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61.
1. Pullets allowed to self-select nutrients from a protein concentrate and either a separate complete diet or cereal-based, energy-rich mixture showed preferences for protein and energy which varied in relation to the time of their onset of lay. 2. The selected protein:metabolisable energy (ME) intake ratio increased from 14 g protein per MJ of ME 2 to 3 weeks before sexual maturity to approximately 19 g protein per MJ of ME at and after sexual maturity. 3. This response to self-selection feeding was consistent with different temperatures, lighting patterns and dietary manipulations. 4. Egg mass output was improved by self-selection feeding at hot (25 degrees to 35 degrees C) temperatures in experiments 1 and 2 and at ambient temperatures in experiment 3. No beneficial response in egg mass from self-selection feeding was observed at cold (6 degrees to 16 degrees C) temperatures in experiment 1. 5. Providing 2 h of additional light during the dark (cool) part of the day, with or without 2 h of darkness in the middle of the extended light (hot) period, had no effect on the egg mass output of pullets at hot (25 degrees to 35 degrees C) temperatures.  相似文献   
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Pigeon circovirus (picv) was detected in cloacal swab samples by means of a newly-developed, sensitive pcr. An initial investigation of 17 Belgian racing pigeons aged up to eight months showed that rates of detection of 88 per cent and above were achieved using samples of cloacal swab, blood and bursa of Fabricius. The sampling of 15 caged pigeons six times when they were from three to 31 weeks of age indicated that picv infections were more readily detected in cloacal swabs than in blood, and that the virus could be detected in cloacal swabs for longer periods after infection than in blood. picv infections were detected in cloacal swabs from 38 of 47 young pigeons aged from two to 31 weeks, from 12 racing lofts, which had clinical signs including diarrhoea and weight loss, regurgitation and respiratory signs. Samples from birds from two infected lofts indicated that picv could be detected in some birds for at least 27 weeks. Although nine of 14 pigeons aged from 32 to 45 weeks were virus-positive, picv was detected in only one of 18 adult pigeons that originated from four infected lofts.  相似文献   
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Letter to the Editor   总被引:1,自引:0,他引:1  
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The bovine and ovine TRG genes have previously been shown to be located in two loci, TRG1 and TRG2, in contrast to human and mouse TRG genes that are located in a single locus. The bovine TRG1 and TRG2 loci are located on chromosome 4 at 4q3.1 and 4q1.5-2.2, respectively. The complete genomic organization of the two bovine loci is described: each locus comprises three cassettes, each one includes one or several variable genes (TRGV) and one or several joining genes (TRGJ) preceding a constant (TRGC) gene. The location of the TRGC5 cassette is conclusively described in 5' of the TRG1 locus. Analysis of 17 TRGV belonging to 10 different subgroups, 8 TRGJ and 6 TRGC genes is conducted which comprises the most comprehensive list to date.  相似文献   
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This review approaches sheep welfare during the periparturient period from a veterinary practitioner viewpoint. At the most fundamental husbandry level, the general hygiene standards adopted on many sheep farms in the United Kingdom (UK) during the lambing period are unacceptable and require urgent improvement. Concerns also arise from obstetrical conditions attended by farmers which cause pain that can be identified using clinical criteria such as altered demeanour and behaviour of the ewe, and the presence of inflammation of the reproductive tract. Reduced production is evidenced by poor milk production and hungry lambs, the necessity to rear such lambs artificially and, in neglected cases, death of the ewe and her lambs. The correction of dystocia, periparturient vaginal, uterine and rectal prolapses is greatly facilitated after epidural injection of lignocaine, or a combination of xylazine and lignocaine administered by a veterinary surgeon. However, the perceived high professional fees charged for these services, and for Caesarean operations, result in few sheep receiving veterinary care, with such neglect directly contributing to poor welfare standards and an increased ewe mortality rate during the periparturient period. Whilst ending any welfare concern, the destruction of ewes rather than requesting veterinary services purely for economic reasons is a disturbing trend in sheep production in the UK and raises concerns regarding positive interaction between veterinary practitioner and farmer. In this article, veterinary treatments which provide effective analgesia are described and costed for obstetrical conditions in sheep. Recommended treatment protocols are described for the common obstetrical problems in sheep. In addition to appropriate treatment of obstetrical problems and alleviation of pain, if veterinary involvement could reduce ewe periparturient mortality from estimated figures of 4-2% this would save an estimated 400,000 ewes annually in the UK. Sheep welfare could be considerably improved by practising veterinarians providing practical instruction to small groups of clients with funding provided by government agencies.  相似文献   
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From 1991 to 2003, 24 cases of larval cyathostominosis were diagnosed at postmortem in equids, 15 (63%) from 2001 to 2003. Cases occurred from September to May, the majority from October to December. Median age was 12 mo. Diarrhea, colic, and weight loss were common clinical signs. Hypoalbuminemia and microcytosis were consistent findings.  相似文献   
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