Cull Cattle Research Articles

Antimicrobial Resistance at Two U.S. Cull Cow Processing Establishments

Culled beef cows (cows that have reached the end of their productive life span in cow-calf operations) and culled dairy cows represent approximately 18% of the cattle harvested in the United States annually, but data on antimicrobial resistance (AMR) in these cull cattle are extremely limited. To address this data gap, colon contents were obtained from 180 culled conventional beef cows, 179 culled conventional dairy cows, and 176 culled organic dairy cows (produced without using antimicrobials). Sponge samples were also collected from 181 conventional beef, 173 conventional dairy, and 180 organic dairy cow carcasses. These samples were obtained on 6 days (3 days each at two beef harvest and processing establishments). At one establishment, 30 samples of beef manufacturing trimmings from conventional cows and 30 trim samples from organic dairy cows were acquired. All 1,129 samples were cultured for Escherichia coli, tetracycline-resistant (TETr) E. coli, third-generation cephalosporin-resistant (3GCr) E. coli, Salmonella, and 3GCrSalmonella. Metagenomic DNA was isolated from 535 colon content samples, and quantitative PCR assays were performed to assess the abundances of the following 10 antimicrobial resistance genes: aac(6')-Ie-aph(2″)-Ia, aadA1, blaCMY-2, blaCTX-M, blaKPC-2, erm(B), mecA, tet(A), tet(B), and tet(M). For colon contents, only TETrE. coli (P < 0.01), 3GCrE. coli (P < 0.01), and erm(B) (P = 0.03) levels were higher in conventional than in organic cows. Sampling day also significantly affected (P < 0.01) these levels. Production system did not affect the levels of any measured AMR on carcasses or trim. The human health impact of the few significant AMR differences could not be determined due to the lack of standards for normal, background, safe, or basal values. Study results provide key heretofore unavailable data that may inform quantitative microbial risk assessments to address these gaps.

Survey of gross pathologic conditions of cattle presented for slaughter in the southeastern United States

According to the United States Department of Agriculture, cattle slaughtered in 2017 totaled 32.2 million animals and approximately 6.4 million animals were adult cull cattle (USDA 2016; USDA-NASS 2016). This harvest accounts for an estimated 5.4 billion pounds of beef or 20.7% of the 2017, US beef production. In the Southeastern US, the production of beef from cull cattle included 583,300 animals or approximately 90% of the total animals harvested in the region. Establishing the prevalence of diseases within this population is necessary for improving the quality and profitability of this sector of the industry. The objectives of this study were; 1) determine the prevalence of gross pathologic conditions, 2) characterize the type and frequency of conditions eliciting carcass condemnation, and 3) evaluate the extent of carcass bruising in cull cattle presented to slaughter and originating from farms in the southeastern United States.

Hot topic: Management of cull dairy cows—Consensus of an expert consultation in Canada

Many cull dairy cows enter the marketing system and travel to widely dispersed and specialized slaughter plants, and they may experience multiple handling events (e.g., loading, unloading, mixing), change of ownership among dealers, and feed and water deprivation during transport and at livestock markets. The objectives of this study were to describe the diverse management of cull dairy cows in Canada and establish consensus on ways to achieve improvements. A 2-day expert consultation meeting was convened, involving farmers, veterinarians, regulators, and experts in animal transport, livestock auction, and slaughter. The 15 participants, recruited from across Canada, discussed regional management practices for cull cattle, related risk factors, animal welfare problems, and recommendations. An audio recording of the meeting was used to extract descriptive data on cull cattle management and identify points of agreement. Eight consensus points were reached: (1) to assemble information on travel times and delays from farm to slaughter; (2) to increase awareness among producers and herd veterinarians of potential travel distances and delays; (3) to promote pro-active culling; (4) to improve the ability of personnel to assess animal condition before loading; (5) to identify local options for slaughter of cull dairy cows; (6) to investigate different management options such as emergency slaughter and mobile slaughter; (7) to ensure that all farms and auctions have, or can access, personnel trained and equipped for euthanasia; and (8) to promote cooperation among enforcement agencies and wider adoption of beneficial regulatory options.

Salmonella in Peripheral Lymph Nodes of Healthy Cattle at Slaughter.

