Effects of ewe breed and management system on efficiency of lamb production: I. Ewe productivity

Performance of 1/2-Suffolk, 1/2-Rambouillet (Western) and 1/2-Suffolk, 1/4-Rambouillet, 1/4-Finnsheep (1/4-Finn) ewes was compared in three different lamb production systems over 3 yr. System 1 (56 ewes) involved late fall lambing over 84 d. System 2 (51 ewes) involved January and February lambing for 60 d. System 3 (47 ewes) involved March and April lambing for 45 d. Pregnancy rates for yearling ewes were lower in System 1 in yr 1 (50.7% vs 87.4% for Systems 2 and 3) but differed little among systems for older ewes or in remaining years. Average pregnancy rates for 2-yr-old and older ewes were 89.5, 94.0 and 85.7% for Systems 1, 2 and 3, respectively. When the pregnancy rate was adjusted to a 45-d lambing season, means for older ewes were 78.6, 89.5 and 85.7% for System 1, 2 and 3, respectively. Ewe breeds did not differ in their pregnancy rates. Prolificacy (lambs born per ewe lambing) was higher for 1/4-Finn ewes (1.83 +/- .06 vs 1.55 +/- .07) and was higher in System 3 (1.86 +/- .06) than in Systems 1 (1.60 +/- .07) or 2 (1.63 +/- .05). Body weight at breeding in postyearling ewes was less in System 3 (64.3 kg); than in Systems 1 or 2 (average of 73.1 kg). Breeds did not differ in weight at 1 or 2 yr of age, but Western ewes were 2.1 +/- 1.1 kg heavier as 3-yr-olds.(ABSTRACT TRUNCATED AT 250 WORDS)     

Associations between farm management practices, productivity, and bovine leukemia virus infection in Ontario dairy herds

The objective of this study was to investigate the associations between herd-level bovine leukemia virus (BLV) status and herd-level management and production variables. The study population consisted of 1330 cows sampled from 102 Ontario dairy herds. The individual-cow prevalence of BLV infection in the population (based on AGID testing) was 23%, with 69.6% of herds having one or more positive animals. The herd-level explanatory variables were divided into two datasets containing winter housing variables and all non-seasonal variables, and summer housing variables and all non-seasonal variables. In both datasets, multivariable analyses found a negative association between herd-level milk production and BLV status, and positive associations between weaning age and purchasing animals from outside sources, and BLV status. Housing pre-weaned calves in hutches or separate calf buildings in either season was associated with an increased risk of BLV. The model containing winter housing variables also included positive associations between contact with older animals and BLV status, and between BLV status and the facilities used to house dry cows in the winter.     

功能型小肽对蛋种鸡产蛋和繁殖性能的影响

选取健康和体质量差异不显著的450只45周龄罗曼褐父母代种鸡,随机分为2个处理组,每处理5个重复,每重复45只鸡。2个处理组分别为空白对照组和添加8%功能型小肽组,在种鸡48周龄时进行孵化试验。观察记录各项生产性能和繁殖性能指标。试验结果表明,功能型小肽能显著提高蛋鸡的蛋质量、采食量、产蛋率和产蛋量。另外,在孵化试验中,试验组种蛋合格率显著提高,受精率、孵化率、母鸡健雏率和繁殖性能指数都有提高的趋势。     

Influence of farm, feed-producer and season on incidence of gastrointestinal disorders in Danish farm mink

The distribution of gastrointestinal disorders in mink in Danish farms is presented based on data collected in a longitudinal design. The time at risk was from weaning in June until pelting in November. The occurrence of gastrointestinal disorders after weaning of the mink kits together with the distribution within farms was studied. The period of highest risk was in the months immediately after weaning (July and August). More than 17% of the farms recorded GI disorders among ≥10% of pairs of animals. A multilevel statistical analysis showed that besides the effect of time after weaning, a significant part of the variation in the incidence could be attributed to the farm and feed-producer. The potential for bias is discussed.     

小议猪场管理中的“归因谬误”

正确"归因"意义非凡,不少猪场在寻找事物发生的原因时,往往注重形式逻辑,而忽略实质逻辑;那些更深层,更隐蔽,更随机的因素很难被发现。很多时候"归因谬误"会出现与真实情况相距甚远的偏差。这种偏差的存在,是猪场管理中的最大障碍,也是很多猪场多走弯路的重要因素。     

Pain management in horses and farm animals

Objective: This review discusses the different analgesic drugs and routes of administration used in large animals for acute pain management. General guidelines and doses are given to assist in choosing techniques that provide effective analgesia. Etiology: Noxious stimuli are perceived, recognized, and localized by specialized sensory systems located at spinal and supraspinal levels. Diagnosis: Localizing the source of the noxious stimulus as well as understanding the behavioral aspects and physiological changes that result from such insult is important to adequately diagnose and treat pain. Pain assessment is far from being definite and objective; not only are there species differences, but also individual variation. In addition, the behavioral and physiological manifestations vary with the acute or chronic nature of pain. Therapy: Pain management should include (1) selecting drugs that better control the type of pain elicited by the insult; (2) selecting techniques of analgesic drug administration that act on pathways or anatomical locations where the nociceptive information is being processed or originating from; (3) combining analgesic drugs that act on different pain pathways; and (4) provide the best possible comfort for the animal. Prognosis: Providing pain relief improves the animal's well being and outcome; however, interpreting and diagnosing pain remains difficult. Continuing research in pain management will contribute to the evaluation of the pathophysiology of pain, pain assessment, and newer analgesic drugs and techniques.     

