影响母猪繁殖性能的传染性疾病及防制措施

影响母猪繁殖性能的因素很多，有遗传、饲养管理及传染性疾病等方面的因素。现就目前影响母猪繁殖性能的主要传染性疾病综述如下。     

提高母猪繁殖力的综合措施

影响母猪繁殖性能的因素很多,如遗传、营养、饲养管理、热应激和疫病等因素。选留优秀的后备母猪,加强母猪饲养管理,及时淘汰性能低的母猪,严格控制各类疾病等综合措施可有效提高母猪的繁殖性能。     

谈母猪的饲养

谈母猪的饲养余佳胜母猪群及其繁殖效率决定了养猪生产的经济效益。母猪繁殖性能的影响因素很多，其中包括遗传因子，因此养猪者应该饲养产仔数多的品种。但营养、环境和疾病对母猪繁殖性能的影响更大；所以母猪的饲养和疾病防治对养猪生产更为重要。本文对母猪的饲养管理...     

小规模场母猪繁殖性能提高措施

母猪繁殖性能指标的高低是衡量一个猪场现代化、专业化的重要指标之一,直接影响到饲养成本、生产成绩及生产利润。母猪繁殖性能与品种、营养、饲养管理、疾病、精液质量等因素密切关联,如何提高母猪繁殖性能显得尤为重要。     

规模化猪场母猪饲养管理要点

提高规模化养猪场母猪的饲养管理水平,有利于控制母猪繁殖障碍的疾病发生,提高母猪繁殖力,增加窝产活仔数和增强母猪的抵抗能力,对养猪行业有重要作用。本文从空怀母猪、妊娠母猪、分娩母猪、哺乳母猪等方面简述了不同生理阶段母猪饲养管理要点;从提高繁殖力、发情鉴定与适时配种等方面阐述了提高母猪生产繁殖性能的饲养管理要点;同时,又简述了猪舍环境卫生控制的技术要点。     

妊娠母猪流产的综合防治

妊娠母猪流产的防治措施可以通过疾病的预防、早期诊断和治疗,妊娠母猪饲养管理措施以及饲养环境的改善,营养饲料的充分供给等方面进行,保障妊娠母猪良好的健康状况和繁殖性能。     

后备母猪的科学饲养管理措施

随着畜牧养殖产业的快速发展,生猪养殖的规模和数量获得显著的提高,生猪养殖产业的快速发展离不开种母猪良好的繁殖性能,其中后备母猪的科学饲养对于母猪繁殖性能的提高具有非常关键的作用。后备母猪养殖中主要需要通过做好母猪的发情管理,饲养环境的合理控制以及常见养殖疾病的预防和治疗等措施改善,同时需要把控好后备母猪养殖中的体重和体况,避免后备母猪出现过肥或者过瘦影响繁殖性能的下降。本文将对后备母猪养殖中科学的饲养管理措施进行介绍,旨在为后备母猪的科学饲养以及我国生猪养殖产业的健康发展提供帮助。     

提高母猪繁殖力的重要措施

正母猪繁殖性能的高低直接影响着全场的生产成绩和经济效益。然而,影响母猪繁殖性能的因素众多,品种、营养、疾病、管理和人工授精技术水平等因素都能影响母猪繁殖性能的发挥。为实现高产、优质、高效的养猪目标,就必须综合考虑以提高母猪的繁殖力。本期主题,我们将从遗传、饲养管理等,以及结合当前的人工授精技术对母猪繁殖力的提高进行探讨     

影响母猪繁殖性能的因素及解决措施

母猪的繁殖性能直接决定着养殖业者的经济效益,本文综述了影响母猪繁殖性能的主要因素,包括母猪的选育、营养水平、饲养管理和疾病等,并结合实践提出了相应的解决措施,以期为养殖业者提供一定的参考。     

母猪各阶段饲养管理技术

母猪在猪群繁殖各环节中占据着重要的地位，高质量的饲养管理措施对母猪繁殖性能的影响也是较为显著的。母猪高饲养管理策略，必需要落实到各个阶段。文章分别自后备母猪及空怀母猪的饲养管理、怀孕母猪的饲养管理、哺乳母猪饲养管理，介绍母猪各阶段饲养管理技术，为今后科学养殖、提升养殖效益，提供理论和技术指导。     

Salmonella in pork cuttings in supermarkets and butchers' shops in Denmark in 2002 and 2006

