 0.05). Treatment with hCG 5 days after AI significantly improved pregnancy rates in those cows that were treated with the H protocol compared with saline treatments (41.5% vs 24.8%; p < 0.01). O and H were more effective in primiparous than in pluriparous cows (46.1% vs 29.9%; p < 0.1 and 43.6% vs 24.6%; p < 0.01). First service pregnancy rates were higher in primiparous hCG‐treated than in pluriparous hCG‐treated cows (57.9% vs 32.3%; p < 0.01). The pregnancy rate was higher for the hCG‐treated cows compared with saline‐treated cows during warm period (37.9% vs 23.6%; p < 0.001).