Effect of organic zinc sources on performance, zinc status as well as carcass, meat and claw quality in fattening bulls.

摘要

4 x 15 growing Red Holstein bulls were used to assess the effect of the chemical form of zinc supplementation on feed intake, growth rate, zinc status as well as carcass, M. longissimus thoracis and claw quality at zinc levels corresponding to recommended requirements. The organic Zn sources Zn proteinate and Zn polysaccharide were compared to Zn oxide and a control diet without Zn supplementation. The feeding trial lasted for 284 days and comprised the weight range 146 kg to 520 kg live weight onaverage. The ration consisted of maize and grass silage supplemented with concentrate and a mineral-vitamin mix. The chemical form of added Zn sources had no significant effect on the average dry matter intake, growth rate or feed conversion ratio. Dietary treatment neither influenced zinc status nor carcass and meat quality in a statistical way. In comparison to inorganic Zn and no added Zn, feeding organic compounds to bulls improved claw quality to some extent.