后备牛的生长发育

在国企奶牛经济调查中,我们注意到,国有奶牛场后备牛的生长发育状况普遍较好,但饲养费用普遍偏高,已成为奶牛场经济负担之一。有些奶牛经营者主张减少后备牛的饲养量,以求降低生产成本,提高经济效益。上述问题,我们在调查中将后备牛的生长发育列为专题进行分析,以求得对此问题的正确认识。１　现状奶牛的世代间隔一般４～５年,比较１９９７年与１９９３年调查资料的表形值差异,可看出一些问题。１．１　初生犊母牛的体高、体重：１９９７年１９７６头犊牛的平均体高７６９９厘米,比１９９３年２４３０头的７４８６厘米增加２…     

獭兔在美姑县的繁殖性能及生长发育

獭兔在美姑县的繁殖性能及生长发育美姑县草原站吉拉维石，俄尔主日，吉色衣服本站先后从四川省草原研究所核心种獭兔场，引进种獭兔，通过三年的词养繁殖，并对其繁殖性能及生长发育指标、疫病发生情况进行观察测定，结果表明，獭兔在本地区适应性强，繁殖成活率高，生长...     

成都麻羊生长发育及繁殖性能研究

在四川省成都麻羊育种场测定成都麻羊的生长发育和繁殖性能。结果表明，成都麻羊初生体重公羔为２．１２±０．５５ｋｇ，母羔为１．９８±０．５３ｋｇ；２月龄断奶体重公羔为８．８９±１．８０ｋｇ，母羔为８．５３±１．９１ｋｇ；周岁公羊为２８．４６±８．３８ｋｇ，母羊为２４．７０±５．２５ｋｇ；成年公羊为３９．９８±５．１５ｋｇ，母羊为３１．８５±４．４８ｋｇ。成都麻羊初情期为４０多日龄，初配年龄公羊为７～８月龄，母羊为６～７月龄，初配时体重为１５～２０ｋｇ；发情周期为２０～２２天，持续期２～３天，妊娠期１４２～１４５天，多一年２胎，各胎平均产羔数为１．９２只。     

大格勒乡小尾寒羊生长发育和繁殖性能观测

大格勒乡小尾寒羊生长发育和繁殖性能观测吴履田，文燕（执笔），王烈煜（格尔木市畜牧兽医站８１６００６）１９９０年我市从民和县引进小尾寒羊２５只（公２只，母２３只）在大格勒乡饲养，到１９９３年底已发展到３７５只。大格勒乡在格尔木市以东约９０ｋｍ处，海拔高...     

汉小梅母猪的生长发育和繁殖性能观察

汉小梅母猪是由小型梅山猪与瘦肉型汉普夏猪的二元杂交母猪.在小型梅山猪的开发利用研究中发现,汉小梅肉猪后腿是加工优质火腿的上等原料;由汉小梅母猪与大约克公猪杂交生产的约小梅肉猪瘦肉率较高,作为中猪出口香港受到欢迎。为了更好地指导约汉小梅瘦肉型商品猪生产。现将数年来积累的资料整理总结如下.一、资料来源本文主要依据1984年以来嘉定县种畜场观察的科研资料,以及嘉定县种畜场、松江县种畜场、松江县五里塘乡种畜场等三个场的汉小梅母猪的生产记录整理而成。     

辐照乳饼对昆明种小鼠生长发育和繁殖性能的影响

乳饼经真空包装后用60Co分别进行8 kGy和16kGy剂量辐照,分别在小鼠基础饲料中按10%和20%添加未辐照乳饼、8 kGy、16 kGy辐照乳饼作为对照组和剂量组,进行昆明种小鼠生长发育和繁殖实验。结果表明,乳饼经8 kGy,16 kGy辐照后并未对小鼠的生长发育和繁殖性能产生不良影响。     

法系獭兔繁殖性能和生长发育的研究

自 80年代以来的七、八年间，我国由美、德等国先后引进獭兔近 4 000只，由于管理混乱，只倒种不育种，导致体形变小，生长缓慢，繁殖力下降等品种退化现象的发生。据报，成年獭兔体重仅有 1． 5kg，而皮张合格率还不到 50％。近年随着政府对引入数量的控制，对科研经费投入的增大，加之獭兔综合开发市场的规范，同时通过育种工作者的辛勤工作，有望改观这一被动局面。本研究根据引入法系獭兔的选育资料，分析了繁殖性状和部分生长发育性状，为选种及饲养管理提供依据。 1材料与方法 1． 1材料 　　来自山东省荣成市玉兔牧业有限公司獭兔育…     

