Cull Dairy Cows Research Articles

Evaluation of a Postbiotic on Salmonella enterica Prevalence, Serotype Diversity, and Antimicrobial Resistance in the Subiliac Lymph Nodes of Cull Dairy Cattle

This study aimed to determine whether the farm-level use of a Saccharomyces cerevisiae-based postbiotic was associated with Salmonella prevalence and concentration, serotype diversity, and antimicrobial resistance in the subiliac lymph nodes (LN) of cull dairy cows. In collaboration with two commercial processing plants in the Southwestern (SW) and Northeastern (NE) regions of the U.S., cull dairy cattle lots processed in the same week from dairy farms that fed or not the postbiotic were sampled. Up to 20 LN were collected from dairy cattle from each supplier farm at least once every season. Samples were analyzed for Salmonella by culture and quantitative PCR methods, and isolates were subjected to serotype identification and antimicrobial susceptibility testing. Although a numerically lower prevalence was observed, the preharvest administration of the postbiotic was not significantly associated with Salmonella prevalence in cull dairy cattle. However, Salmonella prevalence significantly varied by region; the SW region showed a higher prevalence than the NE region. Whereas dominant Salmonella serotypes included Montevideo, Mbandaka, Muenster, Cerro, Meleagridis, and Anatum, the probability of isolating a dominant serotype did not significantly vary by feed additive status (FAS) or region, but varied by season. Up to 34 isolates (out of 391) exhibited resistance to each antimicrobial, with the highest number of isolates exhibiting resistance to streptomycin and ciprofloxacin; however, this did not significantly vary by FAS, season, or region. The precise reasons for the lack of effectiveness of the postbiotic in reducing Salmonella burden are unknown; however, varied administration durations of the postbiotic due to culling at different lactation cycle stages or during dry periods may have hindered its impact, especially if dairy cows were culled early. Other factors may include dietary components, farm management practices, and external environmental influences.

The Overall Situation of the Livestock and Evaluation of the Quantity of Beef Production in Batna City (Algeria)

Background: This study aims to determine the evolution of beef production during the last five years (2019-2023) in Batna city (Algeria) Methods: For the realization of this work we carried out an investigation at the municipal slaughterhouse of the city. During this investigation, we also took slaughter data. These include the weight of the carcasses and the classification of the slaughterhouse according to the categories of animals slaughtered. Moreover, a study was conducted to gather data from the Directorate of Agricultural Services (DSA) and the Ministry of Agriculture and Rural Development (MADR) regarding the number of cow herds in the studied city. The goal of this strategy is to comprehend the general state of the city’s livestock, including those destined for fattening and slaughter. Result: The animals intended for slaughter are mainly male cattle; of the young bulls and calves, the females admitted are cull dairy cows ( greater than 8 years). The results of this investigation showed that the beef production has experienced a remarkable drop from 1262560 kg in 2019 to 473430 kg in 2022, a slight change observed in 2023 but which still remains weak.

Metabolites and physical scores as possible predictors for postpartum culling in dairy cows

The purpose of the study was to explore the associations of serum non-esterified fatty acids (NEFA) and β-hydroxybutyrate (BHBA) concentrations with the body condition score (BCS) and rumen fill score (RFS) in order to predict the risk of postpartum culling, and to further investigate effective monitoring stages during the dry period. From October 2012 to March 2014, clinically healthy Holstein heifers and cows were sampled once before calving, and the occurrence of culling within 60 days in milk (DIM) was investigated. The discriminatory ability of each parameter was evaluated using receiver operating characteristic (ROC) analysis. Of the 720 cows sampled between 14 and 2 days before the actual day of calving in the study, 42 cull cows (mean DIM ± SE: 22.0 ± 2.6) were confirmed. The areas under the curve (AUC) of the ROC for predicting culling using serum NEFA concentrations were 0.6 and 0.7 at 14 to 2 and 7 to 2 days before calving, respectively. The AUC for the RFS was 0.7 for both periods, indicating the same diagnostic level as the serum NEFA concentration. Both the serum NEFA concentration and RFS were possible predictors in cows with ≥ 2 parities, but not in cows with 0–1 parity sampled even at 7 to 2 days before calving. The serum BHBA concentration and BCS were not suitable predictors of culling for any period or parity. These results indicate that RFS has a discriminatory ability comparable to the serum NEFA concentration for predicting culling within 60 DIM.

