Case life of seven retail products from beef cattle supplemented with alpha-tocopheryl acetate.

Packages (n = 660) of clod, strip loin, tenderloin, bottom round, eye-of-round, and top round steaks, as well as ground beef, from beef cattle fed diets supplemented with vitamin E (500 IU/d for 100 d preharvest) were compared with packages of products derived from carcasses of beef cattle fed control diets to determine the duration of acceptable muscle color during simulated retail display. In addition, the effect of storage before steak fabrication, simulating distribution time, on the acceptability of each treatment and each cut during retail display was investigated. Dietary supplementation of animals with vitamin E increased muscle alpha-tocopherol concentrations (P < .05) in all cuts. The acceptable retail display time of ground beef from vitamin E-supplemented cattle was longer (P < .05) compared to ground beef from unsupplemented cattle by 10.2, 15.6, and 17.6 h following 7, 14, and 21 d of storage in chub packages prior to final grinding and retail display, respectively. However, length of storage in a vacuum package before retail display did not have a consistent effect on retail case life of steaks. Product drip loss during retail display was not affected by storage time or vitamin E treatment. The trained panel color score during retail display of high vitamin E strip loin, bottom round, inside round, and eye-of-round steaks remained acceptable longer (P < .05) by 11.5, 25.2, 8.4, and 29.4 h, respectively, than that of control steaks. The results demonstrated that vitamin E supplementation of cattle feed can be used as a management tool to reduce the economic losses associated with beef muscle color deterioration during retail display of products.     

Role of the Food and Drug Administration concerning chemical contaminants in animal feeds.

Chemical contamination of animal feeds and feed ingredients is of concern to the Food and Drug Administration. Contamination by industrial chemicals such as polychlorinated biphenyls and polybrominated biphenyls; heavy metals such as lead, cadmium, and mercury; and pesticides such as dieldrin and chlordane exemplify the problem in feeds and the resulting problem of tissue residues in human foods.     

Bioavailability of vitamin A sources for cattle

An experiment was conducted to evaluate the bioavailability of 5 sources of vitamin A. It was hypothesized that some vitamin A products have protective coatings that are more resistant than others to rumen destruction and that such protection would result in greater tissue concentrations of vitamin A. Fifty-three yearling Angus x Brahman cattle, consisting of 39 steers and 14 heifers, were stratified by BW and sex and randomly assigned to 6 high-concentrate diet groups receiving no vitamin A supplementation (control) or vitamin A supplemented from the following sources: Microvit A (Adisseo, Acworth, GA), Rovamix A (DSM, Parsippany, NJ), Sunvit A, Lutavit A, and Microvit A DLC (Adisseo). The vitamin A treatment groups were fed daily 80,000 IU of retinol/animal in a low-retinol concentrate diet (78.5% oats, 10% cottonseed hulls, 8% molasses, and 2% cottonseed meal; DM basis) and a free-choice, poor quality (low carotene) hay for 84 d. Every 28 d, BW was determined and liver biopsies and plasma were collected and analyzed for retinol concentrations. All retinol treatments showed significant increases in liver retinol concentrations compared with control animals (P < 0.0001), which steadily decreased over time. At all collection times, Microvit A led to numerically, but not significantly, greater concentrations of retinol in liver than did all other treatments. However, at the end of the experiment, there was no significant difference in liver retinol concentration among Microvit A, Rovamix A, Lutavit A, and Microvit A DLC diets. When liver retinol concentrations at all collection times were considered, Microvit A and Rovamix A appeared to provide the most bioavailable vitamin A.     

Prevalence and Characteristics of Salmonella in the Beef Chain in the Republic of Ireland

The study investigated the prevalence, concentration and characteristics of Salmonella spp. in the Irish beef chain. A total of 900 samples including bovine hides, carcasses and ground beef were examined for the pathogen over a 2‐year study (July 2007–June 2009). Salmonella prevalence was low in all sample types; bovine hide (0.75%, 3 of 400); carcasses (0.25%, 1 of 400); and ground beef (3%, 3 of 100). All positive samples contained the pathogen in low concentrations (<10 CFU per cm² or per g). Serovars recovered were S. Dublin from hide and carcasses and S. Braenderup in ground beef. All isolates were susceptible to 13 anti‐microbials. The study highlights that Salmonella can be found at low levels at all stages of beef chain production, processing and retail and that there is a need for multiple hurdle interventions and practices along the beef chain, which will reduce consumer exposure to this pathogen.     

Vesicular stomatitis virus (New Jersey strain) infection in two California dairy herds: an epidemiologic study

The course of vesicular stomatitis in cattle was investigated in 2 dairy herds (A and B) located in the southern San Joaquin Valley of California. Cattle were examined and specimens were obtained for virus isolation and for serologic survey for one year after an epizootic in December 1982. All 33 lactating cows selected for study had oral lesions, but only 19 (58%) were drooling or frothing around the mouth. Lesions on feet and teats were not observed. The healing time (longer than has been reported previously) for oral lesions ranged from 34 to 59 days. The mean serum neutralizing antibody titer for all cows tested in both herds 21 days after clinical signs were first observed was greater than 1:512. The mean titer decreased in the first 11 months after the epizootic, but remained greater than 1:128, and then increased during December 1983. Vesicular stomatitis virus/New Jersey strain was not isolated from 239 blood samples, 235 swab specimens of oral cavities, 38 swab specimens of oral epithelium, 206 urine specimens, or 232 fecal specimens collected from cows; however, it was isolated from tongue epithelium of 3 cows at 1, 4, and 21 days after signs of frothing were first noticed. For 20 lactating cows brought into dairy A during the epizootic, a mean time of 8.9 days elapsed between time of entry and appearance of clinical signs of vesicular stomatitis.(ABSTRACT TRUNCATED AT 250 WORDS)     

Analysis of the risk of introduction and spread of porcine reproductive and respiratory syndrome virus through importation of raw pigmeat into New Zealand

AIMS: To determine the frequency with which porcine reproductive and respiratory syndrome (PRRS) virus (PRRSv) would become established in a non-commercial pig herd in New Zealand due to illegal feeding of uncooked food waste containing virus-contaminated pigmeat. To determine the likelihood of a single incursion resulting in a multi-farm outbreak of the disease, and describe the spatio-temporal characteristics of such an outbreak.