To more fully characterize the burden of Salmonella enterica in bovine peripheral lymph nodes (PLN), PLN (n = 5,450) were collected from healthy cattle at slaughter in 12 commercial abattoirs that slaughtered feedlot-fattened (FF) cattle exclusively (n = 7), cattle removed (or culled) from breeding herds (n = 3), or both FF and cull cattle (n = 2). Qualitative and quantitative methods were used to estimate prevalence and concentration of Salmonella in PLN. Isolates were subjected to a variety of phenotypic, serological, and molecular assays. Overall, Salmonella prevalence in PLN from FF and cull cattle was 7.1 and 1.8%. However, burden varied by season in that observed prevalence in PLN collected in cooler or warmer seasons was 2.4 and 8.2%, respectively. Prevalence in PLN from cull cattle in the southwest region of the US was 2.1 and 1.1% for cool and warm seasons, respectively; however, prevalence in FF PLN was far greater in that it was 6.5 and 31.1%, respectively. Salmonella was recovered from 289 (5.6%) PLN and 2.9% (n = 160) of all PLN tested had quantifiable concentrations that varied from 1.6 to 4.9 log10 colony forming units/PLN. The most common serotypes isolated from PLN were Montevideo (26.9%), Lille (14.9%), Cerro (13.0%), Anatum (12.8%), and Dublin (6.9%). In all, 376 unique isolates were collected from the 289 Salmonella-positive PLN. Antimicrobial susceptibility testing revealed the majority (80.6%) of these isolates were pansusceptible; however, 10.7% of isolates were found to be resistant to two or more antimicrobial classes. We were able to document an observed increased in prevalence of Salmonella in PLN during the warmer season, particularly in FF cattle from the southwest region of the US. The mechanisms underlying the observed association between season, region, and production source have yet to be elucidated. Nevertheless, these findings increase our understanding of the sources of contamination of beef products and shed light on transmission dynamics that may be useful in targeting these sources.

Liver copper concentrations in cull cattle in the UK: are cattle being copper loaded?

With the release of the Department for the Environment, Food and Rural Affairs/Advisory Committee on Animal Feed Guidance Note for Supplementing Copper to Bovines it was noted that the current...

Cull Cow Beef Quality Issues: Hide Defects, Contamination, and Non-Ambulatory Cattle

Cull cattle are those that are sold from a herd for lack of performance, lack of resources, or genetic improvement. The non-fed beef cattle market (cattle that are not managed through traditional feedlot finishing systems) is comprised primarily of cull cows and bulls. This 3-page article is one of the Cull Cow Beef Quality Issues series, which addresses liability and food safety concerns. It also discusses some quality defects identified in the non-fed beef market, how to prevent them, and how to address them when they appear in cattle. Written by Amie Imler, Matt Hersom, Todd Thrift, Joel Yelich, and Max Irsik, and published by the UF Department of Animal Sciences, December 2014.

Cull Cow Beef Quality Issues: Injection Sites and Abscesses

Cull cattle are those that are sold from a herd for lack of performance, lack of resources, or genetic improvement. The non-fed beef cattle market (cattle that are not managed through traditional feedlot finishing systems) is comprised primarily of cull cows and bulls. This 3-page article is one of the Cull Cow Beef Quality Issues series, which addresses liability and food safety concerns. It also discusses some quality defects identified in the non-fed beef market, how to prevent them, and how to address them when they appear in cattle. Written by Amie Imler, Matt Hersom, Todd Thrift, Joel Yelich, and Max Irsik, and published by the UF Department of Animal Sciences, December 2014.

Cull Cow Beef Quality Issues: Bruising, Condemnation, and Foreign Objects

Cull cattle are those that are sold from a herd for lack of performance, lack of resources, or genetic improvement. The non-fed beef cattle market (cattle that are not managed through traditional feedlot finishing systems) is comprised primarily of cull cows and bulls. This 4-page article is one of the Cull Cow Beef Quality Issues series, which addresses liability and food safety concerns. It also discusses some quality defects identified in the non-fed beef market, how to prevent them, and how to address them when they appear in cattle. Written by Amie Imler, Matt Hersom, Todd Thrift, Joel Yelich, and Max Irsik, and published by the UF Department of Animal Sciences, December 2014.