Reasons and Criteria for Selecting and Culling Dairy Cows in Small and Medium Farms in the Northeastern Region of Thailand

The objective of this study was to investigate the criteria for cow culling and the methods used for semen selection in small and medium dairy farms in Thailand. Dairy cows on small and medium farms are culled for many different reasons. Methods of selection and culling were examined using data collected from a questionnaire asking about the number of milking cows, farm experience in raising dairy cows, criteria used for culling cows, selection of new cows, replacement cattle, and semen for breeding. Ninety-one farms were randomly selected using a snowball technique from dairy cooperatives in Khon Kaen, Maha Sarakham, and Sakon Nakhon Provinces, Thailand, with data analyzed using ANOVA and Chi-square statistics. The results showed that most farmers did not cull cows due to low milk production or aging (71.43%, 72.53%) and used 5 to >12 insemination events as a criterion for involuntary culling (50.55%). Chronic mastitis was the highest health reason for culling cows (52.10%). Farmers usually kept on-farm female calves as replacement cows (41.67%), chosen by considering their dams’ milking ability. Most farmers (67.00%) let an artificial inseminator select suitable semen for their cows. When selecting pregnant heifers for replacement, the farmers considered body conformation, udder characteristics, and cow price. Farmers with small and medium farms conducted low levels of voluntary culling and paid less attention to the genetic information of the semen. In summary, this study explains various factors influencing the selection and culling of dairy cows. Challenges leading to cattle culling included mastitis and infertility. Educating farmers on hygiene, reproductive systems, and household accounting is imperative as it facilitates sustainable cattle rearing practices.

Awareness and perceived barriers to the adoption of best management practices for the transportation of lactating cull dairy cows of dairy producers in Ontario

The objectives of this study were to understand dairy farmers' awareness and perceived barriers to the implementation of best management practices (BMP) for the transportation of lactating culled cows being moved to auction or abattoir. An invitation to participate was emailed to all dairy farms in Ontario, Canada. Responses to this invitation were used to recruit additional participants through criterion purposive snowball sampling. In total, 28 dairy producers participated in one of 5 semi-structured focus groups. All focus groups were audio recorded, transcribed verbatim, and analyzed with applied thematic analysis. Four themes were identified including 1) transfer of responsibility, 2) interpersonal relationships, 3) juggling priorities, and 4) complexities of long-term planning. While individual participant knowledge varied, participants described misconceptions that other producers held surrounding transport duration and distances, or the number of possible sales points for lactating culled cows. Participants did not agree whether the producer's responsibility ended once the cow left their property or if shared responsibility remained among all stakeholders from the farm to the final destination. Participants discussed the importance of existing trusted relationships with local cattle transporters and veterinarians to ensure information on best practices are shared. Participants also discussed how business pressures (e.g., production demands, space limitations) often challenge their ability to dry off lactating cows before transport; however, participants mentioned the degree of milk production may influence the destination of their animal (e.g., direct to slaughter for animals with high milk production). Some participants described a dynamic balance between business pressures and the potential for declining welfare of the animals under consideration to be culled during lactation. Participants posited that producers who did not prioritize proactive herd management and producers nearing retirement had limited long-term planning for culling individual cows, which might lead to transport of vulnerable or unfit animals. Finally, the lack of access to transportation direct to local slaughter was identified as an important barrier to adherence with the BMP for cull cows. In summary, many participants did not have an accurate understanding of what happens to cull cows after departing the farm and were unsure if they maintained a level of responsibility for an animal after being transported from their farm. Given the priority placed by participants on trusted interpersonal relationships, greater availability of peer-to-peer training of farmers and professional accreditation of animal transporters in addition to structural changes to increase local slaughter capacity may increase implementation of BMP and enhance lactating cull cow welfare.

