猪胎盘性状与繁殖性能关系的研究

胎盘效率是对猪窝产仔数进行间接选择最主要的性状之一。本研究以60头纯种大白猪为试验群体，在测定其窝产仔数、窝产活仔数、仔猪初生重及各胎盘性状指标的基础上，分析了各胎盘性状之间的相关性，胎盘效率与窝产仔数、窝产活仔数之间的关系。结果表明，胎盘性状与繁殖性能间存在积极的相关性，胎盘效率高，其窝产仔数和窝产活仔数也高。     

猪胎盘效率与生长肥育性能的关系

采集77头纯种大白母猪的469个仔猪胎盘性状和生长性状资料．应用个体动物模型和MTDFREML，软件进行了遗传统计分析，估计了胎盘效率(初生重与胎盘重的比率)和遗传力及其与生长性状的遗传相关。结果表明，胎盘效率有较高遗传力0．46；胎盘效率与断奶重、达100kg日龄、日增重和背膘厚的遗传相关分别为0．03、-0．45、0．37和0．12，选择胎盘效率对生长性状的影响较小。     

法系大约克、丹系杜洛克母猪胎盘效率与产仔数关系研究

母猪繁殖性能高低是决定整个猪场经济效益的关键。产仔数是猪繁殖性状中最重要的性状,由于母猪窝产仔数的遗传力低(0.05～0.30),所以通过表型选择来提高母猪窝产仔数,效果不显著。为此,人们希望探索窝产仔数指标选择以外的途径来提高母猪的产仔数。针对这一问题,国内外的许多养猪学者都对与窝产仔数有关的因素如子宫容积、子宫内膜毛细血管的分析、胎盘重量等进行了大量的研究。最近研究得出母猪胎盘效率不同会对其产仔数有很大的影响,即母猪胎盘效率高的,其窝产仔数就高,胎盘效率低的,其窝产仔数就低。母猪胎盘效率就是指仔猪出生窝重与胎…     

以母猪胎盘效率为指标的产仔数选择效果研究

本文通过对长大二元杂母猪胎盘效率与总产仔数、产活仔数等的相关关系分析,进行了基于高低胎盘效率的产仔数选择效果研究。结果表明:①按胎盘效率分组,胎盘效率高(6.70)、中(5.30)和低(5.00)的长大二元杂母猪,其窝均产仔数分别为12.68±2.76、10.58±2.33和9.12±2.80;窝产活仔数相应分别为10.70±2.76、10.08±2.70和8.88±2.03;三个组的胎盘效率差异均极显著(P<0.01)。②用杜洛克公猪的精液作人工授精后,长大二元杂母猪高胎盘效率组(6.12±0.40)的总产仔数(12.75±0.45对10.78±0.52)、活产仔数(12.20±0.23对10.20±0.58)均极显著高于低胎盘效率组(5.13±0.37)(P<0.01)。     

大白猪胎盘效率遗传规律的初步研究

本文分析了 77头纯种大白母猪的 469头初生仔猪的胎盘效率、胎盘面积、胎盘长度、胎盘重及初生重等性状资料 ,估计了各性状间的简单相关系数 ,应用非求导约束最大似然法 (MTDFREML)估计大白猪胎盘效率、胎盘面积、胎盘长度、胎盘重及初生重的遗传力 ,估计结果分别为0 46 ,0 2 5 ,0 1 1 ,0 1 4和 0 2 9     

长白、大白母猪胎盘效率与产仔数关系的研究

本论文测定了长白、大白和长大二元杂母猪共 2 5 3胎次的胎盘效率与窝均总产仔数、窝均产活仔数之间的关系。结果表明 ,长白、大白和二元母猪之间胎盘效率无显著性差异 ;长白和所有试验母猪的胎盘效率高的 2 / 3的母猪的窝均总产仔数高于胎盘效率低的 1 / 3的母猪 ;大白和长大二元母猪的窝均总产仔数胎盘效率高的组与胎盘效率低的组的差异不显著 ;各类母猪中 ,胎盘效率高的 2 / 3母猪的窝均活仔数显著高于胎盘效率低的 1 / 3的母猪。说明母猪胎盘效率与窝均产活仔数有较高的正相关关系     

