Effects of maize and lucerne particle size on ruminal passage rate, chewing activity of cows in midlactation
This study evaluated the effects of maize and lucerne particle size on ruminal passage rate and chewing activity in midlactation cows. Four multiparous Holstein cows with ruminal cannulas were assigned randomly to a 4 × 4 Latin square design. Treatments were arranged in a 2 × 2 factorial design; two lucerne particle sizes: 2.54 mm (short) and 6.22 mm (long) were combined with concentrates based on either ground maize (711 μm) or cracked maize (1755 μm). Diets were fed as a total mixed ration with a ratio of concentrate to forage of 39:61. No significant difference in dry matter intake, ruminal passage rate and chewing activity between ground maize and cracked maize were observed. Ruminal liquid passage rate increased from 11.3 to 12.1％/h (P=0.02) and ruminal solids passage rate tended to decrease from 6.4 and 6.0％/h when short lucerne was fed to cows. Cows fed long lucerne hay spent more time ruminating compared to cows fed short lucerne hay (P<0.001). Total time spent on chewing by cows increased from 505 to 574 min/d (P=0.002) for short lucerne and long lucerne, respectively.
physical structure lucerne hay maize processing ruminal digesta kinetics ruminating activity
Z.J.Cao M.Ma L.L.Wang P.Chen S.L.Li
State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University 100094 Beijing, PR.China
国际会议
The 7tb International Symposium on the Nutrition of Herbivores(ISNH-7)(第七届国际草食动物营养研讨会)
北京
英文
924-929
2007-09-16（万方平台首次上网日期，不代表论文的发表时间）