|BELESKY, DAVID - Retired ARS Employee
|ZAJAC, ANNE - Virginia Polytechnic Institution & State University
Submitted to: Grass and Forage Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/28/2014
Publication Date: 7/22/2015
Citation: Turner, K.E., Belesky, D.P., Zajac, A.M., Dowd, M.K. 2015. Performance and blood parameters when lambs and meat-goat kids were finished on pasture with and without whole cottonseed (Gossypium hirsutum) supplementation. Grass and Forage Science. 70:451-464.
Interpretive Summary: In the Appalachian Region of the USA, lamb and meat goat production is growing rapidly to produce meat for ethnic markets. Most farms use forage-based systems for lamb and goat production, but control of gastrointestinal parasites in sheep and goats is a major challenge for producers when finishing livestock on pasture. Energy and protein supplementation when finishing animals on pasture can improve livestock performance and help maintain resilience to gastrointestinal parasite infection. We evaluated forage production patterns, weight gains, and health patterns from 2006-2008 when lambs and meat goat kids were finished on a mixed sward of orchardgrass, red clover and white clover with and without whole cottonseed supplementation. Botanical composition of the sward varied with year and with time during the growing season with greater amounts of red clover relatively early and more orchardgrass late in the season. Suffolk lambs had the heaviest body weights, Katahdin lambs were intermediate, and meat goat kids were lightest at the start and end of each year. Supplemented lambs and meat goat kids typically had greater weight gains but higher fecal eggs counts which indicated a greater resilience to gastrointestinal parasite infection. Katahdin lambs typically had the lowest fecal egg counts compared to Suffolk lambs or meat goat kids. Using the FAMACHA© system to selectively deworm sheep and goats resulted in a 54% reduction in the number of doses of chemical dewormer administered over the three-year duration of the study. Findings benefit on-farm economics by helping producers develop and refine animal selection, feeding, grazing, or finishing systems to produce lamb and meat goats for niche markets.
Technical Abstract: We evaluated forage production patterns, weight gains, and health patterns when lambs (Ovis aries) and meat goat (Caprus hircus) kids were finished on a mixed sward of orchardgrass (Dactylis glomerata L.), red clover (Trifolium pratense L.), and white clover (Trifolium repens L.) with (SUP) and without (UNSUP) supplemental whole cottonseed (Gossypium hirsutum; WCS). Accumulated herbage mass was similar at the start of each grazing season. Botanical composition of the sward varied with year and with time during the growing season with greater amounts of red clover relatively early and more orchardgrass late in the season. Suffolk (SX) lambs had the heaviest body weights, Katahdin (KA) lambs intermediate, and meat goat (GX) kids the lightest at the start and end of each year. Supplementation with WCS increased average daily gain. Blood parameters changed as the animals adapted to treatments each year and reflected forage nutrient and supplement availability (Date x Treatment interactions). Only in 2008, did SUP animals have higher blood urea nitrogen levels which may indicate less efficient use of dietary nitrogen compared to UNSUP animals. Fecal egg count (FEC) was variable over the grazing season (Date x Treatment interaction) each year, but tended to be greater for SUP compared to UNSUP animals. At the level of supplement offered, WCS gossypol concentrations did not reduce gastrointestinal parasites based on FEC. The KA lambs typically had lower FEC than SX and GX. Supplementation with WCS did not improve FAMACHA© scores (Date x Treatment interaction P < 0.001), but KA lambs consistently had lower (Date x Breed interaction, P < 0.001) FAMACHA© scores than GX and SX; GX were highest. Using the FAMACHA© system resulted in a 54% reduction in the number of doses of dewormer administered over the three-year duration of the study. More research is needed to help refine supplementation strategies when finishing lambs and meat goat kids on pasture.