Inactivation of Avian Influenza Virus Inoculated into Ground Beef Patties Cooked on a Commercial Open-Flame Gas Grill

With the emergence of clade 2.3.4.4b H5N1 highly pathogenic avian influenza virus (AIV) infection of dairy cattle and its subsequent detection in raw milk, coupled with recent AIV infections affecting dairy farm workers, experiments were conducted to affirm the safety of cooked ground beef related to AIV because such meat is often derived from cull dairy cows. Specifically, retail ground beef (percent lean:fat = ca. 80:20) was inoculated with a low pathogenic AIV (LPAIV) isolate to an initial level of 5.6 log10 50% egg infectious doses (EID50) per 300 g patty. The inoculated meat was pressed into patties (ca. 2.54 cm thick, ca. 300 g each) and then held at 4 °C for up to 60 min. In each of the two trials, two patties for each of the following three treatments were cooked on a commercial open-flame gas grill to internal instantaneous temperatures of 48.9 °C (120°F), 62.8 °C (145°F), or 71.1 °C (160°F), but without any dwell time. Cooking inoculated ground beef patties to 48.9 °C (ave. cooking time of ca. 15 min) resulted in a mean reduction of ≥2.5 ± 0.9 log10 EID50 per 300 g of ground beef as assessed via quantification of virus in embryonating chicken eggs (ECEs). Likewise, cooking patties on a gas grill to 62.8 °C (ave. cooking time of ca. 21 min) or to the USDA FSIS recommended minimum internal temperature for ground beef of 71.1 °C (ave. cooking time of ca. 24 min) resulted in a reduction to nondetectable levels from initial levels of ≥5.6 log10 EID50 per 300 g. These data establish that levels of infectious AIV are substantially reduced within inoculated ground beef patties (20% fat) using recommended cooking procedures.

Association of uterine health in the first lactation with transition cow health and reproductive performance in the second lactation of Holstein dairy cows.

The objective of this study was to evaluate the effects of puerperal metritis (PM) diagnosed and treated during the early postpartum period of the first lactation on transition cow health, milk production, reproduction, and culling of dairy cows in their second lactation. Diagnosis of PM was based on fetid watery red-brown uterine discharge and rectal temperature above 39.5°C. Two farms were enrolled in this retrospective observational cohort study (Farm A and B). In both farms, the following diseases were recorded during the first 30 DIM in lactation 1 and 2: clinical hypocalcemia (CH), retained fetal membrane (RFM), PM, hyperketonemia (KET), left displaced abomasum (LDA) and clinical mastitis (MAST). Statistical analyses were performed using SPSS for Windows separately for each farm. Linear and logistic regression models were used for continuous (e.g., milk yield) and binary (e.g., disease, pregnancy per AI, pregnancy loss) outcomes, respectively. Cox proportional hazard regression models were calculated to model the time to event outcomes for culling or death during the first 60 DIM and for pregnancy within 250 d of the second lactation. The initial models contained the following variables: year of calving, month of calving, calving ease, stillbirth, twins, days open in lactation 1, 305 d milk yield in lactation 1, PM in lactation 1, and PM in lactation 2 as explanatory variables. A total of 4,834 cows (Farm A) and 4,238 cows (Farm B) in the second lactation were considered for statistical analyses. On farm A, the incidence of PM in lactation 1 and 2 was 20.1% and 11.2%, respectively. On farm B, the incidence of PM in lactation 1 and 2 was 14.4% and 8.5%, respectively. On both farms, cows with PM in their first lactation had greater odds for RFM and PM in their second lactation, while there was no association of PM in the first lactation with any other non-uterine diseases (i.e., CH, KET, LDA, and MAST) in the second lactation. Cows with PM in lactation 2 had reduced milk yield. The reduction in milk yield in second lactation was greater for cows that already experienced PM in lactation 1. On Farm A, cows with PM in their first lactation had a greater hazard for culling within 60 DIM of the second lactation; however, the same association was not present on Farm B. Cows with PM in lactation 1 had reduced pregnancy per AI at first service in the second lactation only on farm B. Cows with PM in lactation 2 had reduced pregnancy per AI at first service in the second lactation on both farms. Pregnancy loss in lactation 2 was only associated with PM in lactation 2 but not with PM in lactation 1. On both farms, cows had a reduced hazard for pregnancy in their second lactation within 250 DIM when they experienced PM in either lactation. In conclusion, PM in the first lactation had long-lasting negative consequences (i.e., risk of uterine disease and lower reproductive performance) for cows in their next lactation.