Influence of type of starch and feeding management on glycaemic control in diabetic dogs

The present study evaluated the effects of two diets with different starch sources and two feeding methods on the glycaemic control in dogs with diabetes mellitus. The diets had similar nutrient contents (40% starch and 16% dietary fibre), one formulated with 46% of broken rice and the other with 42% sorghum and 10% lentils (as-fed). Ten client-owned diabetic dogs were fed with each diet for 2 months, in a crossover design. Five dogs received NPH human insulin and food every 12 h (feeding method 1), and the other five received insulin every 12 h but were fed three times a day (feeding method 2). In feeding method 2, morning insulin was higher than the evening dose and dogs received the second meal after 4 to 5 h of the morning insulin and meal. Parameters evaluated included insulin dosage, 12- and 8-h glycaemic curves, complete blood count, biochemical profile and urinalysis. Glycaemic curves were analysed by ANOVA with repeated measures. Glycaemic control parameters (fasting, mean, minimum and maximum glycaemia and serum fructosamine) and glucose area under the curve (AUC) were calculated and analysed by paired t test (p < 0.05). In feeding method 1, dogs fed the sorghum-based diet presented lower mean (p = 0.04) and minimum blood glucose concentrations (p = 0.03), and a tendency to lower maximum blood glucose (p = 0.06) and glucose AUC (p = 0.08) than when fed the rice-based diet. When food was provided twice a day, the ingestion of the rice-based diet resulted in higher post-prandial glucose response than the diet with sorghum and lentil. In feeding method 2, there was no effect of diet on the assessed parameters (p > 0.05). No differences in insulin dosage were observed between groups or feeding methods (p > 0.05). Providing two meals a day followed by insulin administration associated with the sorghum- and lentil-based diet improved glycaemic control in diabetic dogs.     

农业部关于发展农产品和农资连锁经营的意见

各省、自治区、直辖市、计划单列市农业厅(局、委): 连锁经营作为当今世界商品流通和服务业中最具活力的经营方式,目前在我国已经得到积极推广,并显示出巨大的发展潜力。近年来,我国农产品和农资连锁经营在一些地区已经起步,并取得了初步进展。但总的看,发展水平还很低,突出表现在连锁经营企业少、规模小、规范化程度低。为了适应我国加人WTO后日趋激烈的农产品和农资市场竞争,提高流通的现代化水平和效率,必须积极引导、大力发展农产品和农资连锁经营。为此,提出以下意见。     

Influence of gender, breed and age on maturity characteristics of sheep

Fifty-one ewes, 50 wethers and 51 rams of Finn x whiteface or Suffolk x whiteface breeding were slaughtered at an average age of 271, 361, 459, 557 or 652 d to study changes in maturity characteristics with changes in age. When metacarpal epiphyseal cartilage (growth plates) ossifies with age, break joints on the distal end of the metacarpals fuse and the end of the bone then appears as a spool joint rather than as a break joint. This fusion occurs earlier chronologically in ewes than in rams or wethers. Most Finn x whiteface-cross ewes, which normally reach reproductive maturity earlier than Suffolk x whiteface-cross ewes, exhibited ossified metacarpal growth plates by 459 d of age; break joints of Suffolk x whiteface crosses were not fused until 557 d of age. Both breed groups of rams exhibited fused joints by 557 d of age, but only 3 of 10 wethers exhibited spool joints at 652 d of age. Microscopic examination showed that even in these three wethers the epiphyseal growth plate could still be detected. Yearling 2-yr-old classifications of sheep from teeth were not gender-dependent within the discrete age classes of this study. About half the sheep in each gender group were classified as yearlings at 459 d of age and about half in each group were classified as 2-yr-olds by 652 d of age. Stepwise multiple regression equations to estimate age of sheep in days were developed. Overall maturity, lean color and texture and rib bone maturity were the best carcass measures of maturity. Maturity scores for characteristics of the break joint did not enter any of the equations studied. When eye lens weight was included in equations with the best measures of carcass maturity, accuracy of estimates for age of sheep was improved.     

