青海省三角城种羊场绵羊体内的矿物元素检测

青海省三角城种羊场绵羊块Ｎａ，Ｓｅ，Ｐ，Ｃｕ和Ｉ。夏季泌母羊唾液Ｎａ：Ｋ＝４．４：１，粪Ｎａ浓度５１０ｍｇ／ｋｇＤＭ。多数季节血浆Ｐ２为０．８０－１．１６ｍｍｏｌ／Ｌ，血浆Ｃｕ浓度为５．８２ｍｍｏｌ／Ｌ，Ｃｕ：Ｍｏ〈２：１。乳汁Ｉ一低于临界值。     

鲁梅克斯K-1杂交酸模和干玉米秸混合青贮料喂牛试验

８头４～５岁的役用秦川母牛按配对原则分为对照组和试验组。两组牛的精料配方基本相同，但试验组牛饲粮用７．７５％的鲁梅克斯Ｋ－１杂交酸模粉（以下简称鲁梅克斯Ｋ－１）代替对照组中同等重量的小麦麸；对照组牛的粗料全部用干玉米秸，试验组半用６０％干玉米秸和４０％的玉米秸＋鲁梅克斯叶混合青贮料。正试期２０ｄ。结果表明：试验组牛的平均日增重为 ０．７８７ｋｇ，对照组０．６９０ｋｇ，试验组较对照组牛日增重提高了 １４．０６％；每增重 １ｋｇ活重试验组牛消耗精、粗料分别为２．５４ｋｇ、５．２５ｋｇ，对照组半分别为２．９０ｋｇ、５．５０ｋｇ，试验组较对照组个节约精料０．３６ｋｇ、粗料０．２５ｋｇ；试验组每头牛毛盈利为７３．３４元，对照组５９．４０元，前者比后者提高经济效益２３．４７％。说明在役用母牛饲粮中，用鲁梅克斯粉代替精料中的小麦麸并用玉米秸＋鲁梅克斯混合青贮料能获得良好的生产性能和经济效益。     

利木赞牛改良秦川牛效果初报

陕西岐山农村开展利木赞牛杂交改良秦川牛,已配母牛２２３０头,已产犊１０００多头。犊牛初生重公犊平均３１．３ｋｇ,母犊平均为３０．４ｋｇ,分别比当地秦川牛犊高出２６．７％和２５．１％;６月龄体重公犊１７２．６ｋｇ,母犊１５８．９ｋｇ,分别比当地秦川牛高出２２．７％和２５．９％。说明用利木赞牛改良秦川牛效果明显。     

秸秆的微贮及喂牛试验

为充分利用当地秸秆资料，１９９５～１９９６年作者在山西吕梁地区用微贮饲料（黄干玉米秸）饲喂６０头试验牛；对照组６０头牛所喂黄干玉米秸未作任何处理，育肥９０天。精料由玉米粉５６．１％、麸皮２１．４％、棉籽饼２０％、食盐０．５％、矿物质及其它添加剂０．３％组成，两组牛精料日喂量均按平均体重的１％分两次饲喂。试验结果表明：试验组日增重为０．８９３ｋｇ，对照组为０．６５ｋｇ，试验组增重提高７２．８％。两组牛的料重比分别为８．１６％和１０．４１％，即对照组比试验组多消耗精料２７．５７ｋｇ。试验组头均盈利１１７．１元，对照为１３．４元，试验组比对照牛多盈利１０．３７元。     

不同断奶日龄对断奶仔猪生长发育的影响

选择杜长大杂交仔猪８窝共７２头，均分为两组，每组４窝３６头。试１组采用２８日龄断奶，试２组采用３５日龄断奶，试期２２ ２１日至６０日龄。结果：在试验期内，试１组仔猪腹泻１６２头次，死亡５头，６０日龄平均窝重１２４．０ｋｇ，个体重１６．０ｋｇ，２１～６０日龄采食量４２７．５ｇ／头，料重比１．８３：１；试２组仔猪腹泻１０６头次，死亡０头，６０日龄平均窝重１３２．１ｋｇ。俱本重１４．７ｋｇ，２１～６０日     

辽宁绒山羊改良宁夏土种山羊效果观察

用辽宁绒山羊改良宁夏土种山羊结果表明：１－４岁杂一代羊产绒量提高近一倍，绒长度，强度，净绒率和含绒率均有明显增加；绒毛细度增加０．４μｍ，仍属优质绒。杂一代羊绒毛中的氨基酸组成，微细结构与宁夏土种山羊相似。杂一代羊皮肤上的毛囊群由１－４个初级毛囊和若干个次级毛囊组成，次级毛囊密度比土种山羊多１２．９个／ｍｍ＾２。成年一代公，母羊抓绒后平均活重２３．８ｋｇ，比土种山羊高２．３ｋｇ；冬季平均活重３４．     

