4 resultados para broiler chicks
em Biblioteca Digital da Produção Intelectual da Universidade de São Paulo (BDPI/USP)
Resumo:
This study aimed at evaluating the thermal performance of a modular ceiling system for poultry houses. The reduced- and distorted-scale prototypes used ceiling modules made of reforested wood and were covered with recycled long-life package tiles. The following parameters were measured for 21 days: the internal surface temperature (ST), globe temperature and humidity index (WBGT), and radiant heat load (RHL). Measurements were made at times of highest heat load (11:00 am, 13:00 pm, and 03:00 pm). Collected data were analyzed by ""R"" statistics software. Means were compared by multiple comparison test (Tukey) and linear regression was performed, both at 5% significance level. The results showed that the prototype with the ceiling was more efficient to reduce internal tile surface temperature; however, this was not sufficient to provide a comfortable environment for broilers during the growout. Therefore, other techniques to provide proper cooling are required in addition to the ceiling
Resumo:
Sampling protocols for detecting Salmonella on poultry differ among various countries. In the United States, the U.S. Department of Agriculture Food Safety and Inspection Service dictates that whole broiler carcasses should be rinsed with 400 ml of 1% buffered peptone water, whereas in the European Union 25-g samples composed of neck skin from three carcasses are evaluated. The purpose of this study was to evaluate a whole carcass rinse (WCR) and a neck skin excision (NS) procedure for Salmonella and Escherichia coli isolation from the same broiler carcass. Carcasses were obtained from three broiler processing plants. The skin around the neck area was aseptically removed and bagged separately from the carcass, and microbiological analysis was performed. The corresponding carcass was bagged and a WCR sample was evaluated. No significant difference (alpha <= 0.05) in Salmonella prevalence was found between the samples processed by the two methods, but both procedures produced many false-negative Salmonella results. Prechill, 37% (66 carcasses), 28% (50 carcasses), and 51% (91 carcasses) of the 180 carcasses examined were positive for Salmonella by WCR, NS, and both procedures combined, respectively. Postchill, 3% (5 carcasses), 7% (12 carcasses), and 10% (17 carcasses) of the 177 carcasses examined were positive for Salmonella by the WCR, NS, and combination of both procedures, respectively. Prechill, E. coli plus coliform counts were 3.0 and 2.6 log CFU/ml by the WCR and NS methods, respectively. Postchill. E. coli plus coliform counts were 1.7 and 1.4 log CFU/ml by the WCR and NS methods, respectively.
Resumo:
This work aimed at evaluating the effects of the supplementation of starter diet with Arg on breast muscle development in broilers and the activation of satellite cells and the aggregation of myofibrillar protein. Male Cobb chicks (n = 990) were randomly assigned to 1 of 5 treatments in a complete random design. Measurements of 33 chicks per treatment were made in 6 repetitions. The treatments consisted of a basal diet with 1.390% digestible Arg (without supplementation) and 4 dietary levels of Arg (1.490, 1.590, 1.690, and 1.790%) with Arg:Lys ratios of 1.103, 1.183, 1.262, 1.341, and 1.421, respectively. Arginine supplementation was used only in the starter phase (1 to 21 d). Dietary supplementation with Arg had a positive effect (P < 0.05) on breast and breast fillet weight on d 7 and 21 and on myofiber diameter on d 14 and 21. However, no effect was observed (P > 0.05) on the protein: DNA ratio, which demonstrates that Arg does not interfere with the mitotic activity of the satellite cells. Independently from mechanism, Arg affected muscle growth in the starter phase positively. Dietary supplementation with Arg in the starter phase had no effect (P > 0.05) on the carcass yield of broilers on d 42. Diet supplementation with Arg at levels above the ones recommended for the starter phase may be necessary for improved muscle development in broilers.
Resumo:
We studied clutch size, hatching and fledging success, and time necessary for chick Kelp Gulls (Larus dominicanus) to leave the nest throughout two breeding seasons (2004 and 2005) on Guararitama Island, Sao Paulo, Brazil. We followed 93 nests in 2004 and 97 nests in 2005. The average (+/- SD) clutch size was 2.09 +/- 0.64 in 2004 and 1.93 +/- 0.59 in 2005. Hatching success was 74% in 2004 and 53% in 2005, and fledging success was 54% in 2004 and 58% in 2005. Chicks grew quickly, following the linear equation y(t) = 61g + 17.03g X age (in days), and began to fly at 40 days. Received 11 August 2008. Accepted 28 August 2009.