Effects of two finishing diets on growth performance, carcass characteristics and feeding behaviour of Slovenian Cika and Simmental young bulls.

摘要

This study aimed at comparing the effects of a traditional finishing roughage-based diet and a higher energy diet, on growth, carcass characteristics, and feeding behaviour of Slovenian Cika and Simmental bulls (20 per breed). The experimental diets were: extensive (EXT) based on grass silage, and semi-intensive (S-INT) in which a part of the roughage was replaced with maize silage and sunflower meal. Each diet was fed ad libitum to 10 Cika (547 days old) and 10 Simmental (442 days old) bulls housed in group pens of five animals each. Growth performance was similar in both breeds, but Cika reached commercial finishing 1 month earlier than Simmental (139 vs 167 days; P=0.016). Bulls fed S-INT had higher final weight (645.3 vs 590.1 kg; P=0.05), average daily growth (1.05 vs 0.83 kg; P=0.026), and feed intake (11.7 vs 10.6 kg dry matter (DM)/day; P<0.001) than EXT bulls. Regardless of breed and diet, bulls ate 77-80% of the daily DM in the first 8 h after feed delivery. Bulls fed EXT showed longer standing (406.4 vs 355.8 min; P<0.001) and eating (217.2 vs 155.3 min; P<0.001) and shorter ruminating (77.5 vs 92.9 min; P<0.001) times than S-INT bulls during the first 8 h of feed delivery. Cika bulls had lower full reticulo-rumen weights relative to slaughter weights (8.7 vs 10.7%; P=0.002) than Simmental. The positive findings obtained with Cika cattle should encourage farmers to finish their young Cika male stocks for beef production, thus contributing to the maintenance of this animal genetic resource, and also to increase the energy density of the grass-based finishing diets by feeding supplements.