The prevalence of Salmonella in fresh pork cuttings in Denmark in the years 2002 and 2006 was investigated at retail and compared with the retail supply pattern. A total of 1025 and 3473 samples were taken in 2002 from butcher's shops and supermarkets, respectively. The corresponding numbers in 2006 were 259 from butchers' shops and 628 from supermarkets. In 2002, 1.2% of all samples were positive for Salmonella; butchers' shops and supermarkets had 1.8% and 1.0% positive samples, respectively. The overall prevalence in 2006 was 4.2%, with prevalence of 8.1% and 2.6% for butchers' shops and supermarkets, respectively. Hence, increases around 3- to 5-fold were found. There was neither observed any parallel increase in Salmonella positive carcasses in Danish slaughterhouses during the study period, nor were any changes in supply routes towards slaughterhouses with higher prevalence observed, which could explain the apparent increase. We hypothesize that hygiene levels and ability to avoid cross-contamination and prevent growth of the organism, in the meat processing chain after slaughter were the most likely responsible factors. Results from this study indicate that the hygiene performance, particularly at retail, has a significant impact on the occurrence of Salmonella. This implies that there is no direct link between slaughterhouse Salmonella surveillance data and the level of Salmonella contamination at retail. To improve risk assessment of Salmonella in fresh pork meat, this study underlines the need for comprehensive retail data.     

Sanguinarine metabolism and pharmacokinetics study in vitro and in vivo

Sanguinarine (SA) is a benzo[c] phenanthridine alkaloid which has a variety of pharmacological properties. However, very little was known about the pharmacokinetics of SA and its metabolite dihydrosanguinarine (DHSA) in pigs. The purpose of this work was to study the intestinal metabolism of SA in vitro and in vivo. Reductive metabolite DHSA was detected during incubation of SA with intestinal mucosa microsomes, cytosol, and gut flora. After oral (p.o.) administration of SA, the result showed SA might be reduced to DHSA in pig intestine. After i.m. administration, SA and DHSA rapidly increased to reach their peak concentrations (C_max, 30.16 ± 5.85, 5.61 ± 0.73 ng/ml, respectively) at 0.25 hr. Both compounds were completely eliminated from the plasma after 24 hr. After single oral administration, SA and DHSA rapidly increased to reach their C_max (3.41 ± 0.36, 2.41 ± 0.24 ng/ml, respectively) at 2.75 ± 0.27 hr. The half-life (T_1/2) values were 2.33 ± 0.11 hr and 2.20 ± 0.12 hr for SA and DHSA, respectively. After multiple oral administration, the average steady-state concentrations (C_ss) of SA and DHSA were 3.03 ± 0.39 and 1.42 ± 0.20 ng/ml. The accumulation indexes for SA and DHSA were 1.21 and 1.11. The work reported here provides important information on the metabolism sites and pharmacokinetic character of SA. It explains the reasons for low toxicity of SA, which is useful for the evaluation of its performance.     

Chlortetracycline in swine-bioavailability and pharmacokinetics in fasted and fed pigs

Chlortetracycline hydrochloride was administered intra-arterially (11 mg/kg) and as an oral drench (33 mg/kg) to ten 21.0-31.5-kg pigs. Five of the pigs were fasted 18 h prior to dosing and five of the pigs were fed ad libitum prior to dosing. The mean volume of distribution determined by area-under-the-curve calculations for the fasted pigs (0.967 +/- 0.210 l/kg) was significantly less (P less than 0.05) than the mean volume of distribution for the fed pigs (1.39 +/- 0.31 l/kg). Mean total body clearance of the drug was also significantly less (P less than 0.05) in the fasted pigs (0.165 +/- 0.055 l/kg/h) as compared to the fed pigs (0.307 +/- 0.053 l/kg/h). The elimination constants (beta) were not found to be statistically different (P less than 0.05): 0.1811 +/- 0.0057 for the fasted pigs; 0.2260 +/- 0.0461 for the fed pigs. The bioavailability for both groups was similar; 19.12 +/- 8.3% for the fasted pigs and 17.88 +/- 5.3% for the fed pigs. In a second experiment three groups of six pigs which weighed 34.5-44.1 kg were fed a corn-soy diet ad libitum. The rations were fortified with chlortetracycline at 100, 400 or 1000 mg chlortetracycline hydrochloride/kg feed. Chlortetracycline concentrations were determined in plasma samples collected over a 6-day period. Plasma chlortetracycline concentrations reach a plateau within 24 h after initial access to the trial diets and were highly correlated with the dose of the drug consumed (r2 = 0.97).     

