9 Reduce Reuse ReRumen: Variability in nutritive value of paunch manure

Ruminant animals develop a diverse and complex microbial ecosystem for digesting fibrous feedstuffs, but this material represents a cost to the industry when bound for rendering at harvest. Our objective was to determine the feed value of paunch manure recovered from an abattoir. Twelve paunch samples were collected from slaughtered cattle at the Tarleton State University Meat Laboratory, Stephenville, TX. Samples were dried under forced air at 55°C to a constant weight and ground to pass through 2-mm screen. A subsample was ground to 1-mm and assayed for DM, CP, and sequential NDF and ADF. Physically effective fiber (peNDF) was calculated with 2 L of unground, dried at 55 ˚C, paunch material using the manually-operated Penn State Particle Separator. Paunch peNDF was determined by multiplying the physical effectiveness factor by the total NDF content of the sample. Samples (2-mm) were subject to batch culture in vitro digestibility assays for determination of digestibility coefficients. Data were analysed as a random effects model using PROC GLIMMIX in SAS. Neutral detergent fiber, ADF, ADL, CP, and peNDF values were 68.1, 39.9, 10.9, 15.0, and 38.7%, respectively. Contribution to variance of the individual animal for NDF, ADF, ADL, CP, and peNDF was 97.2, 97.9, 95.4, 19.1, and 97.5%, respectively. In vitro true digestibility (IVTD) and in vitro neutral detergent fiber digestibility (IVNDFD) was recorded as 46.2% and 21.6%, respectively. Contribution to variance of the animal for IVTD and IVNDFD was 99.05 and 98.49%, respectively. Data collected suggest paunch manure could provide valuable nutrients for livestock production, specifically fiber and protein. For full viability of application in a sustainable system, a centralized receiving and compositing system may be useful for development of a consistent product.