Evaluation Protein Nutritional Value And Feed Value Of DDGS In Dairy Cow Feeding

In this study four lactating dairy cows equipped with ruminal and duodenal cannulas were used to determine the ruminal degradablity and intestine digestibility of different sources DDGS, further also evaluated the effect of feeding DDGS to Chinese Holstein dairy cow. Study included four parts:1. The results chemical nutrient analysis of different sources DDGS showed that most of the samples has a DM content above 90%, CP content differed between plants (26.5-32.5%), ether extract content differed largely, from 3.1 to 15 .5%, ADF content ranged from 14.9-42.6%, All of the NDF content was more than 50%, and the highest was about 75%, ADICP and NDICP content differed lagely. The ED, RUP and IDP of DDGS of different resources had relatively smaller differences.2. Ruminally degradability of DM of DDGS samples of different plants differed to some extent. The results appeared to be no significant regional characteristics. The content of rapid degradation part of dry matter in all samples was higher than the same part of the CP, whereas the potential degradable part was higher for CP compared with DM. The degradation rate of potential degradable part of DM ranged from 0.025 to 0.044h-1, and was higher than the degradation rate of the same part of CP. The effective degradability of DM for DDGS of different plants ranged from 41.0% to 58.2% and higher than the corresponding effective degradability of CP. Rumen undegradable protein was higher than 60% for all of the samples, and up to a 77.5%.3. The content of RUP of DDGS of different plants and its intestinal digestibility, and intestinal digestibility of single amino acids were all different to some extent. RUP of GD was significantly higher than other samples. The intestinal digestibility of single amino acid was higher for LY and SZ, and lower for GD. Intestinal digestibility of esential amino acids of SZ was significantly higher than JY, TG and GD. Intestinal digestibility of essential amino acid of GD was significantly lower than CY, LY, SZ, ZD1, ZD2, JL, and FY. The intestinal digestibility of essential amino acids of YX was similar with the other samples. Intestinal digestibility of total amino acids and RUP differed to some extent, CY, LY, SZ, ZD1 and JL had a higher intestinal didigestibility of total amino acids than GD. Intestinal digestibility of total amino acids was similar for JY, TG, YX, ZD2, FY and other samples.4. The content of DDGS in diet did not affect the dry matter intake, milk yield of trial dairy cow. But as the proportion of DDGS increased, milk yield tended to increase first and then decreased numerusly. Milk fat content and milk fat yield were similar for all treatments (P < 0.05). Milk protein content gradually decreased with the increase levels of DDGS (P < 0.01), while milk protein yield was similar for all treatments (P > 0.05). The content of DDGS did not affect the blood parameters of trial cow. Diet supplemented with DDGS can reduce costs and improve feed efficiency, enhance the economic benefits of dairy farm, but if DDGS was added excessive, feed efficiency will decreased.The results of this study showed that no more than 25% of DDGS (DM basis) should be added to the diets of dairy cow. And it is also needed to develop a quick testing technique...