Search

Through the process of enteric fermentation, cattle produce methane (CH4), a potent greenhouse gas (GHG). Growing public concern about climate change has increased the need for accurate methods of measuring CH4 emissions from cattle directly to improve emission inventories and evaluate emissions mitigation techniques. The present study evaluated a ventilated head box system capable of measuring CH4 and carbon dioxide (CO2) emissions, and oxygen (O2) consumption from cattle. Six Holstein heifers were used to measure CH4 and CO2 emissions and O2 consumption from 2 ad libitum intake measurement periods (ADAPT and ADLIB) and 1 measurement period (RESTRICT) with intake restricted to 2% of BW on a DM basis. Methane emissions during RESTRICT were significantly lower (P < 0.0001) than both ad libitum periods. Daily CH4 emission rates per animal were 235.0 ± 6.19 L/d, 228.3 ± 6.18 L/d, and 193.2 ± 8.88 L/d for the periods ADAPT, ADLIB, and RESTRICT, respectively. Carbon dioxide emission rates were 3627 ± 90.72 L/d, 3632 ± 90.47, and 3184 ± 104.79 L/d for the ADAPT, ADLIB, and RESTRICT periods, respectively. Oxygen consumption rates were 3391 ± 99.77 L/d, 3454 ± 99.57 L/d, and 3002 ± 111.36 L/d for the periods ADAPT, ADLIB, and RESTRICT, respectively. The head box system evaluated provides an accurate method of measuring emissions from cattle and can provide information about daily variations and peaks in emissions. [ABSTRACT FROM AUTHOR]

Dairy calves in the Southwest regions of the United States are typically raised individually in wooden hutches with 1.23 m2 of space. The objective of the study was to determine if increased space allowance in wooden hutches influences measures of innate immunity and behaviors of Holstein bull calves pre- and post-castration. Calves were randomly assigned at 4 d of age to conventional (CONV; 1.23 m2 of space; n = 18), moderate (MOD; 1.85 m2 space; n = 17), or maximized space allowance (MAX; 3.71 m2 space; n = 19) in hutches. Calves were surgically castrated at 24 d of age. Peripheral whole blood samples were collected at -1, +1, +5, and +12 d of castration. Accelerometer loggers (n = 16 calves per treatment) were used from -3 to +5 d of castration to assess standing behaviors. All calves decreased total standing duration the day of castration versus precastration. Overall, MAX spent the most time in the stand position postcastration versus CONV and MOD. Within treatments, MOD and MAX had increased plasma cortisol 1 d postcastration versus precastration. A treatment × time tendency was observed for cortisol at 12 d postcastration; MAX had the least circulating cortisol. A treatment × time tendency for circulating haptoglobin (Hp) was observed and Hp was greatest among CONV 1 d pre- and 12 d post-castration. Compared with precastration, CONV had increased Hp at 1, 5, and 12 d, whereas MOD had increased Hp at 5 d, and Hp remained similar within MAX. A treatment × time tendency for tumor necrosis factor-α (TNF-α) from lipopolysaccharide-stimulated whole blood was observed; at 1 d postcastration, MOD had the most TNF-α, whereas MAX had the least. Within MAX, calves had increased TNF-α from precastration to 5 d postcastration. A treatment × time interaction was observed for whole blood bactericidal activity against Escherichia coli (WB anti-E). The CONV tended to have the greatest WB anti-E at d -1, but at d 1 and 5 postcastration, CONV had the least WB anti-E. Overall, MAX had less intensity of neutrophil oxidative burst versus CONV and MOD. The lower response of neutrophil oxidative burst and slower Hp secretion after castration is indicative that the wound site likely had less microbial exposure. The findings of this study suggest that calves housed with more space are potentially at less risk of too much inflammation after castration, which may likely be due to the effects of increased space on hide cleanliness and increased standing time. [ABSTRACT FROM AUTHOR]

