Journal of Animal Science

Izquierdo, Vinicius S; Cappellozza, Bruno I; Ashrafi, Nadia; Mimi, Romana Ashrafi; Graham, Stewart F; Vendramini, João M B; Gonella-Diaza, Angela; Moriel, Philipe

doi: 10.1093/jas/skaf135pmid: 40296267

This study evaluated the effects of maternal supplementation of a Bacillus-based direct-fed microbial (DFM) on the plasma metabolome of cow–calf pairs. At the start of the study (day 0), 72 pregnant Brangus crossbred beef heifers (20 to 22 mo of age) were stratified by body weight (BW; 431 ± 31 kg) and body condition score (6.0 ± 0.36) and randomly allocated into 12 bahiagrass pastures (1 ha and six heifers/pasture). Treatments were assigned to pastures (six pastures/treatment) and consisted of heifers supplemented with 1 kg/head/d (dry matter basis) of soybean hulls, either alone (CON) or combined (BAC) with DFM containing a mix of Bacillus subtilis and B. licheniformis (Bovacillus; Novonesis, Hørsholm, Denmark) from day 0 to 242 (139 ± 4 d prepartum until 104 ± 4 d postpartum). Calves were weaned on day 242 and then allocated to drylot pens and fed the same diet until day 319. On days 271 and 287, calves were vaccinated against pathogens associated with bovine respiratory disease. Blood samples were collected from all heifers on days 0 and 63 (prepartum) and from all calves on days 271 (pre-vaccination), 274 (during the inflammatory response), and 287 (post-inflammatory response) to assess the plasma concentration of metabolites. There was a separation on day 63 (R2 = 0.96) for the plasma metabolome profile of BAC and CON heifers. Heifers fed BAC had increased (P ≤ 0.05) plasma concentration of 17 metabolites, including glycerophospholipids and amino acids, but decreased (P ≤ 0.05) plasma concentration of 4 triacylglycerols. Eight pathways related to amino acids metabolism were increased (P ≤ 0.01) in BAC vs. CON heifers. For the calf metabolome, a separation was observed on days 271 (R2 = 0.95), 274 (R2 = 0.95), and 287 (R2 = 0.99). Supplementation with BAC decreased (P ≤ 0.05) plasma concentrations of three and six metabolites from amino acids and triacylglycerols on days 271 and 274, respectively, and increased (P ≤ 0.05) plasma concentrations of 9, 10, and 28 metabolites associated with amino acids and lipids metabolism on days 271, 274, and 287, respectively. Maternal supplementation with Bacillus-based DFM altered calf amino acid metabolism before vaccination (P ≤ 0.03) but enhanced pathways associated with immune response after vaccination (P ≤ 0.05). Thus, maternal supplementation of a Bacillus-based DFM modified the maternal prepartum metabolome and the calf metabolome before, during, and after a vaccination-induced inflammatory response.

Latack, Brooke C; Carvalho, Pedro H V; Moura, Gustavo A B; Zinn, Richard A

doi: 10.1093/jas/skaf113pmid: 40233197

The objective of the current study was to determine the influence of biochar supplementation on steer growth performance, carcass characteristics, and ruminal temperature of calf-fed Angus × Holstein (AXH) crossbred steers versus calf-fed Charolais × Holstein (CXH) crossbred steers fed for over 300 d. Fifty-six AXH crossbred steers (body weight (BW) = 192 ± 12 kg), and 56 CHX steers (BW = 188 ± 13 kg) were blocked by initial BW and assigned randomly to 28 pens. Dietary treatments consisted of a steam-flaked corn-based diet supplemented with 1) no biochar supplementation (control); 2) 0.2% (dry matter (DM) basis) of Biochar. Data were analyzed as a randomized complete block in a 2 × 2 factorial arrangement, using pens as the experimental unit. From 112 to 224 d on feed, dietary supplemental biochar decreased (P = 0.05) cattle average daily gain (ADG). However, there were no other dietary effects (P ≥ 0.11) on steer growth performance or performance-adjusted net energy values. Biochar supplementation tended (P ≥ 0.08) to decrease the marbling score and increase calf morbidity. Biochar had no other effects (P > 0.13) on carcass characteristics. Angus cross steers had a greater (P ≤ 0.05) final live weight and DM intake compared to CXH steers. Moreover, AXH steers tended (P = 0.09) to have overall ADG, and had a 9.4% greater (P = 0.03) overall ADG in the last 78 d compared to CXH. There were no differences (P ≥ 0.44) between breeds for gain efficiency or net energy for maintenance or gain based on growth performance. Charolais cross steers had the lesser (P ≤ 0.04) average ruminal temperature during the months of June, July, August, and November, while there were no ruminal temperature differences in September and October (P > 0.10). Angus cross steers demonstrated an increase (P ≤ 0.04) in kidney, pelvic, and heart fat, backfat thickness, marbling, and yield grade compared to CXH; however, CXH had a larger (P = 0.01) longissimus muscle area. There were no other differences (P ≥ 0.11) in carcass characteristics, health, or liver abscesses between breeds. Results indicate that biochar supplementation at 0.20% (DM basis) did not affect growth performance or carcass characteristics; however, breed (Angus vs. Charolais) used in a beef on dairy cross did affect carcass characteristics, including carcass weight, and muscle and fat deposition; showing the importance of proper breed selection when a beef on dairy crosses production.