以母猪胎盘效率为指标的产仔数选择效果研究

本文通过对长大二元杂母猪胎盘效率与总产仔数、产活仔数等的相关关系分析,进行了基于高低胎盘效率的产仔数选择效果研究.结果表明①按胎盘效率分组,胎盘效率高(6.70)、中(5.30)和低(5.00)的长大二元杂母猪,其窝均产仔数分别为12.68±2.76、10.58±2.33和9.12±2.80;窝产活仔数相应分别为10.70±2.76、10.08±2.70和8.88±2.03;三个组的胎盘效率差异均极显著(P＜0.01).②用杜洛克公猪的精液作人工授精后,长大二元杂母猪高胎盘效率组(6.12±0.40)的总产仔数(12.75±0.45对10.78±0.52)、活产仔数(12.20±0.23对10.20±0.58)均极显著高于低胎盘效率组(5.13±0.37)(P＜0.01).     

母猪胎盘效率研究进展

本文对近年来母猪胎盘效率与产仔数关系的研究进行了综述 ,母猪的胎盘效率与其繁殖性有正相关关系 ,特别是与总产仔数和产活仔数 ,达极显著相关 ;不同品种猪的胎盘效率因猪体型、品种而有差异 ;胎盘效率遗传力为 0 .4 6 ,基于胎盘效率的选择是提高猪的窝产仔数的有效方法之一。     

断奶至配种间隔的遗传参数估计及影响因素分析

本研究旨在对断奶至配种间隔(下文简称"断配间隔")进行表型与遗传分析,探究其与各繁殖性状之间的相关,为其在育种中应用奠定基础。试验选取某核心场近6年繁殖记录,围绕断配间隔性状,对不同品种共7 843条繁殖记录进行影响因素的分析;利用DMU软件和动物模型估计了大白猪产后1周之内断奶发情间隔共3 297条繁殖记录断配间隔、总产仔数、产活仔数、初生窝重和仔猪均匀度的遗传力;并评估了各性状之间的表型和遗传相关。结果表明:胎次、母猪分娩季节和断奶日龄均对断配间隔有极显著影响(P0.01),不同水平总产仔数有显著影响(P0.05),品种效应接近显著;断配间隔、总产仔数、产活仔数、初生窝重和仔猪均匀度遗传力分别为0.046、0.077、0.093、0.110和0.047;断配间隔与产仔性能表型相关接近于0,遗传相关呈弱的正相关;与仔猪均匀度表型和遗传相关均呈弱的负相关。可见,总产仔数越多,断奶至配种间隔越长;仔猪均匀度越差,断配间隔反而越短。因此,在提高总产仔数的同时,应综合考虑对断奶发情间隔的选择。     

仔猪均匀度表型及遗传分析

本研究旨在对仔猪均匀度进行表型与遗传分析,探究其与各繁殖性状之间的相关,为其在育种中应用奠定基础。试验选取某核心场近6年产仔记录,利用DMU软件和动物模型估计了仔猪均匀度的加性方差、与配公猪效应方差和永久环境效应方差,计算各品种该性状遗传力;并评估了大白猪仔猪均匀度与主要繁殖性状(总产仔数、产活仔数、初生窝重、断奶仔猪数和21日龄窝重)之间的表型和遗传相关。结果表明:品种、胎次和母猪分娩年季对仔猪均匀度均有显著影响(P0.05);大白猪、长白猪和杜洛克猪遗传力分别达到0.059、0.065和0.027,与配公猪效应变化范围为0.008~0.014,永久环境效应变化范围为0.000~0.017;此外,表型与遗传相关结果较为接近,仔猪均匀度与总产仔数、产活仔数和初生窝重呈中等正相关,与断奶仔猪数和21日龄窝重相关均接近于0。随着产仔数的增加,仔猪整齐度逐渐减小。因此,在增加产仔数的同时,应考虑对仔猪均匀度的选择。     

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 -