Performance of beef heifers supplemented with extruded fat on italian ryegrass pasture

Productive and reproductive performance of beef heifers grazing on Italian ryegrass (Lolium multiflorum Lam.) were analyzed, comprising animals exclusively on pasture and supplemented animals with extruded fat (0.15 or 0.30% of body weight). The grazing method was continuous with variable stocking rate. The experimental design was completely randomized following a repeated measure arrangement. Variables related to pasture were similar when the heifers received different supplementation levels, with similar grazing conditions. Mean values of forage mass and canopy height were 1,500 kg DM ha-1 and 17 cm, respectively. Heifers ingested forage with a similar content of crude protein (21.90%) and neutral detergent fiber (49.30%), regardless of supplementation levels. Beef heifers supplemented with extruded fat, regardless of the level, had higher average daily gain, body weight, body condition score, body weight: height ratio than heifers fed exclusively on pasture. The use of extruded fat as a supplement caused no change in pelvic area and reproductive tract score in beef heifers. Regardless of their nutritional status, 14/15-month-old heifers were not able to conceive during the mating season.