Helminth and protozoan parasites in dogs and cats in Belgium

This study investigates the level of helminthic and protozoal infestation over the last 10 years in strays, well-cared-for dogs and cats. Determination of the prevalence of infections was based either on faecal examination or on worm counts at necropsy. Of 2324 faecal flotations (NaCl sp.gr. 1.20) of stray dogs, 34.2% had eggs or proglottids of one or more worm species consisting of Toxocara canis (17.4%), Toxascaris leonina (10.1%), Uncinaria stenocephala (11.4%), Trichuris vulpis (7.0%) and cestodes (2.1%). Isospora oocysts were observed in 5.2% of the dogs. The data on the distribution of the various worm species in the positive dogs indicate that T. canis eggs were by far the most common (50.9%). Necropsy data from 212 infected dogs indicate that 38.9% were infected with T. canis and 33.7% with T. leonina. The overall prevalence of worm infestation of 246 well-cared-for kennel dogs, based on worm egg counts by the McMaster technique, was 36.1%. Of 30 feline faecal samples examined by flotation, 83.3% were positive for parasites, including Toxocara cati (60%), Ancylostoma tubaeformae (36.6%), Taenia (Hydatigera) taeniaeformis (20%) and coccidia (30%). Toxocara cati was the most frequently found worm species at the necropsy of 25 cats (52%). Toxoplasma was not observed.     

2005年国内蛋、肉鸡市场分析回顾及2006年走势预测

2005年如果没有年底的禽流感疫情,对于我国蛋鸡、肉鸡生产来说应该是一个非常完美的丰收年,是哪些因素导致了2005年蛋鸡市场如此好的行情?2006年我国家禽市场又将走向何方?……作者对以上热点问题进行了深入分析研究,供读者参考。     

Pharmacokinetics of penicillin-G in ewes and cows in late pregnancy and in early lactation

Concentrations of penicillin-G in serum were determined after single intravenous doses of potassium penicillin-G (10 mg/kg body wt) to ewes and cows in late pregnancy and in early lactation. Penicillin-G in serum was analysed by a microbiological method and pharmacokinetic parameters were calculated by model-independent methods. Serum concentrations were lower in early lactation than in late pregnancy in both ewes and cows. The differences were statistically significant at most sampling times in ewes but only during the first hour in cows.
Weight corrected values of clearance and volume of distribution were significantly higher in early lactation than in late pregnancy in both ewes and cows. Mean residence time and elimination-half life were shorter in lactating than in pregnant ewes, however for the latter parameter the difference was not statistically significant. Neither of these parameters changed in cows.
It is concluded that in both ewes and cows pharmacokinetic parameters of penicillin-G are altered from late pregnancy to early lactation but that these changes have little practical impact and do not call for a revised dosage regime of the studied drug.     

Salmonellae and Campylobacters in Household and Stray Dogs in Northern Taiwan

Rectal swabs were collected from 437 household and 491 stray dogs in northern Taiwan from May 2003 to June 2005 to investigate the prevalence and antimicrobial susceptibilities of salmonellae and campylobacters. The results revealed that 2.1% of household dogs and 6.3% of stray dogs were positive for salmonellae, with Salmonella Duesseldorf being the most dominant serotype in both. Additionally, 2.7% of the household dogs and 23.8% of the stray dogs were positive for campylobacters. Campylobacter jejuni was the most prevalent species (86.8%), followed by C. upsaliensis (9.3%) and C. coli (3.9%). Both salmonella and campylobacter isolation rates from the stray dogs were significantly higher than those from the household dogs (p < 0.01). The susceptibility of 33 C. jejuni isolates to eight antimicrobials was studied by the E-test. A high rate of resistance was observed to azithromycin (93.9%), clindamycin (87.9%), erythromycin (81.8%), tetracycline (78.8%), chloramphenicol (69.7%), nalidixic acid (51.5%), gentamicin (33.3%), and ciprofloxacin (18.2%). The susceptibility of 40 Salmonella isolates to 15 antimicrobials was also studied by the disc-diffusion method. All the Salmonella isolates were susceptible to ciprofloxacin and ceftriaxone. Resistance was observed most frequently to tetracycline (77.5%), chloramphenicol (52.5%), and ampicillin (50%).