Dairy calves in the western United States are commonly raised individually in wooden hutches with a space allowance of 1.23 m2/calf. Recent legislative initiatives in California and across the United States were passed regarding concern over space allowance for farm animals. The objective of this study was to determine if rearing male Holstein calves in wooden hutches modified to increase space allowance would influence measures of performance, lying time per day, health, and respiratory immunocompetence. At 4 d of age, 60 calves were randomly assigned to 1 of 3 housing treatments: (1) conventional housing (CONV; 1.23 m2/ calf), (2) 1.5 × CONV (MOD; 1.85 m2/calf), or (3) 3 × CONV (MAX; 3.71 m2/calf). Intakes of milk and solid feed were recorded daily and body weight was measured at 0, 3, 6, 10, and 12 wk of age. For the first 3 wk of the trial, calves were scored daily for fecal consistency, hydration, and hide cleanliness. In addition, calves were scored for respiratory health (i.e., nasal and eye discharge, ear position) until 7 wk of age. The total lying duration per day was recorded using data loggers at 3, 6, and 10 wk of age. Eight clinically healthy calves from each treatment were sensitized with subcutaneous ovalbumin (OVA) and then challenged with aerosolized OVA to assess calf respiratory immunity at 11 wk of age. Bronchoalveolar lavage fluid (BALF) was collected 4 d after the OVA challenge and analyzed for leukocyte differentials and OVA-specific IgG, IgG1, IgA, and IgE. Calf average daily gain and body weight were positively associated with space allowance at approximately 3 wk before weaning and throughout postweaning, respectively. A greater space allowance decreased lying time after 46 d. Space allowance did not influence fecal consistency, but there was a tendency for MAX calves to take 1 d longer to recover from loose feces than MOD calves. The MAX calves had the fewest (%) observations with feces on their body compared with CONV or MOD. At 3 wk of age, peripheral eosinophil concentrations decreased with increased space allowance. However, observations (%) of eye discharge increased with greater space allowance. Among calves challenged with OVA, MOD calves had the least BALF OVA-IgE, and the percent of BALF eosinophils decreased with increased space allowance. Increased space allowance for calves raised in wooden hutches may improve some measures of calf performance, health, and respiratory immunocompetence. [ABSTRACT FROM AUTHOR]

The objectives of this study were to examine the effects of feedlot production systems with and without the use of a β-adrenergic agonist compared to an all-natural production program on feedlot performance and carcass characteristics. Crossbred beef steers (n = 336; initial BW = 379 ± 8 kg) were randomized to 1 of 3 treatments in a randomized complete block design (RCBD; 14 steers/pen; 8 pens/treatment). Treatments consisted of an all-natural treatment (NAT), a conventional treatment (CONV), and a conventional treatment with a β-agonist (CONV-Z). All treatments were fed the same basal diet with NAT cattle receiving no growth promoting technologies. The CONV and CONV-Z cattle were implanted with 40 mg of estradiol and 200 mg of trenbolone acetate (TBA) on d 0 and were fed 33 and 9 mg/kg of monensin and tylosin daily, respectively. The CONV-Z cattle were fed zilpaterol hydrochloride (ZH) at 6.76 mg/kg (90% DM basis) for the last 20 days on feed (DOF) There was no effect of treatment on DMI (P = 0.83); however, CONV-Z steers gained 3.8% faster (1.64 vs. 1.58 kg/d; P < 0.01) and were 5.3% more efficient (0.160 vs. 0.152; P < 0.01) than CONV steers, and CONV steers gained 32.8% faster (1.58 vs. 1.19 kg/d; P < 0.01) and were 26.7% more efficient (0.152 vs. 0.120; P < 0.01) than NAT steers. There was a 35.7% improvement in estimated carcass gain (1.29 vs. 0.95 kg/d; P < 0.01) and a 32.6% improvement in carcass efficiency (0.126 vs. 0.095; P < 0.01) for CONV-Z steers compared to NAT steers. Hot carcass weight was increased by 8 kg for CONV-Z steers compared to CONV steers (394 vs. 386 kg; P = 0.05) and 46 kg compared to NAT steers (394 vs. 348 kg; P < 0.01). Longissimus muscle area was increased by 3.6 cm2 for CONV-Z steers compared to CONV steers (92.29 vs. 88.67 cm2; P = 0.02) and 12.1 cm2 for CONV-Z steers compared to NAT steers (92.29 vs. 80.16 cm2; P < 0.01), resulting in a 9.6% unit increase in USDA yield grade (YG) 1 (15.14 vs. 5.52%; P < 0.05) and a 21.6% unit reduction in USDA YG 3 for CONV-Z steers compared to CONV steers (30.70 vs. 52.32%; P < 0.05). The CONV-Z steers had a lower marbling score compared to the other treatments (432; P < 0.01), resulting in an 11.7% unit increase (20.70 vs. 9.03%; P < 0.05) in USDA Select carcasses compared to CONV steers. The results of this experiment show that CONV-Z and CONV production results in a significant improvement in feedlot performance and USDA YG compared to NAT. [ABSTRACT FROM AUTHOR]

