影响仔猪均匀度和活力的几个因素

正仔猪均匀度是指同一窝内仔猪之间的体重差异。近年来,作为最主要的育种目标之一,母猪产仔数得到很大提高。但是随着产仔数的提高,仔猪初生重下降、均匀度越来越差、死亡率升高等问题越来越严重。仔猪均匀度差,产后仔猪的生长性能差,生产管理复杂。文章概述了均匀度对猪生长性能,产后管理的影响,并对影响仔猪均匀度的因素进行总结,以期为提高仔猪均匀度起到指导作用。     

影响仔猪初生重和均匀度的因素及调控机理研究进展

在养猪生产中,随着窝产仔数提高,仔猪初生重和均匀度降低,从而影响仔猪后期的生长发育.目前对仔猪初生重和均匀度调控的主要方式是营养调控,本文综述了仔猪初生重和均匀度的影响因素及调控机理,特别关注了氨基酸、蛋白质和能量等在调控仔猪初生重和均匀度的作用效果及其相关机理,以期为提高猪生产效率提供依据.     

如何提高母猪的生产性能

母猪的生产性能指的主要是母猪的繁殖能力,主要受到母猪的利用年限。生产仔数(每胎产仔数。年产仔胎数)和仔猪的成活率。均匀度等指标构成。综合提高母猪的生产性能,就需要做好母猪选种。配种技术繁殖母猪的饲养管理。早起断奶,提高仔猪断奶窝重。做好疾病预防。     

有效微生物群对仔猪生产性能的影响初探

对产后母猪和断奶仔猪饲喂有效微生物菌群(EM),研究其对仔猪生产性能的影响。从产前7d开始给母猪基础饲料中添加5mL/kg的EM菌液,选产仔数不少于8头的3头母猪及其仔猪连续饲喂EM菌28d,仔猪进行断奶,统计母猪的增重、仔猪初生重、断奶重,仔猪成活率等,分析添加EM菌后对母猪生产性能的影响。在这24头断奶仔猪饲料中添加EM菌的饲料,饲喂至60日龄,统计仔猪的增重、采食量、料重比、发病数等,分析EM菌断奶仔猪生产性能的影响。另外选取3头同品种、同批次生产、产仔数相同的母猪及其仔猪饲料中不添加EM菌作为对照。结果表明,母猪产后日均采食量较对照组提高12.07%,仔猪的初生重较对照组提高15.90%,产活仔数提高了12.09%,断奶重增加9.09%,断奶头数增多20.99%,断奶成活率提高8.81%。断奶后仔猪试验组的平均采食量较对照组提高10.26%,料重比降低了7.14%,发病率下降了50.03%。说明EM菌对母猪和仔猪的生产性能均有提高作用,研究结果为EM菌在生猪养殖中的应用提供了基础资料。     

仔猪均匀度遗传参数估计及影响因素分析

本研究对仔猪均匀度遗传参数进行估计并对影响仔猪均匀度的固定效应(年份、配种季节及胎次)进行统计分析。旨在为育种工作提供仔猪均匀度遗传参数数据支持,了解非遗传因素对养猪生产的影响,为猪场生产管理提供参考。本研究对2 766窝纯种大白母猪产仔记录进行统计分析,利用动物模型REML(约束最大似然)法估计群体重要繁殖性状的遗传力及性状之间的遗传相关,并建立固定效应模型对仔猪均匀度影响因素进行最小二乘分析。结果表明:群体仔猪均匀度、总产仔数、产活仔数、产死仔数及初生窝重的遗传力分别为0.096、0.107、0.101、0.068、0.171;仔猪均匀度与总产仔数以及仔猪均匀度与产死仔数之间都存在正的遗传相关,遗传相关系数分别为0.205、0.157。固定效应方差分析表明,季节对仔猪均匀度影响显著(P=0.023 6);胎次与产仔数对仔猪均匀度影响极显著(P=0.001)。仔猪均匀度是可遗传的,其遗传力与产仔数遗传力相近。结合现代育种手段,制定合理的育种方案,仔猪均匀度是能够得到改良的。仔猪均匀度与总产仔数、产死仔数之间存在正的遗传相关。因此,育种工作中不能一味追求高产,应适当考虑仔猪均匀度,减少仔猪死亡率,最大限度的提高母猪年生产力。     

