Location: Livestock Nutrient Management Research
Title: The effect of high levels of dietary zinc on growth performance, carcass characteristics, blood parameters, immune response and tissue minerals in growing Boer-cross goat kidsAuthor
SOLAIMAN, SANDRA - Tuskegee University | |
Min, Byeng Ryel |
Submitted to: Small Ruminant Research
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 5/27/2019 Publication Date: 6/15/2019 Citation: Solaiman, S., Min, B. 2019. The effect of high levels of dietary zinc on growth performance, carcass characteristics, blood parameters, immune response and tissue minerals in growing Boer-cross goat kids. Small Ruminant Research. 177:167-174. https://doi.org/10.1016/j.smallrumres.2019.05.018. DOI: https://doi.org/10.1016/j.smallrumres.2019.05.018 Interpretive Summary: An adequate amount of zinc (Zn) is essential for the normal functioning of all livestock and a deficiency may adversely affect their health and performance. However, effects of high dietary Zn supplementation on performance, metabolism and health of growing goats are contradictory and warrant further study. Therefore, scientists from ARS-USDA (Bushland, TX) and Tuskegee University assessed animal performance, immune responses, blood plasma metabolites, carcass traits, and body tissue deposition of Zn in goats fed high levels of Zn. Scientists from USDA-ARS (Bushland, TX) and Tuskegee University (Tuskegee, AL) studied how the elevated Zn supplementation affects animal growth performance, blood metabolites, immune responses, animal health, and carcass traits in meat goats. High Zn supplementation had no effect on animal performance, and carcass traits in meat goats. Tissue Zn was not elevated with high levels of Zn in the diet, indicating that body has no significant storage of Zn. These results indicated that Zinc is not stored in tissues, and daily supply of Zn maybe needed for optimum goat health and performance. Technical Abstract: An experiment was conducted to determine animal performance, carcass traits, blood metabolites, immune responses, and tissue minerals in goats fed high levels of zinc (Zn). Twenty-one Boer-cross (Capra aegagrus hircus) growing goat kids (BW, 22.9 ± 1.4 kg, 4-5 months old) were housed individually and fed twice a day 80:20 grain mix: bermudagrass hay (BGH) diet ad libitum for 86 days. Goats in control group (0Zn) received orally 5 mL of water (1.95 + 0.03 ppm Zinc) with no added Zn. Treatment groups, 100Zn and 200Zn received 5 mL water containing additional 100 or 200 mg Zn as Zn sulfate heptahydrate, respectively. Average daily gain (ADG), DM intake, feed conversion ratio (gain: feed), carcass traits, majority of blood attributes and metabolites, and humoral immunity were similar among the treatment groups. However, cell-mediated immune response was higher for 100Zn group (quadratic; P = 0.04). Goats receiving high levels of Zn increased serum calcium (linear; P = 0.03), glucose (linear, P = 0.02), and lymphocytes (linear, P = 0.05 and quadratic; P = 0.01). Manganese (Mn) level in the liver increased (linear, P = 0.01), while liver copper (Cu) decreased (linear, P = 0.04) as the level of Zn was increased in the diet. Zinc in the feces increased (linear, P = 0.001), with no changes in urine Zn. Blood mineral phosphorus was reduced (linear, P = 0.03), and magnesium, and potassium tended to decrease (linear, P = 0.06 and 0.07, respectively) with increasing Zn levels in diet. High levels of Zn supplementation did not affect animal performance and carcass characteristics; however, improved immunity and impacted liver Mn and Cu. |