Effects of Corn Silage Diets on Intestinal Morphology in Dairy Calves

Abstract Text: A calf’s diet in the first few weeks of life is critical for gastrointestinal tract development. Current feed prices are causing producers to experiment with less expensive alternatives. The gastrointestinal tract of ruminants takes weeks to develop after birth. Evaluating intestinal morphology is an indicator of how well the animal is absorbing nutrients. The objective of the study was to determine the post-weaning effects of calf starter and corn silage fed to pre-weaned dairy calves on intestinal morphology. A total of 45 calves (n=15/trmt) were fed a diet of whole milk with 100% calf starter (STA), milk replacer with 60% calf starter and 40% corn silage (SS), or 100% corn silage (SIL). Nine calves were sacrificed after 8 weeks of age. Jejunal samples were collected to compare between the three treatment groups. Samples were preserved in formalin and later phosphate buffered saline until further analysis. Slices of tissue were made into nine slides per calf, and stained with methylene blue. Pictures were taken with a compound light microscope and measured using the ImageJ computer program (NIH, Bethesda, MD). Measurements were recorded including villi length, crypt depth, and villi width. Least squares means of villi lengths were 97.65, 89.57, and 105.61 um for treatments STA, SS, and SIL, respectively (P=0.12).  Least squares means of crypt depths were 46.10, 38.69, and 48.58 um for treatments STA, SS, and SIL, respectively (P=0.03) and villi diameters were 14.51, 17.17, and 15.38 um for treatments STA, SS, and SIL, respectively (P=0.69).  Results from the study indicated that the calves fed SS had significantly smaller crypt depths compared with the other treatments.  This may indicate better intestinal development in calves fed either 100% calf starter or corn silage. More research is needed. 

Keywords: Corn Silage, Calves, Ruminant