Susceptibility to heartwater of calves born to non-immune cows

The resistance to artificial infection with Cowdria ruminantium of calves born to cows fully susceptible to heartwater is no different from that of calves bred in heartwater endemic areas where the tick challenge is negligible to considerable. The sub-inoculation into mice of blood collected 14-26 days after infection proved the presence of the heartwater agent in the blood of 8 out of 10 calves with no other clinical signs than mild to moderate fever. The combined use of a mouse model and the indirect fluorescent antibody test revealed considerable variation in the degrees to which calves become infected and react to artificial infection.     

如何确定奶牛成母牛的投料系数

据有关报道 ,奶牛成母牛的投料系数一般在１５～２５ %之间 ,但是实际情况到底要多少才能既节约成本 ,又满足奶牛成母牛的营养需要 ,也不影响牛奶的质量和产量。为此 ,我们进行了为期一年的实测 ,经过总结和分析认为 :①因为能量所需的投料系数大于其他项（包括ＤＭ、ＤＣＰ、Ｃａ、Ｐ等）的系数 ,所以投料系数以满足能量的需要为主。②投料系数根据不同的月份在７ ３４ %～３３ ５８ %之间。且环境温度越高 ,所需的投料系数越大。大家知道 ,奶牛成母牛的营养需要包括产奶需要、维持需要、生长阶段营养需要、妊娠的营养需要。环境温度变化 ,…     

Failure of young goats to acquire resistance to Haemonchus contortus

Two experiments were carried out to investigate the acquisition by goats of resistance to Haemonchus contortus. In Experiment 1, five Saanen wethers reared worm-free and averaging 51/2 months of age at the start of the experiment, were dosed with 200 H. contortus infective larvae three times per week for 10 weeks (approximately 23 infective larvae/kg mean initial liveweight/week) and then given anthelmintic treatment. Each goat and an equal number of worm-free controls were then challenged with 10,000 infective larvae. Post mortem worm counts were carried out 30 days later. In Experiment 2, eight worm-free Saanen wethers, 14 months old at the start of the experiment, were dosed with 825 infective larvae per week for 14 weeks (approximately 23 infective larvae/kg mean initial liveweight/week) except for one week when only 300 larvae were given and one week when no larvae were given. After anthelmintic treatment, each received, together with seven worm-free control animals, a challenge dose of 15,000 infective larvae. Post-mortem worm counts were carried out 28 days later. There were no significant dii- ferences in post-mortem worm counts between previously infected and uninfected groups in either experiment. In both experiments, serum pepsinogen values rose significantly as a result of infection but there was no significant (p>0.5) correlation between worm counts and pepsinogen values on the day of slaughter.     

Efficacy of the Boar-Operated-System to deliver baits to feral swine

Feral swine (Sus scrofa) pose a significant disease threat to livestock and humans. Emerging technologies to reduce feral swine disease transmission risks include fertility control, vaccination, and toxicants. However, for these technologies to be appropriate for field application, a feral swine-specific oral delivery system is needed. We used two field trials to generate information related to appropriate field application of the Boar-Operated-System (BOS?), an oral delivery system designed to provide bait access only to feral swine. Our objectives were to determine whether pre-baiting BOS? units increased bait removal and to evaluate the proportion of feral swine and non-target animals that ingest baits designed to deliver pharmaceuticals through the BOS?. During both trials we used baits housed within 10 BOS? units. We monitored wildlife visitation, bait removal, and ingestion using motion sensing digital photography and baits containing the bait marker tetracycline hydrochloride (TH). During trial 1 we found three of five pre-baited BOS? units were used by feral swine only. Additionally, we found the five BOS? units that were not pre-baited were not used by feral swine or non-target wildlife. During trial 2 we determined bait removal from the BOS? to be reduced by only 10% for feral swine when activated, whereas bait removal from the BOS? by all other wildlife was reduced by 100% when activated. We captured 81 feral swine and 23 raccoons and found 90% and 13% to have TH-marked teeth, respectively. With minor modifications, the BOS? should be considered a valuable tool to be used in feral swine disease management in conjunction with existing technologies.     

Failure of lungworm-larvae-infected earthworms to transmit mycoplasmal pneumonia to swine

Two herds of swine, believed to be free from mycoplasmal pneumonia of swine (MPS) based upon negative Mycoplasma hyopneumoniae microtiter complement fixation test (CFT) results, subsequently exhibited clinical signs of MPS.Lungworms (Metastrongylus spp.) were common to both herds. The possibility that lungworms could serve as a reservoir for M. hyopneumoniae was investigated. Lungworm-larvae-infected earthworms, collected from each of the farms, were fed to swine free of lungworms and MPS. This procedure resulted in lungworm infection in the recipient pigs, but failed to produce pneumonic lesions or CFT antibody titers against MPS.     

Failure of young goats to acquire resistance to Haemonchus contortus

Two experiments were carried out to investigate the acquisition by goats of resistance to Haemonchus contortus. In Experiment 1, five Saanen wethers reared worm-free and averaging 5 1/2 months of age at the start of the experiment, were dosed with 200 H. contortus infective larvae three times per week for 10 weeks (approximately 23 infective larvae/kg mean initial liveweight/week) and then given anthelmintic treatment. Each goat and an equal number of worm-free controls were then challenged with 10,000 infective larvae. Post mortem worm counts were carried out 30 days later. In Experiment 2, eight worm-free Saanen wethers, 14 months old at the start of the experiment, were dosed with 825 infective larvae per week for 14 weeks (approximately 23 infective larvae/kg mean initial liveweight/week) except for one week when only 300 larvae were given and one week when no larvae were given. After anthelmintic treatment, each received, together with seven worm-free control animals, a challenge dose of 15,000 infective larvae. Post-mortem worm counts were carried out 28 days later. There were no significant differences in post-mortem worm counts between previously infected and uninfected groups in either experiment. In both experiments, serum pepsinogen values rose significantly as a result of infection but there was no significant (p>0.5) correlation between worm counts and pepsinogen values on the day of slaughter.     