近交对黑白花奶牛生长发育及繁殖性能影响的研究

据78头黑白花奶牛资料计算各个体近交系数,并分为12.50、6.25、3.125、1.5625和0%五个水平组,分别统计各组牛的初配日龄、1—5胎产后空怀期、产犊间隔、妊娠配种次数、分娩正产率、初生及一胎的体重体尺。各水平组均与0%组作方差分析比较。试验结果表明:12.5%组牛的初生体重、体高、胸围、管围均显著较低,分别比非近交     

云南黄牛的生长发育与繁殖性能调查

云南黄牛的公牛初生、6月龄、1岁、1.5岁、2岁和5岁体重分别为17.40 kg±3.32 kg、107.88 kg±24.65kg、158.57 kg±25.08 kg、223.82 kg±27.99 kg、264.72 kg±27.57 kg和407.50 kg±29.58 kg,母牛相应的体重分别为16.41 kg±2.31 kg、100.10 kg±21.10 kg、146.74 kg±21.90 kg、209.18 kg±19.32 kg、249.32 kg±26.51 kg和356.40 kg±20.14 kg.青年母牛初配年龄为613.67 d±115.53 d,初配体重222.36 kg±38.39 kg,产第一胎年龄925.13 d±116.10d,妊娠期286.50 d±8.51 d;繁殖母牛妊娠期为288.23 d±5.54 d,产犊间隔368.46 d±29.48 d.     

夏洛来母牛生殖性能及利用年限观察

对法系纯繁夏洛来母牛生殖性能的统计表明:初情期平均13.0±1.89月龄,性成熟期平均14.62±2.6月龄,始配年龄21.56±1.23月龄,绝情期15岁左右;发情周期平均20.51±8.49d,卵泡出现至排卵结束约39.26±8.28h;妊娠期平均283.91±8.05d;犊牛初生重43.49±6.85kg;产后发情平均71.18±49.25d;产犊间隔平均452.26±124.59d。母牛淘汰年龄平均94.77±40.84月龄,利用年限平均69.94±40.66月龄,终生产犊4.78±2.95头。     

Effect of the bovine viral diarrhoea virus (BVDV) infection on dairy calf rearing

The aim of this study was to compare the cumulative incidence of mortality, clinical diarrhoea and respiratory disease in calves, during their first six months of age, in herds with different bovine viral diarrhoea virus (BVDV) infection status. Calves’ health indicators were tested by comparing proportions in 101 farms with dissimilar infection condition. The results indicate that there was a significant relationship between the BVDV status (actively infected herd or not) and the cumulative incidence of mortality and respiratory disorders.     

饲用苎麻粉对母兔繁殖性能的影响

试验旨在研究日粮中添加不同水平饲用苎麻粉对母兔繁殖性能的影响.选择第3胎的空怀新西兰母兔480只,随机分为4组,每组6个重复,每个重复20只.对照组日粮不含苎麻粉,试验组分别饲喂含8％、16％和24％饲用苎麻粉的日粮.试验期从空怀母兔配种前3周开始直至仔兔断奶结束.结果表明:日粮添加苎麻粉对母兔空怀和妊娠期采食量影响不...     

早期断奶后备母牛繁殖效果研究

选择后备母牛１８头，每组各６头，采用不同的日粮饲喂，进行对照试验，结果试验１组后备母牛初情月龄平均为１０．３个月，第一、二情期受胎率８３．３％，繁殖成活率８３．３％。试验２组后备母牛初情期平均为１１．１个月，第一、二情期受胎率６６．７％，繁殖成活率６６．７％。对照组后备母牛初情期平均为１２．７个月，一、二情期受胎率５０．０％，繁殖成活率５０．０％。     

环境温湿度对母猪繁殖性能的影响

浙江中白母猪繁殖成绩与地面温湿气象资料相结合进行统计分析的结果表明,母猪在60天哺乳期饲养制度下,产后发情并配种受孕平均需66.57天。其中离仔后配种占75.41％,就这部分母猪而言,离仔次旬平均日最高气温超过30℃或RH78％以上或THI值大于75,离猪后7天内的受孕率显著降低;配种时和配种后20天内受高温剌激,胎几发育数减少,平均气温25℃以上时的窝仔数(11.73头、11.83头)较20—25℃条件下少0.68头和0.37头;产前当旬处于高温的,产仔成活率较高;20日龄仔猪存活率以出生后次旬环境温度在20℃以上或THI值大于65时为高,而35—45日龄时的环境温湿度对20—60日龄仔猪存活率影响不明显。     