复合蛋白粉替代鱼粉饲喂育肥猪试验

采用中国人民解放军３４１９工厂研制的Ｄ、Ｆ、Ｇ号复合蛋白替代鱼粉饲喂育肥猪，经６０天试验，对照组猪头均总增重３７．５５ｋｇ、日增重０．６２６ｋｇ，Ｄ、Ｆ、Ｇ三个试验组砂均总增重３５．７４、３６．９３、３６．５７ｋｇ、，日增重０．５９６、０．６１６、０．６１０ｋｇ、Ｐ〉０．０５；每增重１ｋｇ活重，Ｄ、Ｆ、Ｇ组的饲料成本分别比对照组降低２．０％、８．７７％、５．５２％，每头猪全期可分别节省饲料费４．４     

皮埃蒙特肉牛胚胎移植及其开发利用研究报告

通过引进４０头皮埃蒙特肉牛冻胚以南阳牛母 和为受体进行胚胎移植,结果妊娠率为６０％,同期发情处理的受体黄牛,７２小时发情率为８７．８８％。胚胎牛与南阳牛比较,其体尺、体重均比南阳牛相应增大,８月龄体重胚移牛比南阳牛高６５ｋｇ（２５％）,以南阳牛作母本,以皮埃蒙特牛作父本杂交试验,结果：１８日龄肥育牛体重达５００ｋｇ,料、活重比为１．６：１,屠宰率为６１％,眠肌面积为１４１．１１ｃｍ＾２。     

驱虫对肉牛生产性能的影响研究

经调查发现云南会泽新街乡肉牛感染肝片吸虫和线虫较为严重，用丙硫苯咪唑驱虫１个月后，每１００ｇ粪便的虫卵数平均从４．５４个下降到０．７８个。通过对３２头１２～２５月龄生长牛和３０头２岁以上育肥牛的试验表明，驱虫使１２～２５月龄生长牛的日干物质采食量（ＤＭＩ）从５．３５ｋｇ提高到７．０６ｋｇ，平均日增重（ＡＤＧ）从４４３ｇ提高到６３７ｇ，２岁以上育肥牛ＤＭＩ从５．９５ｋｇ提高到６．９９ｋｇ，ＡＤＧ从５９８ｇ提高到７０３ｇ。驱虫使生长牛和育肥牛的单位增重的饲料消耗平均降低了８．３９％，但对各项生理指标无明显影响。     

秸秆的微贮及哺牛试验

为充分利用当地秸秆资料，１９９５～１９９６年作者在山西吕梁地区用微贮饲料（黄干玉米秸）饲喂６０头试验牛，对照组６０头牛所喂黄干玉米秸未作任何处理，育肥９０天，精料由玉米粉５６．１％，麸皮２１．４％，棉籽饼２０％，食盐０．５％，矿物质及其它添加剂０．３％组成，两组牛精日喂量均按平均体重的１％分两次饲喂，试验结果表明：试验组日增重为０．８９３ｋｇ，对照组为０．６５ｋｇ，试验组增重提高７２．８％，两组牛     

Comparison of crossbred cows containing various proportions of Brahman in spring or fall calving systems: III. Productivity as three-, four-, and five-year olds

Productivity of 3-, 4-, and 5-yr-old crossbred cows containing various proportions (0, 1/4, or 1/2) of Brahman breeding out of Angus or Hereford dams was evaluated using 489 spring-calving and 427 fall-calving records collected over a 4-yr period. Cows were bred to Limousin sires for the first 3 yr and to Limousin and Salers sires the 4th yr. Interactions between crossbred cow group and season of calving were not significant. Percentage of cows exposed to breeding that weaned a calf increased (P less than .01) as proportion Brahman breeding increased, was higher (P less than .01) for cows out of Angus dams than for cows out of Hereford dams, and was higher (P less than .01) for spring-calving cows. As the proportion Brahman increased, the percentage requiring assistance at birth decreased, and cows out of Angus dams required less (P less than .05) assistance than those out of Hereford dams. Preweaning ADG, adjusted weaning weight, weaning conformation, weaning condition, and adjusted weaning hip height increased a proportion Brahman breeding increased. Spring-born calves gained .12 kg/d faster (P less than .01) than fall-born calves. However, weight at weaning was similar for the two groups; spring-born calves were weaned at an average age of 205 d, and fall-born calves were weaned at an average age of 240 d. Fall-calving cows were heavier (P less than .05) than spring-calving cows, and 0 and 1/2 Brahman cows were heavier (P less than .01) than 1/4 Brahman cows. These data indicate that Brahman-cross dams can be used to improve reproductive rate and increase preweaning growth rate, and thus weaning weight.(ABSTRACT TRUNCATED AT 250 WORDS)     

