Effects of axial and ceiling fans on environmental conditions, performance and rumination in beef cattle during the early fattening period

An analysis of the influence of preslaughter management factors on welfare and meat quality outcomes in fed beef cattle in the United States

During the preslaughter phase, cattle are transported from their place of origin to a slaughter facility, experiencing transportation, lairage, environmental factors, and novel environments. Although research exists that has focused how the preslaughter phase impacts cattle welfare and meat quality, some significant preslaughter management factors and subsequent welfare and meat quality outcomes have not been thoroughly explored. The objective of this study was to assess the effects of preslaughter management factors on welfare and meat quality outcomes in fed beef cattle in the United States. Transportation factors, environmental characteristics, lairage factors, cattle characteristics, and several meat quality variables were collected from 5 federally inspected commercial processing facilities in the United States. After excluding slaughter lots that included <75% complete datasets, a total of 619 slaughter lots representing 84,508 head of cattle were used for further analysis. Predictor variables of interest included processing plant, cattle breed, sex class, operation shift at the plant, distance traveled to the plant, truck waiting time to unload at the plant, lairage duration and space allowance, temperature humidity index, and windspeed. Outcome variables of interest included cattle mobility, carcass bruising, dark cutting (DC), quality grades, and hot carcass weights. Logistic and linear regressions were used to analyze the associations between the predictor and outcome variables of interest. Increased distance traveled and truck waiting time were associated with higher odds of mobility impairment (P = 0.0009 and P = 0.007, respectively), with each 10 km increase in distance traveled having an odds ratio (OR) of 1.001 (95% confidence interval [CI]: 1.000 to 1.001) and each 1-min increase in waiting time having an OR of 1.003 (CI: 1.001 to 1.004). Conversely, a 10-km increase in distance traveled decreased the odds of carcass bruising (OR: 0.997, CI: 0.996 to 0.998; P < 0.0001). Longer lairage was associated with increased odds of DC (P = 0.0415), with each 60-min increase in duration having an OR of 1.034 (CI: 1.001 to 1.068). The results demonstrate the importance of truck arrival management (i.e., scheduling, prioritizing unloading) on mobility. Focusing on lairage management (i.e., density and time) may provide some opportunities to improve meat quality.

Influence of Ageing Time and Method on Beef Quality and Safety

The effectiveness of dry ageing with regard to retaining meat quality is still subject to debate. At 4 d post mortem, samples of boneless strip loins were excised from young Charolais carcasses and then stored for a further 26 d in a cooler, either vacuum-packaged (VP) or dried-aged (DA). Loin samples were also dissected 7 d post mortem as a control treatment (CT). Chemical, instrumental and microbiological data (n = 18) were determined in longissimus dorsi and underwent ANOVA to estimate the differences in the ageing fixed factor split into two orthogonal contrasts: control vs. aged and VP vs. DA. Ageing loss (both surface dehydration and water purge) was greater in DA compared to VP samples, resulting in the lowest moisture content and highest crude protein and fat percentage in DA loins. The ageing method did not affect meat surface colour, except for redness, which had the lowest value in DA samples. Meat tenderness improved a similar amount following both VP and DA ageing treatments. Compared to the control, prolonged ageing raised both the peroxide value and the total microbial count, especially in DA samples, though both remained within the recommended limits. In summation, both ageing methods improved beef meat tenderisation, preserving its shelf life.

Uncovering Patterns in Dairy Cow Behaviour: A Deep Learning Approach with Tri-Axial Accelerometer Data

The accurate detection of behavioural changes represents a promising method of detecting the early onset of disease in dairy cows. This study assessed the performance of deep learning (DL) in classifying dairy cows' behaviour from accelerometry data acquired by single sensors on the cows' left flanks and compared the results with those obtained through classical machine learning (ML) from the same raw data. Twelve cows with a tri-axial accelerometer were observed for 136 ± 29 min each to detect five main behaviours: standing still, moving, feeding, ruminating and resting. For each 8 s time interval, 15 metrics were calculated, obtaining a dataset of 211,720 observation units and 15 columns. The entire dataset was randomly split into training (80%) and testing (20%) datasets. The DL accuracy, precision and sensitivity/recall were calculated and compared with the performance of classical ML models. The best predictive model was an 8-layer convolutional neural network (CNN) with an overall accuracy and F1 score equal to 0.96. The precision, sensitivity/recall and F1 score of single behaviours had the following ranges: 0.93-0.99. The CNN outperformed all the classical ML algorithms. The CNN used to monitor the cows' conditions showed an overall high performance in successfully predicting multiple behaviours using a single accelerometer.

