Balanço nutricional e ganho de peso de potros mangalarga marchador alimentados com capim-elefante (Pennisetum purpureum) e concentrados com diferentes relações Ca:P

Abstract

Objective to evaluate the nutritional balance and weight gain of weaned foals fed with elephant grass (Pennisetum purpureum) and different Ca:P relations diet. The experiment was conducted at the Department of Animal Science of the Federal University of Lavras lasting 190 days. Sixteen male Mangalarga Marchador foals were used, with an average initial age of 6,7 ± 1,6 months and 127,38 ± 26,55 kg body weight. The experimental design was in blocks. The experimental diets were composed of elephant grass (Pennisetum purpureum) and concentrated with different Ca: P relations of 2:1 (treatment A), 3:1 (treatment B), 5:1 (treatment C) and 6:1 (treatment D) (duration 60 days). The concentrate was provided at 8, 13 and 16:30 hours, and forrage ad libitum at 9 and 17:30 hours in the collective. The foals were weighed weekly on a balance totaling 8 periods assessment for daily weight gain (DWG), and calculated for body condition score (BCS). Ca (CaFE) and P (FEP) digestibility and excretion assay were performed to evaluate the mineral balance of animals. All variables were subjected to analysis of variance and Tukey test at 5%. There was no significant difference in DWG of foals fed different Ca: P ratios in the diet (p> 0,05) and there was no change in BCS. There was no significant difference in the calcium, phosphorus and urea tests in the animals' blood and urine (p> 0,05). For Ca values, although there is no significant difference, all values, except D, are below the normal Ca values in equine chemicals (10,04 to 11,77 mg / dL). Serum P values were within the normal range (between 3,73 and 4,78 mg / dL). There was no significant difference in CaFE (p> 0,05). A FEP differed between treatments A and B. The treatment with the lower concentration of Ca (A = 2: 1) in the diet, showed the higher value of FEP (5,09 ± 1,54.%). body's reaction in an attempt to maintain a homeostasis of these minerals. For apparent digestibility (AD) there was statistical difference (p <0.05) only for the values of AD of Dry Matter (ADDM), Crude Energy (ADCE) and Calcium (CaAD). ADDM was higher in treatment A and lower in treatment D. CaAD was lower in treatment D and may be related to higher levels of dietary Ca in this treatment. The highest Ca treatment (treatment D) at ADDM was lower (12,67 ± 4,43). These experimental conditions, it was not possible to verify the influence of mineralization on DWG and BCS of forage fed foals with oxalate. Dietary Ca: P ratio 3: 1 for foals fed elephant grass with 2.51% oxalate concentration and 0.16 Ca: Oxalate ratio maintains the body's homeostasis of Ca: P minerals.