丹系长白、大白猪繁殖性能分析

为研究胎次、年度、季节对丹系长白猪、大白猪窝产仔数、仔猪初生重、仔猪均匀度等繁殖性能指标的影响,并比较两个品种的差异,对300头丹系长白猪、299头丹系大白猪繁殖记录进行分析。结果显示：丹系长白猪、大白猪初产母猪窝产仔数低于经产母猪,长白猪仔猪初生重随胎次的增加逐渐降低,而大白仔猪初生重随着胎次的增加逐渐升高;仔猪均匀度均随着胎次的增加而升高;2018—2021年窝产仔数逐年升高,仔猪均匀度年度间没有表现出规律性;春季与秋季分娩的母猪窝产仔数高于夏季和冬季,秋季仔猪初生重表现最差,仔猪均匀度秋季表现最佳;从窝产仔数、初生重与仔猪均匀度来看丹系长白猪性能略优于大白猪。     

仔猪饲养管理技术措施

仔猪的饲养管理可分为：哺乳和断奶仔猪的饲养管理。搞好仔猪饲养管理的目的,一是使仔猪成活率高;二是哺乳仔猪生长速度快,个体小,对外界不良因素的抵抗力差。据统计,哺乳期死亡的仔猪中85％是在产后30日龄内死亡的．而产后一周内死亡的约占其中的60％,因此,要加强护理,尤其是仔猪出生后第一周。     

给哺乳仔猪饲喂代乳品可增强活力

窝产仔数的加大,使代乳品的使用越来越普遍。研究表明,哺乳仔猪在饲喂教槽料的同时,补充代乳品仍能有效地提高教槽料的摄入量,进行对仔猪随后的生长带来有利影响。但代乳品的补充不应影响仔猪初乳的摄入量,因此补充时间有严格的限制。     

早期断奶仔猪腹泻的原因及防治措施

随着现代化养猪生产的发展,养猪技术水平不断提高仔猪断奶的时间也由过去的60日龄提前到28日龄或更早些,这大大提高了母猪的年产仔数,也提高了肉猪年出栏率。但是早期断奶后饲养管理跟不上,就会造成仔猪腹泻(仔猪下痢),影响仔猪成活率。据统计,仔猪腹泻导致的死亡率占总仔猪死亡的49%;患腹泻病的仔猪的生长也受到影响。因此,防治仔猪腹泻是养猪生产的重要环节。     

中草药制剂对母猪哺乳和发情效果的试验研究

在母猪饲料中添加中草药制剂可达到调节自身免疫功能、减少母猪产后无乳综合征、改善母猪生殖系统健康等功效。笔者及所在团队通过对添加中草药制剂的猪群的总产仔数、健仔数、仔猪初生重、仔猪断奶个体重、仔猪日增重、哺乳仔猪育成率以及断奶母猪发情效果的测定,以期探讨出中草药及其制剂对提高母猪泌乳性能和促进发情效果的作用。     

Phase I evaluation of CCNU (lomustine) in tumor-bearing cats

1-(2-Chloroethyl)3-cyclohexyl-1-nitrosourea (CCNU) is an alkylating agent in the nitrosourea subclass. A prospective evaluation of CCNU was done to determine the maximally tolerated dosage of CCNU in tumor-bearing cats. Response data were obtained when available. Twenty-five cats were treated with CCNU at a dosage of 50-60 mg/m3 body surface area. Complete hematologic data were available for 13 cats. Neutropenia was the acute dose-limiting toxicity. The median neutrophil count at the nadir was 1,000 cells/microL (mean, 2,433 cells/microL; range, 0-9,694 cells/microL). The time of neutrophil nadir was variable, occurring 7-28 days after treatment, and counts sometimes did not return to normal for up to 14 days after the nadir. Based on these findings, a 6-week dosing interval and weekly hematologic monitoring after the 1st treatment with CCNU are recommended. The nadir of the platelet count may occur 14-21 days after treatment. The median platelet count at the nadir was 43,500 cells/microL. No gastrointestinal, renal, or hepatic toxicities were observed after a single CCNU treatment, and additional studies to evaluate the potential for cumulative toxicity should be performed. Five cats with lymphoma and 1 cat with mast cell tumor had measurable responses to CCNU. Phase II studies to evaluate antitumor activity should be completed with a dosing regimen of 50-60 mg/m3 every 6 weeks.     