Cull Cow Beef Quality Issues: Cow Condition and Muscling

Cull cattle are those that are sold from a herd for lack of performance, lack of resources, or genetic improvement. The non-fed beef cattle market (cattle that are not managed through traditional feedlot finishing systems) is comprised primarily of cull cows and bulls. This 3-page article is one of the Cull Cow Beef Quality Issues series, which addresses liability and food safety concerns. It also discusses some quality defects identified in the non-fed beef market, how to prevent them, and how to address them when they appear in cattle. Written by Amie Imler, Matt Hersom, Todd Thrift, Joel Yelich, and Max Irsik, and published by the UF Department of Animal Sciences, December 2014.

Overview of Cull Cow Beef Quality Issues

Cull cattle are those that are sold from a herd for lack of performance, lack of resources, or genetic improvement. The non-fed beef cattle market (cattle that are not managed through traditional feedlot finishing systems) is comprised primarily of cull cows and bulls. This 2-page article is one of the Cull Cow Beef Quality Issues series, which addresses liability and food safety concerns. It also discusses some quality defects identified in the non-fed beef market, how to prevent them, and how to address them when they appear in cattle. Written by Amie Imler, Matt Hersom, Todd Thrift, Joel Yelich, and Max Irsik, and published by the UF Department of Animal Sciences, December 2014.

Cull Cow Beef Quality Issues: Horns, Ocular Squamous Cell Carcinoma, and Lumpy Jaw

Cull cattle are those that are sold from a herd for lack of performance, lack of resources, or genetic improvement. The non-fed beef cattle market (cattle that are not managed through traditional feedlot finishing systems) is comprised primarily of cull cows and bulls. This 3-page article is one of the Cull Cow Beef Quality Issues series, which addresses liability and food safety concerns. It also discusses some quality defects identified in the non-fed beef market, how to prevent them, and how to address them when they appear in cattle. Written by Amie Imler, Matt Hersom, Todd Thrift, Joel Yelich, and Max Irsik, and published by the UF Department of Animal Sciences, December 2014.

Salmonella spp. in lymph nodes of fed and cull cattle: Relative assessment of risk to ground beef

Ground beef products have been implicated as the vehicle for the transmission of Salmonella in a number of outbreaks. Although carcass surface interventions have proven effective, Salmonella contamination in ground beef still occurs. Recent studies indicate that deep tissue lymph nodes (DTLNs) may be an important source of Salmonella contamination in ground beef products. We developed a stochastic simulation model covering the pre-to post-harvest stages to assess the relative contribution of DTLN as compared with carcass surface, to Salmonella in ground beef, and the impact of various pre- and post-harvest interventions. The model addressed fed and cull cattle, and in high and low prevalence seasons. Contamination from carcass surfaces and DTLNs was simulated separately. Linear relationships were used to describe the changes of Salmonella surface concentration and prevalence at different processing stages. The baseline results indicate that on average over 90% of the Salmonella CFU load in a 2000 lb (907 kg) production lot originates from DTLN contamination as compared with carcass surface contamination. The relative contribution of DTLN contamination was fairly robust to changes in model parameters for ground beef from fed cattle, while it was comparatively more sensitive to changes in model parameters for cull cattle. The predicted mean Salmonella CFU load from DTLN contamination was considerably greater in ground beef production lots from fed cattle compared with cull cattle. Correspondingly, our scenario analysis suggested that generic pre-harvest interventions which can reduce Salmonella contamination in DTLNs would cause a greater total CFU load reduction in ground beef production lots from fed cattle compared with cull cattle. The study provides some valuable information for prioritizing control measures targeted at Salmonella contamination from the beef carcass surface or DTLNs based on the current knowledge.

Livestock stewardship

The definition of stewardship from Webster's dictionary is "the careful and responsible management of something entrusted to one's care". As livestock stewards, we have a responsibility to manage and utilize the resource of cull animals. Cattle culled from beef and dairy herds fill an important role in meeting the nutritional needs of consumers. Currently the US population consumes approximately 60 lb (27 .2 kg) of beef per person each year. Of this, nearly 50% is consumed as ground beef, and one of the primary uses of cull cattle is the production of ground beef. Based on cow-calf budgets the estimate of the income contribution of cull cows to the gross returns are approximately 15%. With proper care, feeding, and good marketing, there is opportunity to increase the market value of cull cows through weight gain, and a change in the grading category to meet the high standards of our food production system, and to provide a more acceptable product to our consumers.

