R. Françoso

Evaluation of body condition score in horses by ultrasonography

Currently, the evaluation of training and nutrition for sport horses has been widely studied in order to achieve maximum performance of sport horses in competitions. The body composition of muscle and fat deposition, as well as in humans, is one of the best indicators of performance. The body condition score (BCS) is a subjective indicator of body state and is mainly based in fat deposition in some regions of the horse. Ultrasonography has proved to be a valuable tool in the evaluation of subcutaneous fat deposition. In order to study the relationship between condition score and measures of body fat and muscle thickness obtained by ultrasonography in three distinct breeds, we used 14 Thoroughbred horses (PSI), 7 Quarter Horses (QM) and 10 Purebred Arabian horses (PSA) with a mean age of 3.5 ± 0.5 years and average weight of 471 kg. The animals were evaluated by ultrasonography in three regions: parallel to the spine, back fat thickness (EGL), thickness of gluteal muscle (EMG) and fat thickness in tail (EGC). Measurements were performed every 30 days for 60 days. The results showed a correlation between body condition score and tail fat thickness, with a higher correlation compared with the other variables. Ultrasonographic evaluation proved to be a reliable and practical tool for assessing body condition in sport horses.

Influence of fat supplementation on mare’s milk composition

With the purpose to evaluate the effect of including dietary sources rich in linoleic acid (soybean oil) or linolenic acid (linseed oil) on the composition of milk, fifteen mares were divided into three groups: control, soybean and linseed. The animals received soybean oil or linseed oil in the proportion of 0.5% of body weight per day, during the final third of pregnancy until two months postpartum. Milk samples were collected weekly up to the eighth week of lactation, and were analyzed for concentrations of fat, protein, lactose and total solids by infrared process. The experimental design was completely randomized with three treatments, five replicates per treatment, and eight repeated measurements over time (weeks) for the composition of milk. The adjusted means of control, soy and linseed oils treatments were respectively 1.93, 1.66 and 1.48% for fat; 2.65, 2.48 and 2.39% for protein; 5.93, 6.14 and 6.26% for lactose; and 9.62, 10.04 and 10.14% for total solids. Time effect was observed for the variables fat (P<0.0001), protein (P<0.0001), lactose (P<0.0001) and total solids (P=0.001), and an interaction between time and treatment was found for the variable fat (P<0.0001). Under the conditions of this experiment was conducted, we conclude that supplementation with soybean or linseed oil does not affect the average composition of mare milk during the first eight weeks of lactation.

Effect of ricinoleic acid from castor oil (Ricinus communis L.) inclusion in equine diet on total apparent digestibility

The aim of the study was to evaluate the inclusion of ricinoleic acid deriving from castor oil as an additive in equine diet on total apparent digestibility. Eight Criollo adult horses, weighting 362.12 ± 16.15 kg, were distributed in 4 treatments: 0 g of ricinoleic acid per day; 1 g of ricinoleic acid per day; 2 g of ricinoleic acid per day, and 3 g of ricinoleic acid per day; distributed in two 4 × 4 Latin squares. Feces total collection was done with the animals in stalls, with concrete floor, without bed, during 5 consecutive days. There was no effect of ricinoleic acid on total apparent digestibility neither on dry matter nor on nutrients. The quantity of ricinoleic acid used in this study did not influence total apparent digestibility of equines.

Effect of the inclusion of ricinoleic acid from castor oil (Ricinus communis L.) in equine diet based on Bermuda grass hay: glycemic and insulinemic response

The aim of the study was to evaluate the inclusion of ricinoleic acid deriving from castor oil as an additive in equine diet on glycemic and insulinemic response. Eight adult Criollo horses, weighting 362.12±16.15 kg, were randomly allotted to four treatments according to a balanced 4×4 Latin square design: 0 g of ricinoleic acid per day; 1 g of ricinoleic acid per day; 2 g of ricinoleic acid per day, and 3 g of ricinoleic acid per day. The data were subjected to an analysis of variance. To assess glycemic and insulinemic response, blood samples were obtained at -30, 30, 90, 150, 210 minutes based on morning feed, always on the 11th day of the experimental period. Quadratic effect was observed (P<0.05) when related to glucose and insulin concentration. In conclusion, addition of ricinoleic acid influenced glycemic and insulinemic responses of equines.

Effect of the use of Saccharomyces cerevisiae on apparent digestibility in horses diet

In order to evaluate the effect of supplementation of the yeast Saccharomyces cerevisiae (SC) on an apparent digestibility in horses fed with high ratio concentrate: roughage diet (HC), eight Mini-horses were used: male geldings, mainly 36-months old, with an initial average weight of 113±12 kg. The diet was composed of 70% concentrate pellets and 30% grass hay, with different levels of SC included: 0 g (control), 10 g, 20 g, and 30 g of product concentration of 5×108 cfu/g. The experiment consisted of 15 days of adaptation to the diet, 5 days for data collection and 3 days interval between periods. The apparent digestibility of dietary nutrients were estimated by total faecal collection. The experimental design was a double 4×4 Latin square and data were subjected to analysis of variance and polynomial regression with a significance level of 5%. A quadratic effect was observed in the apparent digestibility of organic matter, neutral detergent fiber, acid detergent fiber and crude protein (P=0.0023, P=0.0334, P=0.0238, P=0.0224, respectively). However, differences were present between treatments including SC. Thus, the results suggest that the level of inclusion of yeast is able to alter the digestion of dietary components.

Effect of omega-3 and omega-6 fatty acids supplementation on development of equine and mule nursing foals

Fatty acids are one of the most important energy reserves in animals, influencing health and development. However linolenic and linoleic acids are not produced by horse organism. This study was realized to evaluate equine and mule foals’ development, nursed by mares supplemented with different sources of omega-3 (linseed oil) and -6 (soy oil) fatty acids. The animals were measured during sixty days and the rate of growth was compared between control, soy oil and linseed oil supplementation groups. Results demonstrated no statistical differences among the groups, but showed the necessity of more studies about the topic.