Search Results (10)

The objective of this study was to evaluate the impacts of varying inclusion levels of soybean hull pellets (SHP) with annual ryegrass baleage (BAL) on animal performance and digestive kinetics in beef cattle. In Experiment 1 (Exp. 1), 60 weaned mixed-sex beef calves were randomly assigned to one of three treatments: 0.0%, 0.5%, or 1.0% body weight (BW) SHP with ad libitum access to BAL for 48 days (d). Animal performance, including BW, dry matter intake (DMI), and average daily gain (ADG), was evaluated for the duration of the study. In Experiment 2 (Exp. 2), six ruminally cannulated beef steers received the same treatments utilized in Exp. 1. Steers were dosed with ytterbium (Yb)-labeled BAL to evaluate ruminal passage rate across three 24 d periods. All data were analyzed using SAS 9.4. In Exp. 1, total BAL intake decreased in calves supplemented with SHP, while cumulative ADG increased from 0.30 (0.0% BW SHP) to 0.54 (0.5% BW SHP) and 0.74 kg/d (1.0% BW SHP), respectively. Final BW at D47 also increased as SHP inclusion increased. In Exp. 2, ruminal retention time decreased from 38.0 h (0.0% BW SHP) to 15.1 h (1.0% BW SHP), while cecum-to-proximal colon passage rate did not differ among treatments (p = 0.06). Baleage DMI did not differ between treatments. Results suggest that SHP supplementation improved calf performance despite reduced BAL intake in Exp. 1, with the greatest cumulative ADG observed in calves supplemented with 1.0% BW SHP. In Exp. 2, 1.0% BW SHP produced the greatest effects on passage rate kinetics, while BAL DMI was unaffected by SHP supplementation. Full article

The objective of this analysis was to compare the greenhouse gas (GHG) emissions from contemporary grazing cattle production with bison grazing, both modern and historical. The data sets used in this analysis were derived from existing research and conservation properties located outside of Manhattan, KS (USA), which are home to stocker cattle, cow–calf production (CCS), and grazing bison. For stocker cattle, 10 years of animal production data (2007–2016) from season-long stocking (SLS, grazing 156 d) and intensive early stocking systems (IES; 76 grazing d and 2× stocking density) were used for GHG calculations. Enteric CH₄, manure CH₄, and direct nitrous oxide emissions were estimated using the IPCC tier 2 methodology. Historic bison (HGB) enteric CH₄ estimates were calculated using a stocking density of 0.15 ha/animal and assuming that only 13% of grassland was used by bison each year. Within contemporary systems, IES had the lowest emissions (463.3 kg CO₂-eq./ha/yr), while SLS, CCS, and MGB had the highest estimates (494.7, 493.9, and 595.9 kg CO₂-eq./ha/yr, respectively). HGB had the lowest estimated annual emissions at 295.7 kg CO₂-eq./ha/yr. These results imply that the historic grazing baseline of this grassland system is lower but similar to that of contemporary grazing cattle in the Great Plains region. Full article

Evaluating different tactics to mitigate the effects of gastrointestinal nematode infection in growing stocker cattle is essential to better understand opportunities to optimize cattle health and performance. Due to the potential development of anthelmintic resistance, parasitologists and industry stakeholders have proposed maintaining refugia in cattle populations and combination treatment as tactics to delay anthelmintic resistance yet limited large-scale field data are available for practitioners to make evidence-based decisions. The objective of this experiment was to compare the effects of extended-release eprinomectin injectable and doramectin injectable on growth and fecal shedding of parasites in stocker calves grazing with non-treated (refugia) cohorts. Steers (n = 995; 243.38 kg) were randomized to one of two experimental treatment groups on Day 0, extended-release eprinomectin (ERE) or doramectin injectable (DOR). A subset of animals (n = 47) was selectively not treated with an anthelmintic to maintain refugia (REF). Individual body weights were recorded on days 0, 105, and 130 to calculate average daily gain and overall body weight gain during each of those time periods. Fecal samples were collected per rectum from approximately 10% of the same animals in each group on days 0, 105, and 130. Mean fecal egg count was significantly lower in the 10% of animals tested in the ERE group on days 105 and 130 when compared to 10% of the animals in the DOR group (Day 105—ERE: 46.45 eggs per gram, DOR: 155.30 eggs per gram, p < 0.01; Day 130—ERE: 9.65 eggs per gram, DOR: 22.51 eggs per gram, p = 0.02). From day 0 to 105, the mean average daily gain in the ERE group was 0.87 kg/day, which tended (p = 0.055) to be higher than the mean for the DOR group, 0.845 kg/day. Full article