Cross-sectional Study ExaminingSalmonella entericaCarriage in Subiliac Lymph Nodes of Cull and Feedlot Cattle at Harvest

Bovine peripheral lymph nodes (LNs), including subiliac LNs, have been identified as a potential source of human exposure to Salmonella enterica, when adipose trim containing these nodes is incorporated into ground beef. In order to gain a better understanding of the burden of S. enterica in peripheral LNs of feedlot and cull cattle, a cross-sectional study was undertaken in which 3327 subiliac LNs were collected from cattle at harvest in seven plants, located in three geographically distinct regions of the United States. Samples were collected in three seasons: Fall 2010, Winter/Spring 2011, and Summer/Fall 2011. A convenience sample of 76 LNs per day, 2 days per season (approximately 1 month apart), was collected per plant, from carcasses held in the cooler for no less than 24 h. Every 10(th) carcass half on a rail was sampled, in an attempt to avoid oversampling any single cohort of cattle. Median point estimates of S. enterica contamination were generally low (1.3%); however, median Salmonella prevalence was found to be greater in subiliac LNs of feedlot cattle (11.8%) compared to those of cull cattle (0.65%). Enumeration analysis of a subset of 618 feedlot cattle LNs showed that 67% of those harboring S. enterica (97 of 144) did so at concentrations ranging from <0.1 to 1.8 log10 CFU/g, while 33% carried a higher burden of S. enterica, with levels ranging from 1.9 to >3.8 log10 CFU/g. Serotyping of S. enterica isolated identified 24 serotypes, with the majority being Montevideo (44.0%) and Anatum (24.8%). Antimicrobial susceptibility phenotypes were determined for all isolates, and the majority (86.1%) were pansusceptible; however, multidrug-resistant isolates (8.3%) were also occasionally observed. As Salmonella contained within LNs are protected from carcass interventions, research is needed to define opportunities for mitigating the risk of Salmonella contamination in LNs of apparently healthy cattle.

Disinfectant and Antibiotic Susceptibility Profiles of Escherichia coli O157:H7 Strains from Cattle Carcasses, Feces, and Hides and Ground Beef from the United States

The disinfectant and antibiotic susceptibility profiles of 344 Escherichia coli O157:H7 strains from cattle carcasses, feces, and hides and ground beef from the United States were determined. A low prevalence of antibiotic resistance was observed (14%). The highest prevalences of resistance were to sulfisoxazole (10.5%), tetracycline (9.9%), streptomycin (7%), and chloramphenicol (4.9%). Four strains were resistant to eight antibiotics (two strains from ground beef and one strain each from hide and preevisceration carcass swabs of cull cattle at harvest). Pulsed-field gel electrophoresis analysis of the E. coli O157:H7 strains revealed two major groups (designated 1 and 2) composed of 17 and 20 clusters, respectively. Clusters 1A, 1B, 1C, and 1G.1 were associated with multidrug-resistant strains. There was no observed correlation between disinfectant resistance and antibiotic resistance. Sixty-nine (20%) of the 344 strains were resistant to chlorhexidine or benzalkonium chloride or the MICs of benzyldimethyldodecylammonium chloride were elevated. Inducible resistance was observed at elevated concentrations of antibiotics (1.4%) and disinfectants (6.1%). The highest rate of disinfectant inducible resistance was to OdoBan, quaternary ammonium chlorides, and the surface disinfectants F25, FS512, and MG, which are used in dairies, restaurants, and food processing plants. High MICs (1,024 to 4,096 m g/ml) of acetic, lactic, and citric acids were found. The decreasing order of acid potency based on molar MICs (MICs(molar)) was acetic, citric, and lactic acid. The correlation of the concentration of dissociated organic acids and MICs(molar) strongly suggests that the observed inhibition of E. coli O157:H7 was primarily due to dissociated forms of the acids.

