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The objective was to determine if a blend of capsicum oleoresin, clove essential oil, and garlic essential oil (CCG; Fytera® Advance – Selko® USA, Indianapolis IN) influences cattle performance, sera metabolites or health outcomes during the 56-d feedlot receiving phase. Charolais × Angus steers (n = 256; BW = 273 ± 26 kg) were allotted to 1 of 32 pens (n = 8 steers; 8 pens/treatment) and assigned to treatments: no test product (MON); CCG at 125 mg/steer/d (CCG125); CCG at 250 mg/steer/d (CCG250); or CCG at 500 mg/steer/d (CCG500). Monensin was fed to all steers (25 g/907 kg,DM basis). MON and CCG500 had greater DMI (quadratic effect; P = 0.01).. However, CCG did not improve ADG nor G:F (P ≥ 0.15). On d 14, CCG500 had elevated NEFA compared to the other treatments (P ≤ 0.05). Ceruloplasmin,was decreased (P = 0.04) in steers from CCG250 and CCG500. There was no effect of supplementation on health outcomes (P ≥ 0.12). [ABSTRACT FROM AUTHOR]

Objective: The objective of this study was to determine if a formulated blend of capsicum oleoresin, clove essential oil, and garlic essential oil (Fytera Advance - Selko USA, Indianapolis IN, USA; CCG) influences measures of cattle growth, efficiency, or carcass traits, during the finishing phase in steers fed a concentrate-based diet. Methods: CharolaisxAngus steers (n = 96; initial shrunk body weight [BW] = 391±34.0 kg) were used in a 144-d (16 February 2023 to 9 July 2023) finishing feedlot experiment in Brookings, SD, USA. Steers were individually weighed and allotted to one of 14 pens (6 to 7 steers; 7 pens/treatment) in a randomized complete block design and randomly assigned to 1 of 2 treatments: control diet without the test product (CON) or a diet including CCG at 500 mg/steer daily (CCG). Steers were fed twice daily, and bunks were managed according to a slick bunk system. Results: There were no differences (p≥0.10) in any growth performance outcomes from d 1 to 35, 36 to 70, or 71 to 98. From d 99 to 144 steers from CCG tended to have 5% greater average daily gain (p = 0.09) and 8% improved feed conversion (G:F) (p = 0.01). No differences (p≥0.15) were noted for cumulative growth performance measures. No differences were noted for any carcass measurements or categorical carcass outcomes, nor lung or liver health outcomes (p≥0.15). Conclusion: The use of CCG had no influence on cumulative growth performance responses. However, the use of CCG improved G:F during the late feeding period. [ABSTRACT FROM AUTHOR]

Camelina sativa is an annual oilseed crop that requires low inputs. Recently, interest in camelina oil for both human use and biofuel production has increased. Camelina oil extraction is performed through two main methods, namely, mechanical expulsion and solvent extraction. The resulting meals from the oil extraction process show promise as an animal feed due to their high crude protein content. Solvent extraction removes more oil from the seed, which results in a meal that is lower in fat and higher in crude protein concentration than expelled meal (3.52 vs. 13.69% and 41.04 vs. 34.65%, respectively). Solvent-extracted camelina meal has a similar chemical composition to canola meal but less crude protein and more fiber than soybean meal. Camelina meal is also limited by its anti-nutritional factors, mainly glucosinolates. Camelina meal contains 23.10 to 44.90 mmol/kg of glucosinolates, but processing methods may be able to decrease the total glucosinolates. Heat-treating the camelina meal can decrease glucosinolates and remove residual solvent in the solvent-extracted meal. The fungal fermentation of canola meal has also decreased glucosinolates, which could be used in camelina meal as well. The selective breeding of camelina varieties to decrease glucosinolates in the plant is also a solution to the high glucosinolates found in camelina meal. Current feed regulations in the US and Canada limit camelina meal to 10% inclusion in broiler chicken, laying hen, and cattle diets. [ABSTRACT FROM AUTHOR]

