补饲与犊牛断乳对产后母牦牛发情周期恢复的影响研究

为了提高当年产犊母牦牛的发情率,我们对选定的120头怀孕母牦牛进行补饲,同时在犊牛产后3个月对犊牛进行隔离断奶,补饲试验于2010年3月初开始：100头母牦牛随机分为两组,试验组Ⅰ 50头母牦牛隔离断奶后进行同期发情和定时授精处理;Ⅱ组50头母牦牛隔离断乳.不进行同期发情处理,发情母牛进行人工授精。人工授精冻精液为荷斯坦和野牦牛冻精。配种45d后进行怀孕诊断。Ⅰ组发情39头,发情率为78%（39/50）,怀孕34头妊娠率为68%（34/50）;Ⅱ组发情31头,发情率为62%（31/50）,怀孕27头,妊娠率为54%（27/50）。相同草场放牧50头适配母牦牛作为对照。对照组母牛和犊牛不进行隔离和短期断乳;对照组发情率为12%（6/50）,妊娠率为6.32%（3/50）。试验结果表明,通过对带犊的母牦牛实施隔离断奶,能够明显提高当年产犊母牦牛的发情率和妊娠率。     

欧宝棉栓影响小尾寒羊同期发情效果初探

为提高绵羊的同期发情效果,对河南省8家羊场的2 314只小尾寒羊采用阴道海绵栓和自制OB棉栓进行同期发情处理。结果显示：阴道海绵栓法的同期发情率66.8%（587/879）,OB棉栓法的同期发情率94.6%（1 271/1 343）,两者相差27.8个百分点,差异极显著（P〈0.01）;阴道海绵栓造成母羊阴道炎发病数243只,达27.6%,而OB棉栓未出现1例阴道炎;45-60 d妊娠率,阴道海绵栓法为49.0%,OB棉栓法为86.7%,两者差异极显著（P〈0.01）。说明自制OB棉栓用于羊的同期发情效果明显好于阴道海绵栓,同时能避免阴道炎的发生。     

应用试情小公牛提高奶牛繁殖效率试验

为了提高奶牛产后发情检出率和繁殖效率,用散户自繁的8-12月龄小公牛作为试情小公牛与母牛同圈饲养,并于比邻的单产水平接近的人工观察发情的散户奶牛繁殖效率进行对比。结果表明：试情小公牛组和人工观察发情组奶牛85 d以内配妊率分别为81.13%（43/53）和70.27%（26/37）,差异不显著（P〉0.05）;120 d内配妊率分别为93.06%（67/72）和79.59（39/49）,差异显著（P〈0.05）;年度总受胎率分别为97.22%（70/72）和82.14%（46/56）,差异显著（P〈0.05）。说明应用8-12月龄尚未达到性成熟的试情小公牛,通过爬跨等多种直接刺激可提高奶牛发情检测效率和繁殖效率,缩短产犊间隔,增加经济效益。     

不同季节绒山羊同期发情效果研究

 试验旨在研究不同季节绒山羊同期发情处理效果,为绒山羊胚胎移植和绒山羊养殖采用新繁殖技术实现集约化、工厂化生产管理提供配套技术。在2007~2008两年期间的四个季节,利用孕激素阴道栓（CIDR）+孕马血清（PMSG）方法,对766只绒山羊进行同期发情处理,48 h内有730只羊发情,发情羊第7 d在进行绒山羊胚胎移植时观察卵巢卵泡发育及排卵情况。结果表明：春、夏、秋、冬季绒山羊的同期发情率分别为94.08%、90.59%、97.54%、92.68%,平均为95.30%。经X2检验,秋季与夏季绒山羊的同期发情率（P＜0.01）存在显著差异,其它季节绒山羊的同期发情率（P＞0.05）差异不大。春、夏、秋、冬季发情绒山羊的排卵率分别为92.31%、90.91%、95.20%、91.23%,平均为93.56%。经X2检验,四个季节发情绒山羊的排卵率（P＞0.05）没多大差异。试验结果表明在四个季节对绒山羊采用的CIDR+ PMSG同期发情处理方法可行,发情率和排卵率均在90%以上,效果好且稳定。季节虽然对绒山羊同期发情率有一定影响,但对发情绒山羊排卵率影响不大。     