Prevalence of gastric lesions in racing Alaskan sled dogs

Human and equine athletes are reported to have a high prevalence of gastric disease, and anecdotal evidence suggests a similar phenomenon applies to racing sled dogs. To investigate the prevalence of gastric disease in racing sled dogs, we conducted 2 gastroscopy studies on dogs competing in the annual Iditarod Sled Dog Race. A pilot study of dogs that were either dropped from the 2000 Iditarod Sled Dog Race because of illness or that finished the race indicated that, approximately 5 days after competing, 10 of 28 dogs (35%) had endoscopic evidence of gastric ulceration, erosion, or hemorrhage. The next year, an endoscopic study of 73 dogs participating in the 2001 Iditarod race was performed in order to evaluate a larger population of dogs. Data from 70 of these dogs could be used; 34 (48.5%) had ulceration, erosion, gastric hemorrhage, or some combination of these findings. When this group of 70 dogs was compared retrospectively to a control group of 87 dogs presented to the Texas A&M University (TAMU) Veterinary Medical Teaching Hospital, the Iditarod sled dogs had a significantly higher prevalence (P = .049) of gastric lesions. These findings suggest that, similar to athletes of other species, elite canine athletes have an increased prevalence of gastric disease compared to the canine population at large.     

Furosemide continuous rate infusion in the horse: evaluation of enhanced efficacy and reduced side effects

Continuous rate infusion (CRI) of furosemide in humans is considered superior to intermittent administration (IA). This study examined whether furosemide CRI, compared with IA, would increase diuretic efficacy with decreased fluid and electrolyte fluctuations and activation of the renin-angiotensin-aldosterone system (RAAS) in the horse. Five mares were used in a crossover-design study. During a 24-hour period, each horse received a total of 3 mg/kg furosemide by either CRI (0.12 mg/kg/h preceded by a loading dose of 0.12 mg/kg IV) or IA (1 mg/kg IV q8h). There was not a statistically significant difference in urine volume over 24 hours between methods; however, urine volume was significantly greater after CRI compared with IA during the first 8 hours ([median 25th percentile, 75th percentile]: 9.6 L [8.9, 14.4] for CRI versus 5.9 L [5.3, 6.0] for IA). CRI produced a more uniform urine flow, decreased fluctuations in plasma volume, and suppressed renal concentrating ability throughout the infusion period. Potassium, Ca, and Cl excretion was greater during CRI than IA (1,133 mmol [1.110, 1,229] versus 764 mmol [709, 904], 102.7 mmol [96.0, 117.2] versus 73.3 mmol [65.0, 73.5], and 1,776 mmol [1,657, 2.378] versus 1,596 mmol [1,457, 1,767], respectively). Elimination half-lives of furosemide were 1.35 and 0.47 hours for CRI and IA, respectively. The area under the excretion rate curve was 1,285.7 and 184.2 mL x mg/mL for CRI and IA, respectively. Furosemide CRI (0.12 mg/kg/h) for 8 hours, preceded by a loading dose (0.12 mg/kg), is recommended when profound diuresis is needed acutely in horses.     

The Epidemiology of Gastrointestinal Nematodes of Dairy Cattle in Central Kenya

The epidemiology of H. placei and of other gastrointestinal nematodes in yearling dairy cattle was examined on two farms in Kiambu District, central Kenya during each of 13 one-month periods from April 1993 to April 1994. On each farm, 32 newly weaned dairy calves were given a single dose of albendazole and then placed on experimental pastures. Twelve of the animals were designated for bi-monthly slaughter (n = 2) and analysis of worm population characteristics and 20 were designated for blood and faecal collection and for weighing. Two parasite-free tracer calves were grazed alongside the weaner calves each month throughout the study period and were also slaughtered for analysis of worm populations. Faecal egg counts, haematological and serum pepsinogen determinations, herbage larval counts, and animal live weight changes were recorded monthly. The study revealed that Haemonchus placei, Trichostrongylus axei, Cooperia spp. and Oesophagostomum radiatum were responsible for parasitic gastroenteritis and that H. placei was the predominant nematode present in the young cattle on both farms. Faecal egg counts from resident cattle and necropsy worm counts revealed that pasture larval levels were directly related to the amount of rainfall. The total worm burdens in the animals were highest during the rainy season (March–June and October–December) and lowest during the dry seasons (July–September and January–February). The very low recovery of immature larvae of H. placei from the tracer calves indicated that arrested development is not a feature of the life cycle of this parasite in central Kenya. The maintenance of the parasite population depended on continuous cycling of infection between the host and the pasture. The agroclimatic conditions of the study area were such that, in general, favourable weather conditions for the development and survival of the free-living stages of gastrointestinal nematodes existed all year round.     

