Effect Of Completed Pellet Diets With Different Straws On Rumen Metabolic Parameters And Nutrient Digestion And Metabolism In Sheep

In a 2 X 3 crossing design trial, Four one years old hybrid wethers with rumen perpetual fistula and duodenal frontal side cannula were didided into 2 groups, and the complete pellet diet with roughage comprising of corn-stalk and alfalfa(diet A, 50% concentrate, 50% roughage) and the diet with roughage comprising of wheat-straw and alfalfa(diet B, 53% concentrate ,47% roughage) were fed alternatively to these 2 groups. The concentrations of digested energy(DE) and nitrogen(N) are equal between two diets. A period of 19 days, there are three periods (57 days)in the trial, the followings were measured by using Cr2O3 to mark digesta and collecting feces completely: The rumen parameters of digestion and metabolism and the concentration of plasma urea nitrogen (PUN) ; The flow of duodenal digesta; The apparent digestibilities of nutrients in rumen, postrumen and total tract and the apparent nitrogen retention of wethers. The results show that (l)there are no significant different about the rumen metabolic parameters of wethers between two treatments (p>0.05 ) . While there is a tendency that the rumen fluid pH value of treatment A is higher than that of treatment B; The variation of rumen fluid ammonia nitrogen(NH3-N) of treatment A is more steady than that of treatment B. Both the parameters above vary within normal range when wethers fed with diet A or diet B. (2)There are no significant differents about the flows of duodenal digesta and N in digesta, and about the apparent digestibilities of dry matter(DM) and N in rumen, postruminal and total tract between two treatments. The differents of the digestibilities of ADF , NDF in total tract and the different of the apparent nitrogen retention are also not significant between two treatments(p>0.05).While there is a tendency that the total tract digestibilities of DM and NDF and the apparent nitrogen retention of treatment A are higher than those of B. Both the apparent digestibilities of all nutrients measured are high in two diets. (3)There is no significant different about PUN of wethers between two treatments (p>0.05) , and both PUN of two treatments vary within normal range. It is concluded that both satisfying consequences can be gained when feeding wethers with two complete pellet diets concerned in the study. But, because there is a tendency that diet A is superior to diets B, formula of diet A should be chosen if corn-stalk is sufficient here. Such can gain better effect and is also beneficial to saving concentrate; While if wheat-straw is sufficient here, formula of diet B should be chosen in order to make full use of native straw and to lower cost of diet.