Background/Objectives: Understanding beef cattle farmers’ knowledge, attitudes, and practices on infectious disease prevention, antimicrobial use, and antimicrobial resistance (AMR) is important to developing stewardship programs. Methods: A cross-sectional stratified mail or phone survey of beef cattle producers in Illinois was conducted between June and August 2022. Ordinal logistic regression models assessed the impact of having a biosecurity plan on beef cattle farmers’ familiarity with cattle diseases. Logistic regression models evaluated associations between antimicrobial treatment practices and the type of cattle operations. Results: A total of 514 producers responded to all or some of the questions. Only 45% of producers were familiar with AMR, and 11% were concerned about cattle infections with antibiotic-resistant bacteria. Producers agreed or strongly agreed (64%) that inappropriate AMU contributes to the development of AMR. Most producers (70%) thought that antimicrobials were as effective in treating infectious diseases as 5 years ago. Only 50% of farms were visited by a veterinarian in the previous year and 35% had their biosecurity evaluated. Producers were more familiar with infectious diseases if their farm biosecurity was assessed. Treating respiratory infections was the most common reason for antimicrobial use. Compared to cow–calf farmers, whole-cycle farmers had a higher probability of having their farm’s biosecurity evaluated (OR = 1.66) and having a veterinarian visit in the previous year (OR = 2.16). Whole-cycle (OR = 3.92) and stocker/backgrounder (OR = 2.18) farmers had a higher probability of treating their cattle with antibiotics than cow–calf farmers. Conclusions: Antimicrobial stewardship and farm biosecurity programs are needed to raise awareness of disease prevention, AMU, and AMR among Illinois beef cattle producers. Full article

Supplementing trace minerals is common in managing bovine respiratory disease (BRD) in post-weaned cattle; however, its influence on host immunity and metabolism in high-risk cattle remains unclear. We aimed to assess the impact of three supplementation programs on liver and serum trace element concentrations and blood gene expression. Fifty-six high-risk beef steers were randomly assigned to one of three groups over 60 days: (1) sulfate-sourced Cu, Co, Mn, and Zn (INR), (2) amino acid-complexed Cu, Mn, Co, and Zn (AAC), or (3) AAC plus trace mineral and vitamin drench (COMBO). Serum and liver biopsies for Cu, Co, Mn, and Zn at d0, d28, and d60 were analyzed from cattle free of BRD (n = 9 INR; n = 6 AAC; n = 10 COMBO). Differences and correlations of mineral concentrations were analyzed via generalized linear mixed models and Spearman’s rank coefficients, respectively (p < 0.05). Whole blood RNA samples from healthy cattle (n = 4 INR; n = 4 AAC; n = 4 COMBO) at d0, d13, d28, d45, and d60 were sequenced and analyzed for differentially expressed genes (DEGs) via glmmSeq (FDR < 0.05), edgeR (FDR < 0.10), and Trendy (p < 0.10). Serum and liver Cu and Co concentrations increased over time in all groups, with higher liver Cu in COMBO (487.985 μg/g) versus AAC (392.043 μg/g) at d60 (p = 0.013). Serum and liver Cu concentrations (ρ = 0.579, p = 6.59 × 10⁻⁸) and serum and liver Co concentrations (ρ = 0.466, p = 2.80 × 10⁻⁵) were linearly correlated. Minimal gene expression differences were found between AAC versus COMBO (n = 2 DEGs) and INR versus COMBO (n = 0 DEGs) over time. AAC versus INR revealed 107 DEGs (d13–d60) with increased traits in AAC including metabolism of carbohydrates/fat-soluble vitamins, antigen presentation, ATPase activity, and B- and T-cell activation, while osteoclast differentiation and neutrophil degranulation decreased in AAC compared to INR. Our study identifies gene expression differences in high-risk cattle fed inorganic or amino acid-complexed mineral supplements, revealing adaptive immune and metabolic mechanisms that may be improved by organically sourced supplementation. Full article

The objective was to examine the effects of dried distillers’ grains supplementation and fertilization strategies on the cattle performance and resource use efficiency of stocker cattle grazing on Plains Old World bluestem. Over 4 consecutive years, heifers and steers (average n = 239) were randomly assigned to 1 of 4 treatments: (1) low input, low stocking density, and no fertilizer or distillers grains supplementation (LOW); (2) high stocking density and no fertilizer with distillers grains supplementation (DDGS); (3) high stocking density and 90 kg of nitrogen/ha with no distillers grains supplementation (NFERT); (4) high stocking density, 90 kg of nitrogen/ha, and 39 kg of phosphorus/ha with no distillers grains supplementation (NPFERT). Cattle grazed in the pastures from mid-May to mid-September each year, except for 2011, when the experiment ended in July due to lack of forage. Data were analyzed using a linear model with fixed effects of treatment, year, and treatment × year (R software). Nitrogen use efficiency (retained/inputs) was affected by a treatment × year interaction, where LOW had the greatest efficiency in all years and DDGS was greater than NFERT and NPFERT in all years except 2012, with NFERT and NPFERT being not different in all years. The estimated total carbon equivalent emissions were greater for DDGS, NFERT, and NPFERT than LOW, but the carbon footprint (kg CO₂eq/kg weight gain) was lesser for LOW and DDGS, which were not different, than NFERT and NPFERT, which were also not different. Replacing nitrogen fertilizer with dried distiller’s grains improved the cattle performance and the efficiency of resource use, and could be a viable economic alternative to traditional systems. Full article