同期发情技术在规模化奶牛场中的应用

目的 为探讨同期发情技术在规模化奶牛场中的应用方案。方法 分别采用3 种不同处理方法对产后80 天奶牛进行同期发情处理,试验结束后比较不同处理方法对奶牛发情率和受胎率的影响。结果 试验A组、B组和C组的发情率分别为72.50%、80.00%和87.50%;受胎率分别为62.07%、65.63%和68.57%,其中试验C组的发情率显著高于另外两组（P<0.05）。结论 同情发情技术的推广可以大大提升奶牛养殖业的经济效益,且在本试验条件下,试验C组的同期发情效果最优。     

绵羊同期发情和两年三羔生产技术的应用研究

为了提高绵羊繁殖效率,研究绵羊同期发情和两年三羔生产技术,试验一采用两次肌肉注射PG法和CIDR+PMSG法分别对蒙古羊和小尾寒羊在繁殖季节和非繁殖季节进行了同期发情处理。结果表明：在繁殖季节,两次PG法对蒙古羊的发情率为85.71%,对小尾寒羊的发情率为93.75%,两者之间差异不显著（P>0.05）;CIDR+PMSG法对蒙古羊的发情率以PMSG剂量200 IU最佳,发情率为92.00%;对小尾寒羊的发情率以PMSG剂量250 IU最佳,发情率为93.75%。在非繁殖季节,两次PG法对蒙古羊的发情率为57.14%,对小尾寒羊的发情率为65.63%,两者之间差异不显著（P>0.05）;CIDR+PMSG法对蒙古羊的发情率以PMSG剂量250 IU最佳,发情率为89.29%,对小尾寒羊的发情率以PMSG剂量300 IU最佳,发情率为93.33%,两者之间差异不显著（P>0.05）,但均极显著高于两次PG法（P<0.01）。试验二应用同期发情技术和羔羊早期断奶技术分别对蒙古羊和小尾寒羊进行处理。结果表明：实施两年三羔繁殖技术,蒙古羊和小尾寒羊的受胎率分别为88.4...     

虫草真菌发酵中草药对母猪繁殖性能的影响

试验1随机选择正常发情母猪120头分为4组,试验2随机选择乏情母猪90头分为3组,研究虫草真菌发酵中草药对母猪繁殖性能的影响。结果表明,正常发情母猪饲粮中添加虫草真菌发酵中草药800、1 000和1 200克/吨,于断奶前后各喂7天,与对照组相比,断奶至发情间隔分别提前1.2、1.3和1.3天（P〈0.05）,乏情率分别降低71.41%（P〈0.05）、85.73%和85.73%（P〈0.01）,产仔数分别提高8.33%、10.71%和10.12%（P〈0.05）,产活仔数分别提高9.24%、9.64%和8.83%（P〈0.05）。乏情母猪注射孕马血清和饲粮中添加虫草真菌发酵中草药1 000克/吨,连续饲喂20天,与对照组相比,断奶至发情间隔分别提前10和8天（P〈0.05）,发情率分别提高999.40%（P〈0.05）和1 299.25%（P〈0.01）,产仔数分别提高9.39%和12.27%（P〈0.05）,产活仔数分别提高13.89%和16.05%（P〈0.05）。结果提示：虫草真菌发酵中草药（商品名＂赚二头＂）能够显著缩短母猪断奶至发情间隔,降低乏情率,提高产仔数和产活仔数。     