Strategies of supplementation of female suckling calves and nutrition parameters of beef cows on tropical pasture

The performance of female calves in creep feeding under different strategies of supplementation and milk production, intake, and digestibility of grazing Nellore and crossbred cows (Nellore?×?Holstein) during the dry-rainy transition season were assessed. Forty-four female beef suckling calves, with initial age between 90 and 150?days and average initial body weight of 117.7?±?4.3?kg, and their respective dams (24 Nellore and 20 crossbred) with average initial body weight of 417.5?±?8.3?kg, were used. The experimental treatments consisted of: control group-mineral mixture only; strategy 1-supplementation from 112?days prior to weaning (0.375?kg/animal/day); strategy 2-supplementation from 112?days prior to weaning, in increasing amounts of 0.15, 0.30, 0.45, and 0.60?kg/animal/day through the four experimental periods, respectively; and strategy 3-supplementation from 56?days prior to weaning (0.750?kg/animal/day). Calves from strategy 1 had greater (P??0.05) for nutrient digestibility among genetic types. It can be concluded that strategies of supplementation that present an equitable distribution of supplement provides greater weight gain in suckling female beef calves. Crossbred cows produce more milk and present greater DMI than Nellore cows. There are no differences in the nutrient digestibility between Nellore and Nellore × Holstein crossbred cows.     

饲养管理方式对甘南牦牛繁殖力及杂交后代影响的研究

[目的]为了研究加强种公牛和母牦牛的饲养管理对母牦牛的繁殖效果和杂交后代生长发育的影响.[方法]本试验用大通牦牛和其冻精杂交甘南牦牛,通过对试验组的种公牛、母牦牛和杂交后代进行补饲、延长放牧时间和提前断奶等措施,研究了203头母牦牛的繁殖效果和其杂交后代的生长发育情况.[结果]表明,自然交配试验组发情率、受胎率、繁殖成活率分别比对照组提高9.19%、11.03%、14.10%,流产率和犊牛死亡率降低3.3%、3.87%;人工授精组发情率、受胎率、繁殖成活率分别提高6.74%、5.48%、10.52%,流产率和犊牛死亡率降低4.07%、4.62%.加强母牦牛的饲养管理,所产犊牛的初生重比传统饲养管理条件下母牦牛所产的犊牛初生重公母分别增加2.92 kg和2.07 kg,提高19.80%和14.22%.6月龄体重分别增加12.82 kg和12.23 kg,提高17.45%和16.88%.[结论] 用大通牦牛改良甘南牦牛,采用人工授精和自然交配都有良好的效果,加强种公牛、母牦牛饲养管理是提高牛群繁殖力的有效方法,对后代生长发育影响明显.     

Effects of age on body condition and production parameters of multiparous beef cows

Pregnancy rate, calving interval, birth weight, weaning weight, and quarterly BCS were collected for 5 consecutive years on 454 fall-calving multiparous British crossbred cattle (3 to 10 yr of age) to evaluate associations of age with BCS and production parameters. Body weight and BCS were collected pre-calving, prebreeding, at weaning, and midway through the second trimester of pregnancy (August). Body condition score was correlated with age during all seasons (P < 0.01). At calving, breeding, and in August, 3-yr-old cows had the lowest BW and BCS, whereas 8-yr-old cows had the greatest. At weaning, these values were maximal in 10-yr-old cows. Pregnancy rate was near 80% up to 9 yr of age but decreased to 57% in 10-yr-old cows. The relationship of pregnancy rate with age appears to be correlated with the BCS decrease at breeding in the older cows, supported by the fact that inclusion of BCS at breeding in the statistical model eliminated the effect of age on pregnancy rate (P = 0.42). Calving interval was longer in 3-yr-old cows compared with 4- to 9-yr-old cows (P = 0.02); however, among older cows, there was little change in the calving interval. Birth weight reached a maximum at 8 yr of age (35 +/- 0.9 kg) and a minimum in 3-yr-old cows (32 +/- 0.7 kg). Birth weights of calves born to both 3- and 4-yr-old cows were lower than for those born to 5-, 6-, 7-, or 8-yr-old cows (P < 0.05). Ten-year-old cows weaned lighter calves (205-d adjusted weaning weight) than younger dams. Furthermore, 3-yr-old cows weaned calves 9 +/- 2.1 and 14 +/- 2.4 kg lighter than 4- and 5-yr-old cows, respectively (P < 0.001). Interpretation of the age analyses of calving interval, birth weight, and weaning weight was independent of the inclusion of BCS in the model. This study documents the effects of age on calving interval, birth weight, and weaning weight that are independent of BCS.     

