Evidence of oxidative stress in horses has been described in reports dealing with intense and endurance exercise. Oxidative stress occurs when antioxidant systems are insufficient causing oxidation to potentially damage DNA, proteins, and lipids, and contribute to degenerative changes. Vitamin E is the most commonly supplemented antioxidant in horses and has been shown that horses in exercise conditioning may require higher intakes of vitamin E than recommended. Also in various species vitamin C potentiates the effects of vitamin E; however, […]

Milk yield records of 754 Murrah female buffaloes were used to evaluate the effects of heterogeneity of variance among herds on genetic evaluation. The restricted maximum likelihood method was used to estimate the (co)variance components using four bi-trait models, considering season and herd-year of birth as fixed effects and age of the cow as covariable (linear and quadratic effects). The following models were used: additive; repeatability; additive with sire x herd-year interaction; and repeatability with sire x herd-year interaction. The […]

The objective in this work was to study the effects of environmental factors on subcutaneous fat thickness (BFT), loin eye area (REA) and body weight (BW) measured at 19 months of age and to estimate genetic parametersfor these traits. It was used information obtained from 987 Canchim (5/8 Charolais + 3/8 Zebu) and MA genetic group (offspring of Charolais bulls and 1/2 Canchim + 1/2 Zebu cows) bulls and heifers, born in 2003, 2004, and 2005. Covariance components were estimate […]

A program to determine optimum contribution selection using differential evolution was developed. The objective function to be optimized was composed by the expected merit of the future progeny and the coancestry among selected parents. Simulated and real datasets of populations with overlapping generations were used to validate and test the performance of the program. The program was computationally efficient and feasible for practical applications. The expected consequences of using the program, in contrast to empirical procedures to control inbreeding and/or […]

This study aimed to verify the existence of genetic variation among guineagrass cultivars regarding the effect of maturity on chemical composition and digestibility, and to classify the genotypes according to productive characteristics and nutritional quality. A randomized block design, with split- plots and three replications, was used. Dates of the cuts were considered as the plots, and the genotypes were considered as the sub- plots. Dry matter yield differed among the genotypes only at 90 days of growth, but the […]

It was evaluated in this work, crop yield, fermentative quality and nutritional value of the silage of cultivars of white (Avena Sativa L.) and black (Avena Strigosa Schreb) oats cut at two development stages. It was used an experimental randomized block design in a 4 x 2 factorial scheme, consisting of four oat cultivars (two cultivars of black oats: Aveia Preta Comum and UTFP 971; and two cultivars of white oats: ER 91156- 1- 2- 1 and SI 98105- b), […]

It was evaluated the addition of calcium oxide (0; 0.5; 1.0; 1.5; and 2.0% of dry matter) effect on the chemical composition and ruminal degradability of the dry matter and neutral detergent fiber, on the losses of dry matter, and on the microbial population in sugar cane silages. A design with five levels of calcium oxide and three replications was used. All the variables were influenced by the addition of calcium oxide in the silages, except the composition in acid […]

The objective of this work was to evaluate the influence of including legumes (clover) and the application of nitrogen on oat forage structural composition and production and the animal production in crop-live stocking integration system. It was used a random block experimental design with three replications. The factors were arranged in split-plots, so the plots were composed of evaluation periods and the split-plots were composed of the combination of clover with nitrogen fertilization(200 kg of N/ha using urea). The pasture […]

Athletic production is what is sought from the horse. As mammary development is important to the dairy cow, skeletal development is important to horses meeting their production goals. As any integrative physiologist will appreciate, the variables that come together to result in optimal skeletal development are complex. Nutrition is one of these, and it contains two broad variables; the supply of dietary nutrients and energy. This presentation will focus on dietary energy and its links with skeletal development. I propose […]

The society has taken a new direction towards a respectable relationship with the animals and a more conscious breeding, use for food, sports and company. The domestication and the use of horses by people have caused wrong feeding management, which is mainly due to reduced knowledge on feeding behavior. The pastures are the appropriate environment to horses feeding, but it is a complex system which interferes on the horse’s decision while it is grazing. The appropriate horse’s feeding management depends […]