Insights into molecular pathways and fatty acid membrane composition during the temperature stress response in the murine C2C12 cell model

Daily and seasonal temperature fluctuations are inevitable due to climate change, which highlights the importance of studying the detrimental effects of temperature fluctuations on the health, productivity, and product quality of farm animals. Muscle membrane composition and the molecular signals are vital for muscle cell differentiation and muscle growth, but their response to temperature stress is not well characterized. Temperature changes can lead to modification of membrane components of the cell, which may affect its surroundings and intracellular signaling pathways. Using C2C12 myoblast cells as a model of skeletal muscle development, this study was designed to investigate the effects of high temperature (39 °C and 41 °C) and low temperature (35 °C) on molecular pathways in the cells as well as the cell membrane fatty acid composition. Our results show that several genes were differentially expressed in C2C12 cells cultured under heat or cold stress, and these genes were enriched important KEGG pathways including PI3K-Akt signaling pathway, lysosome and HIF- signaling pathway, Wnt signaling pathway and AMPK signaling pathway. Our analysis further reveals that several membrane transporters and genes involved in lipid metabolism and fatty acid elongation were also differentially expressed in C2C12 cells cultured under high or low temperature. Additionally, temperature stress shifts the fatty acid composition in the cell membranes, including the proportion of saturated, monounsaturated and polyunsaturated fatty acids. This study revealed an interference between fatty acid composition in the membranes and changing molecular pathways including lipid metabolism and fatty acids elongation mediated under thermal stress. These findings will reinforce a better understanding of the adaptive mechanisms in skeletal muscle under temperature stress.

Characterizing heat mitigation strategies utilized by beef processors in the United States

During lairage at slaughter plants, cattle can be exposed to extreme heat conditions from pen densities and holding pen microclimates. While research outlining heat mitigation strategies used in other sectors of the beef supply chain is available, there is no published data on the use of heat mitigation strategies at slaughter plants. The objective of this study was to characterize short-term heat mitigation strategies used by commercial beef slaughter plants in the United States. Twenty-one beef slaughter plants, representing an estimated 60% of beef slaughter in the United States, were included in the study. All plants indicated use of at least one heat mitigation strategy, and five of them used more than one type. Sprinklers/misters were the most commonly used heat mitigation type (n = 17, 81%), and fans were the least common type (n = 4, 19%). Shade usage was present in several plants (n = 7, 33%), ranging from barn style roofs to shade cloths. Respondents indicated that they believed heat mitigation strategies provide benefits both to cattle well-being and meat quality outcomes. Future research should focus on the effectiveness of these techniques in improving animal well-being and quality outcomes in the slaughter plant environment and protocols for optimum implementation.

Machine Learning to Detect Posture and Behavior in Dairy Cows: Information from an Accelerometer on the Animal's Left Flank

Simple Summary

This study analyzed the possibility of automatically detecting dairy cow behavior by combining the use of a single triaxial accelerometer applied to the animal’s left flank with a machine learning technique. This combination enabled the detection of posture and the main types of behavior that are extremely useful in evaluating the animal’s welfare and health such as resting, feeding, and rumination with a high degree of accuracy. The novelty of the study was the success in reaching a high accuracy in detecting five different behaviors and the animal posture by using a single sensor and allowing farmers to save money. To the best of our knowledge, this is the first study that has successfully explored the feasibility of locating a sensor on the animal’s left flank, showing the opportunity of automatically measuring some physiological parameters, such as those ones related to respiration and rumen health, in a non-invasive way.

