Planned control of reproduction processes in industrialized pig production

A planned process of concentration and specialisation in pig production has been introduced in the USSR, GDR, and other socialist countries in recent years and is likely to open up wider opportunities for the use of up-to-date technologies and latest findings of the biological sciences. Large-scale use of bio-engineering and methods of reproduction control is quite logical, in this context. This will provide a real chance for cyclogram control of all events important to management, planning, and follow-up of reproduction processes and for a planful implementation of industrialised production methods. Processes of cycle control are being increasingly applied to industrialised sow breeding units against the background of artificial insemination of pigs which is gaining widespread popularity after its emphasised introduction in the USSR. Research and field results regarding biological engineering in sow of oestrus, ovulation, pregnancy, and birth are reported in this paper and will, hopefully, help in determining mating and farrowing deadlines for breeding on the basis of artificial insemination and, consequently, contribute to widest possible programming of life cycles for the breeding animals concerned.     

Planned control of reproduction processes in industrialized sheep breeding

Discussed in this paper are possibilities at present available for bio-engineering action to control reproduction processes in ewes under the aspect of their applicability to industrialised lamb production. Reference, in this context, is make to the requirements of industrialised sheed breeding in establishing groups of young animals on the basis of cyclograms. Described is the most appropriate method at present to use feed pellets with megestrol acetate for oestrus synchronisation. The conclusion is that for the time being there is no method with sufficient economy by which to stimulate oestrus in sheep during the season and the non-oestral lactation period by which to bring forward the onset of sexual maturity.     

牧业工厂化生产五点优势吉

林省是我国的粮食大省、牧业大省.目前,吉林省农区的牧业生产向工厂化生产转型已具契机.一是吉林省规模生产已具雏形.二是养殖者专业技术储备已达一定水平.三是政策、措施的拉动使生产力水平得到较大提高.     

Beta-ligands in cattle production

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Feeding the growing population in a sustainable, environmentally-friendly manner will require implementation of management strategies and metabolic effectors that facilitate efficient protein deposition in livestock (Dunshea et al., 2016). Beta adrenergic receptor ligands fed to cattle improve live animal performance that translates into positive effects on muscle protein accretion and carcass parameters (Bittner et al., 2016; Bittner et al., 2017; DeClerck et al., 2020; Lockard et al., 2020). A recent review discusses the differences in the β-ligands, the receptors they interact with and the resulting tissue outcomes (Dilger et al., 2021).     

Relationship between nutrition and reproduction in beef cattle

The primary nutrient consideration for optimum reproductive performance in beef cattle is energy. Low energy intake delays the onset of puberty in heifers and bulls. Heifers should reach approximately 66 per cent of mature body weight by 14 to 15 months of age and be bred 30 days prior to breeding the main cow herd. Body conditioning scores (BCS) (1 = emaciated, 9 = obese) should be used to evaluate pregnant cows entering their third trimester. Cows should calve with body conditioning score 5 to 7. Forage quality and environmental factors influence maximum dry matter intake and nutrient requirements and must be considered in the clinical setting. Crude protein dietary content should be 11 to 12 per cent for lactating beef cattle. Mineral (calcium, phosphorus, magnesium, potassium, sulfur, sodium, chloride) nutrition is not a major cause of decreased reproductive performance in beef cattle. Trace mineral deficiencies (particularly selenium, copper, and zinc) can cause decreased reproductive performance. Diagnosis of these trace mineral deficiencies can be confirmed by elemental analysis of blood or tissues.     

Studies on the replacement policies in dairy cattle. III. Influence of variation in reproduction and production

The optimum policy of insemination and replacement of dairy cows was determined by the dynamic programming technique. The model used in the previous study was extended to allow variation in time of conception. From 2 to 7 months after calving three alternatives were considered for an open cow namely (a) inseminating the cow, with a calculated probability of success, (b) leaving her open, and (c) replacing her immediately. When it was profitable to leave a cow open, the optimum time for replacement during the lactation period was determined.The minimum production level for insemination to be the optimum choice depended on the stage of lactation and the parity of the cow. In the optimum situation the average calving interval was 371 days, while 13% of the cows had an interval of 14 months or longer.The optimum policy was greatly affected by changes in the replacement heifer price. Changes in the probability of conception and persistency of milk production had significant but smaller effects. In herds with a smaller decline in production after the peak, insemination should be continued for longer than in herds with a larger decline.The relation between production and calving interval that resulted from the optimum policy was determined. When a measure of milk production was used that was not affected by gestation, the average correlation was 0.09. The correlation increased to 0.35 when the total 305-day production was used.     