Diversity of Ectoparasites in Sheep Flocks in Sa~o Paulo,Brazil

The occurrence of ectoparasites in sheep flocks is frequently reported but seldom quantified. Sheep production used to be a predominantly family activity in the state of Sa~o Paulo (Brazil), but it began to become a commercial activity in the past decade. Thus, information about the ectoparasites existing in sheep flocks has become necessary. The present data were obtained by means of questionnaires sent to all sheep breeders belonging to the `Associaça~o Paulista de Criadores de Ovinos' (ASPACO; Sa~o Paulo State Association of Sheep Breeders). Response reliability was tested by means of random visits paid to 10.6% of the respondents. Most of the properties (89.5%) reported the presence of one or more ectoparasites. Screw-worm (Cochliomyia hominivorax) was the most frequent ectoparasite (72.5%), followed by bot fly larvae (Dermatobia hominis, 45.0%), ticks (Amblyomma cajennense) and Boophilus microplus, 31.3%) and finally lice (Damalinia ovis, 13.8%). Combined infestations also occurred, the most common one being screw-worm with bot fly larvae (36.0%) followed by bot fly larvae with ticks (13.9%), screw-worm with ticks (9.3%), bot fly larvae with lice (6.9%), and ticks with lice (5.0%). The most common triple combination was screw-worm, bot fly larvae and ticks (12.8%). Breeds raised for meat or wool were attacked by bot fly larvae and ticks more often than other breeds. Lice were only absent from animals of indigenous breeds. The relationships among these ectoparasites are discussed in terms of sheep breeds, flock size, seasonality and the ectoparasitic combinations on the host.     

Evaluation of biohydrogenation rate of canola vs. soya bean seeds as unsaturated fatty acids sources for ruminants in situ

An experiment was conducted to study disappearance of C14 to C18 fatty acids, lag times and biohydrogenation (BH) rates of C18 fatty acids of ground soya bean and canola seeds in situ. Three ruminally fistulated Dallagh sheep were used to determine ruminal BH of unsaturated fatty acids (UFAs). Differences in the disappearance of fatty acids through the bags and lag times were observed between the oilseeds. We saw that the longer the incubation time of the oilseeds in the rumen, the lower the content of C18:2 and C18:3. Significantly higher lag times for both C18:2 and C18:3 were observed in ground canola compared to ground soya bean. BH rates of C18:2 and C18:3 fatty acids in soya bean were three times higher than those of canola. These results suggest that the fatty acid profile of fat source can affect the BH of UFAs by rumen micro‐organisms. So that UFAs of canola had higher ability to escape from ruminal BH. It seems that fatty acid profile of ruminant products is more affected by canola seed compared to soya bean seed.     

Serum biochemical values and mineral element contents of tissues in yaks

Serum biochemical values and the wet weight to dry weight ratios of tissues were determined in yaks in Shandan county of Gansu province. The liver, kidney, heart and muscle contents of seven elements in yaks were also analysed. Most serum biochemical values were similar to those of cattle, camels and sheep, but the calcium concentration was considerably above the normal range for other ruminants. The liver contained the highest concentrations of copper, manganese and cobalt and the kidney of selenium, iron and calcium.Abbreviations Alb albumin - ALT alanine aminotransferase - AST aspartate aminotransferase - BUN blood urea nitrogen - Chol cholesterol - Glob globulin - -GT -glutamyl transpeptidase - IP inorganic phosphorus - TP total protein     

Avian brood parasitism — a growing research area in behavioral ecology (part Ⅱ)

正We are pleased to publish the second special issue on avian brood parasitism and to be responsible guest editors for the two special issues of Chinese Birds (Vol. 3, No. 4, 2012 and Vol. 4, No. 1, 2013), entitled "Avian Brood Parasitism - A Growing Research Area in Behavioral Ecology". The first issue was published in December 2012. The goal of the two special issues is to publish accumulated knowledge and some of the recent developments in     

Internal Parasites and Haematological Values in Cattle Slaughtered in Buea Subdivision of Cameroon

Tropical Animal Health and Production -