Optimisation of the protein supply of dairy cows fed forage-based diets using ensiled Italian ryegrass under the conditions of Austrian organic agriculture
Abstract
Generally speaking, organic dairy cow nutrition aims at a high total dry matter intake, a high passage rate and the best possible synchronisation of the degradation rates of carbohydrates and protein from home-grown feedstuffs. Therefore the primary goal of the proposed project is: 1. To find new ways of improving the efficiency of organic dairying. This should be achieved by reducing the relative amount of purchased concentrates in the diet and improving the use of the protein in home grown feedstuffs. Thus organic dairying is closer to the ideal of closed nutrient cycles. This aim can in part be achieved by using Italian ryegrass silage in the diet, therefore another aim can be formulated as follows: 2. To examine the possibilities and limits of the use of Italian ryegrass silage in the diet of organic dairy cows. No scientific literature about the use of Italian ryegrass silage in organic dairy cow rations is known, thus another aim is: 3. To determine whether knowledge from international sources on the use of Italian ryegrass silage in conventional dairy cow rations is applicable to the Austrian organic agriculture. The methods to examine the suitability of Italian ryegrass are three feeding trials with organic dairy cows, which will take place in winter 2008/09, 2009/10 and 2010/11. The cows will be divided into two groups, one receiving the control ration, the other receiving the experimental ration. Both groups will be fed the same type of purchased concentrate, but rations will differ in the forage base. The control group´s forage will consist of grass silage and grass/clover silage, part of it will be replaced by Italian ryegrass silage in the experimental ration. The collected data will include nutrient values of all feedstuffs, dry matter intake, milk yield and content of fat, protein etc., and the cow´s body condition scores (BCS) and live weight. If possible, the yield of the Italian ryegrass and the percentages of clover in both the grass/clover crops and the meadows should be measured. The expected results are, apart from a satisfying yield and energetic value of the Italian ryegrass silage, a slightly decreased crude protein content and increased energetic value of the experimental ration as compared to the control ration. This should lead to an increased N-efficiency of milk production in the cows fed the experimental ration and therefore, a better use of the protein in the home-grown feedstuffs. To document the expected decrease of nitrogen losses through urine and faeces, a master´s thesis is planned in addition to the main project. It will start after the second feeding trial and calculate the N-surplus both of the whole farm and the barn alone, using as much of the collected data as possible. Its aim is: 4. To find out if the N-surpluses resulting from the Italian ryegrass silage-ration and the control-ration differ and what total scales they reach
keywords dairy cows, protein supply Italian ryegrass
Publikationen
Siliertes italienisches Raygras als Futter für Bio-Milchkühe - Bericht aus drei Versuchsjahren
Autoren: Baldinger, L., Zollitsch, W., Knaus, W.F. Jahr: 2013
Conference & Workshop proceedings, paper, abstract
Project staff
Wilhelm Friedrich Knaus
Ao.Univ.Prof. Dipl.-Ing. Dr.nat.techn. Wilhelm Friedrich Knaus
wilhelm.knaus@boku.ac.at
Tel: +43 1 47654-93235
Project Leader
01.10.2008 - 30.09.2011
BOKU partners
External partners
HBLA Ursprung
Dr. Wolfgang Stehrer
partner
HBLFA Raumberg-Gumpenstein
Dr. Andreas Steinwidder
partner