objective of this study was to determine the effect of limit feeding yearling beef steers for 56 or 86 d before offering ad libitum feed for the remainder of the 140-d finishing period on growth performance and carcass traits. Black Angus steers [n = 194; initial body weight (SBW) = 410 ± 17.9 kg] were allocated into 24 pens (8 steers/pen). Pens were randomly assigned to one of three treatments in a randomized complete block design; feed offered ad libitum for the entire finishing period (ADLIB), feed offered at 92% of ad libitum for 56 d then ad libitum for the remainder of the finishing period (RES56), and feed offered at 92% of ad libitum for 86 d then ad libitum for the remainder of the finishing period (RES86). Feed restrictions began on d 22 after diet adaptation with RES56 and RES86 pens being offered 92% of the ADLIB pen within the daily feed offering of their block. Bunks were evaluated daily, and refusals were weighed weekly. Data were analyzed using the MIXED procedure of SAS 9.4 with treatment and block as the fixed and random effects, respectively. From d 1 to 21 RES56 had lesser average daily gain (ADG), feed efficiency (gain to feed; G:F), and a lighter SBW than ADLIB and RES86 (P ≤ 0.02), but DMI did not differ (P ≥ 0.31). From d 22 to 107, G:F was similar (P = 0.45), but ADLIB had a greater SBW, ADG, and DMI than RES56 and RES86 (P < 0.01). From d 78 to 107 RES56 were allowed ad libitum feed intake while RES86 was still restricted. The d 108 SBW tended to be greatest in the ADLIB and least in the RES86 group (P = 0.07), and DMI was least in the RES86 group (P < 0.01). RES56 had the greatest ADG, RES86 the least, and ADLIB were intermediate (P < 0.01). RES56 and RES86 also had increased G:F than ADLIB during this period (P < 0.01). From d 108 to 140 all cattle had ad libitum access to feed, and DMI did not differ (P = 0.31). RES86 had greater ADG and G:F than ADLIB and RES56 during this period (P ≥ 0.31). Cumulatively, final SBW, ADG, and G:F did not differ between the treatments (P ≥ 0.13), but the ADLIB group had increased DMI (P < 0.01). Ribeye area and hot carcass weight (HCW) did not differ (P ≥ 0.12), but rib fat thickness (P = 0.05) and marbling were greater for ADLIB (P = 0.03). Limit feeding yearling beef steers for a portion of the finishing period before resuming ad libitum feed intake resulted in less cumulative DMI without affecting ADG, G:F, final shrunk BW, or HCW; but decreased fat and marbling scores [ABSTRACT FROM AUTHOR]

Efficiency of mature beef cows consuming high-forage diets is not comparable with standard definitions of beef cattle efficiency such as feed conversion or residual feed intake in the feedlot setting. This study aimed to conduct a genome-wide association study (GWAS) to identify regions of the bovine genome associated with efficiency in mature beef cows. Ninetyeight black Angus cows were managed under extensive feeding programs over a two-year period. Using rump fat at calving, calving date, and calf weaning weight as a percentage of the body weight of the dam, a weighted percentile scoring system was used to rank efficiency. Eighty-three of the cows were retained for the GWAS. The 20 most and 20 least efficient cows (HD dataset, n=40) were genotyped with the Illumina BovineHD BeadChip (777,000 SNPs) while the remaining cows were genotyped with the Neogen GGP Bovine 100K chip (LD dataset, n = 43). The LD dataset was imputed to the HD SNP array density using Beagle5.4 (FULL dataset, n = 83). Three separate GWAS were conducted using GAPIT (version3). The first GWAS was performed on the HD dataset using a quantitative phenotype determined by the ranking system. The second GWAS was performed with the HD dataset using a qualitative phenotype (efficient vs non-efficient cows). For the final GWAS, the FULL dataset with ranked phenotypes was used. Five models were evaluated for each GWAS, including the general linear model (GLM), mixed linear model (MLM), multiple loci mixed model (MLMM), fixed and random model circulating probability unification (FarmCPU), and Bayesian-information and linkage-disequilibrium iteratively nested keyway (BLINK). The model that best represented each dataset as determined by quantilequantile plots was used for downstream analysis. Although results of the GWAS were not significant (Bonferroni threshold), associations were identified on BTA10, 16, 17, 25, 27 and 29. Positional candidate genes in the associated regions include: FOXN3, UPB1, SNX29, DDX54, LOC112444612, RITA1, and TACC1. Further functional analyses are required to confirm these findings; however, this work provides a foundation for identifying genes and gene mutations influencing this newly described phenotype. [ABSTRACT FROM AUTHOR]

This study evaluated beef cows identified as having high or low efficiency when managed in extensive systems and whether they differ in terms of digestive physiology. Nine high (HE) and low efficiency (LE) cows were selected from a group of 86 Angus cows using 2 years of selection data. Yearly ranks were assessed based on three weighted criteria: cow rump fat at calving; calving interval; and calf weaning weight. The 18 cows were then ruminally cannulated and used to evaluate their response to high (HQ; 41.0±0.78% NDF), medium-high (MHQ; 56.9±1.17% NDF), moderate (MQ; 62.5±3.40% NDF), and low-quality forage (LQ; 64.3±1.40% NDF) diets using four consecutive 26-d periods where diet quality progressively decreased by period for all cows. There was no phenotype'diet interactions. Start and end BW were 48 and 45 kg less (P< 0.01) and rump fat was thicker for HE than LE cows (P=0.02). Although total DMI did not differ (13.0 kg/d; P=0.93), DMI (%BW) was greater for HE (2.12%) than LE (1.97%, P< 0.01). Ruminal pH, shortchain fatty acid concentration, and the molar proportion of acetate, butyrate, and propionate did not differ. Ruminal digesta weight was 4 kg greater (P=0.04) and the pool sizes of DM (P=0.01), NDF (P=0.03) and undigested NDF (P< 0.01) were greater for LE than HE. Ruminal NDF passage rate was greater for HE than LE cows (3.11 vs. 2.89%/h, P=0.05), but there were no differences for the rate of NDF digestion. Ruminal contraction amplitude (P=0.01) and peak area (P< 0.01) were higher for LE than HE cows. Apparent total tract nutrient digestibility did not differ (P≥0.23). Cows identified as being efficient under an extensive management system have greater DMI as a proportion of BW, less ruminal digesta weight, and greater NDF passage rate but did not differ for total tract digestibility. [ABSTRACT FROM AUTHOR]