Influence of elevated protein and tannin-rich peanut skin supplementation on growth performance, blood metabolites, carcass traits, and immune-related gene expression of grazing meat goats

Authors: Min, Byeng Ryel; MCTEAR, KRISTIE - Tuskegee University; WANG, HONG - Tuskegee University; JOAKIN, MORRIS - Tuskegee University; GURUNG, NAR - Tuskegee University; ABRAHAMSEN, FRANK - Tuskegee University; SOLAIMAN, SANDRA - Tuskegee University; EUN, JONG-SU - Cj Cheiljedang Corporation; LEE, JUNG - Fort Valley State University; DIETZ, LUCAS - University Of Wisconsin; Zeller, Wayne

Submitted to: Journal of Animal Physiology and Animal Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/25/2019
Publication Date: 11/14/2019
Citation: Min, B., McTear, K., Wang, H.H., Joakin, M., Gurung, N., Abrahamsen, F., Solaiman, S., Eun, J., Lee, J.H., Dietz, L.A., Zeller, W.E. 2019. Influence of elevated protein and tannin-rich peanut skin supplementation on growth performance, blood metabolites, carcass traits, and immune-related gene expression of grazing meat goats. Journal of Animal Physiology and Animal Nutrition. 104(1):88-100. https://doi.org/10.1111/jpn.13250.
DOI: https://doi.org/10.1111/jpn.13250

Interpretive Summary: Feed efficiency of animals directly affects the profitability, production efficiency and sustainability in ruminants. However, supplementing elevated protein to stockers and meat goats on wheat pasture have not proven beneficial effects. Furthermore, little is known about the use of commercially available rumen undegradable protein (RUP) interactive with tannin-rich peanut skins (PS) as a supplement for winter forages and effects of long-term use of the supplementation on animal performance, carcass traits, blood plasma metabolites, and immune-related and lipogenic gene expressions. In addition, molecular mechanisms by which nutrients regulate immune-related and lipogenic gene expressions have yet to be well identified. Scientists from USDA-ARS (Bushland, TX, and Forage Dairy Lab., Madison, WI), Tuskegee University (Tuskegee, AL), Fort Valley State University (Fort-Valley, GA), and Institute of Integrated Technology, South Korea, studied how the elevated rumen undegraded protein (RUP) and tannin-rich peanut skin (PS) supplementation affects animal growth performance, rumen fermentation, blood metabolites, carcass traits and immune-related gene expression from grazing ruminants. The current study highlighted that tannin-rich PS supplementation has the potential to increase average daily gain (ADG) and carcass production via enhanced lipogenic and immune-related gene expressions in meat goats grazing winter wheat, and therefore warrants further investigation. Diets contained 30% PS ingredient up to 0.45%/body weight/day (BW/d) or tannins up to 1.3% DM supplementation or elevated RUP supplementation up to 0.25% of kg BW/d improved animal production but had no adverse effect on blood metabolites and gastrointestinal parasite reduction in meat goats grazing on winter wheat. This data will be used to feed supplementation strategies to improve feed efficiency and animal growth promotors in small ruminants.

Technical Abstract: The aim of the present study was to define whether elevated rumen undegradable protein (RUP) and tannin-rich peanut skin (PS) supplementation would affect animal growth performance, average daily gain (ADG), blood metabolites, carcass traits associated with lipogenic and immune-related gene expressions in meat goats grazing winter wheat (WW). Thirty-six Kiko-crossbreed male goats at approximately 6 months of age were blocked by body weight (BW; 25.6 ± 1.1 kg) and randomly assigned to one of four treatments with 2 replicates based on a 2 × 2 factorial design. Diets contained PS replacing alfalfa meal (ALM), without or with RUP supplementation. Both PS and ALM were incorporated into grain mix portion of the diet and pelletized, with remaining diets fed ad libitum of WW forage for a period of 51-days. Lipogenic genes examined included SCD, ACLY, YWHAZ, PPIA, and FABP4, while immune-related genes examined included ACTB (as a control gene), H3F3A, PPIA, IRF3, STAT2, HERC3, and IFIT3 antibody genes. The meat goats on PS-pellet supplemented group with or without RUP supplementation grew 38.5% faster ADG (P < 0.001) when compared to control supplemented group. When goats received PS diet, empty body weight, hot carcass, cold carcass, shoulder, hind shank, rack, loin, and fat thickness were greater (P < 0.05) than control diet. Animals on PS-pellet had higher ACLY, YWHAZ, PPIA, and FABP4 gene expression (P < 0.05) when compared to ALM-pellet control, with RUP by PS-pellet interactions (P < 0.01). Goats receiving additional RUP supplementation had increased (P < 0.05) STAT2 gene expression, whereas goats receiving PS-pellet supplementation showed increased STAT2 (P < 0.05) and a tendency to increased IRF3 (P = 0.07) gene expressions. In conclusion, addition of PS-pellet or RUP supplementation has the potential to improve ADG and altered selected lipogenic and immune-related gene expressions.