Objective

:To evaluate the weight gain of developing male cattle, supplemented with minerals during the dry season, in a rotational system with Bothriochloa pertusa (L.) A. Camus.

Materials and Methods

:The study was conducted in grazing areas located at the Motilonia Research Center, Cesar Valley, Colombia. Animals of the commercial breed Brahman were used. The forage availability, live weight, mean daily gain and bromatological composition, were determined. Two treatments were evaluated: T1) with mineral supplement and T2) without mineral supplementation. Each treatment had 10 crossbred animals in two hectares. The design was complete randomized and the information was evaluated through a mixed model, with repeated measures in time through Proc Mixed of SAS®.

Results

:The group with mineral supplement had increase in live weight of 16,3 % with regards to the one that did not receive it. The values were 78,9 vs 66,1 kg, and the mean daily weight gain was significant (p < 0,001) (0,438 vs 0,367 kg animal-1 day-1, respectively). The daily average intake of mineral salt showed significant variations (p < 0,001) among the months (between 29,0 and 48,8 g animal-1 day-1). The nutritional balances proved that the treatment without minerals showed deficit of Ca, P, Na, Cu and Zn.

Conclusions

:With the utilization of a rotational system of B. pertusa it is achieved that the growing male cattle gain weight during the dry season, if their dry matter requirements are covered. In addition, if salts that satisfy the deficit of missing minerals (Ca, P, Na, Cu and Zn) are incorporated in the diet, a higher response is obtained.

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