北京地区家畜养殖数字化现状

数字农业是迈向农业强国的必经之路,数字化是农业现代化的标志,是北京地区家畜养殖场发展的必然趋势。本文从家畜养殖环境、养殖过程、养殖管理等方面介绍了北京地区家畜养殖数字化现状,特别是个体信息感知、个体精准饲喂、生产性能测定等技术的发展与应用情况。从政策支持、过程管理和技术创新三个方面进行了展望,促进现代信息技术与智能化装备在家畜养殖领域的发展应用,加快转型效率,提升养殖水平,增加养殖经济效益,为北京地区家畜养殖业的高质量发展提供支撑。     

Variation in resistance to the Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) in Pietrain and Miniature pigs

Porcine reproductive and respiratory syndrome (PRRS) is one of the economically most important diseases of swine. Viraemia and the prolonged persistence of the virus are among the most critical factors. Virus replication and severity of disease vary with virus isolates, and there is rising evidence for a genetic component of the host susceptibility. Dissecting the genetic basis of resistance/susceptibility to PRRS virus (PRRSV) might lead to improved knowledge on the molecular mechanisms of PRRS and the establishment of genetic markers for future disease control. The aim of this study was to establish a porcine model with emphasized genetic differences in PRRSV susceptibility. Seven ‘Wiesenauer Miniature’ pigs (MI), a local German breed and eight commercial Pietrain (PI) pigs were challenged with 10⁵ TCID₅₀ of an attenuated PRRSV strain (Ingelvac^® PRRSV MLV). Clinical status, viraemia and seroconversion of the pigs were compared. No clinical signs were observed during the experiment. Viraemia peaked on day 6 p.i., with 100% of viraemic pigs in PI and on day 12 p.i with 87% of viraemic MI. Viraemia lasted for up to 35 days in MI and for at least 72 days in PI. This surprising result was confirmed by a second study with another four MI. MI and PI showed maximum virus titres of 10^2.5 TCID₅₀/ml of serum and 10^4.5 TCID₅₀/ml, respectively, indicating a virus replication in MI of approximately 3.3% that of PI over the complete period. MI were more efficient in antibody production. With such pronounced breed differences, the model is of high relevance for the genetic dissection of PRRS pathogenesis and susceptibility.     

我国猪囊虫病的研究概况

囊虫病是一种危害严重的人兽共患病，在我国的发生率较高。近年来，我国学者在该病的流行病学、诊断方法、防制措施以及免疫预防等方面都进行了深入研究，本文就该病的研究进展进行了综述。     

Changes in productivity and profitability of wool-growing farms that follow recommendations from agricultural and veterinary studies

Objective To estimate the changes in productivity and profitability in a group of wool-growing farms as they adopted major recommendations from agricultural and veterinary studies.
Farms Four wool-growing farms in south western Victoria were selected from the clients of the Mackinnon Project, a farm consultancy service run from the University of Melbourne. Each farm had closely followed recommended procedures, kept comprehensive financial and physical records and had been clients for at least 5 years. The comparison group was the South Western Victoria Monitor Farm Project (SWVMFP), about 45 farms in the same region as the study farms that were monitored annually by Agriculture Victoria.
Procedure For a 7-year period, the financial and physical performance of both groups of farms was estimated. Stocking rate, wool production, gross farm income, farm operating costs, net farm income and return on assets were compared.
Results Mean gross farm income of the four study farms steadily rose from 86% of the average SWVMFP farm before the adoption of recommendations to an average of 155%. During the same period, net farm income rose from 70% to 207% of the average of the SWVMFP. Return on asset of the four farms rose irregularly from 26% to 145% of the average of the SWVMFP. Farm operating costs on the four farms were higher than for the SWVMFP group, but the ratio of costs remained relatively constant.
Conclusion The adoption of proven research results was associated with large increases in net farm income. An increase in gross income, rather than a reduction in costs was the main reason for this. Research results offer a way to increase the financial viability of wool-growing farmers, many of whom are currently unable to maintain their lifestyle, resources and infrastructure.     

Comparison of production systems for efficient use of indigenous pig breeds in developing countries

Conserving pig genetic resources and improving their productivity is important to increase returns over investment in developing countries. The purebred, first‐cross, rotational cross and backcross matings representing production systems based on pig breeds indigenous to the country and exotic pig breeds were investigated. The number of pigs in the nucleus and commercial herds necessary to produce a defined quantity of pork was considered. The amount of heterosis between the indigenous and exotic breeds, superiority in meat production, and degree of inferiority in reproductive performance of the exotic breed compared with that of the indigenous breed were investigated. The number of breeding pigs in the whole system was in the following order: pure breeding (PB) > first‐cross (F1) > rotational cross (RC) > backcross (BC) systems. The number of breeding pigs in the nucleus herds of the RC and BC systems was smaller than that in the nucleus herds of the PB and F1 systems. The degree of inferiority in reproductive performance of the exotic breed compared with that of the indigenous breed affected the efficiency of the production system.     

