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AIMS: To determine the effect of providing water within the area grazed by dairy cows on milk yield and quality, compared to requiring cows to walk to a distant water trough, on a dairy farm in the Pampa region of Argentina during summer.

METHODS: Holstein dairy cows were allocated to two herds with similar parity, days in milk and milk production. They were grazed in one paddock that was divided in two, with a fixed water trough at one end. Cows were moved twice daily to grazing plots within the paddock. Control cows (n=66) could only access water from the fixed trough, whereas supplemented cows (n=67) also received water from a mobile trough within the grazing plot. Milk production of each cow, and water consumption of the two herds were measured daily over 62 days. Milk composition for each herd was determined weekly from Days 18 to 60 of the study, and grazing behaviour was observed between 08:00 and 16:00 hours on Days 11–15, 19–22 and 39–43.

RESULTS: Over the 62 days of the study, supplemented cows produced 1.39 (SE 0.11) L/cow/day more milk than Control cows (p=0.027). Estimated mean daily water intake was 50.4 (SE 2.1) L/cow/day for supplemented cows and 58.2 (SE 2.7) L/cow/day for Control cows (p=0.004). Percentage total solids in milk was higher for supplemented (12.5 (SE 0.06)%) than Control (12.4 (SE 0.04)%) cows (p=0.047). During the periods of behavioural observation, a higher percentage of cows in the water supplemented than the Control herd were observed in the grazing area (p=0.012).

CONCLUSIONS AND CLINICAL RELEVANCE: This preliminary study demonstrated that provision of water to dairy cows within the grazing plot was beneficial for milk production and composition, and may be associated with longer periods spent within the grazing area, during hot weather in the Pampa region of Argentina.  相似文献   

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Cooling stored epididymal samples for several days allows facilities to transport and process genetic material post‐mortem. Improvements to this practice allow the preservation of sperm from domestic cats, which are the ideal study model for wild felids. However, the modifications in spermatic features and the oxidative profile are not fully understood in cats. This information is necessary for the development of biotechniques, such as new extenders for cryopreservation. Therefore, the purpose of this study was to evaluate the spermatic and oxidative profile in samples from the epididymal cauda of domestic cats cooled at 5°C for 24, 48 and 72 hr. Spermatozoa were collected from the epididymis cauda. Evaluations consisted of computer‐assisted sperm analysis (CASA), plasma membrane integrity (eosin/nigrosin), acrosome integrity (fast green/rose bengal), sperm morphology, sperm DNA integrity (toluidine blue), mitochondrial activity (3′3 diaminobenzidine), activity of the antioxidant enzymes glutathione peroxidase (GPx) and superoxide dismutase (SOD), measurement of lipid peroxidation (TBARS) and protein oxidation. A decrease in sperm motility parameters was observed after 72 hr of cooling (i.e. total and progressive) with a higher percentage of minor (37.7 ± 6.3%) and total defects (53.4 ± 6.3%). Additionally, a decrease in high mitochondrial activity (Class I: 16.6 ± 2.2%) occurred after 72 hr. The decrease in motility rates after a long cooling time probably was caused by the increase in sperm abnormalities. A long cooling time causes cold shock and mitochondrial exhaustion, but there was no observed change with the oxidative stress condition. Therefore, cat epididymal sperm stored at 5°C appear to maintain a high quality for up to 48 hr of cooling time.  相似文献   
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The bovine embryonic signal interferon‐τ (IFN‐τ) produced by the trophoblast is known to pass through the uterine fluid towards the endometrium and further into the maternal blood, where IFN‐τ induces specific expression of interferon‐stimulated gene expression (ISG), for example in peripheral leucocytes. In sheep, it was shown experimentally by administration of IFN‐τ that ISG is also detectable in the liver. The objective was to test whether ISG can be detected in liver biopsy specimens from Holstein–Friesian heifers during early pregnancy. Liver biopsies were taken on day 18 from pregnant and non‐pregnant heifers (n = 19), and the interferon‐stimulated protein 15 kDa (ISG‐15) and myxovirus‐resistance protein‐1 (MX‐1) gene expression was detected. The expression of both MX‐1 (p: 24.33 ± 7.40 vs np: 9.00 ± 4.02) and ISG‐15 (p: 43.73 ± 23.22 vs 7.83 ± 3.63) was higher in pregnant compared to non‐pregnant heifers (p < 0.05). In conclusion, pregnancy induced ISG‐15 and MX‐1 gene expression in the liver already at day 18 in cattle.  相似文献   
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This article considers the experiences of a Samoan female geographer undertaking community‐based field research in her home country, and identifies some lessons for researchers working in similar circumstances. The paper suggests that ethical behaviour in research is ‘place‐specific’, and there is therefore a need to employ culturally sensitive and ‘location‐specific’ methodologies when undertaking community‐based research fieldwork. For the lead researcher, growing up in Samoa played a significant role in gaining an understanding of a set of robust and effective procedures to evaluate citizens' resilience to climatic and other environmental challenges. Fluency in everyday and more formal local languages, and awareness of local differences, each with multi‐layered connections to local communities, understanding cultural nuances and practising respect for va tapuia [sacred space or relationships] protocols, together facilitated the process of knowledge acquisition and helped to confirm the validity of the conclusions derived from the study.  相似文献   
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Sheep peripheral blood lymphocytes have been studied using a number of surface markers. Thus 16.6 ± 2.4% (mean ± S.E.) were surface immunoglobulin positive (sIg+) by direct immunofluorescence, 35.9 ± 2.1% formed Fc rosettes with bovine red blood cells (RBC) sensitized with rabbit antibody (Fc+) and 28.4 ± 2.0% formed rosettes with sheep red blood cells (RBC) in the presence of 4% dextran (DS+). The percentage of both Fc+ and DS+ lymphocytes tended to increase with age of the animals. Demonstration of these markers allowed computation of two further subpopulations: null cells lacking sIg and a receptor for sheep RBC, and Fc·null cells lacking a receptor for Fc and sheep RBC. The former population, which contained a proportion of Fc+ lymphocytes comprised 49.8 ± 3.8% of blood lymphocytes and the latter 38.4 ± 3.0%.Separation on nylon wool columns, selective rosette enrichment and depletion on density gradients and stimulation with phytomitogens have shown sIg+ and Fc+ lymphocytes to be nylon wool adherent and unresponsive to phytohaemagglutinin (PHA) and Concanavalin A (Con A) and DS+ lymphocytes to be nylon wool non-adherent and responsive to PHA and Con A. The data also indicates a major overlap of the lymphocyte subpopulations bearing sIg and Fc which are apparently B lymphocytes. Moreover these data support the contention that E-rosette formation with sheep RBC in the presence of dextran is a marker for sheep T cells. The data also indicates that Fc·null cells are T cells, eluting in the non-adherent fraction from nylon wool. It is probable that a proportion of these cells bear a SRBC receptor too weak for present detection methods.  相似文献   
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Blood samples from 426 healthy and sick cats in the UK were tested in a PCR assay for 'Candidatus Mycoplasma haemominutum' and Mycoplasma haemofelis (basonym Haemobartonella felis). Seventy-two of the cats (16.9 per cent) were positive for 'Candidatus M. haemominutum' alone, six (1.4 per cent) were positive for M. haemofelis alone and one (0.2 per cent) was positive for both. Logistic regression analysis indicated that older male cats were significantly more likely to be infected with 'Candidatus M. haemominutum', but there was no significant association between it and any of the haematological variables measured. M. haemofelis infection was uncommon in the anaemic cats sampled, and there were too few positive cases for multivariable analysis to be performed for M. haemofelis-positive status.  相似文献   
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