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K Ashley S Wilson JR Young HP Chan S Vitou S Suon PA Windsor RD Bush 《Tropical animal health and production》2018,50(1):63-73
Forage technology has been successfully introduced into smallholder cattle systems in Cambodia as an alternative feed source to the traditional rice straw and native pastures, improving animal nutrition and reducing labour requirements of feeding cattle. Previous research has highlighted the positive impacts of forage technology including improved growth rates of cattle and household time savings. However, further research is required to understand the drivers, challenges and opportunities of forage technology for smallholder cattle households in Cambodia to facilitate widespread adoption and identify areas for further improvement. A survey of forage-growing households (n = 40) in July–September 2016 examined forage technology adoption experiences, including reasons for forage establishment, use of inputs and labour requirements of forage plot maintenance and use of forages (feeding, fattening, sale of grass or seedlings and silage). Time savings was reported as the main driver of forage adoption with household members spending approximately 1 h per day maintaining forages and feeding it to cattle. Water availability was reported as the main challenge to this activity. A small number of households also reported lack of labour, lack of fencing, competition from natural grasses, cost of irrigation and lack of experience as challenges to forage growing. Cattle fattening and sale of cut forage grass and seedlings was not found to be a widespread activity by interviewed households, with 25 and 10% of households reporting use of forages for these activities, respectively. Currently, opportunities exist for these households to better utilise forages through expansion of forage plots and cattle activities, although assistance is required to support these households in addressing current constraints, particularly availability of water, if the sustainability of this feed technology for smallholder cattle household is to be established in Cambodia. 相似文献
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PA Accorsi N Govoni R Gaiani C Pezzi E Seren C Tamanini 《Reproduction in domestic animals》2005,40(3):217-223
Leptin may play a role in the endocrine-metabolic processes that guarantee the physiological course of lactation in dairy cattle. This study was aimed at determining the changes in plasma concentrations of leptin and some of the main hormones and metabolites involved in the lactogenetic process in high-yielding dairy cows throughout lactation; we also wanted to assess whether leptin secretion is subjected to seasonal influences. Blood samples were collected from 23 Italian Friesian dairy cows from the end of a lactation to the ninth month of the subsequent one; in addition, blood was sampled from 47 dairy cows in different phases of lactation during February and July. Plasma concentrations of leptin, growth hormone (GH), insulin, prolactin (PRL), glucose, non-esterified fatty acids (NEFA) and urea were quantified by either validated radioimmunoassay (RIA) or enzymatic colorimetric methods. At the beginning of lactation, GH concentrations significantly increased, while a significant reduction occurred in leptin and insulin. This endocrine condition, such as the significant increase in NEFA plasma concentrations, is indicative of a marked lipid mobilization. In the more advanced stages of lactation, when both energy and protein balances become positive, leptin plasma concentrations increased, whereas GH and NEFA concentrations declined. During the summer months, a significant increase in leptin plasma concentrations, irrespective of the phase of lactation, was observed. Collectively, our findings suggest that, in dairy cows, leptin may represent a 'metabolic signal' of animal's status of fattening and nutritional level; in addition, leptin seems to be influenced by photoperiod and environmental temperature. 相似文献
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Arp H 《Science (New York, N.Y.)》1971,174(4015):1189-1200
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L H Arp 《American journal of veterinary research》1985,46(12):2644-2647
Young turkeys (n = 20) were inoculated IV with fimbriated, virulent Escherichia coli ECl (O78:K80: H9:F1). Blood samples were collected for bacterial quantitation at postinoculation minutes (PIM) 10, 20, 30, 40, 50, and 60. Immediately after the PIM 30 sampling, the turkeys were allotted into 4 groups (5 turkeys/group) and were injected IV with 1 of the following antisera: group 1, antibodies to F1 fimbriae (AF); group 2, antibodies to E coli O78 antigen (AO); group 3, antibodies to live, fimbriated (F1+) homologous E coli (ALEC); or group 4, normal turkey serum (NTS) collected from a healthy turkey. Compared with NTS, ALEC and AO caused a significant reduction in blood-borne E coli, whereas AF did not reduce bacterial numbers. In addition, 2 groups of 10 turkeys were inoculated IV with live, F1+ or nonfimbriated (F1-) E coli ECl. Numbers of viable bacteria were determined in blood samples and liver specimens collected 2 minutes after inoculation. Compared with F1- bacteria, significantly more F1+ bacteria were found in liver specimens and significantly fewer F1+ bacteria were found in blood samples. Results indicated that antibodies to F1 fimbriae do not enhance clearance of F1+ E coli from the bloodstream of turkeys probably because F1+ bacteria are selectively cleared by the liver, even without antibody. 相似文献
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Identification of Bordetella avium antigens recognized after experimental inoculation in turkeys 总被引:3,自引:0,他引:3
Sera and tracheal washings (TW) were used to identify antigens of Bordetella avium recognized during experimentally induced bordetellosis in young turkeys. Pooled sera and TW were examined for antibody by a microtitration agglutination test and by western immunoblotting. In addition, comparable samples collected from 1-day-old turkeys and uninoculated control turkeys also were examined. At least 8 outer membrane proteins of B avium were recognized in immunoblots of sera and TW from infected turkeys. Reactivity of TW in immunoblots was qualitatively similar but less intense, compared with reactivity of corresponding sera collected on postinoculation (PI) weeks 2, 3, and 4. Molecular weights of the major outer membrane proteins of B avium recognized by sera and TW at PI week 4 were 100,000, 97,000, 36,000, 31,000, 21,000, 18,000, 14,000, and less than 14,000. A protein with a molecular weight of 55,000 reacted nonspecifically in all samples tested. Antibody, detectable by microtitration agglutination, was in sera of 1-day-old turkeys and in sera and TW of B avium-infected turkeys during PI weeks 2 to 4. 相似文献