Bovine respiratory disease (BRD) is recognized as a complex multifactorial disease often resulting in significant economic losses for the stocker industry through reduced health and performance of feeder calves. Conventional approaches to manage BRD in stocker production systems can be challenged with a restricted view of the system, most importantly the structure, which drives the behavior of the system and fails to anticipate unintended consequences. The translation and implementation of systems thinking into veterinary medicine can offer an alternative method to problem-solving. Fundamental to the success of the systems thinker is the conceptualization of the Iceberg Diagram intended to identify root causes of complex problems such as BRD. Furthermore, veterinary and animal health professionals are well-positioned to serve as facilitators to establish creative tension, the positive energy necessary to identify high-leverage strategies. The interrelationships and interconnected behaviors of complex stocker systems warrant an understanding of various archetypes. Archetypes provide the systems thinker with a decision-making tool to explore tactics in a nonlinear fashion for the purpose of recognizing short- and long-term outcomes. Developing literacy in the discipline of systems thinking will further equip professionals with the skillset necessary to address the multitude of challenges ingrained in complex stocker cattle systems. Full article

Winter annual cereal forages perform well in semiarid, subtropical regions forming, a significant component of livestock operations for autumn through spring stocker cattle (Bos taurus) backgrounding in either grazeout or graze-grain systems; however, little information is available about their relative seasonal productivity and animal preference. Seasonal growth and regrowth under grazing and grazing preference of oat (Avena sativa), rye (Secale cereale), triticale (×Triticosecale rimpaui Wittm.), and wheat (Triticum aestivum) were compared over two years at New Mexico State University’s Rex E. Kirksey Agricultural Science Center at Tucumcari. Seasonlong (Nov–Apr) average forage dry matter yield was rye > oat > wheat > triticale (5.03, 4.44, 3.58, and 2.79 Mg ha⁻¹, respectively; p < 0.0001). Rye also had greater average monthly growth than the other cereals, among which there was no difference (1.58, 1.05, 0.96, and 0.85 Mg ha⁻¹ mo⁻¹ for rye, oat, wheat, and triticale, respectively; p < 0.0331). Growth of ungrazed cereals was reduced in mid-winter and regrowth of grazed forage did not equal removal by growing cattle. When given a preference and allowed to deplete available forage, growing cattle preferred oat followed by rye, then wheat and triticale. Regrowth of grazed forage did not differ among cereals. Full article

Forage-based beef production is one of the most productive agricultural systems, especially in semiarid, subtropical environments, yet it is temporally variable due to climatic factors. Dormant native perennial warm-season grasses are available for grazing from autumn through spring; however, their protein concentration is inadequate to support growing cattle. Winter cereal forages, such as triticale [×Triticosecale Wittm. ex A. Camus (Secale × Triticum)], can fill fall through spring forage gaps with sufficient protein concentration. Triticale productivity was evaluated, and beef stocker performance on triticale was compared with supplemented native grassland for late winter pasture in each of three years at New Mexico State University’s Rex E. Kirksey Agricultural Science Center in Tucumcari, NM USA. Study results indicated that triticale pasture forage mass varied over the three years due to precipitation and different triticale planting dates each year, influencing the length of grazing period. Triticale provided late winter average daily gain approximately twice that of cattle grazing dormant native grass with protein supplementation (0.70 vs. 0.36 kg hd⁻¹ d⁻¹, p < 0.0001). Therefore, triticale can be utilized to provide adequate growth of young calves without the added costs of supplementation. Full article

Low forage quality of available perennial warm-season grasses during mid-summer through late summer affects the production of stocker cattle in the U.S. Southern Great Plains (SGP). Finger millet (Eleusine coracana Gaertn L.), which is a drought tolerant annual grass, could be a promising forage for the SGP. This field study assessed the adaptability and forage characteristics of 11 finger millet accessions originally sourced (1964–1981) from different parts of the world. Results of this study suggested that finger millet can generate forage yields ranging from 5.0 to 12.3 Mg ha⁻¹ 165 days after planting. Finger millet forage contained 105 to 156 g kg⁻¹ crude protein, 598 to 734 g kg⁻¹ neutral detergent fiber, 268 to 382 g kg⁻¹ acid detergent fiber, 597 to 730 g kg⁻¹ in vitro true digestibility, and 387 to 552 g kg⁻¹ neutral detergent fiber digestibility. Ten of the 11 accessions flowered and produced grains with yields varying from 60 to 1636 kg ha⁻¹. Overall, finger millet has the potential to serve as an alternative crop for the production of forage and possibly grain in the SGP. Further research needs to be focused on developing strategies for agronomic management and evaluating the capacity of finger millet under different grazing and hay production settings in the SGP. Full article