论陇东紫花苜蓿的产业化生产

从生物学特性、社会需要、经济合理性角度综合考虑 ,陇东地区具有紫花苜蓿生产的理想条件 ,发展苜蓿草产业在技术上和效益上是可行的 ,走产业化发展道路是实现紫花苜蓿开发生产的正确道路     

Effects of meloxicam on reproduction parameters in dairy cattle

This study was carried out in dairy cattle with the NSAID meloxicam to investigate possible drug effects on different reproductive parameters as well as on the progeny. Forty-one cows received intravenous injection of either meloxicam (Metacam^® 20 mg/mL solution for injection) or placebo at a dose volume of 7.5 mL/100 kg, corresponding to a dose of 1.5 mg meloxicam/kg, i.e. three times the recommended therapeutic dose. Treatment was performed in each phase of reproduction, i.e. once prior to breeding, twice shortly after breeding, once at the beginning of the second and third trimester of gestation and once at the end of the third trimester of gestation. Offspring of the cows were weighed and clinically examined for vitality at birth and after 28 days. No relevant difference between the meloxicam and control group was found in the reproductive performance of the cows or in the body weight development or vitality of the calves.     

工厂化生产中影响酸牛奶质量的因素研究

从原料质量、菌种及接种量、加糖量、培养温度等影响因素加以分析，确定最佳生产工艺条件，以稳定和提高工厂化生产酸牛奶的质量和商品性，优化工艺，降低成本，增加效益。     

吉林省细毛羊生产状况与产业化方向

1　细毛羊生产概况吉林省绵羊存栏 65 0万只 ,其中细毛羊存栏 42 0万只。细毛羊主要集中在西部半农半牧区。该地区属于科尔沁草原的东部 ,草原面积 160万hm2 ,粗饲料资源 2 5 0多万t,有两个国家级重点种畜场 (镇南种羊场和查干花种畜场 )、两个省级重点种畜场 (双辽种羊场和红星牧场 )。全省羊毛总产量 1 94万t,其中细羊毛产量 1 7万t ,占羊毛总产量的 87 6%,占全国细羊毛总产量的 14 %。近年来 ,通过实施国家“良种工程”项目 ,镇南种羊场和查干花种畜场都进行了全面的技术改造和基础设施建设 ,使这两个种源基地的供种能力大为增强 ,所提供…     

Aspects of reproduction in female Bos indicus cattle: a review

SUMMARY Differences occur between female Bos indicus and Bos taurus cattle in various aspects of reproductive physiology and behaviour. These may be associated with different natural and human selection pressures, compounded by strong genotype-environment interactions. B indicus cattle are better adapted for tropical environments (despite overall poor cattle reproductive rates in these regions) which tend to be more stressful for B taurus genotypes. Conversely, B taurus cattle generally show superior reproductive and productive traits under more favoured, temperate conditions. Despite genotype-environment effects, B indicus females are generally considered to take longer to achieve puberty and to have longer gestation lengths, exhibit prolonged postpartum anoestrus, show greater seasonality of reproductive traits (tending to be long-day breeders), display a shorter, less overt oestrus as well as less tendency to allow riding behaviour by subordinate females. Some groups appear to have increased losses both during pregnancy and in the neonatal period. On the positive side, B indicus females respond well to managerial and nutritional interventions, tend to have greater reproductive longevity and they generally exhibit strong maternal traits. Culling of infertile females and selection for greater male scrotal circumference and sex-drive, in conjunction with the use of target weights, body condition scoring and weaning stratagems can improve reproductive rates in B indicus females.