Browsing by Author "Tarsia, Essi"

Lots of protein feeds are imported to Europe. In Finland at most 25 % of all protein feeds used are home-grown. Legumes and single-cell protein are of interest to replace imported protein feeds. The aim of this study was to explore faba bean (Vicia faba) and Spirulina-algae (Spirulina platensis) as protein source for dairy cows. The study design was replicated 4 x 4 Latin square with four diets and four periods of three weeks. The experiment was 2 x 2 factorial. Rapeseed meal and rolled faba bean were compared as protein sources. The partial replacement (half) of rapeseed meal and faba bean protein with Spirulina-algae was also investigated. All the protein supplements were isonitrogenous. In this study, effects of protein supplements on dry matter intake, milk yield and milk composition, production of microbial protein in the rumen, plasma amino acids and mammary uptake of amino acids and nitrogen partitioning were examined. This study was made at the research farm of the University of Helsinki in 21.2.–15.5.2015. There were eight multiparous Finnish ayrshire dairy cows at mid-lactation. The cows were divided in two blocks the other block having rumen fistulated animals. All the total mixed ratios contained grass silage of good quality, barley, sugar pulp and minerals supplemented with different protein sources. Cows were offered total mixed ratios ad libitum. Replacing rapeseed meal and faba bean with Spirulina-algae reduced dry matter intake. The milk yield was 1,4 kg/d greater on rapeseed meal diets compared with faba bean diets. Mixing Spirulina-algae with faba bean increased milk, protein and lactose yields, but when mixed with rapeseed meal decreased them. Both milk urea and rumen ammonia concentrations were higher in faba bean diets than in rapeseed meal diets. The concentration of several essential amino acids in plasma and mammary uptake of histidine and methionine were lower in faba bean diets than in rapeseed meal diets. Replacing faba bean partially with Spirulina increased AV-difference of essential amino acids. Nitrogen balances were positive in all experimental diets. There were no differences in nitrogen intake. Feeding faba beans reduced nitrogen secretion in milk and faeces compared to rapeseed meal diets. Replacing rapeseed meal and faba bean partially with Spirulina increased the proportion of nitrogen secreted in urine and lowered nitrogen balance. According to this study replacing rapeseed meal completely with faba bean seeds reduce milk and protein yields on diets based on grass silage and cereals. Mixing Spirulina with faba bean increased milk, protein and lactose yields, but decreased them when mixed with rapeseed meal. Protein of faba bean and Spirulina probably completed each others. More research is needed with high levels of micro algae on dry matter intake, animal performance and degradability of microalgal protein in rumen.