Submitted to: American Society of Animal Science Southern Section Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 12/17/2008
Publication Date: 2/2/2009
Citation: Nusz, S., Walker, E.L., Brown, M.A. 2009. The effects of free choice protein supplementation on growth of lambs and meat goat kids grazing warm season grasses [abstract]. American Society of Animal Science Southern Section Meeting, January 31-February 3, 2009, Atlanta, GA. p. 33. Available on-line: http://www.asas.org/southern/meetings_past.asp. Interpretive Summary: Abstract only.
Technical Abstract: Grazing provides most nutrients for growth in ruminants, however; there are times when nutritional needs of the animal exceed the nutritional quality of forages. Forages common to pastures in the South and Midwest may be insufficient in crude protein to meet the demands of growing lambs and meat goat kids, particularly after late June when some forages have become mature. This study was an extension of a previous study conducted in 2007. The objective was to test the effects of protein supplementation, via protein tubs, on growth of lambs and kids grazing 1.22 ha bermudagrass/foxtail pastures. Boer influenced (BI) and Savanna x Spanish (SP) kids (n = 27 and 28; respectively) and Katahdin (KK), Katahdin x Suffolk (KS), Suffolk x Katahdin (SK), and Suffolk (SS) lambs (n = 11, 15, 21, and 25; respectively) were grouped by weight, breed, and gender and randomly assigned to one of two treatments: 1) common bermudagrass/foxtail supplemented with a 21% natural protein block (n=2) and 2) common bermudagrass/foxtail with no supplement (n=2). Animals were weighed every two weeks for the 56 day study. Sheep had greater ADG than goats (45.4 ± 7 g/d vs 15 ± 7 g/d; P < 0.05). Protein supplementation did not increase ADG of the BI or SP kids. However, the BI kids had a higher ADG than the SP kids (22.14 + 7.5 g/d vs 7.7 + 7.4 g/d; P < 0.05). Protein supplementation did not increase ADG of the KK, KS, SK, or SS lambs. However, the SK had the greatest ADG (52.8 + 7.7 g/d) and were heavier than SS (34.4 + 8 g/d; P = 0.006). Results of this study suggest that protein supplementation had no effect on ADG in 2008. In total, 44.44 kg of protein supplementation was consumed in the two pens receiving supplementation, and on average, only 1.38 kg of supplementation per animal was consumed. It is possible that the kids and lambs met their protein requirements through forage protein this year whereas they may have met it by supplemental protein consumption last year due to pasture and climate differences. Further research is needed to determine the impact of low-level protein supplementation on lambs and meat goat kids productivity on warm-season pasture.