Effect of feed ration keeping system and farm on growth and carcass value of young black pied dairy bulls to be fattened at a uniform dietary energy level
Grosse, F.; Ender, K.; Papstein H J.
Archiv fuer Tierzucht 33(4): 313-325
A complex trial was made to analyze the efficiency of a uniform dietary energy level of 1,200 kilo energetic feed equivalents (cattle) per animal or animal group when subject to different feed energy concentrations, feeding intensities, keeping systems and farms. Among the influencing factors, farm had the greatest effect followed by type of ration, keeping system and feeding intensity. Animals responded with highest gain rates to the combination of favourable on-farm conditions, rations with at least 30% of the energy coming from concentrates a constant feeding intensity and tied housing. Extreme differences between the variants were 115 kg finishing weight, 59.6 kg carcass weight, 199 g daily net weight gain (I), 122 g non-fat edible tissue per day, 50 g edible fat per day and 14 g bones per day. Upper limits of optimum fat contents are reached in tied animals fed rations where 15% of the energy comes from concentrates or in loose-housed animals receiving rations where 30% of the energy source are concentrates. Under less favourable on-farm conditions, more than 45% of the feed energy must be supplied in form of concentrates. Loose housing reduces the quality of lean meat in terms of brightness, intramuscular fat content and shear value.