Can 60 days of feeding lead to increased fitness for transport in cull dairy cows?

The welfare of cull cows during transport to slaughter is a current concern in the Canadian dairy industry. Cull cows sold through auction often have a high prevalence of lameness, low BCS, hock lesions, and udder engorgement. To evaluate whether drying off and feeding cull dairy cows before transport can mitigate these challenges, 45 cows designated for culling were randomly assigned to either be fed for 60 d after being dried off (fed group; n = 24) or to serve as controls by being sent directly to slaughter (direct group; n = 21). Two fed group cows were removed for health reasons before completing the feeding period. Both fed group and direct group cows were assessed for locomotion (5-point scale), BCS (5-point scale), hock lesions (3-point scale), udder engorgement (3-point scale), and BW at the time of enrollment. Fed group cows, locomotion, BCS, hock, and udder engorgement scores were assessed weekly until slaughter. Weights of the fed group cows were measured again the day before slaughter. Mixed linear regression models were used to assess continuous outcomes BCS and weight. Mixed logistic regression models were used to assess dichotomous outcomes presence of hock lesions and lameness. Fed group cows gained an average of 116.9 kg over the feeding period (SE ± 8.20). Fed group cows had an average weight at slaughter of 834.2 kg, whereas direct group cows' average weight was 767.3 kg (SE ± 26.8). The fed group cows' average BCS at the start of the trial was 2.4, and at slaughter was 3.6, with an average gain of 1.2 BCS points. At slaughter, the proportion of udders involuted in the fed group was 45.1% (10/22) and in the direct group cows, was 0% (0/21). No differences were found in locomotion or hock lesions between the fed group and direct groups. It is important to weigh potential benefits for the fed group cows with the fact that direct group cows did not endure a drying off procedure, nor were they placed at risk of potential adverse health events. However, despite these potential limitations, due to the improved BCS and udder engorgement scores, cows fed for 60 d may be better prepared for the transportation to slaughter, as well as sell for a higher price due to increased BW and body condition.

The effect of bta-miR-1296 on the proliferation and extracellular matrix synthesis of bovine mammary fibroblasts.

Mammary fibrosis in dairy cows is a chronic condition caused by mastitis, and can lead to serious culling of dairy cows resulting in huge economic losses in the dairy industry. MicroRNAs (miRNAs) exert an important role in regulating mammary gland health in dairy cows. This study investigated whether exosomal miRNAs in mammary epithelial cells can regulate the proliferation of bovine mammary fibroblasts (BMFBs) in mastitis. Liposome transfection technology was used to construct a cellular model of the overexpression and inhibition of miRNAs. The STarMir software, dual luciferase reporter gene test, real-time quantitative PCR (qRT-PCR), a Cell Counting Kit-8 (CCK-8), and a Western Blot and plate clone formation test were used to investigate the mechanism by which bta-miR-1296 regulates the proliferation of BMFBs. Target gene prediction results revealed that glutamate-ammonia ligase was a direct target gene by which bta-miR-1296 regulates cell proliferation. It was found that bta-miR-1296 significantly inhibited the proliferation of BMFBs. After BMFBs were transfected with a bta-miR-1296 mimic, mRNA expression in the extracellular matrix (ECM), α-smooth muscle actin (α-SMA), collagen type I alpha 1 chain (COL1α1) and collagen type III alpha 1 chain (COL3α1), and various cell growth factors (basic fibroblast growth factor (bFGF), vascular endothelial growth factor (VEGF), platelet-derived growth factor-BB (PDGF-BB), and transforming growth factor-β1 (TGF-β1)) were down-regulated, and the expressions of α-SMA, COL1α1, COL3α1, phospho-extracellular regulated protein kinases, phospho-protein kinaseB, TGF-β1, and phospho-Smad family member3 proteins were inhibited. In conclusion, bta-miR-1296 can inhibit the proliferation of BMFBs and the synthesis of ECM in BMFBs, thus affecting the occurrence and development of mammary fibrosis in dairy cows and laying the foundation for further studies to clarify the regulatory mechanism of mammary fibrosis.

