Assessment of Rumen Mucosa, Lung, and Liver Lesions at Slaughter as Benchmarking Tool for the Improvement of Finishing Beef Cattle Health and Welfare

Bioactive metabolites of Asparagopsis stabilized in canola oil completely suppress methane emissions in beef cattle fed a feedlot diet

Asparagopsis taxiformis (Asparagopsis) has been shown to be highly efficacious at inhibiting the production of methane (CH4) in ruminants. To date, Asparagopsis has been primarily produced as a dietary supplement by freeze-drying to retain the volatile bioactive compound bromoform (CHBr3) in the product. Steeping of Asparagopsis bioactive compounds into a vegetable oil carrier (Asp-Oil) is an alternative method of stabilizing Asparagopsis as a ruminant feed additive. A dose-response experimental design used 3 Asp-Oil-canola oil blends, low, medium, and high Asp-Oil which provided 17, 34, and 51 mg Asparagopsis derived CHBr3/kg dry matter intake (DMI), respectively (in addition to a zero CHBr3 canola oil control), in a tempered-barley based feedlot finisher diet, fed for 59 d to 20 Angus heifers (five replicates per treatment). On four occasions, live weight was measured and CH4 emissions were quantified in respiration chambers, and blood, rumen fluid, and fecal samples were collected. At the end of the experiment, all animals were slaughtered, with carcasses graded, and samples of meat and edible offal collected for testing of consumer sensory qualities and residues of CHBr3, bromide, and iodide. All Asp-Oil treatments reduced CH4 yield (g CH4/kg DMI, P = 0.008) from control levels, with the low, medium, and high Asp-Oil achieving 64%, 98%, and 99% reduction, respectively. Dissolved hydrogen increased linearly with increasing Asp-Oil inclusion, by more than 17-fold in the high Asp-Oil group (P = 0.017). There was no effect of Asp-Oil treatment on rumen temperature, pH, reduction potential, volatile fatty acid and ammonia production, rumen pathology, and histopathology (P > 0.10). There were no differences in animal production and carcass parameters (P > 0.10). There was no detectable CHBr3 in feces or any carcass samples (P > 0.10), and iodide and bromide residues in kidneys were at levels unlikely to lead to consumers exceeding recommended maximum intakes. Overall, Asp-Oil was found to be safe for animals and consumers of meat, and effective at reducing CH4 emissions and yield by up to 99% within the range of inclusion levels tested.

Estimation of genetic parameters for visceral diseases of fattening Japanese Black cattle in Shimane Prefecture, Japan

In this study, the genetic parameters of major visceral diseases were estimated using the postmortem inspection records of 9057 fattening Japanese Black cattle in Shimane Prefecture, Japan, and the genetic correlation between visceral diseases and carcass traits was analyzed. There were six visceral diseases with a prevalence of 5% or higher, namely, pleurisy, pneumonia, bovine abdominal fat necrosis (BFN), rumenitis, hemorrhagic hepatitis, and perihepatitis. Variance components were estimated using the Gibbs sampling method, and the heritability of the visceral disease ranged from 0.07 to 0.49 for perihepatitis and BFN, respectively. Significant negative genetic correlations were identified between pleurisy and rib thickness (-0.32), BFN and carcass weight (-0.29), and BFN and rib eye area (-0.22). No significant genetic correlation was observed among the visceral diseases. The least squares analysis of variance suggested that some visceral diseases decrease the value of carcass traits. In particular, carcass weight and rib eye area in individuals with BFN were 11.7 kg and 1.87 cm2 lower than those of healthy cattle, respectively. Thus, it was inferred that genetic factors were involved in the visceral diseases of fattening Japanese Black cattle in Shimane Prefecture.

Development and application of a new liver pathology recording system for use in cattle abattoirs

Liver disease in beef cattle has a significant global economic impact on feedlot and abattoir industries due to reduced animal performance, carcase yield, and carcase quality. This study aimed to create a post-mortem data collection tool which could be deployed at chain speed on an abattoir floor, as well as to evaluate pathological findings in both normal and condemned livers from an Australian beef cattle population. The first 1006 livers were used to formulate a user-friendly, high-throughput liver grading tool for use in an abattoir setting and to evaluate the histological features of common liver abnormalities. Subsequently, over 11,000 livers from a Southeast Queensland abattoir were analyzed. The most observed defects in condemned livers were liver abscessation, fibrosis, adhesions, and liver fluke, with histological features similar to previous reports. Bacterial culture was performed in 29 cases of liver abscessation, revealing a different balance of flora to that reported internationally. This study has developed an easy to use, efficient data collection tool that enables rapid, highly detailed assessment of large numbers of beef cattle livers at slaughter. This tool will allow thorough investigation into the effect of liver disease on beef production, in both industry and research contexts.

Data on Gastrointestinal and Claw Disorders as Possible Predictive Factors in Beef Cattle and Veal Calves’ Health and Welfare

Today, consumers have a growing concern about the welfare of beef cattle, and specific schemes have been proposed to assess their wellbeing during the fattening. On-farm assessments can be integrated and partially replaced by animal-based measures recorded postmortem at the abattoir. Postmortem organ inspection data are of value, as several lesions can be reflective of subclinical diseases not easily detected in the live animal. The present data collection aimed to evaluate the slaughterhouse prevalence and location of hoof, gastric, hepatic, and liver lesions in beef cattle and veal calves and retrospectively associated this information with the animals’ housing and feeding management systems. Individual data on gastrointestinal and claw disorders of beef cattle (bulls and heifers) and veal calves were collected through a postmortem inspection by trained veterinarians directly at the slaughter line. Around 15 animals/batch, belonging to 97 batches of young bulls, 56 batches of beef heifers, and 41 batches of veal calves were inspected in three slaughterhouses located in Northern Italy during 30 sampling days, and information on the animals’ rearing systems were gathered a posteriori from farmer interviews. The implementation of this recording system should promote a continuous improvement of beef cattle management from a health and welfare perspective.