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The backgrounding period is a post-weaning management strategy to add weight and build the health status in beef calves. This phase is used to prepare beef calves to enter the next phase of the production supply chain. Weaning and backgrounding management methods can be strategies to reduce calf morbidity and mortality in the feedlot. The objective of this study was to assess beef calf growth performance based on weaning management strategy and subsequent backgrounding using commonly used forage-based diets by Alabama beef producers. A twoyear study was conducted using 427 steers (n = 216, year 1, average BW 306kg; n = 213, year 2, average BW 294kg). Steer calves from three Auburn University research farms were randomly assigned based on weaning weights to one of three different weaning method groups: fenceline weaning, nose-flap weaning, or abrupt weaning. After the weaning period calves were brought to a centralized farm and began a 60-d backgrounding period where they were randomized according to previous weaning management, farm of origin and body weight to one of three nutritional management strategies in a 3×3 factorial design: coolseason baleage (oats, ryegrass and crimson clover) and 1% BW dried distillers' grains (DDGS), bermudagrass hay and 1% BW DDGS, or grazing mixed warm-season annuals and 1% BW DDGS. Body weights were collected on d 0, 30 and 60 of the backgrounding phase. In both years, fenceline weaned calves had the greatest average daily gain (year 1, 0.76 kg/d; year 2, 1.03 kg/d; P = 0.0225) in the first 30 days of the backgrounding period regardless of backgrounding diet type. Calves fed the bermudagrass hay-based diet also had a greater average daily (year 1, 0.78 kg/d; year 2, 1.24 kg/d; P < 0.0001) than both the grazing and baleage diet groups in the first 30 days of backgrounding. From d 30 to 60 of backgrounding in each year, calves on the hay-based diet had the least average daily gain (year 1, 0.19 kg/d; year 2, 0.42 kg/d; P < 0.0001). Steers on both the warm-season annual grazing and cool-season baleage diets supported greater average daily gains (P =0.0041) during the last 30 days of the backgrounding period (0.74 kg/d and 0.75 kg/d, respectively). Steers in year 2 had a greater total gain (year 1, 45.55kg; year 2, 51.56 kg; P = 0.0042) than steers in year 1. However, results in both years indicate that weaning and backgrounding management strategies may influence calf performance during the transition period into the post-weaning phase. [ABSTRACT FROM AUTHOR]

Warm-season perennial pastures are the base of livestock production systems in lower Alabama. To overcome the shortage in forage production during the late fall and winter months, during bahiagrass dormancy, overseeding pastures with cool-season annuals can be used as an option for providing forage during this period. Diverse forage mixtures of multiple species and functional groups have gained popularity in use among forage-livestock producers, but few evaluations have been conducted in overseeded sods. The objective of the study was to evaluate forage mass and nutritive value of cool-season forage mixtures overseeded into bahiagrass pastures. Six, 0.40-ha paddocks of 'Pensacola' bahiagrass were overseeded with one of three cool-season forage mixtures (n = 2 paddocks/treatment) on November2, 2021: 1) oat (Avena sativa), wheat (Triticum aestivum), and balansa (Trifolium michelianum), red (Trifolium pratense), and white clover (Trifolium repens; 'clovers'); 2) oat, cereal rye (Secale cereale), and clovers; and 3) cereal rye, annual ryegrass (Lolium multiflorum), and clovers. When forage mixtures reached a target grazing height of 20 cm, paddocks were managed using flash mob stocking with beef cow-calf pairs to graze to a target height of0 cm. Herbage mass, nutritive value, botanical composition and height samples were collected pre- and postgrazing events. There was no treatment (P = 0.240) or treatment × harvest (P = 0.4239) effect on forage mass. Harvest date affected (P = 0.029) forage mass, with greater forage mass at late harvest (1,903.33 kg DM·ha- 1) than at early (1,253.33 kg DM·ha-1) in the growing season. There were no treatment effects observed for species components (P > 