如何训练母鸡使用产蛋箱

产在地面垫料和棚架等产蛋箱外的种蛋统称地面蛋,地面蛋是脏蛋不能孵化,即使勉强上孵也会造成孵化器污染,增加实验室检测费用等.地面蛋过多使生产成绩大打折扣,无形中损失了很多利益.     

Benefits to foals of feeding soybean meal to lactating broodmares

In order to test the hypothesis that an improvement in the quality of the dietary protein fed lactating mares would improve the growth of their nursling foals, Thoroughbred mares were fed approximately isonitrogenous diets differing slightly in their amino acid compositions during the last 2 weeks of gestation and the first 7 weeks of lactation. The differences in the diets resulted from the substitution of a portion of the complete pelleted feed with soybean meal (SBM). The crude protein content of mares' milk was significantly increased by SBM substitution during the first 5 weeks of lactation. However, SBM did not prevent the gradual decline in protein content typical of mares' milk during the course of lactation. The relative amino acid composition of mares' milk was not changed by SBM substitution, suggesting that more growth-limiting amino acids were provided to the foals suckling from SBM-supplemented mares. The plasma concentrations of lysine, methionine, leucine, phenylalanine, histidine and valine were significantly greater in the foals of SBM-supplemented mares. Those foals grew in withers height about 10% more rapidly during their first 7 weeks of life. These findings indicate that the growth of nursing foals is responsive to the amino acid composition of their dams' diets.     

Effects of Betaine and Choline on Response to Methionine Supplementation to Broiler Diets Formulated to Industry Standards

A study was conducted to evaluate the Met-sparing effects of the methyl donors, choline (CHO) and betaine (BET). Male broilers of a commercial strain were fed corn-soybean meal-based diets formulated to meet nutritional levels typical of top broiler producers. Diets were fortified with a complete vitamin premix devoid of CHO. In test diets, Met levels were as formulated, or less 0.05, 0.10, 0.15, or 0.20% Met. Within each Met level, diets received no supplemental CHO or BET or 1,000 mg of CHO/kg, 1,000 mg of BET/kg, or a combination of 500 mg each of CHO and BET/kg. This resulted in a 4 × 5 factorial arrangement with each of the 20 treatments fed to 4 pens of 60 birds for a 56-d feeding trial. Samples of birds were processed at 42, 49, and 56 d to determine parts yield and dressing percentage. Intestinal segments were evaluated for tensile strength at these same ages.The dietary Met level had no significant impact on BW at 14 or 56 d of age, but at 35, 42, and 49 d reduction of the Met content resulted in loss of BW. Feed conversion was not affected by the Met level at 14 d but was significantly affected by reducing the Met level at all other ages. Breast meat yield was reduced in a linear manner by reductions in Met supplementation. The CHO or BET supplementation had no apparent sparing effect on Met needs but did improve feed conversion at 35 and 42 d. There was a positive effect of CHO and BET on breast yield that was independent of Met levels; CHO was as effective as BET for this purpose. No effect of CHO or BET on intestinal strength was observed in the present study.     

Use of laboratory data to reduce the time taken to detect new diseases: VIDA to FarmFile

The analysis of laboratory data can provide information about the health of livestock populations; in Great Britain the Veterinary Investigation Diagnosis Analysis (VIDA) system has provided such data since 1975. However VIDA covers only known diagnoses, with limited epidemiological characterisation. The unexpected outbreak of bse showed that it was necessary to improve surveillance to detect new diseases, and a necessary update of the VIDA database for the millennium date change provided the opportunity. The information required to enhance the value of laboratory data was identified, a new form and database, 'FarmFile', were designed to record it, and they began to be used in 1999. The detection of new diseases depends on making comparisons with the expected or 'usual' levels of unexplained disease. The data are analysed quarterly to assess any changes in the levels of unexplained disease in different species, categorised in terms of clinical sign or body system, by comparison with previous years. No new diseases have been detected either through FarmFile or more traditional means since the new analyses started in earnest in 2004, but they have indicated that an unexplained event was not a new disease of concern, and developments continue to improve the system's sensitivity and specificity.     

Gustatory responses of pigs to sixty compounds tasting sweet to humans

The gustatory responses of pigs to 60 compounds perceived as sweet by humans were studied via a semi-quantitative behavioural method derived from the Richter two-bottle preference test. Among the 60 compounds tested 35 are effective in pigs, but with an effectiveness much lower in pigs than in humans. Lugduname and carrelame, which are the two most potent sweeteners in humans, are also the most effective compounds in pigs.     

畜牧业如何应对金融危机

一、影响因素分析 1.宏观形势的间接影响.人们常说"猪粮安天下",畜牧业是国民经济中的基础产业,更多的是依赖自然资源、国内市场拓展、国内政策环境.近年来,河南省济源市的畜牧业在市委、市政府大力扶持下,得到较快发展.