Direct and indirect effects of Johne's disease on farm and animal productivity in an Irish dairy herd

Johne's disease (JD) is caused by infection with the organism Mycobacterium avium spp. paratuberculosis, leading to chronic diarrhoea and ill thrift in adult cattle. JD is considered to adversely affect farm performance and profitability. This retrospective case study was undertaken on a single commercial dairy herd in the south west of Ireland. Animal production records were interrogated to assess the effect of JD on milk yield (total kg per lactation), somatic cell count (the geometric mean over the lactation), reasons for culling, cull price and changes in herd parity structure over time. JD groups were defined using clinical signs and test results. One control animal was matched to each case animal on parity number and year. Specific lactations (clinical, pre-clinical and test-positive only) from 1994 to 2004 were compared between JD case and control cows. A significantly lower milk yield (1259.3 kg/lactation) was noted from cows with clinical JD in comparison to their matched control group. Clinical animals had an average cull price of €516 less than animals culled without signs of clinical disease. In contrast, little effect was noted for sub-clinical infections. These direct effects of JD infections, in combination with increased culling for infertility and increasing replacement rates, had a negative impact on farm production. Results from this study provide preliminary information regarding the effects of JD status on both herd and animal-level performance in Ireland.     

一个体猪场生产与经营的成功经验

广东某个体养猪场,在四年的生产过程中,母猪年产2.2胎,母猪年均提供上市肉猪19.3头,上市肉猪(25kg保育出栏到135kg上市)饲料报酬3.3(全场,包括种猪),25～135kg肉猪日增重950g/日,生产成绩和经济效益突出。     

Influence of age and breed of equid on plasma copper and zinc concentrations

Plasma ceruloplasmin activities and plasma Cu and Zn concentrations were determined in 215 clinically normal equids of various ages and breeds. Newborn foals, regardless of breed, were hypocupremic, compared with adolescent and mature horses. The mean plasma Cu concentration of newborn Standardbred-Thoroughbred (STD-TB) foals was 2.9 mumol/L, which was about one-sixth of plasma Cu concentrations of mature horses. Newborn draft-cross foals had higher (4.6 mumol/L) plasma Cu concentrations than did newborn STD-TB foals, but plasma Cu content was only one-fifth of the dams' concentrations. Draft-cross horses, regardless of age, had plasma Cu concentrations 15% to 40% higher than did STD-TB horses. Plasma Cu concentrations of Quarter Horse yearlings were similar to those in draft-cross yearlings. Plasma ceruloplasmin activities revealed a curvilinear relationship to plasma Cu concentrations. Plasma Zn concentrations of newborn and 1-week-old STD-TB foals were 30% to 80% higher than those for yearling and mature STD-TB horses. There were no differences between draft-cross neonates and their dams in plasma Zn concentration. Plasma Zn concentrations of neonatal and mature draft-cross horses were 22% higher than those obtained for all other equids. Age and breed of equid should be a consideration in interpretations of plasma Cu and Zn concentrations in equids.     

Influence of litter size and breed on variation in length of gestation in the dog

Summary

The variation in the length of gestation, the period from mating until parturition, was studied in 77 dogs of different breeds; the time for mating was determined by measuring peripheral blood progesterone levels. The mean length of gestation was 62.1 ± 0.2 (S.E.M.) days, with a variation of 11 days. The number of pups appeared to influence the length of gestation. Length of gestation was negatively correlated (r = ‐0.96, P < 0.001, n = 44) with litter size in litters with 7 or fewer pups. The intra‐breed variation in length of gestation in the five breeds represented by five or more bitches was 3 ‐ 6 days. The mean gestation of Alsatians (60.1 ± 0.5, n = 9) was shorter (P < 0.005) than that of the other breeds combined (62.3 ± 0.3, n = 68). The primiparous/multiparous status of the bitch did not influence the length of gestation.     

Influence of breed, age and body weight on organ weight in the chicken

Body, liver, heart and spleen weights were measured in 3 different breeds and 2 breed crosses over an age range of 0–8 weeks. Correlation coefficients, linear regression equations, standard deviations of observations around regression lines, and the standard errors of the slopes were calculated to study the effects of age, breed, and body weight on organ weight. The principal findings were:

1. Regardless of breed, organ weight does not change at the same rate as body weight during the first 8 weeks of life.

2. The ratio of liver or heart weight to body weight reaches a peak at about one to two weeks of age and then decreases gradually with age until 8 weeks. Spleen‐body weight ratio, however, increases to about the 3rd week of age after which it remains relatively constant.

3. Significant negative correlations were obtained between body weight and both liver‐ and heart‐body weight ratios; while significant positive correlations were obtained between body weight and spleen‐body weight ratios. The correlation between liver weight and heart weight was found to be higher than that between liver weight and spleen weight or between heart weight and spleen weight.

4. The ratio of organ weight to body weight differed with different breeds. The faster growing breeds had lower ratios of organ weight to body weight and higher correlation coefficients between body weight and organ weight ratios.

5. Regression equations are presented that enable the estimation of organ weights from body weights or from other organ weights in the three different breeds and two breed crosses studied.