0.05), although grasses dominated the forage mixtures with an average of 80% grass presence. Legume establishment was poor (less than%) and the remaining species composition consisted of weed species (19%). There was a treatment effect (P = 0.003) on CP, where oat-rye-clovers had the greatest CP and rye-ryegrass-clover had the least CP. Oat-wheatclover mixtures had greater TDN (79.2%), less NDF (39.8%), and ADF (18.7%) than cereal rye-ryegrassclover (75.4%, 46.1%, and 22.2% for TDN, NDF, and ADF, respectively), but did not differ from oat-cereal rye-clover mixtures (76.6%, 45.7%, 21.0% for TDN, NDF, and ADF, respectively). In year of this study, overseeding bahiagrass supported forage production over a 2-month period and can be a management tool used to reduce the need for supplementing in the dormancy periods of warm season perennial grasses. [ABSTRACT FROM AUTHOR]

Grazing of cool-season cover crops has been shown to be a viable tool in extending the grazing season while mitigating environmental risks associated with row crop farming systems. While there is a vast amount of research available on cover crops in relation to soil health, a more novel approach would be to focus on forage production and animal performance when grazing cover crops. Therefore, our objective was to evaluate the effects of cattle removal date on forage yield, forage quality, and steer performance when grazing cool-season cover crops. A cool-season forage mix consisting of 'Cosaque' oats (Avena strigose), 'FL401' cereal rye (Secale cereal), 'AU Sunrise' crimson clover (Trifolium incarnatum), and 'T-raptor' brassica (Brassica napus × B. rapa) was established in twelve, 0.62 ha paddocks in Headland, AL. Each paddock was then randomly allocated to one of four cattle removal treatments: 1) no grazing (CON); 2) February removal (FEB); 3) March removal (MAR); or 4) April removal (APR). Three tester steers were randomly allotted, based on body weight (BW), to each of the grazing treatments, excluding CON. The tester steers were weighed every 30 d for calculation of initial BW, final BW, and average daily gain (ADG). At inception and every subsequent two weeks, forage was harvested to analyze average forage yield, neutral detergent fiber (NDF), acid detergent fiber (ADF), and crude protein (CP). All data were analyzed using GLIMMIX procedure of SAS version 9.4 (SAS Inst., Cary, NC). Significant differences in forage yield were detected between CON and FEB (3,913 vs. 2,261 kg/ha; P < 0.001), CON and MAR (3,913 vs. 1,790 kg/ha; P < 0.001), and CON and APR (3,913 vs. 1,810 kg/ha; P < 0.001). There were no differences found for ADG (1.2 kg/day; P = 0.56), NDF (50.94%; P = 0.46), or ADF (30.34%; P = 0.25) among treatments. Results indicate that grazing of cool-season annual cover crops will reduce forage yield, but removal date of cattle will not further affect forage yield, quality, or individual cattle performance. Thus, we can reduce winter supplementation needs for cattle by increasing grazing days; however, under continuous grazing for stocker cattle production, forage availability may inevitably be the limiting factor. [ABSTRACT FROM AUTHOR]

For in vitro digestibility experiments addressing both horses and cattle, feces have long been thought to be an equivalent surrogate for ruminal or cecal inoculum that would eliminate the need for fistulated animals. However, this assumption requires similar microbial and chemical properties among inoculum sources. Validation of the relationship of fecal to ruminal metabolic properties would allow for more readily accessible information on fermentation across nutrition experiments. Thus, the purpose of this study was to compare ruminal and fecal VFA production from heifers fed four bermudagrass (Cynodon dactylon [L.] Pers.) cultivars. Ruminally-fistulated heifers (n = 4) were assigned randomly to one of four bermudagrass cultivars (Coastal [COS], Russell [RUS], Tifton 44 [T44], or Tifton 85 [T85]) for four 30-d in vivo periods (21-d adaptation and 9-d collection). On d 28, rumen fluid (RF) samples were collected at 13 timepoints (0, 0.25, 0.5, 0.75, 1, 2, 3, 4, 8, 12, 16, 20, 24 h) and rectal fecal samples were collected at 7 timepoints (0, 0.5, 1, 2, 4, 8, 12 h). Samples were acidified with meta-phosphoric acid, and 