Maize stovers in ruminant feeding. Utilisation of ammonia and urea-treated maize stovers by cattle with moderate requirements

Abstract

Maize stovers, round baled after grain harvesting and preserved by the injection of 3 kg ammonia per 100 kg stovers, can contribute to the major part (80 %) of the diet of wintering dairy and beef heifers and gestating-lactating beef cows. Fed ad-libitum as such (they are already coarsely chopped at harvest) their intake, which is slightly lower than that of husks (1.60 vs 1.30 UEB), enables :
- dairy and beef heifers, fed with 1.5 kg cereals and 100 g sulfur-supplemented minerals (15- 15) per day, to achieve liveweight gains of 400 g/d when two years-old and of 500 to 600 g/d when one year-old. When the growth target is higher it is advised to resort to a slow fermentable protein source (e.g. 300 to 500 g/d soybean meal),
- beef cows around calving, fed with 1.5 kg - then 2.0 kg after calving - and 180 g/d of the same mineral mixture, to limit their body weight loss to 30 kg between calving and pasturing. Such losses are entirely acceptable in the case of early calving. The reproductive performances, recorded over a three year observation period, as well as the calving conditions, the body weight of calves at birth and their vitality are not affected.