Weir, Colton D; Duncan, Zachary M; Spore, Tyler J; Corrigan, Mark E; Ellis, William Cole; Hollenbeck, William R; Titgemeyer, Evan C; Blasi, Dale A

doi: 10.1093/jas/skaf129pmid: 40259483

We compared reticulorumen pH measurements determined using smaXtec boli (SMAX; smaXtec Inc., Graz, Austria), Moonsyst boli (MOON; Moonsyst International, Kinsale, Republic of Ireland), and a handheld pH meter (METER; PH8500 pH/mV Meter, Apera, Columbus, OH) over time and during an ex vivo acidosis challenge. Eight ruminally cannulated heifers were used for 6 consecutive 21-d periods. On day 0, SMAX and MOON were placed in the reticulum of each heifer to continuously measure ruminal pH. On day 20 of each period, pH of ruminal digesta samples collected from 4 locations within the rumen were measured with METER prior to feeding and 2, 4, 6, 8, 12, 18, and 24 h post-feeding. Over the 126-d, ruminal pH was lesser for MOON than METER in every period (P ≤ 0.01) with the difference becoming larger in periods 4 through 6 (treatment × period, P < 0.01). Measurements of pH with SMAX were greater (P < 0.01) than METER from periods 1 to 3 and period 6. On day 21 of each period, boli were removed and placed sequentially in pH 4 and 7 solutions, each for 3 h. In pH 4 solution, a treatment × period interaction (P = 0.02) was observed where MOON and SMAX yielded measurements that were not different from pH 4 (P ≥ 0.13), except in period 6. Similarly, in pH 7, a treatment × period interaction (P < 0.01) was observed where MOON yielded measurements less than pH 7 (P ≤ 0.05) in periods 4 to 6 whereas pH measurements with SMAX were greater than 7 (P ≤ 0.05) in periods 1 to 3. Boli were then placed in a container of strained ruminal fluid, and pH was measured using SMAX, MOON, and METER. Subsequently, vinegar was added to the ruminal fluid to simulate an acidosis challenge and pH was measured. The change in pH in response to vinegar addition as measured by METER was considered the true response. During the acidosis challenge, there were no treatment × period interactions (P = 0.34), pH measurements from MOON were similar (P = 0.36) to pH measurements from METER, and pH measurements from SMAX were greater (P < 0.01) than those from METER. Overall, ruminal pH measurements determined using SMAX and MOON drifted over time. During an acidosis challenge, MOON detected changes in pH similar to METER which may suggest that MOON could be capable in detecting acidotic events. Conversely, indwelling ruminal pH measurements determined using SMAX were more closely related to METER throughout the experiment.