肉牛同期发情效果影响因素的研究

[目的]为了研究同期发情处理方法、繁殖状况、品种、体重等对肉牛同期发情效果的影响,[方法]选择140头不同繁殖状况、品种、体重的肉牛,随机分为3组,分别采用CIDR+第10天肌注PMSG+第11天肌注PGF_2α（埋栓Ⅰ组）、CIDR+第9天肌注PMSG+第11天肌注PGF_2α（埋栓Ⅱ组）、肌注PGF_2α+PMSG(PGF_2α组)的方法进行同期发情处理。[结果]3种不同处理方法相比,PGF_2α组发情率为87.10%,埋栓Ⅰ组、Ⅱ组母牛发情率分别为97.83%、98.41%,显著高于PGF_2α组（P<0.05）;PGF_2α组处理牛受胎率为83.87%,埋栓Ⅰ组、Ⅱ组处理牛受胎率分别为89.13%、84.13%,高于PGF_2α组,但差异不显著（P>0.05）;育成牛与经产牛发情时间相比,埋栓组12～24 h内出现发情症状的经产牛占比为27.27%,育成牛占比为60%,显著高于经产牛（P<0.05）,2...     

欧拉羊同期发情处理方法研究

为了研究欧拉羊群在春秋两季规模化同期发情效果,利用CIDR＋PG法及两次PG法对大群体舍饲和半舍饲欧拉羊进行同期发情实验,比较不同处理方法的同期发情效果、不同季节对同期发情效果及不同饲养方式的发情效果。结果表明：采用CIDR＋PG法同期发情率为92.3%,与两次PG法同期发情率78.7%,差异显著（P〈0.05）;采用两次PG法在春季、秋季对欧拉羊同期发情处理,春季与秋季欧拉羊的0～48h同期率分别为73.3%、76.5%,差异不显著（P〉0.05）;对不同饲养方式的欧拉羊同期发情处理,舍饲养殖的欧拉羊0～48 h的同期发情率为58.0%,放牧＋舍饲同期发情率为78.9%差异显著（P〈0.05）。     

水牛发情期唾液生殖激素和结晶与卵泡发育的关系

本研究旨在探明水牛唾液生殖激素、唾液结晶和卵泡发育变化的规律。应用ELISA试剂盒测定水牛唾液和血清中的生殖激素,制作唾液结晶,并分析生殖激素和唾液结晶与卵泡变化的关系。运用唾液结晶法、直肠检查法、唾液结晶+B超法、直肠检查+B超法4种方法在生产中进行验证。结果表明,水牛发情当天唾液雌激素（E₂）的水平为233.51 pg/mL,达到一个峰值,随后开始缓慢降低。水牛唾液中孕激素（P₄）水平在发情前2 d达到16.17 ng/mL,发情当天降到8.91 ng/mL。促卵泡素（FSH）在水牛发情前2 d逐渐下降,从37.91 ng/mL降到34.64 ng/mL,但在发情2 d后逐渐升高,达到61.20 ng/mL。促黄体素（LH）在发情前1 d逐渐下降,从5.15 ng/mL降至发情当天4.12 ng/mL,但在发情1 d后升至5.77 ng/mL。B超监测卵巢卵泡从发情前2 d迅速生长,到发情当天达到20 mm大小,直到破裂排卵卵泡的大小变化不显著。排卵后形成黄体,黄体期一直维持到下次发情前4 d左右,期间在发情后14~17 d的黄体最大,与水牛唾液中LH分泌峰一致。唾液结晶+B超鉴定方法判定的发情率最高（86.67%）,与其他几种方法比较差异显著（P<0.05）;妊娠诊断结果也表明,唾液结晶+B超鉴定方法判定的妊娠率（61.53%）显著高于直肠检查法、唾液结晶法和直肠检查+B超法3种方法鉴定的结果（P<0.05）。综上所述,卵巢上卵泡的发育与唾液中生殖激素的浓度显著相关,发情当天唾液结晶呈现典型的树枝状,唾液结晶+B超法的发情鉴定准确率最高。     

Plasma LH, Ovulation and Conception Rates in Cats Mated Once or Three Times on Different Days of Oestrus