Technological solution of a modular family farm

The technological solution of a modular family farm for producing high-quality and environmentally friendly beef is presented. The development aims to make beef using bulls-producers of meat and graded dairy cows. The family farm project was developed considering the generalisation of the best practices of organising peasant farms and scientific research of SIBNIPTIZH. It assumes a comprehensive solution for a family farm, including, in addition to industrial housing facilities with outbuildings and a personal plot, the introduction of the most acceptable methods for keeping animals, type of feeding, design parameters of industrial buildings and elements of technology equipment, small-sized machinery, as well as the organisation of labour and production. The technological solution is to grow and fatten young animals using the low-cost technology of beef cattle breeding "cow-calf" from culled dairy cows suitable for reproduction. The optimal scheme of placement and movement of technological groups of cows and repair young animals has been determined. Variants of space-planning solutions for building a modular family farm for 26 cows have been developed. Cows, repair heifers and calves are kept in a lightweight cowshed. Cows are kept on a leash. Calves are kept loose. Young animals, after weaning from cows, are transferred to another room. From the age of 6 months, heifers and bulls are kept separately. Young animals in winter are in a lightweight room with a deep litter. Bulls older than 12 months are not grazed. They are intensively reared and fattened up to 17 months when they reach a live weight of 439 kg.

Quantification of cooling effects on basic tissue measurements and exposed cross-sectional brain area of cadaver heads from Holstein cows > 30 mo of age.

Penetrating captive bolt (PCB) is the primary method of preslaughter stunning for cattle and is also used for on-farm euthanasia. The objective of this study was to quantify the impact of cooling on the soft tissue thickness, cranial thickness, total tissue thickness, and cross-sectional brain area of cadaver heads collected from mature (> 30 mo of age) dairy cows following the application of a PCB stun in a frontal placement. Hide-on cadaver heads were obtained from culled dairy cows (N = 37) stunned in a frontal location using a handheld PCB device (Jarvis Model PAS-Type C 0.25R Caliber Captive Bolt, Long Bolt) at a commercial slaughter establishment. Following transport to the University of Wisconsin-River Falls, heads were split at midline along the bolt path by a bandsaw and then underwent FRESH, CHILL24, CHILL48, and CHILL72 refrigeration treatments. The FRESH treatment involved images collected immediately after splitting each head, the CHILL24 treatment involved images collected after 24h of refrigeration, the CHIL48 treatment involved images collected after 48h of refrigeration, and the CHILL72 treatment involved images collected after 72h of refrigeration. Measurements of soft tissue thickness, cranial thickness, total tissue thickness, and cross-sectional brain area were recorded for each refrigeration treatment. Soft tissue thickness did not differ caudal to (P = 0.3751) or rostral to (P = 0.2555) the bolt path. Cranial thickness did not differ caudal to (P = 0.9281) or rostral to (P = 0.9051) the bolt path. Total tissue thickness did not differ caudal to (P = 0.9225; FRESH: 24.77mm, CHILL24: 23.93mm, CHILL48: 24.27mm, CHILL72: 42.30, SE: 0.86) or rostral to (P = 0.8931; FRESH: 24.09mm, CHILL24: 23.99, CHILL48: 24.26, CHILL72: 24.43mm, SE: 0.79mm) the bolt path. Cross-sectional brain area was not different (P = 0.0971) between refrigeration treatments (FRESH: 9,829.65 ± 163.87mm2, CHILL24: 10,012.00 ± 163.87mm2, CHILL48: 9,672.43 ± 163.87mm2, CHILL72: 10,235.00 ± 166.34mm2). This study demonstrated that FRESH tissue parameters can be determined from cattle cadaver heads refrigerated for 24, 48, or 72h.

