Evaluation of Diets with Different Soy Rations of Service Heifers

GARCIA, DANIELA CELESTE; MARTIN, AA; VELLA, MA; PEÑA, M; LUJÁN, EE; NASCA, JA; ROLDÁN-OLARTE, M

Tafi del Valle

Jornada; XXXIV Jornadas Científicas de la Asociación de Biología de Tucumán; 2017

Asociación de Biología de Tucumán

Livestock rearing is one of the most important activities in Argentina and it is essential to control the cattle feeding at different growthstages. In order to determine the effect of soy on the nutrition of heifers managed for service, 34 braford females from INTA-IIACS wereused. Two groups of animals were fed for six months with the following diets, BS: low soy content (0.3% based on live weight, LW) andAS: high soy content (0.8% based on LW). For four months, during the management for service period, the BS group was fed withoutaddition of soy in the diet, according to Rhodes grass pasture, while the AS group was fed with 0.6% of soy based on LW and grazing.Productive parameters were evaluated monthly: LW and average daily gain (ADG) and hematological: hematocrit and leukocyte formula.During service, the % of pregnancy of both groups was registered by rectal examination. There were no changes in the parametersevaluated between the animals before the service. During service, the heifers in the AS group showed an increase in the ADG andhematocrit values, while in the BS group lower increases in these parameters were registered. There were no significant changes inleukocyte formulas. It should be noted that despite the differences observed, the females in both groups had a 100% of pregnancy. The dataobtained from ADG and hematocrit indicate that supplementation with high soy rations favors the nutritional status of the animals withoutaffecting their reproductive parameters.