Although cats are induced ovulators, the relationship between the day of breeding, the number of matings and the likelihood of ovulation and conception have not been extensively investigated. In this experiment, cats were mated either once or three times on day 1 or day 5 of oestrus to study the incidence of the LH surge, ovulation and conception rates. The percentage ovulating and the conception rates after a single mating on day 1 of oestrus were 60% (6/10) and 33.3% (2/6), respectively, and for cats mated once on day 5 of oestrus were 83.3% (10/12) and 40% (4/10), respectively. When cats were mated three times on day 1 of oestrus, the ovulation rates and conception rates were 70% (7/10) and 85.7% (6/7), respectively, and for those mated three times on day 5 of oestrus were 100% (10/10) and 100% (10/10), respectively. The concentration of LH did not increase in non-ovulating cats, and cats that were mated three times had LH concentrations that were numerically higher than those that were mated once. Litter size was neither related to the day of mating nor to the number of matings. Although an increase in the number of matings on day 1 of oestrus produced a numerically larger LH surge, it did not increase the ovulation rate, suggesting that plasma oestradiol concentrations were not sufficiently elevated to induce a high pituitary response to mating stimulation. The conception rate after a single mating was low, suggesting that the number of sperm per mating was not sufficient. These results suggest that mating more than once in the middle of oestrus is required to improve ovulation rates and conception rates in cats.     

母牛发情的季节性规律初探

通过对甘州区1997～2006年十年发情授配母牛数的逐月统计分析,以揭示母牛发情随季节、温度的变化规律.结果发现一年中,发情母牛1月所占的比例最小,只有3.5%;9月最高,达14.0%;按季节分布看,12、1、2月所占比例最小,只有全年的12.81%,7、8、9月所占的比例最高,为38.0%,其中8、9月间差异不显著,与7月间差异显著(P＜0.05),与其它各月间差异极显著(P＜0.01),显示母牛发情具有明显的季节性.将月平均温度与发情母牛所占的比例进行相关性分析可知相关系数(r)为0.869,说明温度与母牛发情呈正相关(t＜0.01).     

An evaluation of milk temperature measurement for detecting oestrus in dairy cattle. II variations in body and milk temperature associated with oestrus

Vaginal and milk temperatures were measured at each milking in 15 postpartum Friesian cows showing recurrent oestrous cycles for a total of 33 oestruses. A significant increase (P<0.001) in both vaginal and milk temperature of 0.29±0.05°C was shown between the milking prior to oestrus and the milking when oestrus occurred. Cows were divided into 3 groups: showing either a definite temperature rise (27% of cases), a limited temperature rise (60%) or no temperature change (13%) associated with oestrus. Various methods of analysis were investigated to determine the usefulness of the milk temperature data for oestrus prediction. The optimum compromise of high oestrus detection rate (73.3±16%) and lowest percentage of false positives (10.8±3.0%) was based on a temperature rise on the day of oestrus of 0.2°C over the corresponding mean temperature of the preceding three days. These rates suggest the measurement of milk temperature is less useful for oestrus prediction than some earlier reports have indicated.     

Resynchrony of previously anoestrous cows and treatment of cows not detected in oestrus that had a palpable corpus luteum with prostaglandin F(2 alpha)