Temperament measures have been correlated to ADG and DMI in feedlot cattle. However, most of these experiments evaluate intake at the pen level, rather than within the individual animal. Moreover, some of these relationships are often investigated using an average temperament score (either over time or numerous measures) rather than a single measure of temperament. The objective of this experiment was to examine relationships between temperament measures and performance in individual beef steers based on initial temperament scores. Steers from one source (n = 105) were randomly allocated to 4 pens in 2 weight blocks. Steers were fed a common TMR 3 times each day at approximately 0700, 1000, and 1400 for 70 d. Individual feed and water intake (WI) were measured daily using an Insentec feeding system. Body weights, exit velocity (EV), and chute score (CS) were measured every 14 d. Exit velocity was measured over 1.5 m; CS was measured by the same trained observer and reported on a 1-4 scale, where 1 is calm and 4 is wild. Animals were assigned an EV and CS ranking based on initial measures. Chute score ranking was assigned according to the first measure. Animals 1 SD above the EV mean were ranked as a 2 and animals 1 SD below the mean were a 0, with animals between ranking a 1. Lower ranks are indicative of calmer temperament. Dry matter intake, ADG, G:F, and WI were split into 5 periods (d 0-14, 14-28, 0-28, 28-70, and 0-70). Data were analyzed using the MIXED procedure of SAS where the model included main effects of EV and CS; block was used as a random effect. There was no effect of EV or CS on DMI or WI for any period (P ≥ 0.90). There were no treatment effects for periods d 0-14, 14-28, or 0-70 (P ≥ 0.72). From d 0-28, steers with a CS of 2 or 3 had a increased ADG and G:F (P = 0.04) compared to steers with CS of 1 or 4. From d 28-70, steers with an EV of 1 had decreased ADG and G:F (P ≤ 0.05) compared to steers with EV of 0 or 2. Chute score may be more important for measures during early periods in the feedlot. Additionally, because each temperament measure related to performance in a different manner, this data supports the concept that CS and EV measure different underlying traits. [ABSTRACT FROM AUTHOR]

Feed and water intake are two important aspects of cattle production that greatly impact the profitability, efficiency, and sustainability of producers. Feed and, to a lesser degree, water intake have been studied previously; however, there is little research on their associated animal behaviors and there is a lack of standardized phenotypes for these behaviors. Feed and water intakes obtained with an Insentec system (Hokofarm Group, The Netherlands) from 830 crossbred steers were used to compute five intake behaviors for both feed and water: daily sessions (DS), intake rate (IR), session size (SS), time per session (TS), and session interval (SI). Variance components and heritabilities were estimated for each trait. Heritabilities for feed intake behaviors were 0.50 ± 0.12, 0.63 ± 0.12, 0.40 ± 0.13, 0.35 ± 0.12, and 0.60 ± 0.12 for DS, IR, SS, TS, and SI, respectively. Heritabilities for water intake behaviors were 0.56 ± 0.11, 0.88 ± 0.07, 0.70 ± 0.11, 0.54 ± 0.12, and 0.80 ± 0.10 for NS, IR, SS, TS, and SI, respectively. Daily dry matter intake (DDMI) and daily water intake (DWI) had heritabilities of 0.57 ± 0.11 and 0.44 ± 0.11. Phenotypic correlations varied between pairs of traits (-0.83 to 0.82). Genetic correlations between DDMI and feed intake behaviors were moderate to high, while genetic correlations between DWI and water intake behaviors were low to moderate. Several significant single nucleotide polymorphisms (SNP) were identified for the feed and water intake behaviors. Genes and previously reported quantitative trait loci near significant SNPs were evaluated. The results indicated that feed and water intake behaviors are influenced by genetic factors and are heritable, providing one additional route to evaluate or manipulate feed and water intake., (Published by Oxford University Press on behalf of the American Society of Animal Science 2023.)

