Studies On Application And Storage Of Wet Corn Gluten Feed In Dairy Diet

Wet corn gluten feed (WCGF) is one kind of by-products from corn milling industry. This study was firstly conducted to evaluate the nutritional values of WCGF ((three kinds of commonly used roughage (chinese wildrye, corn silage and alfalfa) and corn were used as references). Then a4×4Latin square designed experiment was carried out to investigate the effect of feeding different addition levels of WCGF on ruminal fermentation traits, bacterial activities, blood parameters, pH and shedding Escherichia coli of fecal of dairy cows, Finally, two series of animal trial were designed to test the animal performance in both dairy cows and beef cattle. As WCGF has high moisture content, it is very hard for storage. We tried to ensile WCGF with dry hay to extend the storage time of WCGF. As to provide theoretical basis for scientific using this feed resources, while to avoid the nutrient loss and air pollution caused by drying it. Experiment1Evaluation of the nutritional values of WCGFThe study of comparing WCGF with commonly used roughage (chinese wildrye, corn silage and alfalfa hay) and corn, to evaluate the nutritional values of WCGF, and further analyze the compositions of amino acids, rumen degradation rate and protein digestive rate of small intestine. The results showed that the CP content of WCGF was higher than that of chinese wildrye and corn silage (17.82%vs.6.11%and7.25%, respectively, P<0.05). The NDF, ADF and Ca contents of WCGF were in the lowest levels (49.93%vs.66.39%,60.42%and57.34%;14.39%vs.36.31%,30.22%and25.54%;0.06%vs.0.41%,0.39%and0.43%, respectively, P<0.05) when compared with other roughages; while the P content of WCGF was in the highest level (0.96%vs.0.21%,0.25%and0.26%, respectively, P<0.05). The percentage of unavailable fiber (CC) of WCGF was lower than the other three kinds of commonly roughage (P<0.05). The contents of glutamic acid (Glu), leucine (Leu) and proline (Pro) of WCGF were higher than those of other roughages (P<0.05). The CP effective degradation rate and intestinal digestibility of WCGF were67.56%and71.02%respectively. The NDF effective degradation rate of WCGF was higher than other three kinds forage (43.14%vs.29.79%,33.48%and38.59%, respectively, P<0.05). The CP, NDF, ADF, P and Ash were higher than corn (P<0.05). The amino acid of WCGF, percentage of crude protein in the feedstuff that is intermediately degraded protein, percentage of carbohydrate of the feedstuff that is available fiber and CP effective degradation rate were higher than corn (P<0.05), but the small intestinal digestibility of CP was lower than corn (P<0.05).Experiment2Effect of feeing different additional levels of WCGF on rumen fermentation, rumen microorganism, blood biochemical parameters and the pH, shedding Escherichia coli of fecal in dairy cowsFour non-lactating Holstein dairy cows fitted with permanent rumen fistula were used in a4×4Latin square designed trial. Each animal was fed one of four treatment diets during each period:0%(control),15%,25%and35%WCGF on a dry matter basis. The results showed that the concentrations of ruminal ammonia and acetate were increased as the level of WCGF increased (P<0.05). Acetate: propionate (A:P) was significant decreased (P<0.05). The percentage of total bacterial16SrDNA of Fibrobacter succinogenes was significantly lower in cows fed ration with35%WCGF than that in cows fed0%(control) and25%WCGF (P<0.05). And The percentage of total bacterial16SrDNA of Butyrivibrio fibrisolvens in cows fed diet with35%WCGF was in the lowest level (P<0.05); while Prevotella ruminicola in the highest level (P<0.05). The concentrations of blood plasma urea nitrogen of the cows fed three treatment diets were all higher than that of cows fed the control diet (2.97%,3.31%and3.14%vs.2.77%, respectively, P<0.05). The concentrations of blood plasma urea nitrogen of25%and35%WCGF inclusion in diets significant higher than15%(P<0.05). The pH value of fecal in35%WCGF group was higher than that in other groups (6.86vs.6.61,6.67and6.72, respectively, P<0.05). The pH of fecal with15%and25%WCGF was higher than control group (P<0.05). The shedding Escherichia coli of fecal in dairy cows fed diet with35%WCGF was significant higher than that in other cows (6.34vs.5.96,5.99and6.13, respectively,P<0.05).Experiment3Effects of feeding WCGF on production performance in high producing dairy cowsSixty high producing dairy cows were selected and used in a single factor randomized design experiment to evaluate the effects of feeding WCGF (25%DM) on production performance of high producing dairy cows. The results showed that the milk production and milk fat percentage of cows in experimental group was significant reduced by2.65%and increased by4.49%, respectively than those in the control,(P<0.05). The somatic cell count was not affected by the treatment (P>0.05).Experiment4Effects of feeding WCGF on animal performance in growing heifersSixty Holstein heifers were weighed to evaluate the effect of feeding WCGF (25%) on weight gain in growing heifers. The results showed that dry matter intake increased when25%WCGF was added in the diet (P>0.05). The heifers fed diets containing WCGF did not gain weight quicker as the ADG increased, in addition, the increase was significantly (P<0.05).Experiment5The strategy of storage of WCGFThe WCGF was ensiled alone (the control), mixed with Chinese wildrye (10%,20%and30%) by the density of1000kg/m3or with alfalfa (10%,20%and30%) by the density of1100kg/m3. The results showed that very low fermentation intensity, that high levels of lactic acid dominated the fermentation of WCGF ensiled alone, the pH values were increased during fermentation with Chinese wildrye or with alfalfa at different ratios. Ammonia-nitrogen was in the highest level in WCGF ensiled alone, decreased as the Chinese wildrye additional level increased, and increased as the alfalfa ratio increased. Adding30%Chinese wildrye or10%alfalfa to WCGF silage had significantly increased acetic acid production, which could improve aerobic stability compared with the control.Therefore, it was concluded that:(1) WCGF contained more rapidly digestible fiber, CP and amino acids, which might be used as a potential fibrous forage resources.(2) The study of WCGF on rumen fermentation, rumen microorganism, blood biochemical parameters and the pH, shedding Escherichia coli of fecal of dairy cows, suggested that the feeding ratio should not be higher than35%, the better feeding ratio was25%.(3) Feeding WCGF could reduce the milk production, but could but increase the milk fat percentage.(4) Feeding WCGF to growing heifers could reduce the feeding cost.(5) Ensiling WCGF with30%Chinese wildrye and10%alfalfa could improve aerobic stability.