Sustainable Southwest Beef Project Annual Meeting Poster Session 2023

Isaac Appiah

Department of Agricultural Economics and Agricultural Business, New Mexico State University

Matthew McIntosh

USDA-ARS Jornada Experimental Range

Virtual fencing (VF) is an alternative method to control livestock dispersal. This method consists of the use of animal wearable collars that employ auditory-electric pulse cues to deter animals from exiting their predefined containment zones. The study aimed to document skin defense (SkinM) and association learning mechanism (AssocM) in describing the conditioning behavior of the VF application. Nursing Brangus cows at the New Mexico State University's Chihuahuan Desert Rangeland Research Center were allotted three days of free access to feeding areas (0.19ha) with VF-deactivated (VF-Off) or VF-Activated (VF-On) collars restricting one-third of the penned area. This training sequence was repeated twice (6-day/Period) with two replications (n=11 and 17cows). The VF collars communicated real-time animal positions at 15-minute intervals. ANOVA was used to compare daily-derived variables per cattle on the percentage of time spent within the containment and restricted zones (SkinM) and the number of auditory and electric pulses emitted during the VF-On configurations (AssocM). The VF-On treatment increased the percentage of time collared animals spent within the containment zone (98.4 vs.72.0 ±1.0 %Time;P<0.01) and reduced the percentage of time within the restricted zone (1.6 vs.28.0 ±1.0 %Time;P<0.01) compared to the VF-Off treatment. Exposure to VF-On in Period 1 triggered a greater frequency of auditory (1.8 vs.0.6 ±0.4;P<0.01) and electrical pulses (0.7 vs.0.2 ±0.2;P<0.01) than in Period 2. Results indicate that groups of cows learn rapidly to respond to VF boundaries by reducing the time spent within the restricted areas (SkinM) and relying increasingly on auditory cues to alter behavior (AssocM).

Shelemia Nyamuryekung’e

1 Department of Animal and Range Sciences, New Mexico State University, Las Cruces, NM, 88003 2 United States Department of Agriculture-Agriculture Research Service, Jornada Experimental Range, Las Cruces, NM, 88003, USA 3 USDA Southern Plains Climate Hub, USDA-ARS OCPARC, El Reno, OK 73036, USA 4 Scotland's Rural College, Future Farming Systems, West Mains Road, Edinburgh, EH9 3JG Scotland, UK

Methane (CH4) is a greenhouse gas that is released as a byproduct of ruminal fermentation. Anthocyanins are polyphenolic compounds that may serve as H2 sinks and inhibit growth of methanogens. Two experiments were conducted to determine if dietary inclusion of a novel high anthocyanin (Hi-A) containing corn cob meal [CCM; 4.99 mg anthocyanin × g-1 of dry matter (DM); developed by Texas A&M AgriLife] influences in vitro CH4 emissions relative to a conventional CCM (CNV; 0.04 mg anthocyanin × g-1 of DM). High-roughage starter (experiment 1) and low-roughage finisher (experiment 2) diets were formulated to contain 20% and 10% total CCM (DM-basis), respectively. Treatments were based on the proportion of Hi-A to CNV CCM and consisted of 0% (0A), 25% (25A), 50% (50A), 75% (75A), and 100% Hi-A (100A) CCM. In experiments 1 and 2, feed samples underwent 48-h in vitro ruminal fermentation using an ANKOM RF system. The concentration of CH4 as a proportion of total gas production (%CH4) was measured using gas chromatography and pH was measured using a pH probe. Total gas production was fit to the Ørskov and McDonald (1979) model to determine gas production. Statistical analyses were conducted using R (v4.1.0). Significance was defined as P < 0.05 and a tendency as 0.05 ≤ P < 0.15. In experiment 1, there tended to be a cubic relationship between Hi-A CCM inclusion and total CH4 (mL CH4 × g DM-1; P = 0.13) as well as %CH4 (P = 0.09), where 50A tended to result in the greatest reduction in total CH4 (13.3%; P = 0.10) and %CH4 (14.2%; P = 0.10). In experiment 2, there was a cubic relationship between Hi-A CCM inclusion and %CH4 (P = 0.04) and there tended to be a cubic relationship between Hi-A CCM inclusion and total CH4 (P = 0.06). Treatment 100A tended to result in the greatest reduction in %CH4 (10.3%; P = 0.10) and resulted in the greatest reduction in total CH4 (15.6%; P = 0.02). Lastly, there tended to be a quadratic relationship between Hi-CCM inclusion and final pH (P = 0.05) such that 50A resulted in the least (P = 0.02) pH decline throughout the 48-h fermentation. Inclusion of Hi-A CCM reduced total in vitro CH4 production relative to 0A in both starter and finisher diets. Further research is needed to determine if Hi-A CCM is effective at mitigating CH4 emissions in vivo and if anthocyanins in Hi-A CCM can be extracted, condensed, and repackaged into a feasible delivery system. This project was previously presented at the 2023 ASAS Southern Section Meeting.