Dong, Xiao; Zhang, Zirui; Liao, Juan; Chen, Jiahong; Zhang, Shunlong; Rao, Yuan

doi: 10.1093/jas/skaf084pmid: 40259470

Having comprehensive access to information on sheep behaviors is essential for acquiring relevant insights into the health status of sheep and preventing diseases promptly. In particular, the ruminating behavior of sheep tends to reflect the health of their digestive system. However, due to the challenging nature of detecting ruminating behavior, traditional research has not yielded satisfactory results. In fact, many computer vision-based methods do not consider ruminating behavior as a distinctive feature for recognizing sheep behavior. To this end, we proposed an efficient model for recognizing active (standing, feeding, drinking, suckling), inactive (kneeling), and ruminating behaviors of sheep flock based on You Only Look Once-v5 (YOLOv5). This model improved the original structure through introducing the latest fully convolutional neural network in the backbone network, thereby reducing parameters cost and improving the classification accuracy. At the same time, the Spatial Pyramid Pooling Cross Stage Partial Connection module from You Only Look Once-v7 was added at the end of the backbone network, which improved the ability of the model to recognize multiscale sheep behaviors by increasing the receptive field. In the neck network part, a new algorithm named Concat optimization algorithm based on channel concatenation (CiConcat) was proposed to optimize the regular Concat operation, which enhanced the filtering ability of the small target detection layer of the model for nonruminating behavior information, thereby improving the ability to accurately extract local details. In addition, Selective Kernel attention mechanism was introduced before the detection head to enhance the feature extraction and expression ability of sheep. Finally, a detection head matching strategy was proposed to promote the accuracy when detecting distant ruminating behavior of sheep. This study used a self-collected and annotated outdoor sheep farm image dataset for experimental validation. The results showed that the improved network achieved the mean Average Precision of 94.1% on outdoor grazing sheep flock images which was more accurate and faster than state-of-the-arts. Simultaneously, the Average Precision for ruminating detection reached 80.2%, showing an improvement of 35.44% compared to YOLOv5, markedly enhancing the accuracy of ruminating behavior recognition. Our model was proved to be able to continuously monitor the behavior frequency of sheep, providing a robust technical foundation for analyzing behavior patterns and understanding the physiological and behavioral needs of sheep.

McClellan, Katlyn A; Fowler, Emily C; Perez-Palencia, Jorge Y; St-Pierre, Benoit; Weaver, Eric M; Levesque, Crystal L; Koch, Kim; Mueller, Shane; Hong, Jinsu

doi: 10.1093/jas/skaf111pmid: 40233213

Incorporating canola meal (CM) into nursery pig diets has been limited due to the adverse effects of glucosinolates, sulfur-containing glycosides, presented in Brassica family oilseeds. This study investigated the effects of acidifier supplementation in high CM diets on the performance, organ weights, blood profiles, and hindgut microbial composition of nursery pigs. A total of 315 nursery pigs, average 6.0 ± 1.2 kg body weight (BW), were assigned to 1 of 5 dietary treatments with 9 replicates (7 pigs/pen) in a randomized complete block design. Treatments included; a corn–soybean meal (SBM) based diet with 20% CM (positive control, PC) and corn–SBM-based diet with 40% CM without (negative control, NC) or with acidifier (NCA), or encapsulated butyrate (NCB), or both (NCAB). Diets met nutrient requirements of NRC (2012) in 3 phases; phase 1 (common diet; 0 to 1 wk), phase 2 (experimental diets; 1 to 3 wk), and phase 3 (experimental diets; 3 to 6 wk). Pig BW and pen feed consumption were measured by phase to investigate the growth performance of pigs. At the end of each phase, 1 pig per pen was bled and then euthanized for measurement of organ weight. Cecal digesta was collected only at the end of phase 3 for microbial composition analysis. Pigs fed the NCA diets had greater (P < 0.05) final BW and average daily gain during phase 3 and had a tendency of greater (P = 0.084) overall gain-to-feed ratio than pigs fed the NC diet. Pigs fed the NCA diet had a greater (χ2 < 0.05) percentage of non-diarrhea feces than pigs fed the PC diet for phase 2 and the overall period. Pigs fed PC diet had higher serum thyroxine (T4) concentration at the end of phase 3 (P < 0.05) than pigs fed NC diets. The addition of acidifier in NC diet decreased (P < 0.05) spleen weight and tended to decrease (P = 0.064) liver weight. Pigs fed the NCAB diet had a lower (P < 0.05) large intestine weight compared with those fed NC diet. Pigs fed the PC or NCA diets tended to have less (P = 0.06) the relative abundance of OTU Ssd-00188 (Agathobacter rectalis 99.23%) and NCAB diet increased (P < 0.05) the relative abundance of OTU Ssd-00001 (Lactobacillus amylovorus 99.64%) in the cecal microbiota compared with those fed NC diet. Overall, these findings support the incorporation of high CM levels (up to 40%) with acidifier supplementation in nursery pig diets, mitigating the negative implications of dietary glucosinolates and providing benefits for both canola growers and pig farmers in regions with substantial canola production.