营养对黄牛繁殖机能的影响

本文就当前饲喂胚胎移植受体黄牛大量低质粗饲料日粮为出发点,通过对常见粗饲料及其营养成分分析,受体黄牛体内胚胎着床机制的探讨以及分析各营养因素对受体黄牛受胎率的影响。目的在于阐明饲喂大量低质粗饲料对受体黄牛受胎率的影响,进而找出合理的解决办法,既能合理利用廉价的低质粗饲料,又能提高受体黄牛的移植受胎率。     

采用犊牛短期断乳方式提高牦母牛繁殖性能的试验

对90头带犊大通母牦牛进行了犊牛短期断乳试验.试验组母牦牛在产犊后3月龄时,实行为期10d的短期断乳,断乳后母牦牛有81头发情,发情率90%,第二年产犊78头,繁殖率86.67%.对照组为带犊,但不断乳的母牦牛,试验期共发情2头,发情率2.22%,产犊2头,繁殖率2.22%.试验组母牦牛的发情率和繁殖率比对照组分别提高了87.78%和84.45%(P＜0.01)     

獭兔生殖器官生长发育规律研究

选择15、30、60、90、120日龄獭兔进行屠宰,测定其睾丸、附睾、阴茎、卵巢、子宫等主要生殖器官的长度和质量,研究獭兔生殖器官发育规律。结果表明：睾丸、附睾、卵巢和子宫生长发育的高峰期均在60-90日龄,阴茎的发育高峰在90日龄以后,且发育平缓。     

大豆黄酮对犊牛生长性能及免疫机能的影响

研究大豆黄酮对犊牛生长发育及免疫机能的影响。方法是选取16头犊牛随机分为两组,分别于鲜奶中添加0g／（d·头）、2．5g／（d·头）大豆黄酮。试验前后采血,采用ELISA分析血浆q-T3、T4、IgG、IgA等指标。试验结果表明,大豆黄酮能明显提高血浆中的T3、T4、IgG、IgA水平。结果显示大豆黄酮可能参与了犊牛的免疫调节过程,可提高犊牛的体液免疫水平。     

Effects of Hand-Fed Versus Self-Fed Fat Supplementation on Growth and Reproductive Performance of Developing Beef Heifers

Growth and digestion trials were conducted to determine the efficacy of supplemental fat for developing beef heifers consuming a bromegrass hay-based diet. In Exp. 1, Angus x Gelbvieh heifers were allotted to one of three treatments in a randomized complete block design experiment for 2 consecutive yr (yr 1: n = 88, BW = 263.6 ± 0.6 kg; yr 2: n = 56, BW = 276.8 ± 3.1 kg). Supplemental treatments included a hand-fed corn- and soybean meal-based supplement (CRN), a hand-fed corn- and soybean meal-based supplement containing 15% soybean oil (OIL), or a self-fed tub supplement containing 16.7% (as fed) soapstocks (TUB). Heifers were inseminated and diagnosed for pregnancy following the conclusion of the feeding period. For Exp. 2, IVDMD and volatile fatty acids (VFA) were determined using the proportions of hay and supplement that heifers consumed in Exp.1, yr 1. Treatment differences for Exp. 1 and 2 were evaluated using the single degree of freedom orthogonal contrasts, CRN + OIL vs TUB and OIL vs TUB. Total feed intake tended to be less (P=0.09) for heifers on the TUB treatment in Exp. 1, yr 1; however, hay intake was greater (P=0.02) for heifers on the TUB treatment than for hand-fed heifers. In both years, hand-fed heifers had greater ADG (P≤0.02) and BW gain efficiencies (P≤0.005) than did heifers on the TUB treatment. Average daily gain and gain efficiency were also greater (P≤0.02) for heifers on the OIL treatment than for heifers on the TUB treatment in yr 1 and 2. Overall pregnancy rate was greater (P≤0.03) for heifers on CRN and OIL than for heifers on the TUB treatment (93.2% vs 72.4%) in yr 1. In yr 2, however, overall pregnancy rates were similar (P=0.30) among all treatment groups. In Exp. 2, IVDMD was greater (P=0.002) for hand-fed diets than for the TUB diet. Total VFA were not different (P=0.34) among supplement treatments; however, the acetate:propionate ratio was less (P=0.0001) for the CRN and OIL treatments compared with the TUB treatment. Less than projected intake of TUB supplement and, thus, an overall lower plane of nutrition contributed to decreased growth in both years and poorer reproductive performance in yr 1 for heifers on the TUB treatment compared with heifers that were hand-fed a supplement.