SmartStretch™ technology VI. The impact of SmartStretch™ technology on the meat quality of hot-boned beef striploin (m. longissimus lumborum)

The impact of SmartStretch™ technology and ageing (0 or 14days ageing) on the meat quality traits of m. longissimus lumborum hot-boned from adult cull cattle was assessed. Tenderness, as reflected in reduced shear force measurement, was significantly (P<0.05) improved in 0day aged stretched samples over the non stretched samples. After 14days ageing there was no longer any difference in the tenderness between stretched and non stretched samples and the aged meat was significantly tenderer than either the SmartStretch™ treated or non stretched meat aged for 0days. Sarcomere length was unchanged by stretching. Presentation traits such as purge loss and fresh colour were unaffected by the stretch treatment, whilst cooking loss was significantly (P<0.05) increased by stretching and ageing for 14days.

Space allowance during commercial long distance transport of cattle in North America1

The objective of the present work was to study space allowance in cattle during commercial long haul transport (≥400 km; n = 6,152 journeys). Surveys, delivered to livestock transport carriers, gathered information on the number, BW, and distribution of cattle by trailer compartment as well as the characteristics of the transport vehicles used. Space allowance (SA; m(2)/animal), allometric coefficient (k = SA / BW(0.6667)), and the percentage of deviation from recommended SA (DRSA; %) in the Canadian Codes of Practice were calculated for each compartment of the trailers. All quad-axle (77%) and tri-axle (23%) cattle trailers were reported with 5 compartments (nose, deck, belly, back, and doghouse). Sixty percent of all animals were carried in the middle compartments (deck and belly), 30% in the rear (back and doghouse), and 10% in the front or nose. Approximately 30% of the journeys required that the cattle be redistributed at the Canada-USA border to comply with different axle weight regulations, and most journeys moved them between the deck and the doghouse. Total loaded weight increased and the number of animals decreased with increasing BW of the animals. space allowance, k-value, and DRSA were least for calves and feeders compared with fat and cull cattle (p < 0.01). Both total loaded weight and number of animals increased with the number of axles in the trailer, being greatest in quad-axle trailers pulled by push tractors, which were most frequently used. Space allowance (k-value) was least in vehicles with greater number of axles and transporting the lightest cattle (i.e., quad-axles trailers transporting calves and feeders). Space allowance, k-value, and variability among journeys were least in the middle compartments (belly and deck), followed by the back, then doghouse and nose compartments of the trailers showing the largest values (p < 0.05). Many factors contributed to the variability in SA such as body size (smaller animals are placed more densely), compartment of the trailer (greater density in belly and deck), and number of axles on the vehicle (greater density with more axles). The present study provides a framework to assess and understand factors affecting SA during commercial long distance transport of cattle. This information is vital in assessing the consequences of changing industry standards, guidelines, recommended values, laws and regulations on animal welfare, the industry, and economics.

Factors affecting body weight loss during commercial long haul transport of cattle in North America1

The objective of the present study was to identify and quantify several factors affecting shrink in cattle during commercial long-haul transport (≥400 km; n = 6,152 journeys). Surveys were designed and delivered to transport carriers to collect relevant information regarding the characteristics of animals, time of loading, origin and destination, and loaded weight before and after transport. In contrast to fat cattle, feeder cattle exhibited greater shrink (4.9 vs. 7.9 ± 0.2% of BW, respectively; P < 0.01), and experienced longer total transport durations (12.4 vs. 14.9 ± 0.99, respectively; P < 0.01) due to border crossing protocols which require mandatory animal inspection. Shrink was greater (P < 0.001) for feeder cattle loaded at ranches/farms and feed yards compared with those loaded at auction markets. Cattle loaded during the afternoon and evening shrank more than those loaded during the night and morning (P < 0.05). Shrinkage was less in cattle transported by truck drivers having 6 or more years of experience hauling livestock compared with those with 5 yr or less (P < 0.05). Shrink increased with both midpoint ambient temperature (% of BW/°C; P < 0.001) and time on truck (% of BW/h; P < 0.001). Temperature and time on truck had a multiplicative effect on each other because shrink increased most rapidly in cattle transported for both longer durations and at higher ambient temperatures (P < 0.001). The rate of shrink over time (% of BW/h) was greatest in cull cattle, intermediate in calves and feeder cattle, and slowest in fat cattle (P < 0.05) but such differences disappeared when the effects of place of origin, loading time, and experience of truck drivers were included in the model. Cull cattle, calves and feeder cattle appear to be more affected by transport compared with fat cattle going to slaughter because of greater shrink. Several factors should be considered when developing guidelines to reduce cattle transport stress and shrink including type of cattle, ambient temperature, transport duration, driving quality, and time and origin of loading.