Taylor, Daniel D; Groenendaal, Huybert; Morley, Paul S; Zagmutt, Francisco

doi: 10.1093/jas/skaf127pmid: 40265468

Liver abscesses (LA) cause significant economic losses in U.S. beef feedlot cattle through a variety of production and performance effects. This research estimated annual economic losses secondary to LA in U.S. beef feedlot cattle using a stochastic simulation model that was based on data from the literature, economic data, and expert opinion. LA prevalence was estimated for 4 U.S. regions and 4 cattle types along with their combinations. Economic losses were estimated by combining modeling results from individual loss categories related to feed efficiency, liver, offal, and trim loss, effects on carcass quality, and processing delays. Losses were also estimated under different antimicrobial use and production scenarios. We estimated that LA result in annual losses of $256M (95% Credible interval: $162M to $378M) to the U.S. beef industry. Decreased average daily gain (ADG) and a lower dressing percentage prior to trimming accounted for nearly half (48.6%) of these losses, while liver and offal condemnation and excess trimming comprised approximately 40% of all losses. Processing delays were estimated to contribute approximately 5% of the total losses. There was also substantial variation in the estimated prevalence and impacts of LA by region and cattle type, with beef-dairy crossbred (BD) cattle in the Western region experiencing the highest economic losses per animal. Scenario analyses predicted that eliminating the use of tylosin may nearly double LA prevalence and associated economic costs while transitioning all beef cattle born on dairies from Holsteins to BD cattle would only slightly increase overall losses. Our findings show that LA cause substantial, yet uncertain, losses to the U.S. beef feedlot industry. The results also emphasize the need for additional research to elucidate the effect of LA on feed efficiency and to improve LA prevention strategies, which could enhance animal health and productivity as well as industry sustainability.

Manenti, Isabella; Viola, Irene; Canto, Francisco; Accornero, Paolo; Toschi, Paola; Versace, Carmine; Macchi, Elisabetta; Martignani, Eugenio; Abecia, José Alfonso; Miretti, Silvia

doi: 10.1093/jas/skaf123pmid: 40243116

For livestock, transport can involve several potential stressors including human handling, stocking density, air temperature, noise, vibration, and loading/unloading procedures. The animal’s perception of and its ability to adapt to those stimuli are not fully understood, which makes it difficult to carry out welfare assessments. This study aimed to detect stressful moments in lambs during transport through changes in physiological and molecular markers. Data obtained from bio-loggers that record physiological variables and an evaluation of molecular biomarkers such as cortisol and circulating microRNAs (c-miRNAs) identified the most stressful moments of transport, which can be a valuable tool for evaluating and improving transport conditions for livestock. Rasa Aragonesa lambs were implanted with bio-loggers that record subcutaneous body temperature (BT) and heart rate (HR). Plasma and saliva were sampled for molecular analyses; specifically, saliva for cortisol concentrations, plasma for creatine kinase (CK), and lactate dehydrogenase (LDH), and plasma and saliva for c-miRNAs expression profiles. Immediately after the lambs were unloaded, the bio-loggers registered a significant (P < 0.05) spike-in HR and a drop in BT, and salivary cortisol concentrations increased significantly (P < 0.05), which indicated unloading as one of the main stressful points for the lambs. Out of the 17 miRNAs tested, 4 showed a significant difference in expression (P < 0.05). MiR-23a and -27a were both expressed in plasma and saliva, while miR-17 and -24 were most expressed in saliva after unloading. Finally, the expression of plasmatic miR-23a, -24, and 27a were significantly (P < 0.05) positively correlated with the LDH whose concentrations together with those of CK are significantly increased (P < 0.01) after unloading. The study identified the timing of a lamb’s adaptation response during and after transport, which reflected the dynamic nature of ovine plasma and salivary miRNAs during transport-induced stress, giving them the potential to be biomarkers that can be useful in animal welfare assessments.

Williams, Courtney M; Bayliff, Corbit L; Garcia-Ascolani, Mariana E; Reuter, Ryan R; Horn, Gerald W; Goad, Carla L; Lalman, David L

