ABSTRACT 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.

Abstract The objective of this study was to determine the influence of soil type, nitrogen and biofertilizer on phenology, total biomass, grain yield and its components on sunflower cultivation. At the Postgraduates College, the study was carried out, where the sunflower cv Victory was sowed. The treatments under study were two types of soil with two nitrogen levels, with and without biofertilizers. The plant’s phenology, total biomass, harvest index, grain yield and its components were evaluated. For the soils under study, nitrogen fertilization and the biofertilizer were found not to affect the phenological stages, but a change in total biomass and grain yield was observed, where the highest production and net income was recorded with the application of nitrogen at 100 kg ha-1 and biofertilizer inoculation, in the soil with the lowest salinity.

Resumen El objetivo de este estudio fue determinar la influencia del tipo de suelo, nitrógeno y biofertilizante sobre la fenología, biomasa total, rendimiento de grano y sus componentes en el cultivo de girasol. El estudio se realizó en el Colegio de Postgraduados, donde se sembró el girasol cv. Victoria. Los tratamientos en estudio fueron dos tipos de suelo en los cuales se aplicó dos niveles de nitrógeno, con y sin biofertilizantes. Se evaluó la fenología de la planta, biomasa total, índice de cosecha, rendimiento y sus componentes. Para los suelos en estudio se encontró que la fertilización nitrogenada y el biofertilizante no modificaron el tiempo a ocurrencia de las etapas fenológicas, pero sí se observó un cambio en la biomasa total y rendimiento de grano, donde la mayor producción se registró con la aplicación de nitrógeno a 100 kg ha-1 y la inoculación del biofertilizante, lo que a su vez generó el mayor ingreso neto, en el suelo con la salinidad más baja.

RESUMO Dois ensaios foram realizados para estudar a planta de Tithonia diversifolia (Td): (1) análise química e digestibilidade in vitro da matéria seca (DIVMS) de partes de plantas e (2) desempenho produtivo de cordeiros alimentados com dieta tradicional ou dieta Td (30% de Td mais 70% da dieta tradicional). As partes vegetais estudadas foram folhas (L), folhas e pecíolos (LP); folhas, pecíolos e caules (LPS). O consumo de ração, o ganho de peso e a conversão alimentar foram registrados semanalmente, durante cinco semanas de experimentação. O L apresentou maior (P<0,05) conteúdo de proteína bruta (26,7%) que o LP e o LPS (25,5 e 19,7%, respectivamente). Fibra bruta (11,2%), fibra em detergente neutro (45,4%), celulose (16,9%) e hemicelulose (33,5%) foram menores em L do que em LP (12,5, 46,7, 18,0 e 35,7%, respectivamente) e LPS (22,6, 59,2, 27,0 e 43,5%, respectivamente). O L e o LP apresentaram o maior DIVMS (89,2 e 88,2%, respectivamente vs. 77,2% do LPS). A dieta Td resultou em maior consumo de ração e maior ganho de peso e menor conversão alimentar que a dieta tradicional. Portanto, Tithonia diversifolia é uma planta forrageira de boa qualidade para cordeiros que não afeta o desempenho produtivo.

ABSTRACT Two assays were conducted to study the Tithonia diversifolia (Td) plant: (1) chemical analysis and in vitro dry matter digestibility (IVDMD) of plant parts and (2) productive performance of lambs fed a traditional diet or a Td diet (30% of Td plus 70% of the traditional diet). The plant parts studied were leaves (L), leaves and petioles (LP); and leaves, petioles and stems (LPS). Feed intake, weight gain and feed conversion were registered weekly during five weeks of experimentation. The L showed higher (P<0.05) crude protein content (26.7%) than LP and LPS (25.5 and 19.7%, respectively). Crude fiber (11.2%), neutral detergent fiber (45.4%), cellulose (16.9%) and hemicellulose (33.5%) were lower in L than in LP (12.5, 46.7, 18.0 and 35.7%, respectively) and LPS (22.6, 59.2, 27.0 and 43.5%, respectively). The L and LP showed the highest IVDMD (89.2 and 88.2%, respectively vs. 77.2% of LPS). The Td diet resulted in greater feed intake and weight gain and lower feed conversion than the traditional diet. Therefore, Tithonia diversifolia is a forage plant of good quality for lambs which does not affect the productive performance.

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.