Lubabegron (LUB; Experior, Elanco, Greenfield, IN, USA) was approved by the U.S. Food and Drug Administration in 2018 and is indicated for the reduction of ammonia (NH 3 ) gas emissions·kg -1 body weight (BW) and hot carcass weight (HCW) when fed to feedlot cattle during the final 14 to 91 d of the finishing period. LUB demonstrates antagonistic behavior at the β  1 and β  2 receptor subtypes and agonistic behavior at the β  3 receptor subtype in cattle and is classified by the Center for Veterinary Medicine as a "beta-adrenergic agonist/antagonist." This report describes a randomized complete block study that evaluated LUB dose (0, 1.5, 3.5, and 5.5 mg·kg -1 dry matter) during the last 56 d of the feeding period on calculated NH 3 gas emissions, live weight, carcass weight, and associated ratios in beef feedlot cattle. Carcass characteristics, mobility, and health were also evaluated. All cattle received monensin and tylosin throughout the study. Ammonia gas emissions were calculated using the equation developed by Brown et al. (Brown, M. S., N. A. Cole, S. Gruber, J. Kube, and J. S. Teeter. 2019. Modeling and prediction accuracy of ammonia gas emissions from feedlot cattle. App. Anim. Sci. 35:347-356). The reduction in calculated cumulative NH 3 gas emissions with LUB ranged from 1.3% to 11.0% (85 to 708 g/hd). When NH 3 gas emissions were expressed on a live weight (unshrunk) and carcass weight basis, calculated NH 3 gas emissions decreased by 3.0% to 12.8% and 3.8% to 14.6%, respectively. Daily dry matter intake was 2.3% greater ( P trt < 0.05) for steers that received LUB. Average daily gain was 13.7% greater ( P trt < 0.05; 1.68 vs. 1.91 kg), while gain efficiency was 10.8% greater ( P trt < 0.05; 0.167 vs. 0.185) for steers fed LUB. Animal mobility was scored in the pen approximately 1 wk prior to harvest, when cattle were loaded on trucks scheduled for harvest, and at antemortem inspection during lairage. No treatment differences ( P trt ≥ 0.170) were observed at any time for the percent of cattle receiving mobility scores of 1 or 2 (normal or minor stiffness but moving with the normal cattle, respectively). Cattle mobility scored as a 1 or 2 equaled or exceeded 92% at all times. Final BW and HCW increased ( P trt < 0.05) 11.6 to 15.7 kg and 11.3 to 17.1 kg, respectively, in cattle receiving LUB compared to cattle receiving monensin plus tylosin alone., (© The Author(s) 2021. Published by Oxford University Press on behalf of the American Society of Animal Science.)

The COVID-19 pandemic had significant consequences on cattle slaughter capacity in the United States. Although industry stakeholders implemented strategies to minimize cattle welfare impacts of increased weights, days on feed (DOF), and increasing temperatures, there were concerns that mobility challenges would be observed at slaughter facilities. The objectives of this study were to characterize mobility in fed cattle during this recovery period and to identify factors impacting mobility. A total of 158 groups of cattle (15,388 animals) from one slaughter facility were included in the study. A 4-point mobility scoring system was used to assess cattle mobility. Cattle at the facility with normal mobility scores were reduced from the historical average of 96.19% to 74.55%. No increase in highly elevated mobility scores was observed. Mobility was impacted by weight, temperature humidity index (THI), distance hauled, sex, and DOF, with results differing by mobility category. Weather was a key contributor to mobility challenges; the relative risk of observing an elevated mobility score was 45.76% greater when the THI changed from No Stress to Mild Stress. Despite the challenges that the industry faced during this period, efforts to minimize negative effects on cattle welfare by enhanced focus on low-stress handling were effective.

In the future, water may not be as readily available due to increases in competition from a growing human population, wildlife, and other agricultural sectors, making selection for water efficiency of beef cattle increasingly important. Substantial selection emphasis has recently been placed on feed efficiency in an effort to reduce production costs, but no emphasis has been placed on making cattle more water efficient due to lack of data. Thus, the objective of this study was to calculate water efficiency metrics for cattle and evaluate their relationship to growth, feed intake (FI), and feed efficiency. Individual daily FI and water intake (WI) records were collected on 578 crossbred steers over a 70-d test period. Animals with low water intake ate less feed, had lower gains, and were more water efficient (as defined by water to gain ratio, W/G, and residual water intake, RWI). However, the amount of water consumed by animals had minimal phenotypic relationship with feed efficiency (residual feed intake [RFI], R2 = 0.1050 and feed to gain ratio (F/G) ratio R2 = 0.0726). Cattle that had low DMI consumed less water, had lower gains, had lower RFI, and had higher F/G. The level of feed consumed had minimal relationship with water efficiency. WI, W/G, RWI, and ADG had moderate heritability estimates of 0.39, 0.39, 0.37, and 0.37, respectively. High heritability estimates were observed for DMI and RFI (0.67 and 0.65, respectively). Feed to gain had a low heritability estimate of 0.16. WI had a strong positive genetic correlation with W/G (0.99) and RWI (0.88), thus selecting for decreased WI should also make cattle more water efficient. The genetic correlation between WI and ADG was 0.05; thus, selecting for low WI cattle should have little effect on growth. There is a low to moderate genetic correlation between WI and DMI (0.34). RWI has a positive genetic correlation with W/G ratio (0.89) and F/G ratio (0.42) and is negatively genetically correlated with RFI (-0.57). Water to gain and F/G had a strong positive genetic correlation (0.68). RFI has a positive genetic correlation with W/G ratio (0.37) and F/G (0.88). Minimal antagonisms seem to be present between WI and ADG, although it should be noted that standard errors were large and often not significantly different from zero due to the small sample size. However, care should be taken to ensure that unintended changes do not occur in DMI or other production traits and incorporation of WI into a selection index would likely prove to be the most effective method for selection., (Published by Oxford University Press on behalf of the American Society of Animal Science 2019.)

