Location: Environmentally Integrated Dairy Management Research
Title: Intake, digestibility, and rumen fermentation in sheep offered alfalfa silage alone or alfalfa and tall fescue-mixtures harvested after a killing frostAuthor
NIYIGENA, V. - University Of Arkansas | |
COFFEY, K. - University Of Arkansas | |
Coblentz, Wayne | |
PHILIPP, D. - University Of Arkansas | |
ALTHABER, C. - University Of Arkansas | |
RHEIN, R. - University Of Arkansas | |
PRUDEN, M. - University Of Arkansas |
Submitted to: Journal of Dairy Science
Publication Type: Abstract Only Publication Acceptance Date: 4/15/2019 Publication Date: 7/7/2019 Citation: Niyigena, V., Coffey, K.P., Coblentz, W.K., Philipp, D., Althaber, C., Rhein, R.T., Pruden, M.C. 2019. Intake, digestibility, and rumen fermentation in sheep offered alfalfa silage alone or alfalfa and tall fescue-mixtures harvested after a killing frost. Journal of Dairy Science. Annual Meeting of ASAS. July 8-11, 2019. Austin, TX. Interpretive Summary: Technical Abstract: The objective of this study was to determine the effect of harvesting alfalfa and fescue after frost and ensiling mixtures of these forages on silage fermentation characteristics, intake, digestibility and ruminal fermentation by ewes. Forages were harvested in October of 2018, wilted, and blended as either alfalfa alone, 67% alfalfa +33% fescue, 33% alfalfa + 67% fescue, or 100% fescue. Twenty bins were lined with 2 plastic bags, packed (n = 5/trt), stored for 3 months, and then randomly assigned to ewes (n = 20; mean BW = 34.7 ± 6.65 kg) for ad libitum consumption, using 5 animals per treatment. Ewes were given 17 d of adaptation followed by 5 d of total feces and urine collection. Data were analyzed using PROC-MIXED of SAS and orthogonal polynomial trends were used to identify the effects of different proportions of fescue-to-alfalfa silage. Silage total acids, lactate, and acetate increased linearly (P < 0.01) while silage moisture and ammonia decreased linearly (P < 0.01) with increasing proportions of fescue in the diet. The proportions of lactate to total acids (mole/100 moles) increased linearly (P < 0.01) and quadratically (P < 0.05) by adding more fescue to alfalfa. Intake (g/kg BW), digestibility (%), and intake of digestible DM and OM (g/kg BW) decreased linearly (P < 0.05) as fescue proportion was increased in the silages. Ruminal acetate and butyrate (%) increased linearly (P < 0.01) with increasing fescue concentrations in the diet. Ensiling alfalfa with fescue may improve forage fermentation characteristics, but may reduce intake and digestibility in sheep compared to feeding alfalfa silage alone. This study was supported in part by USDA-ARS specific cooperative agreement 58-3655-4-052. |