Impact of nutrition of food animals on quality of animal products

It is an often overlooked, but vital, research question to understand how what is fed to food-producing animals ultimately affects quality and consumer acceptability of food products produced by those animals. Of interest in recent years, particularly in the Midwest, has been the effect of inclusion of dried distillers grains with solubles (DDGS) in the rations of lactating dairy cows on milk and cheese quality. Because of the high unsaturated oil content of DDGS, feeding DDGS to dairy cows could potentially lead to decreased oxidative stability of milk and cheese and also contribute to the late blowing of eyes in Swiss type cheeses. Therefore, it was of interest to investigate if feeding full-fat DDGS (~13 % fat) would result in increased development of off-flavors in milk and could result in milk that was unsuitable for use in baby Swiss cheese production. Additionally, the recent development of reduced-fat DDGS (RF-DDGS) (~6% fat) offers the possibility of feeding increased amounts of DDGS, compared to feeding full-fat DDGS, without adversely affecting milk and milk fat production. Because of the possibility of higher rates of inclusion of RFDDGS in the rations of dairy cows than was possible with full-fat DDGS, it was necessary to investigate the effects of feeding RFDDGS on milk production efficiency and the quality of milk for the production of baby Swiss cheese. Finally, feedstuffs containing high concentrations of unsaturated fatty acids, in particular DDGS, can adversely affect the quality of pork fat, potentially resulting in pork that is unacceptable to the producer and consumer. Specific project summaries are described in the subsequent pages.