Many dairy calves in the southwestern regions of the United States are raised in wooden hutches with 1.23 m 2 of free space that house 3 calves individually. Producers claim that calves in hutch systems are not ready to wean and be placed in groups at the country-average age of 6 wk. Calves may remain in this individual housing system until as late as 10 wk of age. The objective of this study was to modify space allowance of hutches and evaluate weaning readiness using age at solid feed consumption, standing behaviors, and measures of immunity. Calves were randomly assigned at 4 d of age to conventional (CONV; 1.23 m 2 of space; n = 18), moderate (MOD; 1.85 m 2 of space; n = 17), or maximized (MAX; 3.71 m 2 of space; n = 19) space allowance in hutches. These modifications also changed the number of calves housed per hutch from 3 (CONV) to 2 (MOD) and 1 (MAX). Calves were fed milk replacer via bottle twice daily until weaning and offered ad libitum feed throughout the experiment. Step-down weaning was initiated (Wi) at age 53 or 54 d by withdrawal of the p.m. bottle and was completed (Wc) 11 d later by removal of the a.m. milk replacer. Accelerometer data for standing behaviors were collected relative to Wi (3 consecutive days to represent -4 wk, -3 d, 3 d, and 3 and 5 wk). Blood samples were collected in the a.m. just before Wi (d 0) and at d 3, 11, 14, and 18 after Wi. Calves provided with more space (MOD and MAX) compared with CONV calves consumed feed at an earlier age and had slightly healthier erythrocytes, greater circulating glucose, and fewer circulating eosinophils. The CONV calves had haptoglobin (Hp) responses to the stressors of both Wi and Wc and had more IFN-γ from whole blood stimulated with phytohemagglutinin-P. The MAX calves had the least active neutrophils (phagocytosis and oxidative burst), but MOD calves' leukocytes secreted the most TNF-α from whole blood stimulated with lipopolysaccharide. Just before and after weaning, MAX calves spent more time per day in the standing position than CONV and MOD calves and had an Hp response to Wc, but MOD calves did not have an Hp response to Wi or Wc. Based on these results, MOD calves were the most ready for weaning; therefore, they potentially can be moved to group housing at an earlier age than CONV calves, thus improving animal welfare concerns over space allowance and individual housing., (Copyright © 2019 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.)

Water is an essential nutrient, but the effect it has on performance generally receives little attention. There are few systems and guidelines for collection of water intake (WI) phenotypes in beef cattle, which makes large-scale research on WI a challenge. The Beef Improvement Federation has established guidelines for feed intake (FI) and ADG tests, but no guidelines exist for WI. The goal of this study was to determine the test duration necessary for collection of accurate WI phenotypes. To facilitate this goal, individual daily WI and FI records were collected on 578 crossbred steers for a total of 70 d using an Insentec system at the Oklahoma State University Willard Sparks Beef Research Unit. Steers were fed in five groups and were individually weighed every 14 d. Within each group, steers were blocked by BW (low and high) and randomly assigned to one of four pens containing approximately 30 steers per pen. Each pen provided 103.0 m2 of shade and included an Insentec system containing six feed bunks and one water bunk. Steers were fed a constant diet across groups and DMI was calculated using the average of weekly percent DM within group. Average FI and WI for each animal were computed for increasingly large test durations (7, 14, 21, 28, 35, 42, 49, 56, 63, and 70 d), and ADG was calculated using a regression formed from BW taken every 14 d (0, 14, 28, 42, 56, and 70 d). Intervals for all traits were computed starting from both the beginning (day 0) and the end of the testing period (day 70). Pearson and Spearman correlations were computed for phenotypes from each shortened test period and for the full 70-d test. Minimum test duration was determined when the Pearson correlations were greater than 0.95 for each trait. Our results indicated that minimum test duration for WI, DMI, and ADG were 35, 42, and 70 d, respectively. No comparable studies exist for WI; however, our results for FI and ADG are consistent with those in the literature. Although further testing in other populations of cattle and areas of the country should take place, our results suggest that WI phenotypes can be collected concurrently with DMI, without extending test duration, even if following procedures for decoupled intake and gain tests.