|Zajac, Ann -|
Submitted to: Grass and Forage Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 22, 2012
Publication Date: June 1, 2013
Citation: Turner, K.E., Cassida, K.A., Zajac, A.M. 2013. Weight gains, blood parameters, and fecal egg counts when meat-goat kids were finished on alfalfa, red clover, or orchardgrass pastures. Grass and Forage Science. 68(2):245-259. Interpretive Summary: In the Appalachian Region of the USA, meat goat production is growing rapidly to produce meat for ethnic markets. Most farms use forage-based systems for goat production, but control of gastrointestinal parasites in small ruminants is a major challenge for producers when finishing goat kids on pasture. There is little information available on performance of meat goats in management intensive grazing systems. We conducted an experiment to evaluate weight gain, blood parameters, and fecal egg count patterns of meat goat kids finished on alfalfa, red clover plus grass, or orchardgrass pastures. Goats finished on alfalfa and red clover plus grass pastures had heavier final weights than those finished on orchardgrass, but all animals were at desirable live weights (less than 31.8kg) for ethnic markets. The forage energy to protein ratios from pastures managed for high nutritive value with rotational stocking and blood urea nitrogen concentrations in grazing goats indicated that animals were wasting forage protein and the need for supplemental energy to improve protein utilization. Goats were managed to maintain low parasite burdens and high resilience to gastrointestinal parasite infection (sustained weight gain, high blood packed cell volume, and low FAMACHA© score). Based on fecal egg counts to determine gastrointestinal parasites loads, goat kids grazing alfalfa and red clover plus grass appeared to be more resilient to gastrointestinal parasite burdens than goats grazing orchardgrass. This work is useful to scientists trying to characterize meat goat growth on pastures. Findings benefit on-farm economics by helping producers develop and refine feeding, grazing, or finishing systems to produce meat goats for niche markets without the use of expensive grain supplements.
Technical Abstract: This experiment was conducted in 2005-2007 to evaluate weight gain, blood parameters associated with forage nutrient-use and anemia from gastrointestinal (GI) parasite infection, and fecal egg counts (FEC) patterns of meat goat kids finished on alfalfa (Medicago sativa L; ALF); red clover (Trifolium pretense L.; RCL); or orchardgrass (Dactylis glomerata L; OGR) pastures. Forage mass displayed a complex interaction between treatment and time (P < 0.001) across the grazing seasons, but tended to be numerically greater for RCL than for ALF or OGR in the last half of the season each yr. Overall, final BW were greater for goats finished on ALF and RCG than OGR, except in 2006 when ALF was greater than RCG or OGR. In 2005, overall ADG (g/d) was similar for ALF (81.7) and RCL (90.8) kids and greater (P < 0.001) than OGR (49.9). In 2006, overall gains were similar (P > 0.10) among groups (35). In 2007, overall ADG (P < 0.001) for goat kids was greater for ALF (100) which was greater than RCL (77.1) which was greater than OGR (50). Forage total digestible nutrients to crude protein (TDN:CP) ratios from pastures managed for high nutritive value were less than 5:1 in all yr. Overall in 2005, blood urea nitrogen (BUN) was higher (P < 0.001) when goats grazed ALF or RCL compared to OGR. In 2006 BUN was greater for ALF compared to RCG and OGR which were similar. In 2007, BUN was greater for ALF and OGR compared to RCG. Packed cell volume (PCV) means were not different in 2005 (mean 28.1) and 2006 (mean 27.9) among groups; in 2007, PCV followed a trend of RCG > ALF > OGR. Each year, FEC were variable over the grazing season (date and treatment x date interaction ; P < 0.001). Based on FEC, goat kids grazing ALF and RCG appeared to be more resilient to GI parasite burdens than goats grazing OGR. Meat goat kids finished on ALF, RCG, or OGR pastures managed for high forage nutritive value without supplementation produced desirable live weights (< 31.8 kg) for ethnic markets. The TDN:CP ratios in forages and BUN concentrations in grazing goats indicated animals were wasting forage protein and a need for supplemental energy to help improve protein utilization. More research is needed to determine whether strategic energy supplementation would improve protein-use efficiency and resilience to parasite infection when finishing meat goats on pastures managed for high forage nutritive value.