DIET SEASONALITY WITH GRAZING IN SHEEP BREEDING: STUDY OF A PRODUCTION UNIT

Abstract

The objective was estimating seasonal variations in the diet of breeding sheep with grazing in irrigated pastures of temperature climate. The study was carried out in a ranch located in Huamantla, Tlaxcala, México, with irrigation in sub-humid temperature climate. The flock had 1,500 sheep whose diet was based on diurnal rotational grazing in 52 ha of Medicago sativa grasslands with Dactylis glomerata and different agricultural residues from the ranch, offered during the daytime and nighttime confinement. Between August 2010 and September 2011, every fortnight samples were taken of offered and residual fodder to estimate the fodder apparently consumed. Likewise, grazed areas were recorded and samples of simulated grazing and supplements were taken to estimate the individual consumption of metabolizable energy (ME). Every 28 days, 70.5±1.9 sheep were weighed and the body condition was defined. Means and standard error of the variables were calculated. During winter the mass of fodder offered and fodder consumption was lower, with negative consequences for live weight and the body condition; since most of the births took place in that season, the imbalance in feeding must have affected the productive efficiency of the ranch.