Abstract

The aim of the present study was to develop a model to identify posture and behavior from data collected by a triaxial accelerometer located on the left flank of dairy cows and evaluate its accuracy and precision. Twelve Italian Red-and-White lactating cows were equipped with an accelerometer and observed on average for 136 ± 29 min per cow by two trained operators as a reference. The acceleration data were grouped in time windows of 8 s overlapping by 33.0%, for a total of 35,133 rows. For each row, 32 different features were extracted and used by machine learning algorithms for the classification of posture and behavior. To build up a predictive model, the dataset was split in training and testing datasets, characterized by 75.0 and 25.0% of the observations, respectively. Four algorithms were tested: Random Forest, K Nearest Neighbors, Extreme Boosting Algorithm (XGB), and Support Vector Machine. The XGB model showed the best accuracy (0.99) and Cohen’s kappa (0.99) in predicting posture, whereas the Random Forest model had the highest overall accuracy in predicting behaviors (0.76), showing a balanced accuracy from 0.96 for resting to 0.77 for moving. Overall, very accurate detection of the posture and resting behavior were achieved.

Environmental stress and livestock productivity in hot-humid tropics: Alleviation and future perspectives

Tropical environments are characterized by persistently high temperature and relative humidity and the harsh environmental conditions pose a serious limitation on the optimal performance of the animals raised in this region. Heat stress causes deleterious effects on welfare, immunology and physiology of farm animals with a resultant impact on their productivity as the use of body resources is re-organized and the metabolic priorities of animals shift away from production, growth, health and reproduction. It is imperative to understand the mechanisms involved in the thermoregulation of animals under tropical conditions in order to develop appropriate strategies for their improvement. This review focuses on the available data on the increasing global temperature and the adverse impact of tropical conditions on animals' adaptive mechanism affected during thermal stress on production performance, intestinal and ileal microbiome, physiological responses, antioxidant system, metabolic responses, cellular and molecular response, adaptive mechanism strategies to heat stress and also strategies to palliate environmental stress on livestock under humid tropical conditions including environmental manipulation, genetic opportunity, epigenetic and feeding modification. Overall, the present review has identified the disturbance in the physiological indices of tropical livestock and the need for concerted efforts in ameliorating the adverse impacts of high ambient temperature aggravated by high humidity on livestock in tropical environments. Further research is needed on genotype-by-environment interaction on the thermotolerance of different livestock species in the tropics.

Puerarin improved growth performance and postmortem meat quality by regulating lipid metabolism of cattle under hot environment

This study aims to evaluate the effect of puerarin on performance, meat quality, and serum indexes of beef cattle under hot environment. Thirty-two bulls were divided into four groups and fed diet supplemented with puerarin at 0, 200, 400, or 800 mg/kg. Results showed that heat stress was employed for 54 out of 60 days, 400 mg/kg group declined serum cortisol (COR) contents, all treatments increased the contents of total cholesterol, high density lipoprotein cholesterol, and total superoxide dismutase activity; in addition, glutathione peroxidase activity of 200 mg/kg group were enhanced, only 800 mg/kg group enhanced immunoglobulin (IgA, IgM, and IgG) and low density lipoprotein cholesterol contents compared with the control (p < .05). Moreover, 400-mg/kg puerarin increased serum growth hormone levels compared with 200 mg/kg group but declined COR concentrations compared with 200 mg/kg and 800 mg/kg groups (p < .05). More importantly, average daily gain and daily matter intake, and intramuscular fat contents of 400 mg/kg group were enhanced, but the shear force of beef in 400 mg/kg and 800 mg/kg groups were declined compared with the control (p < .05). These findings indicated that supplemental with puerarin enhanced immune and antioxidant, and 400 mg/kg of puerarin improved performance and meat quality by normalizing levels of stress hormones and increasing intramuscular fat deposition of beef cattle under hot environment.

