Effects of carbohydrate composition in concentrate mixture of a total mixed ration on feed intake, performance and ruminal fermentation in dairy cows | Einfluss der kohlenhydratzusammensetzung von Kraftfuttermischungen in totalen Mischrationen auf Futteraufnahme, Leistung ung Pansenfermentation bei Milchkûhen
2006
Weber, I., Hohenheim Univ. (Germany). Institut für Tierernährung | Steingass, H. | Tafaj, M. | Drochner, W.
A feeding trial was carried out with 22 Holstein cows, in which the effect of type of carbohydrates (starch versus cell wall constituents) and differences in rumen fermentability (fast versus slow) on feed intake, milk production, ruminal fermentation and chewing behavior was studied. Variations in starch content and rumen fermentability were achieved with different components in the concentrate mixture of a total mixed ration (TMR). The basal diet of the TMR consisted of 19% corn silage, 19% grass silage and 13% hay in total dry matter (DM). The concentrate mixture comprised 49% of the DM. Cows were blocked into 4 groups. In every group was one ruminal cannulated cow. All diets were fed to the groups ad libitum as a 4 x 4 Latin square design with a 2 x 2 factorial arrangement of the treatments. All diets had similar NEL and CP contents. Total intake of DM and FEC milk yield were higher in cows fed slowly fermentable diets. Milk fat percentage was lower and milk protein was higher in cows consuming the starch rich rations. Substituting starch by cell wall in concentrate mixtures tended in higher ruminal pH and bicarbonate concentrations. Total VFA concentration in the rumen did not differ between treatments. But cell wall rich diets increased acetate and butyrate concentration while starch rich diets tended to higher propionate in the rumen. This was also reflected by a increased ruminal acetate : propionate ratio. Chewing and ruminating activity was not affected by type of concentrate.
显示更多 [+] 显示较少 [-]