2-ethylbutyric acid was included as an internal standard. Samples were assayed for acetic (A), propionic (P), isobutyric (IB), butyric (B), isovaleric (IV), valeric (V), 4-methylvalteric (4MV), and caproic (C) acids by gas-liquid chromatography. Data were analyzed using SAS v. 9.4. Heifers receiving COS produced less (P < 0.05) RF concentrations of A (25.01 mM), P (5.21 mM), and total VFA (34.2 mM) than T85 (43.4, 8.9, and 58.0 mM, respectively), T44 (42.0, 9.0, and 57.3 mM, respectively), and RUS (39.8 8.9, and 55.3 mM, respectively), which were all similar. Ruminal B was greatest (P < 0.05) from RUS (5.4 mM) and least from COS (3.1 mmol/L), with T44 and T85 intermediate (4.9 and 4.4 mM, respectively). There was no effect of cultivar (P = 0.10) on RF IB, IV, V, or 4MV concentrations. Fecal IB was correlated (P < 0.05) with RF IV (r = 0.59) and tended to be correlated (P = 0.09) with RF A (r = 0.39), P (r = 0.39), C (r = 0.37), and total VFA (r = 0.38). Fecal P was correlated (P < 0.05) with RF IV (r = 0.51). No other fecal VFA were correlated with RF VFA. Results are interpreted to mean that COS results in decreased ruminal fermentation relative to the other cultivars tested. However, there is little indication that fecal VFA can serve as an indicator for ruminal fermentation. [ABSTRACT FROM AUTHOR]

The beef calf weaning period is a time of transition in the cow-calf production cycle and can be one of the most stressful stages in the life of a beef calf. This transition can have a major impact on both calf short- and long-term health, growth performance and economic returns. There are several different weaning management strategies cattle producers can use in this transition period. The objective of this study was to assess the effects of weaning management practices on beef calf performance and health before backgrounding. A two-year study was conducted using 427 steer calves (216 year 1, average BW 297 kg; 213 year 2, average BW 291 kg) from three Auburn University research farms were randomly assigned based on weaning weight to one of three different weaning method groups for a 14-day observation period: fenceline, nose-flap, or abrupt weaning. On day 0, all calves assigned to the abrupt weaning group traveled 3 hours to one central location. Calves in the fenceline and nose-flap groups traveled to the same location on day 14 of study. Calves were weighed on day 0, day 14 and 24 hours following any travel event. Blood samples were also collected to determine haptoglobin concentrations surrounding the travels events and blood titers following vaccinations. In both years of the study, fenceline weaned calves had the greatest average daily gain at 1.08 kg/d (P < 0.0001) and abruptly weaned calves had the least average daily gain, losing 0.15 kg/d during the 14-d observation period. In Year 1, steers had a significantly greater (P < 0.0001) gain across all treatments than calves in Year 2, with Year 1 calves gaining 7.72 kg more during the weaning period than Year 2 calves. Over both years of the study, fenceline weaned calves gained more (P =0.0008) than both nose-flap and abruptly weaned calves. In Year, abruptly weaned calves had greater blood concentrations of haptoglobin (0.084mg/mL; P < 0.0001) than both the fenceline and noseflap weaned calves (0.023mg/mL; 0.020mg/mL). This data demonstrates how weaning management strategies may influence calf growth performance and the transition into the post-weaning period. [ABSTRACT FROM AUTHOR]

Maintenance of pastures for grazing accounts for $132.50/animal in the United States (23% of operating costs), and pasture nutrient input represents the single greatest influence in productivity per unit area. Cultivar differences in the forage offered to cattle have the potential to manifest differences in digestive efficiency, resulting in different nutrient excretion profiles. The objective of this study was to assess the growth potential and incorporation of N, P, and K into forage material from manure from cattle fed one of four bermudagrass (Cynodon dactylon [L.] Pers.) cultivars. Ruminally fistulated heifers (n = 4) were assigned randomly to one of four bermudagrass cultivars (Coastal, Russell, Tifton 44, or Tifton 85) for four 30-d in vivo periods (21-d adaptation and 9-d collection). On