Location: Livestock Nutrient Management ResearchTitle: Meat goat diet supplementation with crude glycerin: Ruminal fermentation metabolism, blood chemistry profile, animal performance, and carcass traits
|GARUNG, NAR - Tuskegee University|
|TUOHO, KWEKU - Tuskegee University|
|ABRAHAMSEN, FRANK - Tuskegee University|
Submitted to: Journal of Animal Physiology and Animal Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/30/2020
Publication Date: 2/15/2021
Citation: Garung, N., Tuoho, K., Abrahamsen, F., Min, B. 2021. Meat goat diet supplementation with crude glycerin: Ruminal fermentation metabolism, blood chemistry profile, animal performance, and carcass traits. Journal of Animal Physiology and Animal Nutrition. 105(3):470-477. https://doi.org/10.1111/jpn.13489.
Interpretive Summary: There is a growing interest in the production of biodiesel as a bio-renewable fuel source. Crude glycerin (CG) is a byproduct of biodiesel production, and it is also a potential feedstuff for ruminant animals. Crude glycerin has been proposed as a replacement for conventional food energy sources such as corn grain. However, previous research results have depended on the level of CG, the production stage of the animal, and the animal species. Scientists from USDA-ARS at Bushland, TX, and Tuskegee University, AL, analyzed how dietary CG affects dry matter intake, animal performance, rumen fermentation, blood metabolites, and carcass traits in meat goats. Results indicated that CG is a viable feedstuff for growing meat goats, and CG can partially replace corn grain as an energy source when fed at 15 percent of the diet.
Technical Abstract: The objective of this experiment was to determine the effects of feeding varying levels of crude glycerin (CG) on dry matter intake (DMI), animal performance, carcass traits and rumen volatile fatty acids (VFA) concentration in meat goats. Twenty-four intact male Boer goats (23.9 +/- 1.0 kg initial BW and 4-5 months of age) were randomly assigned to one of four experimental diets (n = 6) containing 30% bermudagrass hay plus 70% concentrate mix with 0, 5, 10 or 15% CG in the diet on an as-fed basis, substituted for the corn portion of the concentrate. Feed offered and refusals were monitored daily for 84 days. Goats were weighed at 28-days interval. Blood and rumen samples were collected on day 84. At the end of the 84-days feeding period, goats were harvested, and carcass characteristics measured. Feed intake, average daily gain (ADG), gain-to-feed ratio (G:F), carcass traits, and VFA concentrations were analyzed as a completely randomized design. The CG did not influence animal body weight (BW) changes, ADG and G:F ratio, but tended to (P = 0.06) decreased DMI. Molar percent propionic acid increased linearly (P < 0.05) with increasing CG. The acetate: propionate (A:P) ratio decreased (P < 0.05) with increasing amounts of CG in the diet. The CG addition tended to increase (P = 0.09) the longissimus muscle (LM area) quadratically (P < 0.09) in meat goats. In conclusion, CG can replace corn in diet for growing meat goats when fed up to 15 percent of diet, improving ruminal propionate concentration, but decreasing A:P ratio without affecting animal performance and carcass traits.