Detection of Helicobacter-like Bacteria in Porcine Gastric Biopsy Samples by Amplification of 16S rRNA,ureB, vacA and cagA Genes by PCR

Preliminary evidence for the presence of Helicobacter-like bacteria was sought in 395 porcine gastric samples by a urease test. Of the samples, 37% (146/395) were urease-positive and 82% (82/100) of the Gram-stained urease-positive samples showed large, tightly spiralled organisms. Several methods were applied to culture the organisms but isolation was unsuccessful, contaminant organisms being considered to be one of the major problems. PCR with Helicobacter genus-specific primers for 16S rRNA and ureB genes, and primers for H. pylori vacA and cagA genes were tested with 102 urease-positive biopsy samples. The PCR results showed some evidence for the presence of the urease and the vacA genes in porcine Helicobacter-like bacteria and raises the possibility of pathogenicity by these organisms.     

The effect of pig farming on copper and zinc accumulation in cattle in Galicia (north-western Spain)

Copper and zinc are frequently added at high concentrations to pig diets as growth promoters. Livestock grazing pasture contaminated with pig slurry may, therefore, be at risk from excessive intake of these elements. High liver copper concentrations have been detected in cattle from the agricultural region of Galicia (NW Spain), especially where there is intensive pig farming. The aim of this study was to evaluate whether pig farming does affect accumulation of copper and zinc in cattle in Galicia. Hepatic copper and zinc concentrations in calves were elevated in areas with naturally high levels of these elements in the soil. The densities of young pigs (piglets and growing-finishing pigs), but not reproductive sows, also influenced copper accumulation in calves. Liver copper levels in calves were significantly and positively related to the density of young pigs in the region. In areas with the highest pig densities, more than 20% of the cattle analysed had hepatic copper concentrations that exceeded the potentially toxic concentration of 150 mg/kg fresh weight. There was no evidence that zinc accumulation in calves was affected by pig density.     

杜湖杂交猪生产性能的测定

以杜洛克为父本、湖北白猪二元配套系为母本所生产的杜湖猪、育肥期平均日增重为７００ｇ,料肉比３．０,屠宰率７３．１％,瘦肉率６５．６％。与原杜湖猪相比,综合生产性能有了很大提高。     

以催乳素受体基因作为撒坝猪部分生产性能候选基因的研究

此文运用PCR-RFLP技术检测催乳素受体(PRLR)基因在撒坝猪群体中的多态性分布,并采用最小二乘分析模型初步统计分析基因多态性与部分生产性能的相关性。结果表明,PRLR基因等位基因B及其基因型BB在群体中占优势,频率分别为0.6594和0.4438;PRLR基因在群体中处于Hardy-Weinberg平衡状态;头胎繁殖性状有利等位基因B对生长性状无不利影响。     

Evaluation of smallholder pig production systems in North Vietnam: Pig production management and pig performances

This study investigated the productive adaptability of pig breeds under different smallholder production conditions in Vietnam, comparing an indigenous with a Vietnamese improved breed. Fieldwork was conducted in four villages with different remoteness in North Vietnam from 2001 to 2002, in 64 households keeping the improved Mong Cai or indigenous Ban as sow breeds and progeny for fattening. Four visits per farm yielded 234 structured interviews. Reproductive performances were derived from 135 litters. Individual weights of pigs (n = 755) were obtained. Data were analysed by regression, linear and generalised linear, especially loglinear models.

Two distinct pig production systems were identified, that differed in remoteness, market access, resource availability, distribution of pig breeds and pig production intensity. Higher performances of 1.4 and 1.5 litters year^− 1, 8.4 and 8.4 piglets weaned litter^− 1, 66.6 and 93.0 kg piglets weaned sow^− 1 year^− 1, and 136 and 177 g day^− 1 ADG were found in two villages near town with semi-intensive production conditions and a high rate of improved Mong Cai sows and MC and LW × MC offspring in the observed population. Lower performances of 1.1 and 1.1 litters year^− 1, 4.6 and 5.5 piglets weaned litter^− 1, 20.5 and 30.9 kg piglets weaned sow^− 1 year^− 1, and 66 and 85 g day^− 1 ADG were observed in parallel to higher incidences of indigenous Ban pigs away from town under extensive conditions. Total live weight offtake per household per year was higher near town and in one village distant to town. MC and LW × MC remained even under demand-driven conditions below the performance potential reported for improved genotypes. Under resource-driven conditions with a saving-oriented production pattern, the higher-yielding but more demanding Mong Cai might not be an efficient production alternative as a further performance reduction can be assumed. A considerable live weight output was observed under resource-driven conditions and with a higher percentage of crossbred LW × Ban offspring in the population, possibly representing a promising production alternative. Factors influencing the performance expression of pigs, and the suitability of different methods for the assessment of performance parameters on-farm are discussed.