Nutrient intake and efficiency of calf production by two-breed cross cows

Individual consumption of total digestible nutrients (TDN) was measured on 105 two-breed cross cows (Hereford X Angus reciprocal crosses, HA; Simmental X Angus, SA; Simmental X Hereford, SH; Brown Swiss X Angus, BA; Brown Swiss X Hereford BH; Jersey X Angus, JA and Jersey X Hereford, JH) and their three-breed cross calves managed in drylot. Cows were 4 to 6 yr of age and mated to Charolais or Limousin bulls. Cows remained in the drylot for a period of approximately 1 yr (from weaning one year to weaning the next year). Ad libitum consumption of corn silage was allowed for about 4 h each day and fixed amounts of grain and protein supplement were fed as needed. Calf creep feed was provided during the latter portion of lactation. Compared with the average weight of HA cows (454 kg), SA cows were 7% heavier, SH, BA and BH cows were similar, while JH and JA cows were 15 and 22% lighter in weight, respectively. Total intake of TDN by cow and calf for the 365-d drylot period was greatest for the SA group (2,309 kg), exceeding that of the HA group by 11.2%. The JA group consumed 7.2% less than HA, while other groups were similar to HA in TDN intake. Daily intake of TDN for the 365-d period, expressed as a percentage of cow weight and cow weight .75, was highest for the smaller J crosses. The ratio of 365-d TDN intake to 205-d calf weight, a measure of weaning efficiency, averaged 10.0 kg/kg for JH, BH and SH, 10.5 kg/kg for HA and BA and 10.9 kg/kg for JA and SA. When TDN intake was adjusted for cow weight change, crossbred cow group was not a significant source of variation for kg TDN/205-d calf weight.     

杂交方式对肉牛产肉性能的影响

从1985起，系统性的选择了国外8个优良肉牛品种西门塔尔、利木赞、夏洛莱、皮埃蒙特牛等的冻精，采用级进和多元杂交的方式，产生了14个不同的肉牛杂交组合，用统一的方案进行了肥育、屠宰试验，研究了不同杂交方式对产肉性能的影响，为现阶段加速发展肉牛产业提供科学依据。     

Life-cycle biological efficiency of Bos indicus x Bos taurus and Bos taurus crossbred cow-calf production to weaning

A deterministic model was developed that accounted for all biological inputs and outputs for a theoretical herd of F1 females at age equilibrium mated to produce three-way terminal-cross calves and for the required proportion of straightbred cows needed to produce replacements. Two Bos indicus x Bos taurus vs two Bos taurus x Bos taurus types of crossbred cows were compared in the production environment of south-central Nebraska. The four types of F1 females were from Hereford (H) or Angus (A) dams and by H or A (HA), Pinzgauer (Pz), Brahman (Bm), or Sahiwal (Sw) sires. The crossbred females were assumed mated to Red Poll (R) sires for their first calving and to Simmental (S) sires thereafter. Two evaluations of efficiency for each of the four breeding systems were total cow and calf feed energy input 1) per unit of only weaned calf weight output (CALFEFF, Mcal/kg) and 2) per unit of weaned calf plus .55 x cull cow weight output (TVALEFF, Mcal/kg). Results for a terminal age of 7 yr in systems using HA, Pz, Bm, and Sw crossbred cows, respectively, were 64.9, 64.5, 60.9, and 59.3 Mcal/kg for CALFEFF and 45.7, 46.4, 44.1, and 43.7 Mcal/kg for TVALEFF. Changing terminal age to 11 yr reduced CALFEFF about 6% but increased TVALEFF about 7%, because total inputs increased more than output value (10 vs 3%) from 7 to 11 yr terminal ages. These results suggest differences in efficiency among these breed crosses favoring the Bos indicus crossbred cows by over 4% in this particular environment.     

Influence of restricted suckling and level of feed supplementation on postpartum reproductive performance of zebu and crossbred cattle in the semi-arid tropics.