Relationships between transport conditions and welfare outcomes during commercial long haul transport of cattle in North America1

The objective of the present study was to document the relationships between selected welfare outcomes and transport conditions during commercial long haul transport of cattle (≥400 km; 6,152 journeys; 290,866 animals). Surveys were delivered to transport carriers to collect information related to welfare outcomes including the number of dead, non-ambulatory (downer) and lame animals during each journey. Transport conditions surveyed included the length of time animals spent on truck, ambient temperature, animal density, shrinkage, loading time, cattle origin, season, experience of truck drivers, and vehicle characteristics. Overall 0.012% of assessed animals became lame, 0.022% non-ambulatory and 0.011% died onboard. Calves and cull cattle were more likely to die and become non-ambulatory during the journey, feeders intermediate, and fat cattle appeared to be the most able to cope with the stress of transport (P ≤ 0.01). The likelihood of cattle becoming non-ambulatory, lame, or dead increased sharply after animals spent over 30 h on truck (P < 0.001). The likelihood of animal death increased sharply when the midpoint ambient temperature fell below -15°C (P = 0.01) while the likelihood of becoming non-ambulatory increased when temperatures rose above 30°C (P = 0.03). Animals that lost 10% of their BW during transport had a greater (P < 0.001) likelihood of dying and becoming non-ambulatory or lame. Animals were more likely to die at smaller space allowances (P < 0.05), particularly at allometric coefficients below 0.015 (P = 0.10), which occurred more frequently in the belly and deck compartments of the trailers, and also at high space allowances in the deck (allometric coefficients > 0.035). The proportion of total compromised animals decreased with more years of truck driving experience (P < 0.001). Mortality was greater in cattle loaded at auction markets compared with feed yards and ranches (P < 0.01). Cull cattle, calves and feeders appear to be more affected by transport based on the likelihood of becoming non-ambulatory and dying within a journey. Most important welfare concerns during long distance transport include the total journey duration, too low or high space allowances, too high or too low ambient temperature, and the experience of the truck drivers.

Prevalence of Mycobacterium avium subsp. paratuberculosis in ileocecal lymph nodes and on hides and carcasses from cull cows and fed cattle at commercial beef processing plants in the United States.

Clinical associations between Crohn's disease in humans and Mycobacterium avium subsp. paratuberculosis (MAP) have been suggested but not confirmed. Cattle could be sources for MAP, but little information on MAP prevalence with beef has been reported. Samples of ileocecal lymph nodes and swabs of hides and carcasses from 343 animals at cull cattle slaughtering facilities and 243 animals at fed cattle slaughtering facilities across the United States were analyzed for the presence of MAP. Amplification of genetic sequences detected MAP DNA predominantly on hides and in lymph nodes of samples taken at both types of processing facilities. More than 34% of the cattle at cull cow slaughtering facilities had ileocecal lymph nodes that tested positive for MAP DNA. From these same cattle, hide prevalence was more than twofold greater than the prevalence in ileocecal lymph nodes, suggesting that cross-contamination could be occurring during transport and lairage. The prevalence of MAP DNA decreased during processing, and less than 11% of the carcasses tested positive after interventions in the cull cow processing facilities. Using standard double-decontamination and culture techniques, less than 1% of the postintervention carcasses tested positive for viable MAP at cull cow facilities. In samples from the facilities processing only fed cattle, MAP prevalence of 1% or less was detected for ileocecal lymph node, hide, and carcass samples, and viable MAP was not detected. Based on this study, fed cattle carcasses are unlikely sources of MAP, and carcasses at cull cow plants have only a slight risk for transmitting viable MAP, due to current interventions.