Productive performance, breast growth and digestive system development in European quail subjected to post-hatch fasting for different periods.

This study assessed the effect of different periods of post-hatch fasting on animal performance and breast and digestive system growth in European quail. Quail chicks were distributed in a completely randomized design, with four fasting periods (0, 24, 36, and 48 hs) and four replications of 40 birds per treatment. In 1 to 14-day-old chicks, weight gain decreased with increasing fasting time. Compensatory gain was observed from 15 days of age onward. Fasted quail had a lower length and relative weight of the digestive system than fed animals for up to 14 days. Histologically, the duodenal villus height was significantly lower in 3-day-old quail fasted for 36 hs than in those fasted for 48 hs, but this effect was not observed at 7 days. Scanning electron microscopy showed no differences in the small intestinal mucosa between fasted and fed birds at 3 days of age. Post-hatch fasting reduced the relative weight of the breast in quail aged 1 to 14 days but did not affect type IIa and IIb fiber diameter at 35 days. On the basis of these results, it is recommended that European quail raised for meat should not be fasted for more than 48 hs post-hatch.

A breeding program for Nile tilapia in Brazil: Results from nine generations of selection to increase the growth rate in cages.

Variance components and heritabilities for daily weight gain (DWG) were estimated for Nile tilapia farmed in cages across nine generations (G1-G9) of selection in a breeding program in Brazil. DWG was measured in 16,272 accumulated tagged animals representing 535 full- and half-sib families of Nile tilapia under cage farming. The additive genetic variance showed a slight variation (0.051-0.066), and heritability estimates ranged from 0.20 to 0.33. The common environmental effect accounted for a higher proportion of the total variance in DWG, especially in the last generations (6%-24%). A genetic trend based on all data available showed a substantial increase in the DWG (about 3.3% per generation) of Nile tilapia across nine generations of selection. Furthermore, our results demonstrate ample scope for further genetic improvement.

Multivariate analysis of milk yield, lactation length, and calving interval in female buffaloes / Análisis multivariado de la producción de leche, duración de la lactancia y el intervalo entre partos en búfalas / Análise multivariada da produção de leite, duração da lactação e intervalo de parto em búfalas

Abstract Background: The global market has an increasing demand for buffalo by-products due to their unique nutritional characteristics. Many buffalo herds lack suitable breeding control programs, hindering the implementation of selection programs. Objective: To evaluate milk production per lactation (MP), lactation length (LL), and calving interval (CI) of a herd of crossbred Murrah buffaloes to support buffalo clustering according to their potential. Methods: Data from 543 lactations between 2002 and 2014 from 105 crossbred Murrah female buffaloes were used. Data were subjected to principal component analysis (PCA) and cluster analysis. Results: The first components (PCs) were responsible for 92.32% of the total variation, of which 61.45 and 30.87% were explained by the first (PC1) and second (PC2) components, respectively. The cluster analysis allowed three female buffalo groups according to their potentials. Conclusion: Buffalo farmers can make decisions on nutritional, reproductive management and cow culling based on grouping.

Resumen Antecedentes: La demanda de productos de leche de búfala en el mercado mundial viene creciendo en virtud de sus características nutricionales únicas. La mayoría de los hatos bufalinos no tienen adecuados controles, lo que dificulta la implementación de programas de selección. Objetivo: Analizar la producción de leche por lactancia (MP), duración de la lactancia (LL) y el intervalo entre partos (CI) para apoyar la clasificación de búfalos según su potencial. Métodos: Se recogieron 543 registros de lactancia de 105 búfalas Murrah mestizas entre los años 2002 y 2014. Los datos fueron sometidos a análisis de componentes principales (PCA) y análisis de conglomerados. Resultados: Los primeros componentes (PCs) fueron responsables del 92.32% de la variación total, de los cuales 61.45 y 30.87% fueron explicados por el primer (PC1) y segundo (PC2) componentes, respectivamente. El análisis de conglomerados permitió la formación de tres grupos de búfalas, según su potencial. Conclusión: Los productores pueden tomar decisiones específicas con respecto a la gestión nutricional, reproductiva, y el descarte de hembras bufalinas basados en estas agrupaciones.

Resumo Antecedentes: A demanda por produtos de origem do leite de búfalas no mercado mundial tem crescido em virtude de suas características nutricionais singulares. Grande parte dos rebanhos de búfalos não possuem controle zootécnicos adequados, dificultando a implementação de programas de seleção. Objetivo: Analisar conjuntamente as características produção de leite por lactação (MP), duração da lactação (LL) e intervalo de partos (CI) para subsidiar a classificação das búfalas de acordo com seu potencial. Métodos: Para esse estudo, 543 dados de lactação de 105 búfalas mestiças Murrah foram coletadas entre 2002 e 2014. Os dados foram analisados por análises de componentes principais (PCA) e análises de cluster. Resultados: Os primeiros componentes (PCs) foram responsáveis por 92.32% da variação total, dos quais 61.45 e 30.87% foram explicados pelo primeiro (PC1) e segundo (PC2) componentes, respectivamente. A análise de cluster permitiu a formação de três grupos de búfalas de acordo com o potencial das características estudadas. Conclusão: Baseado nesses agrupamentos, os produtores podem tomar decisões específicas quanto aos manejos nutricional e reprodutivo, e sobre o descarte de búfalas, de acordo com os agrupamentos.