Effect of season on scrotal circumference, semen characteristics and testosterone serumconcentration in Mexican Corriente and other beef breed bulls

To evaluate the effects of season on semen,scrotal circumference and testosterone concentration inCorriente and European-breed bulls, 758 samples wereanalyzed in four years. Comparisons were madebetween bulls of the same breed in different seasons andbetween bulls of different breeds in the same season.Scrotal circumference of both breeds was higher in thesummer and autumn (P < 0.01). Sperm concentration,individual motility and live cells were lower in summerand autumn in European-breed bulls (P < 0.01). Allpercentages of sperm defects were higher, andtestosterone was lower in European-breed bulls duringsummer and autumn (P < 0.01). Gross motility tended tobe lower (P = 0.09) in European-based bulls duringwinter. Scrotal circumference was higher in Europeanbreedbulls than Corriente bulls in all seasons (P < 0.01).Ejaculate volume and sperm concentration were similarin Corriente and European-breed bulls in all seasons(P > 0.1). Individual motility was lower in Europeanbreedthan in Corriente bulls in summer and autumn(P < 0.01 and <0.01). Live cells count was lower inEuropean-breed than in Corriente bulls during thesummer and autumn (P < 0.01 and <0.01). Major spermdefects were higher for Corriente than European-breedbulls during winter (P < 0.01). Minor cell defects werehigher in summer and autumn (P < 0.01) in Europeanbreedthan in Corriente bulls. Total defects were lowerin Corriente than in European-breed bulls duringsummer and autumn (P < 0.01), and higher duringwinter (P < 0.01). Testosterone was higher in Corrientebulls during summer (P < 0.01) and autumn (P < 0.01)than in European-breed bulls. Gross motility was lower(P < 0.05) in European-breed than in Corriente bulls inwinter. Season had no effect on most semencharacteristics in Corriente bulls, while European-breedbulls had lower semen quality during the hotter seasons.(AU)

Effect of season on scrotal circumference, semen characteristics and testosterone serumconcentration in Mexican Corriente and other beef breed bulls

To evaluate the effects of season on semen,scrotal circumference and testosterone concentration inCorriente and European-breed bulls, 758 samples wereanalyzed in four years. Comparisons were madebetween bulls of the same breed in different seasons andbetween bulls of different breeds in the same season.Scrotal circumference of both breeds was higher in thesummer and autumn (P 0.1). Individual motility was lower in Europeanbreedthan in Corriente bulls in summer and autumn(P < 0.01 and <0.01). Live cells count was lower inEuropean-breed than in Corriente bulls during thesummer and autumn (P < 0.01 and <0.01). Major spermdefects were higher for Corriente than European-breedbulls during winter (P < 0.01). Minor cell defects werehigher in summer and autumn (P < 0.01) in Europeanbreedthan in Corriente bulls. Total defects were lowerin Corriente than in European-breed bulls duringsummer and autumn (P < 0.01), and higher duringwinter (P < 0.01). Testosterone was higher in Corrientebulls during summer (P < 0.01) and autumn (P < 0.01)than in European-breed bulls. Gross motility was lower(P < 0.05) in European-breed than in Corriente bulls inwinter. Season had no effect on most semencharacteristics in Corriente bulls, while European-breedbulls had lower semen quality during the hotter seasons.

Productive performance of white leghorn hens based on the type of housing during rearing: floor versus cage

Poultry farmers in the southeastern of Mexico consider that the productivity of the hens that comes from rearing on floor has a higher productive performance than reared hens in cages, mainly due to higher percentage of egg laying and lower mortality. The aim of this study was to evaluate the productive performance of the laying hen in relation to the type of rearing. A total of 79680 pullets Bovans White of 17 weeks of age were housed in cages with five pullets cage-1 (405 cm2pullet-1). They were divided in two treatments according to their type of rearing (floor vs cage) with four replicates. The study period was from week 20 to week 40 of age. The variables evaluated were daily (%) and cumulative mortality (%), egg production (%), egg weight (g), feed intake (g pullet d-1), cumulative feed intake (g pullet-1), daily and cumulative egg mass, number of eggs per hen housed, egg loss (%) and productivity index. The variables were analyzed using a randomized block design. It was observed that daily and cumulative mortality, feed intake and egg loss was higher (p < 0.05), while the number of eggs per hen housed and productivity index (p < 0.05) was lower for hens in cages. We conclude that it is possible to associate detriments in the productive performance of laying hens based on the type of housing during its growth phase.(AU)

Productive performance of white leghorn hens based on the type of housing during rearing: floor versus cage

Poultry farmers in the southeastern of Mexico consider that the productivity of the hens that comes from rearing on floor has a higher productive performance than reared hens in cages, mainly due to higher percentage of egg laying and lower mortality. The aim of this study was to evaluate the productive performance of the laying hen in relation to the type of rearing. A total of 79680 pullets Bovans White of 17 weeks of age were housed in cages with five pullets cage-1 (405 cm2pullet-1). They were divided in two treatments according to their type of rearing (floor vs cage) with four replicates. The study period was from week 20 to week 40 of age. The variables evaluated were daily (%) and cumulative mortality (%), egg production (%), egg weight (g), feed intake (g pullet d-1), cumulative feed intake (g pullet-1), daily and cumulative egg mass, number of eggs per hen housed, egg loss (%) and productivity index. The variables were analyzed using a randomized block design. It was observed that daily and cumulative mortality, feed intake and egg loss was higher (p < 0.05), while the number of eggs per hen housed and productivity index (p < 0.05) was lower for hens in cages. We conclude that it is possible to associate detriments in the productive performance of laying hens based on the type of housing during its growth phase.