Nathan Long

Texas A&M University

Meeting metabolizable protein requirements of finishing cattle without overfeeding protein requires reliable estimates of site and extent of digestion. Current estimates of rumen degradable (RDP) and undegradable protein (RUP), as well as intestinal digestibility of RUP (dRUP) may be inadequate. Thus, the objectives of this experiment were to quantify RDP, RUP, and dRUP of common feedstuffs and evaluate nutrient composition as a predictor of RDP, RUP, and dRUP. Ruminally cannulated steers (n = 6) consuming a finishing diet were enrolled in a replicated 3 × 3 Latin square design. Within period, steers were assigned a feedstuff classification for in situ ruminal incubation. Single-source ingredients were classified as grain (steam-flaked and whole-shelled corn, wheat, and milo), protein (wet and dried corn distiller’s grains, Sweet Bran, cottonseed meal, canola meal, and soybean meal), and roughage (cotton burrs, alfalfa hay, wheat hay, sorghum × sudangrass hay, wheat silage, and corn stalks). Feedstuffs were lyophilized, ground through a 2-mm screen, aliquoted into in situ bags, and ruminally incubated for 0, 4, 8, 12, 24, or 48 h. Samples were composited within incubation time point, analyzed for crude protein (CP), corrected for microbial contamination, and fit to non-linear models to estimate RDP and RUP using calculated passage rate. Subsamples of in situ digested feedstuffs underwent in vitro pepsin-pancreatin digestion and CP analysis to estimate dRUP. Statistical analyses were conducted using JMP Pro 16.0 and R (v4.1.0). On average, RUP estimates were 37.0% lower (P < 0.05) for protein ingredients, yet grains and roughages were not different (P > 0.73) compared to NASEM (2016) empirical values, respectively. However, dRUP was, on average, 11.9% and 33.1% lower (P < 0.01) for protein ingredients and roughages, yet grain dRUP was not different (P = 0.16) when compared to NASEM (2016) values, respectively. Neutral detergent fiber (NDF) and CP explained a substantial portion of the variation in RDP (P < 0.01, R2 = 0.94, RMSE = 2.26). Acid detergent fiber, NDF, and CP explained the majority of the variation in dRUP (P < 0.01, R2 = 0.91, RMSE = 5.43). Models had high predictive capability when applied to independent data (P < 0.01, R2 ≥ 0.83). Collectively, these data suggest that dRUP of protein ingredients and roughages are lower than values recommended by the NASEM (2016). Furthermore, CP and fiber values may be capable of predicting RDP, RUP, and dRUP.

Jarret Proctor

Texas A&M University, Department of Animal Science

Ryan Foster <ryan.foster@ag.tamu.edu>

Texas A&M University, Department of Animal Science

CONTEXT The southwestern United States is experiencing an increasingly warmer and drier climate, which is affecting cattle production systems of the region. Adaptation strategies are needed that will not compromise environmental quality or profitability. Options include the use of desert-adapted beef cattle biotypes, such as Rarámuri Criollo cattle, and crossbreds of Criollo with more traditional British breeds. Currently, most calves raised in the Southwest are grain finished, often with irrigated crops produced in the hydrologically-threatened Ogallala Aquifer region. A viable alternative may be grass finishing with the rainfed forage of the arid and semi-arid rangeland of the Southwest or in the temperate grasslands of the Northern Plains. OBJECTIVE Compare the environmental impacts and production costs of grain- and grass-finishing with traditional Angus cattle vs. Criollo and Criollo x Angus cattle. METHODS Nine supply chain strategies were simulated using the Integrated Farm System Model to compare farm-gate life cycle intensities of greenhouse gas emissions, fossil energy use, nitrogen losses, blue water consumption and production costs using representative (appropriate soils, climate, and management) ranch and feedlot operations. RESULTS AND CONCLUSIONS For both finishing options (grass, grain), Criollo x Angus cattle had the best environmental and economic outcomes, followed by pure Criollo and then Angus cattle. Crossbred production combined the desert-adapted grazing behavior of Criollo cows with heavier final carcasses of offspring from Angus genetics. Crossbred cattle with grass finishing in the Southwest or Northern Plains outperformed on most environmental variables as well as production costs, mostly due to reduced external input requirements (primarily feed). A downside for grass-finished crossbreds was greater carbon emission compared to grain finishing due to greater methane emissions from high forage diets and an extended time to finish. Where soil C sequestration can be supported, sequestration may offset the greater greenhouse gas emission from grass-finished beef. Grass finishing in the Northern Plains may provide a more reliable meat supply chain than grass finishing in the Southwest due to the lower risk and less severe consequences of drought. SIGNIFICANCE Alternative beef supply chain options using Criollo cattle were found to be sustainable production systems that can be adopted by ranchers in the southwestern United States to deal with the changing climate.

José P. Castaño-Sánchez

1) Jornada Experimental Range, USDA-ARS, Las Cruces, NM 88003, USA; 2) Pasture Systems and Watershed Management Research Unit, USDA-ARS, University Park, PA 16802, USA; 3) Evergreen Livestock & Ranching LLC, Custer, SD 57730, USA; 4) Animal Sciences and Natural Resources, New Mexico State University, Las Cruces, NM 88003, USA; 5) Clayton Livestock Research Center, New Mexico State University, Clayton, NM 8841, USA