Application Of Mulberry(Morus Alba) Leaves And Dried Distillers Grains With Solubles On Ruminant Feeding

Four experiments were conducted to study the chemical compositions of treated mulberry leaves and different sources of dried distillers grains with soluble (DDGS), as well as their effect on rumen fermentation characteristics, growth performance, carcass and meat quality of beef cattle. Results indicated that adding alkali treated DDGS can improve rumen fermentation. Moreover, ensiled mulberry leaves (EML) not only reduced feeding expenses, but also improved the meat quality to some extent.Exp.1In order to investigate nutritional value of different treated mulberry leaves and sources of dried distillers grain with soluble (DDGS). Two different treated mulberry leaves and6sources of DDGS were assessed for their chemical compositions and energy value. Two treated mulberry leaves were:ensiled mulberry leaves (EML) and sun-dried mulberry leaves (SML). DDGS were collected from5different places were:America, Qingdao, Beijing, Jilin, and Chengdu, respectively. The results showed that different treated mulberry leaves had similar nutritional value except NDF and ADF, which SML had higher value than EML (P<0.05). However, EML had more Ash and Ca than SML (P<0.05). Energy values of the two treated mulberry leaves were almost the same, but EML had numerical higher metabolizable energy (ME) than SML. These indicated that the ensiled mulberry leaves is more acceptable in practice than sun-dried mulberry leaves. There were much more difference among the6DDGS samples, especially for No.4sample, which had much lower CP and EE, but higher NDF and ADF. The CP of DDGS was average at25.99%DM making it a good protein feedstuff. Sample6had the highest TDN, NEm and NEg; however, sample4got the lowest energy value. On the whole, high CP and low fiber content make DDGS a good feedstuff for ruminant feeding, but more attention should be paid on chemical analysis because different processing methods give much more variation on nutritional value for animals.Exp.2The effect of types and addition levels of dietary sulfur on in vitro fermentation characteristics, sulfide production, methane emission, and total Archaea population were examined using in vitro rumen cultures. The results showed that increased addition level of DDGS in the substrate decreased total gas production, DM and NDF disappearance, meanwhile increased ammonia concentration. However, it had no dose effect on DM and NDF disappearance for SS and SA, either linear or quadratic effects were observed with addition levels of all three sources of dietary sulfur. Increased DDGS content resulted in decreased methane emission, but total Archaea population was not changed significantly. Although methane was not inhibited dramatically, total Archaea population was increased for both SS and SA. Compared to addition levels, sources of dietary sulfur were more important at affecting in vitro fermentation and microbial population.Exp.3The effects of three types of dietary sulfur on in vitro fermentation characteristics, sulfide production, and microbial populations at two different buffer capacities were examined using in vitro rumen cultures. Addition of DDGS generally decreased total gas production, disappearance of dry matter and neutral detergent fiber, and concentration of total volatile fatty acids, while increasing ammonia concentration. High buffering capacity alleviated these adverse effects on fermentation. The population of sulfate reducing bacteria (SRB) was increased in a sulfur type-dependent manner. These results suggest that type of dietary sulfur and buffering capacity can affect rumen fermentation and sulfide production. Diet buffering capacity, and probably alkalinity, may be increased to alleviate some of the adverse effects associated with feeding DDGS at high levels.Exp.4This experiment was conducted to study the effect of addition levels of ensiled mulberry leaves in the diet of beef cattle on their growth performance, serum biochemical indices and feeding cost. Forty-four Limousin crossbred heifer and44local breed bulls were selected and randomly allocated into four groups according to their body weight and gender with each group11cows and11bulls. Trial groups were fed basal diet added with0%,7.5%,15.0%and22.5%DM of EML for14weeks. All animals were given diets at1.2times of estimated intake, as well as water ad libitum. Dry matter intake (DMI) was measured every other week. Blood samples were collected at the end of feeding trial via venepuncture from jugular vein3h after morning feeding. The results showed that adding EML in the ration of beef cattle had no significant effect on average daily gain, DMI and feed conversion ratio, however, it could reduce feeding expenses by somewhat extent. Furthermore, all the serum biochemical indices except low density lipoprotein (LDL) were not significantly affected by adding different levels of EML. More specifically, adding7.5%DM of EML in the diet significantly increased LDL than the control group, but no difference between the other two addition levels and control. To sum up all the results, adding EML in the diet of beef cattle up to22.5%have no adverse effect on growth performance and blood index, but reduce feeding cost of beef cattle.Exp.5A slaughter experiment was conducted to investigate the effect of adding ensiled mulberry leaves on slaughter performance and meat quality in finishing beef cattle. After feeding trial,4heifers and4bulls were randomly selected from each treatment group to be slaughtered and Longissimus dorsi muscle was sampled from each animal to examine carcass characteristics, as well as meat chemical composition. The results showed that low addition level (7.5%) and medial addition level (15.0%) had significant higher (P<0.05) dressing percentage than control and high addition level (22.5%), which had no difference (P>0.05) between each two. Furthermore, rib eye area had no significant difference (P>0.05) between low addition level and medial addition level, but higher than control (P<0.05), with high addition level in the middle (P>0.05). Although adding ensiled mulberry in the ration of beef cattle had no significantly effect on meat chemical composition, meat color, cholesterol and taurine content, fatty acid profile of meat were significantly affected by different addition level of ensiled mulberry leaves. Palmitoleic acid in the high addition level group was higher than that in control and medial addition level group, which had no difference with low addition level (P<0.05). Low and high addition level had higher oleic acid content than control and medial addition level did (P<0.05). Moreover, medial addition level got both higher linoliec and linolinic acids than the other three groups. To sum it up, low addition level had more mono-unsaturated fatty acids, thus medial addition level had more poly-unsaturated fatty acids. In conclusion, adding ensiled mulberry leaves in the ration of beef cattle has no adverse effect on slaughter performance, carcass quality and meat color, meanwhile it can improve fatty acid profile of meat to somewhat extent.