AIMS: To determine if resynchrony, using a progesterone (P4) / oestradiol benzoate (ODB) regime, of previously treated, anovulatory anoestrous (AA) cows would increase the probability of oestrus, conception and pregnancy compared to no resynchrony. Additionally, the effect of prostaglandin F2alpha (PG) treatment of cows not detected in oestrus, but in which a corpus luteum (CL) was palpable transrectally (NDO/CL+), was compared with no treatment. METHODS: Cows not detected in oestrus by 1 week before the start of the seasonal breeding programme were categorised as AA or NDO/CL+, based on absence or presence of a palpable CL, respectively. All AA cows were treated with an intravaginal device containing 1.36 g P4 (CIDR-B) for a period of 6 days, and with 1 mg ODB by intramuscular (I/M) injection 1 day after the device was removed (Day 0). Half the AA cows that were detected in oestrus between Days 0 and 3 were randomly assigned to be resynchronised by reinsertion of a clean used CIDR-B device on Day 15, for a period of 6 days, followed by an I/M injection of 0.5 mg ODB, 1 day after the device was removed (resynchrony, RS), while the other half were not resynchronised (no-RS). NDO/CL+ cows were alternately assigned to be either treated with 25 mg of the PG, dinoprost tromethamine, on Day 0 or left as untreated controls (Con). RESULTS: Resynchrony increased the percentage of cows detected in oestrus between Days 14 and 28 (212/282 = 75.2% vs 155/285 = 54.4%, for RS vs no-RS, respectively; p<0.001), but had no effect on conception rate to a service within the first 3 days of the mating period (146/397 = 36.8% vs 148/399= 37.1%, for RS vs no-RS cows, respectively; p>0.9), or to a service between Days 14 and 28 (84/159 = 52.8% vs 114/217 = 52.5%, for RS vs no-RS cows, respectively; p>0.9). Resynchrony increased the Day 28 pregnancy rate (264/432 = 61.1% vs 237/435 = 54.5%, for RS vs no-RS cows, respectively; p=0.03), but had no effect on the Day 56 or final pregnancy rates (p>0.1).Prostaglandin treatment of NDO/CL+ cows did not affect the percentage of cows detected in oestrus by Day 7 (43/106 = 40.6% vs 51/101 = 50.5%, for Con vs PG, respectively; p=0.15), or Day 28 (92/106 = 86.8% vs 91/101 = 90.1%, for Con vs PG, respectively; p>0.4). Treatment did not affect the Day 28 pregnancy rate (55/103 = 53.4% vs 54/98 = 55.1%, for Con vs PG, respectively; p>0.9), the Day 56 pregnancy rate (81/103 = 78.6% vs 74/98 = 75.5%, for Con vs PG, respectively; p>0.6), or the final pregnancy rate (98/103 = 95.1% vs 89/97 = 91.8%, for Con vs PG, respectively; p>0.3). CONCLUSIONS: Resynchrony of AA cows treated using the present protocol increased the proportion of non-pregnant cows detected in oestrus between Days 14 and 28 and increased the Day 28 pregnancy rate. This resynchrony protocol may be useful for increasing the proportion of the herd pregnant in the first month of the breeding programme, especially in herds that have a history of a low proportion of non-pregnant cows detected in oestrus between Days 14 and 28. There was no benefit in treating NDO/CL+ cows with PG compared to no treatment. KEYWORDS: Dairy cows, anoestrus, treatment, resynchrony, prostaglandin, progesterone, oestradiol benzoate.     

伊维菌素干混悬剂对羊狂蝇蛆的驱杀效果试验

选择自然感染羊狂蝇蛆绵羊131只,分别按体重0.1,0.2和0.3mg/kg剂量口服伊维菌素干混悬剂,进行驱除效果观察,同时设空白对照组。结果表明,口服伊维菌素干混悬剂0.2,0.3mg/kg剂量组绵羊的羊狂蝇蛆驱净率和驱虫率均达100%。口服0.1mg/kg剂量组绵羊的羊狂蝇蛆驱净率93.9%、驱虫率98.6%。试验证明伊维菌素干混悬剂对羊狂蝇蛆驱虫效果明显,临床使用0.2mg/kg体重剂量高效安全。     

人工授精+胚胎移植法诱发肉牛双胎的试验研究

应用AI ET法分别对三组试验牛进行处理,人工诱导生产肉牛双胎,双胎率达60.8%(79/130),产犊率147.7%(192/130)。其中试验组2(自然发情后AI ET)双胎率达66%(33/50),产犊率150%(45/30),显著提高了母牛的繁殖率。     

The Effect of Intravaginal Applied GnRH-agonist on the Time of Ovulation and Subsequent Reproductive Performance of Weaned Multiparous Sows