doi: 10.1093/jas/skaf126pmid: 40255100

A 2-yr experiment was conducted to determine the impact of maternal metabolizable energy intake (MEI) on energy partitioning and performance of beef cows and calves. Forty mature crossbred Angus beef cows (6 ± 2.0 yr, 534 ± 60 kg BW) were used each year along with their suckling steer calves (84 ± 8.7 d, 130 ± 15 kg BW). Cows were stratified by early lactation milk yield and randomly assigned to 1 of 5 levels of MEI. Each treatment group was housed in a dry lot pen. During year 1, maternal MEI ranged from 225 to 320 kcal·BW0.75·d−1, while in year 2, MEI ranged from 215 to 288 kcal·BW0.75·d−1. Calves were provided ad libitum access to the same TMR diet as the cows in a creep area. Parameters evaluated included apparent total tract nutrient digestibility, milk production and nutritional composition, cow body weight (BW), body condition score (BCS), ultrasound carcass characteristics, calf BW, and calf creep feed intake. Data were analyzed using the GLIMMIX procedure of SAS (SAS Inst. Inc., Cary, NC) as a general linear mixed model. The final model included the linear effect of maternal MEI as a fixed effect and the year of the experiment as a random effect. Significance of the fixed effects was declared when P ≤ 0.05, while tendencies were declared when 0.05 < P ≤ 0.10. Cow 100-d BW, BCS, and ADG linearly increased (all, P < 0.01) with increasing levels of maternal MEI. Similarly, calf 100-d BW and ADG linearly increased (P = 0.03, P < 0.01, respectively) with increasing maternal MEI. Milk yield, milk energy production and all milk nutrients linearly increased (P ≤ 0.04) with increasing maternal MEI, except for milk urea nitrogen which significantly decreased (P < 0.01). Cow energy partitioned to tissue accretion and milk production linearly increased (both, P < 0.001). As maternal MEI increased, the proportion of net retained energy partitioned to maternal tissue accretion initially increased. However, at approximately 275 kcal·BW0.75·d−1 of maternal MEI, the proportion plateaued. Increased maternal MEI reduced the efficiency of calf BW gain (BW gain per unit of calf MEI from both creep feed and milk) in a linear fashion (P = 0.03). These findings suggest that maternal energy intake, rather than genetic capacity for milk yield, limited milk energy production in these cows. Furthermore, the maximum proportion of retained energy as maternal tissue was achieved at about 275 kcal·BW0.75·d−1.

Wei, Wenyan; Gao, Junjie; Qin, Feng; Zhao, Xilun; Jiang, Xuemei; Che, Lianqiang; Lin, Yan; Zhuo, Yong; Feng, Bin; Hua, Lun; Liu, Guangmang; Sun, Mengmeng; Wu, De; Xu, Shengyu

Terry, Stephanie A; Yang, Wenzhu; Beauchemin, Karen A; Schwartzkopf-Genswein, Karen S; Penner, Gregory B; Wood, Katharine M; McAllister, Tim A

doi: 10.1093/jas/skae392pmid: 40202033

This study evaluated the impact of grain processing method (dry- vs. steam-rolling) and diet uNDF concentration (low vs. high; 5.7% vs. 6.6% on DM basis by replacing silage with straw) in finishing diets on feed intake, feeding behavior, growth performance, ruminal pH, fermentation parameters, inflammatory stress responses, and carcass traits of 376 intact (initial body weight (BW) ± SD, 440 ± 33.6 kg), and 24 ruminally cannulated steers (initial BW ± SD, 474 ± 30.5 kg). Steers were housed in 32 pens with 4 pens of 30 steers, and 28 pens of 10 steers. Eight of the pens with 10 steers, and all of the pens with 30 steers were equipped with GrowSafe to record individual feed intake and feeding behavior. Three cannulated and 7 intact steers were housed in the smaller GrowSafe pens. Diets included (1) dry-rolled barley and barley silage; (2) dry-rolled barley and barley straw; (3) steam-rolled barley and barley silage; and (4) steam-rolled barley and barley straw, formulated to contain 89% barley-grain, 6% roughage and 5% vitamin and mineral supplement (DM basis). Interactions between the processing method and uNDF concentration were observed for maximum ruminal pH, and concentrations of blood glucose and lipopolysaccharide-binding proteins. Compared to dry-rolling, steam-rolling did not improve growth performance, ruminal pH, fermentation parameters, or liver abscess scores, but did increase longissimus muscle (LM) area (P = 0.01) and decrease the proportion of AAA carcasses (P = 0.01). Steam-rolled barley decreased (P = 0.04) glucose and increased (P = 0.01) blood concentrations of insulin and acute phase proteins. Increasing uNDF did not affect feed intake, growth, carcass traits, or liver abscess scores, but did increase (P = 0.01) bunk attendance, meal duration, and to a lesser extent meal intervals (P = 0.04) and eating rate (P = 0.01). Increased uNDF raised (P = 0.04) mean ruminal pH and reduced the duration of pH below 6.0, 5.8, and 5.2, and tended (P = 0.06) to increase the acetate to propionate ratio. The lack of growth response to dietary uNDF concentration could be due to the small differences in uNDF intake, or that uNDF concentration was sufficient to prevent digestive disturbances. Increasing dietary uNDF altered eating behavior and ruminal pH in a manner that could reduce the risk of clinical and subclinical ruminal acidosis.