This study was carried out in central Tanzania on a group of 45 Zebu and 37 crossbred cows which were 4 to 10 years old. At calving time, the animals were allocated to one of the 4 treatment groups. In addition to free access to grazing for all cows in the study, in group H:AR (n = 18), cows were fed a high level of concentrate supplementation (4kg/day) and calves were artificially reared; in group H:RS (n = 24), cows were fed a high level of concentrate supplementation (4kg/day) and calves were only allowed restricted suckling up until the weaning age of 6 months. In group L:AR (n = 23) cows were fed a low level of concentrate supplementation (2kg/day) and calves were artificially reared; and in group L:RS (n = 17) cows were fed a low level of concentrate supplementation (2kg/day) and calves were only allowed restricted suckling up until the weaning age of 6 months. Milk progesterone was used as a means of determining the postpartum resumption interval (PRI) and the interval from parturition to conception (PCI). The overall PRI was 47.4 +/- 0.4 days and was significantly affected by breed but not by calving season, with crossbred cows exhibiting a shorter PRI than Zebu cows. The effect of the treatments was significant, with cows in the group H:AR displaying a significantly shorter PRI than those in the other groups, while cows in group L:RS showed a significantly longer PRI than those in the other groups. The overall PCI was 149.5 +/- 3.7 days, and was not significantly affected by breed or calving season. The effect of the treatments was significant, with cows in the group H:AR having a significantly shorter PCI than cows in the other groups, while cows in group L:RS showed a significantly longer PCI than those in the other groups. Crossbred cows had higher live weights at calving (299.4 kg) than Zebu cows (272.6 kg), while all cows gained weight during the first 3 months after calving. The treatments had a significant effect on weight gain, with cows in the group H:AR gaining significantly more weight than those in the other groups. Cows which had high live weights at calving exhibited significantly shorter PRI and PCI than the lighter cows. Animals which had gained more than 5 kg during the first month after calving, or which had gained more than 8 kg during the first 3 months after calving, showed significantly shorter PRI and PCI than cows which had gained less weight. The results show that the calf rearing system and the level of feed supplementation interact with each other and can influence the postpartum anoestrous period in Zebu and Zebu crossbred cattle. Increasing the level of nutrition in restricted suckling cows tended to improve the postpartum anoestrous period, but the positive effects of supplementation could not completely compensate for the negative effects of suckling.     

Feed handling of lactating crossbred cows maintained in a semi‐arid region during the hot season: physiological parameters,ingestive behavior and performance

The effects of time of feed delivery (14.00 hours; 14.00 and 20.00 hours; 16.00 and 18.00 hours) on the physiological parameters, ingestive behavior, nutrient intake and production of lactating cows maintained in a semi‐arid region during the hot season were evaluated. Regardless of treatment, all animals received the first feeding supply at 06.00 hours. Eight cows with an average body weight of 600 kg, average milk yield of 20 kg/day and 80 days in milk were utilized. The rectal temperature, respiratory rate and sweating rate were not affected (P > 0.05), with average values of 38.5°C, 53.8 movements/min and 104 g/m²/h respectively. There was no effect (P > 0.05) on the eating time (314 min/day), ruminating time (564 min/day), drinking time (61 min/day) and idle time (502 min/day). Similarly, the intake of nutrients and performance of lactating cows were not affected (P > 0.05), with average dry matter intake of 19.8 kg/day, 4% fat‐corrected milk of 20.6 kg/day and milk fat concentration of 4.03 g/100 g. Since the behavior and performance have not altered, any times of feed delivery evaluated could be used to crossbred Holstein × Zebu cows maintained on a feedlot in semi‐arid regions during the hot season.     

Comparative evaluation of raw and roasted soybean in lactating crossbred cows

An experiment was conducted to evaluate the effect of roasting whole soybean in the local level on their chemical composition, nitrogen fractions, in situ degradability, and feeding performance in crossbred (Karan Swiss and Karan Fries) dairy cows. Twelve lactating crossbred cattle (369.08 ± 17.53 kg body weight) were randomly divided into two groups on the basis of milk yield (10.18 kg/day) and day of calving (89 days) in a randomized block design. Cows were fed green maize fodder and concentrate mixtures with 1 kg raw soybean as fed basis (7.6% of total diet) in the control group, where as roasted soybean replaced raw soybean in the treatment group to make both diets isonitrogenous and isocaloric. The roughage to concentrate ratio was around 55:45 in both diets. The cows were housed in individual byres and fed experimental diet for 90 days. The total dry matter intake per animal in both groups was similar. The digestibility of dry matter, organic matter, crude protein, ether extract, and neutral detergent fiber was comparable in both groups. The average milk production and fat-corrected milk yield per day was similar during the trial. Milk fat, milk protein, and solids not fat content remained unaffected and similar in both groups. All the animals maintained their body weight in both groups. Thus, rumen bypassing of protein fractions at the present method of bypassing did not have the desired level of beneficial effect in medium producing crossbred cows.