d 23, total fecal collections were subsampled from each heifer. As a hierarchical addition, a controlled greenhouse experiment was conducted for each period [15 pots per period; 5 manure treatments (four bermudagrass diets plus a negative control) × 3 replications]. Manure was added to 4.58 L pots based on stocking rate estimates for Central Alabama (1,110 kg/ha). The pots were seeded with bermudagrass (cv. Giant) as an indicator for forage nutrient uptake. At harvest (d 70), herbage, root, and soil samples were collected. Herbage and root samples were assayed for CP. Soil samples were assayed for pH, N, P, K, Mg, and Ca. Data were analyzed using SAS v. 9.4. There was no effect of manure treatment on herbage (P = 0.88) or root DM yield (P =.00;.54 and.73 g/pot, respectively). Similarly, there was no effect of manure treatment on soil pH (P = 0.18; 5.5), P (P = 0.78; 24.2 kg/ha), or K (P = 0.42;56.7 kg/ha). Results are interpreted to mean that, regardless of the cultivar effects on ruminal digestive dynamics, there is little to no effect of the resulting manure on subsequent forage production and nutrient uptake. [ABSTRACT FROM AUTHOR]

Dual-purpose wheat (Triticum aestivum L.) systems increase farm sustainability by diversifying on-farm income. While these systems are common in the Southern Great Plains of the U.S., they are not often utilized in the Southeast. This study aimed to evaluate pre- and post-grazing herbage mass (HM) of four winter wheat varieties managed under a dual-purpose grazing and grain production system. The wheat varieties evaluated were generic feed-type wheat (unknown variety blend, Feed), seed-type wheat 'GA Gore' (Seed) and two forage-type varieties, 'AGS 2024' (AGS) and 'Pioneer 26R41' (Pioneer). The experiment was a randomized complete block design (n = 4) conducted during the winter of 2021 and 2022. Three grazing frequencies were utilized: an ungrazed control (NG), low frequency (LF) and high frequency (HF) grazing schedule. Low frequency plots received monthly grazing in January and February while HF treatments received a third grazing in March. Plots were grazed with 20 cow-calf pairs (Bos taurus) until an even defoliation height of 10 cm was achieved. Herbage mass was determined using three 0.1m2-quadrats per plot and clipped to a 10 cm stubble height before (PreG) and after (PostG) each grazing event. Forage samples were then dried at 45°C for 72 h. Data were analyzed using PROC GLIMMIX of SAS (SAS Inst., Cary, NC) with forage sample date as a repeated measure. Differences were declared at P < 0.05. Final biomass, including stems, chaff, and grain, was greatest for Pioneer but was not different from AGS or Feed (4,112 kg/ha and 4,003 kg/ha; P = 0.94). Before grazing, AGS herbage mass (2,646 kg/ha) was greater (P = 0.03) than all other varieties. There was an interaction (P = 0.01) of variety and grazing frequency for Pre-G herbage mass. Compared with all other varieties, AGS had greater ADF (24.93%; P < 0.01) and least TDN (72.49%: P < 0.01). Forage nitrate-nitrogen was not different (P = 0.49) among all varieties or grazing frequencies (157.73 ppm). Across grazing frequencies, Pioneer had greater final grain yield (3,619.43 kg/ha; P < 0.01) with Seed having the least (1,272.12 kg/ha; P < 0.01). These results indicate that common Southeastern wheat varieties can be successfully utilized in a dual-purpose management system; however, grazing frequency should be monitored to prevent grain yield losses. [ABSTRACT FROM AUTHOR]

While much effort has been devoted to both the characterization of ruminal fermentation dynamics and the evaluation of bermudagrass production, independently, there is a lack of information regarding ruminal digestive kinetics using beef cattle in southern forage systems. Thus, the objective of our study was to evaluate in situ digestive kinetics of four bermudagrass (Cynodon dactylon [L.] Pers.) cultivars in heifers consuming typical southern forages. (Coastal, Tifton 44, Tifton 85, and Russell). Ruminally fistulated heifers (n = 4) were assigned randomly to one of four bermudagrass cultivars (Coastal [COS], Russell [RUS], Tifton 44 [T44], or Tifton 85 [T85]) for four 30-d in vivo periods (21-d adaptation and 9-d collection). On d 31 of periods 2 and 3, an in-situ experiment was conducted as a randomized complete block design with a 3-factor factorial treatment structure. The first factor (n = 4) was diet consumed by the animal (described above). The second factor (n = 4) was the incubated forage (same cultivars as the in vivo experiment). The third factor was incubation timepoint (n = 19; 0, 0.25, 0.50, 0.75, 1, 2, 3, 4, 8, 12, 16, 20, 24, 48, 72, 96, 120, 144, and 168 h). Four in situ bags were incubated in each animal at each timepoint; two were used for NDF, ADF, and ADL, and two were used for CP determination. Data were analyzed using SAS v. 9.4. There was a decreased (P < 0.05) potentially degradable fraction from COS (30.0%) compared with T85 (55.1%), T44 (48.1%), or RUS (47.1%). Similarly, COS presented the greatest (P < 0.05) undegradable fraction (37.0%) and T85 the least (15.9%), with RUS and T44 intermediate (25.0 and 21.9%, respectively). There was no effect of bermudagrass cultivar, however, on the rate constant of digestion (0.94%/h; P = 0.26) or lag time (3.2 h; P = 0.38). A visual appraisal of the degradation curve suggests that the asymptote of digestion was not reached at the measured 168 h. Results are interpreted to mean that T44 is the preferable bermudagrass cultivar, followed by T85 and RUS, while COS is the least favorable. Further, given the lack of visible asymptote, we speculate that bermudagrass likely passes the rumen before full digestion is realized. [ABSTRACT FROM AUTHOR]

Tall fescue (Schedonorus arundinaceus) is the predominant cool-season perennial forage in the Eastern U.S. However, a symbiotic endophyte reduces performance of animals grazing tall fescue. This results in losses of around $2 billion annually. Due to the vasoconstriction caused by the endophyte, a decrease in conception rates among cows and heifers consuming tall fescue has been observed. With rising input costs, it is necessary to explore alternative mitigation strategies these production losses. The objective of this study was to mitigate the toxic effects of 'KY 31' tall fescue by limit-grazing cool-season annuals as an alternative to feed supplementation. In January 2022, 48 heifers [14 months of age; 365.9 ± 11.89 kg body weight (BW)] were randomly assigned to tall fescue only, tall fescue with supplemental feed at 1% of BW, tall fescue with limit grazing of cool-season annuals for 24 h per week, and cool-season annuals only. Four animals grazed in each of three replicated paddocks per treatment. Cool-season annual pasture was a mixture of crimson clover (Trifolium incarnatum), annual ryegrass (Lolium multiflorum), and oat (Avena sativa). Body condition scores (BCS), hair coat scores (HCS), and BW were recorded every 30 d. Forage samples were taken for biomass, nutritive value, and ergovaline concentration every 30 d. On April 1, 2022, heifers were artificially inseminated (AI), and conception rates were determined 45 d after AI. Data were analyzed using the Glimmix procedure of SAS 9.4 (SAS Inst, Cary, NC) with a = 0.05. There were no differences among treatments in HCS at any weigh date (P > 0.05). The BCS for all treatments was less in February than January or March (5.6, 6.1, 6.1, respectively; P < 0.0001), but there were no differences among treatments at any sampling date (P > 0.05). Conception rates were not different among treatments (P > 0.10) but averaged 75, 67, 42, and 50% for the continuous-cool season, limit graze, supplemental feed, and tall fescue treatments, respectively. Crude protein (CP) concentrations for the control and limit grazing fescue treatments were greater than the limit grazing cool-season annual treatment, continuous grazing cool-season annual treatment, and the supplemental feed treatment (13.5, 10.7, 10.4, and 8.9%, respectively, (P < 0.012). Neutral detergent fiber (NDF) and acid detergent fiber (ADF) were different among the supplemental treatment when compared with the limit grazing fescue, limit grazing cool-season annual, control, and continuous cool-season annual (48.2 vs 64.7% NDF and 25.8 vs. 37.0% ADF; P < 0.0361). At this time, the results indicate that limit grazing coolseason annual forages may be an advantageous option to mitigate fescue toxicosis in replacement heifers grazing tall fescue pastures in the spring. [ABSTRACT FROM AUTHOR]