Physical and Semen Characteristics of Mexican Creole Roosters in Summer and Autumn, at 19° North Latitude with a Constant Photoperiod

The objective of this study was to evaluate the effect of the seasons (Summer and Autumn), on live weight, body condition, mass motility, percentage of live spermatozoa, and sperm-cell concentration of Creole roosters (Gallus domesticus) from Mexico. Semen from 35-week-old Creole roosters was collected weekly during 10 weeks in Summer and Autumn, through the dorso-abdominal massage technique. Roosters were individually kept under a constant photoperiod (16 hours light:8 hours dark). The average live weight was 4.5% higher (p<0.05) in Autumn (2.78 kg) than in Summer (2.66 kg), therefore this variable increased with age (r = 0.85, p<0.05). Category 2 of body condition occurred (p<0.05) with higher probability than the others (0, 1 and 3), being practically the same (p>0.05) in Autumn (99.96%) and in Summer (99.81%). On average (and in weeks 1 and 3-10), the percentage of live spermatozoa was higher in Summer than in Autumn. Accordingly, the percentage of live spermatozoa decreased with age (r = -0.82, p<0.05). However, on average, sperm-cell concentration did not change between seasons (p>0.05). In conclusion, Mexican Creole roosters showed higher percentage of live spermatozoa in Summer than in Autumn. Therefore, it is advisable to select these animals of about 2.7 kg and reproduce them in Summer.(AU)

Partially Dehulled Sunflower Seeds in Diets for Grazing Chickens: Effect in Meat Quality

The effect of including partially dehulled sunflower seeds in the diet of grazing chickens in meat quality was evaluated. Two hundred and forty, one-day-old, Ross 308 chickens were used, randomly distributed into four treatments with six replicates of 10 birds each. Seventy-two birds were slaughtered at seven weeks of age, 18 per treatment, extracting the Pectoralis major muscle to analyze meat quality. The treatments were completely randomized in a 2x2 factorial arrangement, where type of rearing (confinement or grazing) and diet (base diet or base diet substituting 10% soybean meal for partially dehulled sunflower seeds) were the independent variables. The grazing chickens spent 8 hours a day in a white clover (Trifolium repens) paddock. Including sunflower seeds improved (p<0.05) the color and crude protein (CP) in breast meat (p<0.05), while grazing increased (p<0.05) CP, dry mater (DM), and shear force (SF), and the percentage of breast fat decreased (p<0.05) by up to 50%. Additionally, grazing increased (p<0.05) saturated fatty acids (SFA) and reduced (p<0.05) lipid oxidation by up to 50%. Partially replacing soybean meal with partially dehulled sunflower seeds in the diet of grazing chickens with white clover improves the physicochemical characteristics and nutritional quality of the breast meat; it also decreases lipid oxidation, extending the shelf life of the meat.(AU)

Lipid Peroxidation in the Plasma, Lungs, Heart and Liver of Broilers Fed a Grape Seed Extract and Raised at 2278 m of Altitude

ABSTRACT The aim of this research was to evaluate the effect of partial substitution of vitamin E (VE) by grape seed extract (GSE) on glutathione peroxidase activity (GPxA), nitric oxide (NO) concentration and lipid peroxidation [malondialdehyde (MDA) concentration] in the plasma, lungs, heart and liver, and live performance of broilers raised at 2278 m of altitude. One-d-old Ross 308 male chickens (n = 420) were randomly distributed into three treatments: Control-AL (basal diet containing 40 IU of VE and fed ad libitum; AL), Control-FR (basal diet and feed restriction; FR) and GSE-AL [basal diet containing 10 mg of GSE (equivalent to 30 IU VE) plus 10 IU of VE and fed AL]. The data were analyzed using one-way analysis of variance. Glutathione peroxidase activity, and NO and MDA concentrations in the plasma were evaluated on d 46. On d 47, MDA was evaluated in the lungs, heart and liver. Live performance parameters were recorded weekly. There were no significant differences (p>0.05) in live performance and NO concentration among treatments. Birds from the GSE-AL treatment presented the lowest (p 0.05) GPxA, the highest (p 0.05) MDA concentration in the plasma, heart and liver, and intermediate MDA concentration in the lungs. Our results suggest that GSE may partially replace VE in broiler diets without impairment of live performance. However, further research is required to determine the optimal level of dietary GSE inclusion to reduce lipid peroxidation in the plasma, lungs, heart, and liver of broilers raised at 2278 m of altitude.

Lipid Peroxidation in the Plasma, Lungs, Heart and Liver of Broilers Fed a Grape Seed Extract and Raised at 2278 m of Altitude

ABSTRACT The aim of this research was to evaluate the effect of partial substitution of vitamin E (VE) by grape seed extract (GSE) on glutathione peroxidase activity (GPxA), nitric oxide (NO) concentration and lipid peroxidation [malondialdehyde (MDA) concentration] in the plasma, lungs, heart and liver, and live performance of broilers raised at 2278 m of altitude. One-d-old Ross 308 male chickens (n = 420) were randomly distributed into three treatments: Control-AL (basal diet containing 40 IU of VE and fed ad libitum; AL), Control-FR (basal diet and feed restriction; FR) and GSE-AL [basal diet containing 10 mg of GSE (equivalent to 30 IU VE) plus 10 IU of VE and fed AL]. The data were analyzed using one-way analysis of variance. Glutathione peroxidase activity, and NO and MDA concentrations in the plasma were evaluated on d 46. On d 47, MDA was evaluated in the lungs, heart and liver. Live performance parameters were recorded weekly. There were no significant differences (p>0.05) in live performance and NO concentration among treatments. Birds from the GSE-AL treatment presented the lowest (p 0.05) GPxA, the highest (p 0.05) MDA concentration in the plasma, heart and liver, and intermediate MDA concentration in the lungs. Our results suggest that GSE may partially replace VE in broiler diets without impairment of live performance. However, further research is required to determine the optimal level of dietary GSE inclusion to reduce lipid peroxidation in the plasma, lungs, heart, and liver of broilers raised at 2278 m of altitude.(AU)