ARS | Publication request: Effects of supplemental organic cobalt on nutrient digestion and nitrogen balance in lambs fed forage-based diets

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: November 17, 2008
Publication Date: N/A

Technical Abstract: The objective of this study was to determine the effects of supplemental organic cobalt on nutrient digestion and nitrogen balance in lambs fed forage-based diets. Sixteen wether lambs (avg initial BW = 28.6 ± 1.3 kg) were used in a 2 × 2 Latin square and randomly allotted to one of two treatments being ad libitum grass hay (7.1% CP 67.9% NDF, DM basis) plus 45.0 g (as fed) dried distillers grains with mineral formulated to provide 1.1 mg•hd-1•d-1 of Cobalt (CONTROL) or mineral plus CoMax 100™ formulated to provide 7.1 mg•hd-1•d-1 of Cobalt (COBALT). Experimental periods were 21 d in length and consisted of 15 d for diet adaptation and 6 d of total fecal and urine collection. Forage DM intake increased (P = 0.091) when lambs consumed COBALT. Likewise, forage OM and NDF intake also increased with COBALT (P < 0.086). Despite the increase in forage intake, fecal DM, OM, and NDF flow (P > 0.654) did not differ across treatment. Due to the increase in intake of DM, OM, and NDF, and no differences being observed for fecal flow, DM, OM, and NDF digested (g/d) was greater for COBALT (P < 0.098) than CONTROL. Nevertheless, total tract DM, OM, and NDF digestibility (% of total intake) did not differ (P > 0.591) when additional cobalt was provided to lambs. No differences were observed between treatments for total N intake (P = 0.129), total tract N digested (g/d) (P = 0.135), or urine N output (P = 0.812) and consequently, differences were not expected for total N output (P = 0.782). The provision of additional cobalt to lambs did not increase (P = 0.251) N retention (g/d). Likewise, treatment did not affect N retention when expressed as a % of intake (P = 0.82) or as a % of N digested (P = 0.95). In conclusion, providing growing lambs consuming a forage-based diet 7.1 mg•hd-1•d-1 of Cobalt did increase forage intake but did not affect total tract digestibility or N balance.