In order to prove the effect of 'fixed time insemination' and insemination at standing oestrus after post-weaning application of GnRH, in a Croatian large breeding unit, 502 sows were assigned to three groups and were artificially inseminated (AI) at their first post-weaning oestrus as many times as they stand, in 24-h intervals. The groups were treated as follows: group 1 (control, n = 160) were AI during their standing reflex; group 2 ['GnRH-fixed time insemination' (GnRH-FT-AI), n = 175] were AI, independent of detection of oestrus and following administration of GnRH-agonist at 96 h post-weaning; group 3 [GnRH insemination at standing oestrus (GnRH-OE-AI), n = 167] the animals were GnRH-agonist treated as group 2 and were AI at their standing reflex. Pre-trial daily average lactational feed intake, average daily feed intake from weaning to oestrus, oestrus within 6 days post-weaning (%), ovulation within 6 days post-weaning (%), weaning-to-oestrus interval (h), duration of oestrus (h), follicle size (mm), interval from oestrus to ovulation (h), subsequent day 24 pregnancy rate (%), farrowing rate (%) and total pigs born were evaluated. Pre-trial average daily lactational voluntary feed intake was 7.1 +/- 0.08 kg in group 1, 7.0 +/- 0.07 kg in group 2 and 7.1 +/- 0.17 kg in group 3 (p > 0.05). Average voluntary daily feed intake from weaning to oestrus was 5.1 +/- 0.3 kg in group 1, 5.2 +/- 0.5 kg in group 2 and 5.2 +/- 0.19 kg in group 3 (p > 0.05). Oestrus was detected within 6 days post-weaning in 134 (83.8%) in control, 164 (93.7%) in GnRH-FT-AI and 155 (92.8%) animals in GnRH-OE-AI groups (p = 0.05). Follicle size did not differ (p > 0.05) among the groups. In control 82.8%, in GnRH-FT-AI 91.5% and in GnRH-OE-AI 91.0% of the sows ovulated within 6 days post-weaning (p = 0.04), and had 80.6, 90.9 and 89.7% 24-day pregnancy rates (p = 0.16), respectively. In GnRH-FT-AI group 90.2%, in GnRH-OE-AI sows 89.7%, in control animals 79.9% farrowing rates were recorded (p = 0.17). Weaning to oestrus interval was 113.1 h in control, 114.1 h in GnRH-FT-AI and 112.6 h GnRH-OE-AI (p > 0.05). Duration of oestrus was significantly shorter in GnRH-FT-AI (44.9 h) and GnRH-OE-AI (48.1 h) animals, compared with the control (62.9 h) sows (p = 0.001). Similarly, the interval from oestrus to ovulation revealed significant (p = 0.004) differences between the groups (control 44.1 h, GnRH-OE-AI 34.1 h and GnRH-FT-AI 32.9 h). GnRH-FT-AI (12.5) and GnRH-OE-AI (12.6) sows had significantly higher (p = 0.01) number of total pigs born (n = 10.4) compared with control sows. GnRH-agonist-gel treatment to the sow shortens duration of oestrus, the interval from oestrus to ovulation, and may eliminate the need for oestrus detection in the hands of skilled personnel.     

Prostaglandin F2α Treatment Associated with Timed Artificial Insemination in Ewes

