Main findings:
The use of rapeseed meal
For pigs, there is a risk of reducing the performance of pigs using high (over 10%) inclusion levels of rapeseed meal (RSM). However, the use of conservative levels (5-7%) are acceptable. Reduced performance largely originates from the presence of anti-nutritive factors in the RSM which promote a bitter taste and the reduced performance observed was due to a reduce palatability (as measured through the feeding behaviour observed) which led to a reduction in feed intake and therefore reduced animal growth rate.
For broilers, inclusion of high levels of RSM (10% starter, 20% grower and 30% finisher) to diets for broilers also resulted in reduced broiler performance in terms of DMI, LWG and feed efficiency. LWG and feed efficiency was approximately 15 and 25% poorer respectively at these high inclusion levels of RSM compared with when no RSM was included. However, unlike pigs, even conservative levels were detrimental.
The use of DDGS
This project evaluated the use of wheat DDGS for broilers and the use of both maize and wheat DDGS for pigs.
For pigs high inclusion levels of both wheat and maize DDGS (30%) did not negatively affect pig performance using the specific sources of DDGS and the specific diet in the formulation. It was noted that the ‘wheat’ DDGS used was considered of good quality compared to the normal quality profile of wheat DDGS and the maize DDGs was consider of ‘average’ quality. There is much variation in the quality of wheat and maize DDGS and as such results from trials can be source specific. However this trial did show that due to high oil B content and high fibre content the DM and nitrogen digestibility of DDGS based diets was poorer than the control diet. Nonetheless DDGS could be considered an alternative protein source should the cost of it be competitive with soya.
For poultry, the inclusion of the wheat DDGS reduced bird performance and diet digestibility. Since this source of wheat DDGS was considered of ‘good’ quality, wheat DDGS may not be an good alternative protein source for broilers.
Identify and assess the feasibility of novel protein sources
Through review of literature and knowledge it was realised that other protein sources were not available in significant quantities for large scale production. In order to deliver answers now for the industry it was agreed to investigate the impact of amino acid profile on pig performance since amino acids are an expensive component of the diet. It was found that there was no requirement to formulate diets to 6 amino acids and that using current formulation protocol where diets were formulated to 3 and sometime 4 amino acids was adequat