Recording of culling reasons in Danish dairy cows

Culling in dairy cows has major impacts on production economy and animal welfare, and has been described and evaluated in many studies. Information about why a cow is culled (culling reason) may be useful for many different purposes. Still, the present study is the first to evaluate explanatory factors for recording of culling reasons. Danish dairy farmers are required to report the culling mode (slaughter, unassisted death, or euthanasia) to the Danish Cattle Database. Further, the reporting of one or two culling reasons – from a list of options – is possible but not mandatory. Data from 281,682 cows culled in Danish dairy herds in 2020 and 2021 were analyzed. The mean age at culling was 1,845 days, 83.3 % of the culled cows were slaughtered, 10.2 % died unassisted and 6.5 % were euthanized. In 66.8 % of the culled cows, the farmer had reported at least one culling reason. The most frequent culling reasons for slaughtered cows were milk production (29 % of all culling reasons reported), followed by reproduction (25 %), and udder health (16 %). For unassisted dead cows, metabolic/digestive disorders were most frequently reported (25 %), followed by unknown reasons (18 %), and udder health (15 %). For euthanized cows, accidents were most frequent (29 %), followed by locomotor disorders (18 %), and metabolic/digestive disorders (17 %). Culling mode, as well as culling reasons, differed by parity and breed. Results from a logistic regression model showed that the odds of at least one culling reason being reported was significantly higher in Jersey cows compared to other breeds. Compared to Holstein cows, the odds of a reason being reported was 2.5 times higher in Jersey cows. The odds increased with increasing parity of the cow. In herds with a high mean milk yield and a low somatic cell count, the odds of reporting a culling reason was higher than in herds with lower milk yield and higher somatic cell counts, and the odds of reporting a culling reason increased with an increasing number of disease treatments recorded per cow per year.

Qualitative welfare risks of cows offered to a Dutch mobile slaughter unit

In the Netherlands, a pilot was initiated of a mobile slaughter unit (MSU) for the killing of cull dairy cattle not fit for transport but suitable for slaughter, in order to save valuable meat. The Office for Risk Assessment & Research (BuRO) was asked to assess the risks for animal welfare. As a thorough risk assessment would have been very time consuming, a qualitative framework was used instead. The goal of the current study was to qualitatively describe the relevant risks for cow welfare involved in the use of an MSU compared with current practice by carrying out a rapid comparative risk assessment of animal welfare. The assessment framework consisted of the following steps: identification and description of scenarios, followed by assessment and comparison of the most relevant animal welfare risks in these scenarios, including hazard identification, hazard characterization, exposure, and characterization of the risk to animal welfare. Two main scenarios were identified, one with and one without an MSU. The second scenario was split into three sub-scenarios: killing on the farm/in a housing unit, emergency slaughter, and conventional transport to the slaughterhouse. The most relevant risks associated with operating an MSU were as follows: leaving the cow alive on the farm when it was not fit for slaughter; forcing the cow to walk to and into the MSU (however, this risk is likely higher under conventional transport of unfit cows); and insufficient stunning and bleeding, leading to questionable unconsciousness (however, this risk is likely higher in an emergency slaughter scenario). The MSU is a means of preventing the exacerbation of welfare deterioration in cows that are unfit for transport but fit for slaughter, and it reduces exposure to stressors (hazards) that are conventionally present during transport and at a stationary slaughterhouse. This rapid comparative risk assessment of animal welfare supported swift decision-making: the national competent authority (i.e., the NVWA in the Netherlands) and policymakers were able to improve and develop risk-mitigating actions and to decide on allowing the use of an MSU. When appropriately designed and used, and with sufficient supervision, mobile slaughter facilities can reduce welfare risks in cull dairy cows that are unfit for transport but fit for slaughter.

Dutch dairy farmers' perspectives on culling reasons and strategies.

Since the abolishment of the milk quota system in Europe in 2014 and the introduction of environmental policies such as the phosphate rights system in the Netherlands, the reasons for culling dairy cows might have changed. The aim of this study was to determine the culling reasons for dairy cattle and to identify farmers' culling strategies and their intentions regarding the alteration of indicated culling strategies. To this end, an online questionnaire was distributed among dairy farmers nationally that resulted in 207 responses. Results showed that the most frequent culling reasons were related to problems with reproduction, udder, and hoof health. Primiparous cows were primarily culled for miscellaneous reasons such as injury, reproduction failure, and low milk yield. Multiparous cows were culled predominantly for reproduction failure, udder health and hoof health reasons. Most respondents indicated that they consider formulating a culling strategy, based on certain rules of thumb regarding the most common reasons for culling. Most farmers also reported that culling decisions on their farms were perceived to be unavoidable, though reproductive culling decisions are primarily voluntary. Most respondents stated that they intended to reduce the culling rate for better economic gain did not intend to alter the amount of replacement stock reared. The applied rules of thumb regarding culling strategies do not seem to have changed since the policy changes in dairy farming. The question remains whether farmers' rules of thumb might have made them unaware of the actual economic consequences of their culling strategies under the altered situation.