Traditional treatments of two prostaglandin F2 alpha (PGF2alpha) doses at 10-day intervals or more did not result in acceptable pregnancy rates in timed artificial insemination (TAI) programmes in ewes. An explanation might be the undefined time-period of the onset of oestrus and ovulation after the treatment. Recently a consistent interval to oestrus and ovulation was obtained by giving PGF2alpha at day 3 post-ovulation, i.e. when the largest follicle of the first follicular wave of the cycle was still growing. This can be achieved when a second dose of PGF2alpha is given 7 days after a first dose. In this work, we evaluated the synchronization of oestrus and determined which of three different moments of TAI was the most successful using a PGF2alpha (PG-7d) protocol in a large flock. A total of 436 nulliparous and multiparous ewes were treated with two doses of a PGF2alpha analogue (delprostenate 160 microg, i.m.) separated by 7 days. Onset of oestrus was recorded twice a day and a single cervical TAI with fresh undiluted semen was performed either at 42 h (n = 152), 48 h (n = 120), or 54 h (n = 164), after the second PGF2alpha dose without taking into account the oestrous response. Pregnancy rate was determined by transrectal ultrasonography 30 days after insemination. Onset of oestrus was detected in 308 of 328 and 89 of 108 multiparous and nulliparous ewes, respectively (p < 0.001), within 72 h after treatment. The distribution of the onset of oestrus did not differ between multiparous and nulliparous ewes and the highest proportion of ewes in oestrus was detected between 25 to 48 h (313/397) from the second PGF2alpha dose. The pregnancy rate in ewes inseminated at 42 h tended to be higher than those inseminated at 48 h (p = 0.09) and was higher than those inseminated at 54 h (p < 0.05) (56/152, 31/120, 37/164; respectively). Therefore, the use of the PG-7d protocol resulted in a very high synchronization of oestrus with the highest concentration (around 80%) between 25 to 48 h from the end of treatment. The best pregnancy rate (37%) was obtained after a single cervical TAI with fresh semen at 42 h.     

Fertility of N'dama and Bunaji Cattle to Artificial Insemination Following Oestrus Synchronization with PRID and PGF2α in the Hot Humid Zone of Nigeria

A study was undertaken to determine the effectiveness of a progesterone-releasing intravaginal device (PRID) and prostaglandin F2 alpha (PGF2alpha) in synchronizing oestrus in N'dama and Bunaji cows and heifers and the fertility following artificial insemination at the synchronized oestrus. A total of 116 cows and heifers (58 N'dama and 58 Bunaji) were used in two separate trials. In the first trial, oestrus was synchronized using a PRID, which was inserted for 12 days; in the second trial, oestrus was synchronized by giving two injections of PGF2alpha 13 days apart. Only animals that did not respond to the first injection were given the second injection. At the end of each treatment period, the animals were observed for oestrus for 7 days and inseminated approximately 12 h following detection of oestrus. Standing to be mounted was the single criterion used to judge an animal to have been in oestrus. PGF2alpha and PRID were both effective in synchronizing oestrus in N'dama and Bunaji cows and heifers. The respective oestrus response rates, pregnancy rate and conception rates for PRID and PGF2alpha were 85.7%, 53.6% and 62.5% for PRID, and 91.7%, 68.3% and 74.6% for PGF2alpha. N'dama cattle showed significantly (p<0.05) better oestrus response rate, pregnancy rate and conception rate than Bunaji cattle following both PRID and PGF2alpha treatments. The pregnancy rate and conception rate following PGF2alpha treatment were better (p < 0.05) than for PRID, although the oestrus response rate did not differ. It is concluded that both PRID and PGF2alpha are effective in synchronizing oestrus in N'dama and Bunaji cattle in the hot humid zone of Nigeria and the fertility to artificial insemination at the synchronized oestrus was normal and acceptable. Thus, PRID and PGF2alpha can effectively be used in intensive breeding programmes for the rapid multiplication and distribution of both cattle breeds, especially the N'dama, which is a unique and beneficial animal genetic resource for the tsetse infested hot humid zone of Nigeria.     

应用智能监控系统改善大型牧场奶牛繁殖性能的探讨

本试验旨在探讨应用智能监控系统对荷斯坦泌乳牛发情揭发率和受胎率的改善情况.试验选用澳亚集团东营神州澳亚四场的2 237头泌乳天数为40～200d的各胎次荷斯坦泌乳牛,随机分为2组,未佩带项圈的806头为对照组,另一组佩带有项圈的1 431头为试验组.对照组依靠尾根涂蜡笔进行发情揭发,试验组依靠智能监控系统进行发情揭发,...