Effects of Airspeed on the Respiratory Rate, Rectal Temperature, and Immunity Parameters of Dairy Calves Housed Individually in an Axial-Fan-Ventilated Barn

At many modern dairy farms, calves raised in barns are kept in individual stalls separated by solid partitions, which act as barriers. Ventilation fans blowing air perpendicular to these stalls only provide the optimal airflow to the first few calves, while those further away receive a slower airflow. To ascertain whatever effects different airflow speeds may have on the health of animals kept in stalls located at increasing distances from ventilation fans, we divided a select group of 43 Holstein dairy calves into six subgroups based on age, and each subgroup was subjected to either a specified high-speed or low-speed airflow as follows: (1) Six 3-day-olds received high-speed airflow (D3-HA); (2) Six 3-day-olds received low-speed airflow (D3-LA); (3) Eight 19 (±3)-day-olds received high-speed airflow (D19-HA); (4) Eight 19 (± 3)-day-olds received low-speed airflow (D19-LA); (5) Eight 29 (±3)-day-olds received high-speed airflow (D29-HA); and (6) Seven 29 (±3)-day-olds received medium-speed airflow (D29-MA). These trials show that the rectal temperatures and respiratory rates of D19-LA (39.37 °C; 72.90 breaths/min) were significantly higher than those of D19-HA (39.14 °C; 61.57 breaths/min) (p ≤ 0.05), and those of D29-MA (39.40 °C; 75.52 breaths/min) were significantly higher than those of D29-HA (39.20 °C; 68.41 breaths/min) (p ≤ 0.05). At 33 (±3) days of age, those calves receiving high-speed airflow (p ≤ 0.05) registered significantly higher immunoglobulins A and M than calves receiving low-speed flow. Those calves subjected to a high-speed airflow also registered significantly lower tumor necrosis factor levels than those receiving low-speed flow (p ≤ 0.05). Among the 29 to 43-day-old calves, no significant differences in immunity parameters were found to exist between groups D29-HA and D29-MA. On the basis of these findings, we were able to conclude that in the warm season, when the calves were less than 0.5 months old, low-speed (0.17-0.18 m/s) airflows had no significant effect on calves; when the calves were 1 month old, low-speed airflow (0.20-0.21 m/s) may impair the immune functions; when the calves were 1 to 1.5 months old, the airflow velocity higher than 0.9 m/s can meet the needs of the calf without a negative impact on the calf.

Heat stress in dairy animals and current milk production trends, economics, and future perspectives: the global scenario

Animal's well-being, growth, and production are modulated by environmental conditions, and managemental practices and can be deleteriously affected by global warming phenomenon. In the recent years, unprecedented climatic fluctuations like sustained higher temperatures and humidity, heat waves, and solar flares have led to economic losses in $ billions to both milk and meat industry. It is estimated that by 2050, the US dairy industry alone will borne more than $1.7 billion loss. As human dependency on animal products like milk, meat, and eggs for nutrition is exponentially rising, there is urgency for maximum production. The high yielding animals are already under tremendous metabolic pressure making them more susceptible to adverse climatic conditions. When exposed to heat stress, livestock display a variety of behavioral and physiological acclimatization as essential survival strategies, but at the cost of decreased milk, meat, or egg production. Most of the studies have explored the heat stress in animals and its effect on different milk productions in a specific region or country. A clear understanding of the impact of global warming on dairy enterprise is yet to be comprehended. So this exploratory study will analyze impact of global warming on current milk production trends, economics, and future perspectives.

Relationship between thermal environment and morphophysiological, performance and carcass traits of Brahman bulls raised on tropical pasture: A canonical approach to a set of indicators