A focus group study exploring dairy farmers' perspectives of cull cow management in Ontario, Canada.

Maintaining the welfare of cull dairy cows from the farm to slaughter is an ongoing challenge for the dairy industry. Recent research suggests that some cull dairy cows within the marketing system are in physical states that are below regulatory standards, and further research is required to determine why these unfit cows are found throughout the journey to abattoirs. Since dairy farms are the origin of these cows, decision making by dairy farmers has been identified as key to preventing cull cows that are considered unfit for transport from entering the marketing system. The objectives of this study were to understand dairy farmers' perspectives on their cull dairy cow management practices, recommendations and requirements of regulations, management tools, and welfare issues. Four focus groups with a total of 21 participants were each conducted virtually, video recorded, and transcribed verbatim, with dairy farmers from Ontario, Canada. A thematic analysis of focus group discussions was conducted utilizing deductive reasoning. There were three themes identified including deciding to cull or not, management of cows being culled, and knowledge and perceptions of cull cow regulations. When making culling decisions, farmers utilize multiple sources of information including personal experiences and values and external referents like veterinarians, family members and other farmers. The welfare of their cows was a high priority but one that was often weighed against the financial outcomes of culling decisions. Finally, most participants considered recent regulatory changes for the management of cows before shipment to be of little importance on their farms. In conclusion, the farmers from this study showed the diversity of considerations they make in culling decisions and the large contribution of animal productivity and economic factors. There was a general lack of knowledge of recent regulatory changes for the shipment of cull cows, and there is room for improving the uptake of new recommendations for culling only cows fit for transportation.

Prevalence and Potential Risk Factors of Bovine Clinical Mastitis in Bonke District, Gamo Zone, Southern Ethiopia

Ethiopia has the largest cattle population in Africa with an estimated population of 56.71 million. Among these, the cow represents the biggest portion of the cattle population of the country. Currently, around 20.7% of the total cattle heads are milking cows. 85-89 percent of milk is contributed from cattle out of the total annual national milk production in Ethiopia that ranges from 797, 9000 to 1, 197, 500 metric tons of raw milk equivalents.. However, this amount does not satisfy the national demand for milk and milk products in the country due to a number of complex and interrelated factors including inadequate feed and nutrition, widespread diseases, the poor genetic potential of local breeds, poor market chain, and inefficiency of livestock development. Concurrently, mastitis is one of the major and expensive diseases which can alter milk composition, reduce the quality and quantity of milk yield, and indeed cause the culling of dairy cows at their age of high productivity. Clinical mastitis is the types of mastitis emphasized in this study. A cross-sectional study was conducted on 384 lactating cows to assess the prevalence of bovine clinical mastitis and its potential risk factors in the study area. Out of these 41(10.7%) were found positive for clinical mastitis. All the potential risk factors considered in this study showed statistically significant difference (P < 0.05). The present study concludes that mastitis was a key health problem of lactating cows in the area. Therefore, deliberate control measures against the disease and regular reconnaissance measures are recommended. Keywords: Bonke; bovine clinical mastitis; prevalence; risk factor.

A randomized controlled trial assessing the effect of intermittent and abrupt cessation of milking to end lactation on the well-being and intramammary infection risk of dairy cows

