gholamhosein Irajian; hamid Amanlou; Asadollah Teimouri Yansari; hamid reza mirzaie almouti; hormoz mansouri
Volume 19, Issue 4 , March 2018, , Pages 803-818
Abstract
This study investigated the effects of alfalfa hay and corn silage particle size on chewing activity, passage rate of solid fraction in the rumen and performance of pregnant ewes. The experiment has been done using 30 ewes (35±0.4 months) in a completely randomized design with five treatments ...
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This study investigated the effects of alfalfa hay and corn silage particle size on chewing activity, passage rate of solid fraction in the rumen and performance of pregnant ewes. The experiment has been done using 30 ewes (35±0.4 months) in a completely randomized design with five treatments and six replicates during a 30 days period. Forages were including alfalfa hay (three sizes, geometric mean 2.42, 4.91 and 7.04 mm) and corn silage (two sizes, geometric mean 3.36 and 7.73 mm). Treatments including fine particles of alfalfa hay and corn silage had the least physical effectiveness factor (pef > 8) and pef values (pef >8, pef >1.18) were reduced with decrease in particle size (p<0.05). Geometric mean also decreased (p<0.05). Following reduction in particle size of forages, passage rate of solid fraction in the rumen and terminal part of digestive tract (TDT) were increased (p<0.05) and retention time in the rumen, TDT and total retention time were decreased (p<0.05). Feed intake time, chewing activity and total chewing time were not affected (p<0.05). Results showed that it is necessary to consider the appropriate balance between particle size as a representative of the physical and chemical characteristics of the diet. The treatment of alfalfa fine particle size plus corn silage long particle size in most cases showed better results, and it seems that this treatment has provided a more appropriate balance in the diet for feeding ewes. Therefore, in preparing the pregnant ewes’ diet, we can expect better performance by considering the particle size.