METHODS: A Monte Carlo simulation model was constructed to determine the expected annual frequency of PRRSv infection being initiated in a non-commercial pig herd as a result of inadvertent feeding of pigmeat imported from countries endemically infected with the disease. Once the likelihood of PRRSv becoming established in a single pig herd was determined, stochastic spatially explicit infectious disease modelling software was utilised to model the temporal and spatial characteristics of the resulting epidemic.

RESULTS: Assuming the proportion of imported pigmeat remained at current levels, consumption patterns of pigmeat in households in New Zealand remained steady, and limited compliance with recently reintroduced regulations to prevent feeding of uncooked food waste, at least 4.3 pig herds per year were predicted to become infected with PRRSv. Simulation modelling of PRRSv epidemics related to initial infection of a non-commercial farm produced an estimate that 36% of these incursions would spread from the initial herd, and that these outbreaks would involve 93 herds on average in the first year. By increasing the estimated persistence of PRRSv infection in small herds, an average of 205 herds became infected in the first year.

CONCLUSIONS: Given a mean of 4.3 infected premises per year and a 36% probability of infection spreading beyond the initial infected herd, there was a 95% likelihood of a multi-farm PRRS outbreak occurring within 3 years.

CLINICAL RELEVANCE: Introduction of PRRSv through importation of virus-contaminated pigmeat presents a high risk for establishment of the disease in the pig industry in New Zealand.     

Cover Image,Volume 15, Issue 3

The cover image, by M. E. Gray et al., is based on the Original Article Dual targeting of EGFR and ERBB2 pathways produces a synergistic effect on cancer cell proliferation and migration in vitro, DOI: 10.1111/vco.12230 .

     

Passive immunisation of neonatal lambs via colostrum and milk of ewes previously immunised with live attenuated Salmonella typhimurium protects neonatal lambs from experimental salmonellosis

Lambs sucking non-immunised ewes or ewes immunised 4-5 weeks before lambing with live attenuated, aromatic-dependent (aroA) Salmonella typhimurium (strain CS 332) were challenged orally at either 2, 4 or 7 days of age with virulent S. typhimurium (strain CS 94) at doses ranging from 10⁹ to 10¹³ colony forming units. No lambs displayed signs of clinical salmonellosis and all survived challenge but those sucking immunised ewes had organisms of the challenge strain in their faeces for much shorter periods of time than lambs of the control ewes. High titres of specific antibodies were measured in colostrum and milk of immunised ewes in comparison with very low titres measured in samples from control ewes; these differences were reflected by the titres of antibodies in the sera of corresponding lambs. At 2 days after lambing, the major antibody isotype in the colostrum of immunised ewes and sera of their lambs was IgM whereas at 7 days IgG1 was the predominant isotype. While it was clear that vaccination of pregnant ewes with the live attenuated vaccination conferred protection against experimentally-induced salmonellosis in their lambs, considerable protection was observed in control lambs in spite of there being very low titres of antibodies in the mammary secretion of their dams. The latter observation could be related to the presence of contain non-antibody potent bactericidal factors previously described in colostrum and milk.

Résumé

Des agneaux qui tètent des brebis non immunisées, ou bien immunisées, 4 à 5 semaines avant la mise bas avec un vaccin atténué constitué d'une souche de Salmonelle typhimurium dépendente pour sa croissance de la presence de composés aromatiques (souche aro A CS 332) ont reçu, à l'âge de 2, 4 ou 7 jours, par voie orale, des doses allant de 10⁹ à 10¹³ Salmonella (souche virulente CS 94). Aucun agneau n'a présenté de signes cliniques et tous ont survécu à cette administration, mais les agneaux des brebis immunisées ont excrété la souche d'épreuve dans leur fécès pendent moins longtemps que les agneaux des brebis non vaccinées. Des titres plus élevés d'anticorps sont détectés dans le colostrum et le lait des brebis vaccinées et comparés aux brebis témoins. Cette différence est également notée pour les titres d'anticorps présents dans le sérum des agneaux issus de brebis vaccinées ou non. Deux jours après la mise bas, la classe des anticorps majoritaires, tant au niveau du colostrum des brebis vaccinées que du sérum de leurs agneaux, est la classe des IgM, alors qu'après 7 jours, les IgG1 prédominent. Bien qu'il soit clair que des brebis pleines vaccinées à l'aide d'un vaccin vivant atténué, apportent à leurs agneaux une protection vis à vis d'une Salmonella expérimentale, une réelle protection est également observée chez les agneaux témoins, malgré les titres faibles d'anticorps présente dans les sécrétions mammaires de leur mères. Cette dernière observation peut être mise en rapport avec la présence d'agents bactériodes ne contenant pas d'anticorps, déjà décrits dans le colostrum et le lait.