RESUMO
The objective was to estimate the incidence of and to determine the effect of some risk factors on the decrease of litter size at parity 2 of sows in three commercial farms in Yucatan, Mexico. Data on 8,592 farrowing records of 4,296 sows were analyzed using a binomial logistic regression procedure. The model included the fixed effect of farm (1, 2, and 3), year of farrowing (2003-2011), season of farrowing (dry, rainy, and windy), number of pigs born alive at first parity (<9, 9-10, 11-12, and >12 piglets), lactation length (<18, 18-24, and >24 days), and weaning to conception intervals (<4, 4-11, and >11 days). Fifty-five point eight percent of all sows presented a reduced or similar litter size at parity 2. The odds of decrease in the second litter size were 1.56 and 2.01 for farms 2 and 3, respectively. Higher odds were found for sows farrowing during the rainy and dry seasons (1.20 and 1.24, resp.) and for sows with large litters at parity 1 (>12 piglets, odds = 33.2). Sows with weaning to conception intervals <4 days and between 4 and 11 days had higher odds of a decrease in the second litter (1.78 and 2.74 pigs, resp.).
Assuntos
Tamanho da Ninhada de Vivíparos/fisiologia , Suínos/fisiologia , Animais , Feminino , Lactação/fisiologia , Paridade , Gravidez , Fatores de Risco , Estações do Ano , Fatores de Tempo , DesmameRESUMO
The objective of this study was to determine the effect of some factors on the length of productive life (LPL), the number of parities (NP), and the culling interval (CI) of sows. The information from 2003 to 2009 of 3,746 sows with LPL and NP records and 5,819 sows with CI records from the four farms of Yucatan, Mexico was used. LPL was defined as the number of days between the first farrowing and culling or death and CI as the number of days between the last farrowing and culling. To determine the effects of farm, litter size at first farrowing (LSF1) and age at first farrowing (AF1) on LPL and NP, and of farm, LSF1 and culling reason on CI general linear models were used. Means and standard errors for LPL, NP, and CI were 496.4 ± 8.42 days, 3.35 ± 0.04 parities, and 48.3 ± 0.52 days, respectively. All factors had significant effects (P < 0.05) on LPL, NP, and CI. The sows from farm 2 stayed longer (806.0 days) and had more parities (5.25) than the sows from the other farms. Sows with the smallest litters (≤8 piglets) at first farrowing stayed the least time in the farm (675.1 days) and had the fewest parities (4.49). Gilts farrowing the first time before 331 days of age stayed longer time in the farm (726.4 days) and had more parities (4.81) in comparison with 331-348 and more than 348 days age groups. With respect to CI, the sows in farm 3 stayed the longest time in the farm. Sows with more than five parities were culled sooner after their last farrowing. In conclusion, differences between farms for LPL, PN, and CI were found. Females that farrowed at a short age and those with large litters stayed longer in the herd. Old sows and those culled for reproductive reasons stayed the least time in the herd after their last farrowing.
Assuntos
Criação de Animais Domésticos/métodos , Longevidade , Paridade , Prenhez , Sus scrofa/fisiologia , Criação de Animais Domésticos/estatística & dados numéricos , Animais , Feminino , Análise dos Mínimos Quadrados , Tamanho da Ninhada de Vivíparos , México , Gravidez , Reprodução , Análise de Sobrevida , Clima TropicalRESUMO
Se utilizaron ocho cerdos castrados para llevar a cabo dos pruebas de digestibilidad con el objeto de evaluar el valor nutritivo de la Leucaena leucocephala y del Brossimum alicastrum en las dietas para los cerdos. En una prueba se estimaron los coeficientes de digestibilidad aparente de la Leucaena y en la otra los del Brossimum en cuanto a los siguientes componentes nutritivos: materia seca, proteína cruda, hemicelulosa, celulosa y energía. También se evaluó el efecto de estos forrajes sobre la digestibilidad de los componentes nutritivos de las dietas. En la primera prueba se utilizaron las dietas A, B, C y D que incluían 4 niveles de leucaena (0 por ciento, 10 por ciento, 20 por ciento, y 30 por ciento) y en la segunda las de las diestas E, F, G y H que incluían 4 niveles de Brossimum (0, 10, 20 y 30 por ciento). El consumo de materia seca tendió a disminuir conforme se incrementó el nivel de forraje en ambos experimentos. Las digestibilidad de las dietas también tendió a disminuir. Los coeficientes de digestibilidad de la materia seca, proteína cruda, hemicelulosa, celulosa y energía de la Leucaena fueron 39.9 por ciento, 34.9 por ciento, 59.7 por ciento, 43.4 por ciento y 33.1 por ciento respectivamente. Los coeficientes de digestibilidad de la materia seca, proteína cuda, hemicelulosa, celulosa y energía del Brossimum fueron 43.2 por ciento, 33.1 por ciento, 65.2 por ciento 57.1 por ciento y 41.2 por ciento respectivamente. La energía digestible calculada a partir de la energía bruta de la Leucaena y del Brossimum para los cerdos correspondió a 1475 y 1578 kcal/kg de materia seca respectivamente. Los resultados en cuanto a consumo y digestibilidad de las dietas indican que los cerdos tienen una baja capacidad para aprovechar dietas fibrosas; sin embargo, la utilización de forrajes es ventajosa desde el punto de vista de su costo y disponibilidad