The purpose of this study was to understand and discuss the relationships of the thermal environment, morphophysiological response, performance, and carcass traits of Brahman bulls from weaning at 18 months exposed to grazing conditions based on the physiological and evolutionary rationale behind the different proposals for the thermal adaptation of zebu cattle. Fifty-three uncastrated and clinically healthy bulls with birth and weaning weight of 34.0 ± 3.32 kg and 215.5 ± 44.75 kg, respectively, were evaluated. Fifteen canonical correlations were estimated, but only six were significant: thermal environment × thermoregulatory responses (r_c = 0.4635; P = 0.0413); thermal environment × performance (r_c = 0.4338; P = 0.0218); thermoregulatory responses × performance (r_c = 0.5119; P = 0.0071); hair coat characteristics × performance (r_c = 0.4939; P = 0.0273); hormone × carcass traits (r_c = 0.5408; P = 0.0698); and performance × carcass traits (r_c = 0.9644; P < 0.0001). Thermal environment, thermoregulatory responses and hair coat morphology influence of 18.81%, 21.49% and 24.40%, respectively, were found in the performance. We also concluded that (i) rectal temperature (R_T) is a homoeothermic indicator; (ii) sweating rate (S_R) is an important heat dissipation mechanism to explain the adaptation of zebu animals in the tropics and is related to weight at 550 days (W₅₅₀); (iii) coat morphology, especially length (H_L), diameter (H_D) and hair density (N_D) are related to animal performance; and (iv) hormonal profile, mainly T₄, influences the carcass traits (yield, weight, subcutaneous fat and marble meat).

Effectiveness of Stocking Density Reduction on Mitigating Lameness in a Charolais Finishing Beef Cattle Farm

Simple Summary

In finishing beef cattle farms, the limited space allowance and the fully slatted floor system could negatively affect animals’ performance, health and welfare. A larger individual space was provided as a strategy to mitigate lameness problems in a commercial farm. A larger space allowance may contain the spread of pathogens, leading to a reduction in the incidence of lameness and infectious diseases, and may decrease the risk of animals stepping into each other causing claw and leg injuries. Increasing the space allowance did not affect animal performance, whereas it had a positive implication through a significant reduction in the number of treatments of lame and sick animals.

Abstract

This study aimed at assessing whether a reduction in stocking density (SKD) would mitigate lameness and positively affect the performance and health of Charolais bulls in an Italian commercial farm. Bulls were distributed in groups of 10 or 8 animals/pen for high (HD) or low density (LD) corresponding to an individual space of 3.5 or 4.7 m², respectively. Bulls were fitted with collars that measured rumination time and activity. Three 8-h observational sessions were conducted to record behaviors. Data about health conditions were collected daily. No differences were found in the animals’ performance. However, performance results might have been impaired by the culling rate experienced during the trial, which prevented from keeping a consistent SKD. Behaviors did not differ between groups, except for rumination time, which was higher for LD bulls during the third observation (p < 0.05). However, rumination time, recorded by collars, did not vary among treatments. There were no differences in the percentage of sick or lame bulls, but the percentage of animals treated repeatedly due to relapse was higher for the HD group (p < 0.05). It was concluded that a larger space allowance could improve the health of bulls kept on fully slatted floors.

The Effects of Decreasing Dietary Crude Protein on the Growth Performance, Feed Efficiency and Meat Quality of Finishing Charolais Bulls

This study aimed to evaluate the effect of decreasing dietary crude protein (CP) on the performance of finishing Charolais bulls in the Italian rearing system. Animals were fed two diets, differing only in the CP level (low protein (LP), 13.5% CP versus control (CON), 15.0% CP). Dry matter (DM) intake (DMI) and animals' weights were recorded to obtain average daily gain (ADG) and feed conversion rate (FCR). Feed and fecal samples were collected to evaluate digestibility of diet components. Daily cost of the ration (DRC), feed cost per kg of daily weight gain (CDG) and daily gross margin (DGM) were calculated to analyze the possible benefits of decreasing the protein level. Meat quality analyses were also conducted. Higher DMI (10.6 versus 10 kg/d; p < 0.05) and ADG (1.47 versus 1.36 kg/d; p < 0.05) were observed for CON. No differences in FCR or digestibility were found. Even if the DRC was lower (p < 0.05) for the LP diet (2.26 versus 1.97 €; CON versus LP), no difference was reported for CDG and DGM. Meat lightness and redness were significantly lower and higher in the LP, respectively. To conclude, the CP requirement in these rearing conditions appeared to be higher than 13.5%.