The objectives were to compare the effects of an intermittent milking schedule with a thrice daily milking schedule during the final week of lactation on the well-being, udder health, milk production, and risk of culling of dairy cows. We hypothesized that cows subjected to an intermittent milking schedule would experience less udder engorgement and pain, lower concentrations of fecal glucocorticoid metabolites (11,17-dioxoandrostanes; 11,17-DOA concentration) after dry-off, lower risk of an intramammary infection during the dry period, higher milk production and lower somatic cell count in the subsequent lactation, and lower culling risk compared with herd mates milked 3 times daily and dried off by abrupt cessation. In a randomized controlled field study, Holstein cows (n = 398) with a thrice daily milking schedule were assigned to treatment and control groups. The treatment consisted of an intermittent milking schedule for 7 d before dry-off (gradual cessation of milking, GRAD). Gradual-cessation cows were milked once daily until the day of dry-off, whereas cows in the control group (abrupt cessation of milking, APT) were milked 3 times daily until the day of dry-off. Udder firmness and pain responses of the udder 3 d after dry-off, as well as the percentage change in fecal 11,17-DOA concentration (3 d after dry-off compared with the dry-off day), were used to assess the well-being of the animals. Compared with cows in the GRAD group, the odds [95% confidence interval (CI)] of udder firmness were 1.55 (0.99-2.42) for cows in the APT group, and the odds of a pain response were 1.48 (0.89-2.44) for cows in the APT group. The least squares means (95% CI) of the percentage change in 11,17-DOA concentration were 129.3% (111.1-150.4) for the APT group and 113.6% (97.5-132.4) for the GRAD group. Quarter-level culture results from the periods before dry-off and after calving were compared, to assess the likelihoods of microbiological cure and new infection. Cows in the APT group had lower odds of a new intramammary infection in the dry period [odds ratio, 95% CI: 0.63 (0.37-1.05)], whereas we observed no meaningful differences in the microbiological cure likelihood among groups. The least squares means (95% CI) for somatic cell counts (log10-transformed) were 4.9 (4.8-5.0) in the APT group and 4.9 (4.8-5.0) in the GRAD group. The odds (95% CI) of clinical mastitis in the first 30 d postcalving were 1.32 (0.53-3.30) in the APT group compared with the GRAD group. We observed no meaningful differences in milk production at the first test date postcalving or the culling risk among groups. We conclude that the gradual-cessation protocol tested herein failed to significantly improve animal well-being, udder health, milk production, and survival in the tested study cohort. However, the observed differences in udder firmness, as well as the numerical differences in udder pain and the percentage change in fecal 11,17-DOA concentrations suggest that this line of research may be useful. Future research is needed to develop drying-off strategies that are appropriate for lowering milk production at the end of the lactation and improve animal well-being without compromising udder health.

Associations of carcass weight and trimming loss with cull dairy cow health observations collected at slaughter.

Cull dairy cows account for around 27 percent of total head EU beef and veal production. For the Netherlands specific, even 42 percent (European Commission, 2022). As they are primarily kept to produce milk, red meat production is an additional source of revenue for dairy farmers. Insights in postmortem health observations that are not always visible on the living animal such as heart or liver issues, bruises, adhesions and injuries on the locomotor system, may contain valuable information for farmers to increase revenue and reduce losses in red meat production from cull dairy cows. Our goal was to obtain insights in the association of postmortem health observations with carcass weight and trimming losses. Data of 592,268 slaughter cows were available for analysis and models were built to explain carcass and trimming loss by the postmortem health observations. Carcass weight is lower for younger cows (-3.2 to -84.9 kg), cows with multiple health observations (-7.4 to -34.3 kg) and specific observations for the locomotor system (-16.7 to -22.7 kg), back (-17.9 kg), hindquarter (-21.6 kg) and chest and ribs (-15.5 to -27.6 kg). Total number of health observations (+2.0 to +6.5 kg), observations on the locomotor system (+3.3 to +5.4 kg) and on the chest and ribs (+2.2 to +9.8 kg) were the main predictors for trimming loss. Carcass weight is more affected by systemic health issues and diseases prior to slaughter leading to a negative energy balance and consequently reduced carcass weight. Trimming loss is more a consequence of the focus on meat quality and food safety in the slaughter process. Better understanding of the effect of on-farm management, on health, carcass weight and trimming loss will provide new insights for farmers and veterinarians but will also give them more action perspective to improve dairy farm preventive management and reduce losses at slaughter.

The influence of productivity indicators on the culling of dairy cows in the sharply continental climate of Kazakhstan.

This article presents the results of the culling of cows of the Simmental and Holstein breeds in the Republic of Kazakhstan. The purpose of the research was to study the actual number of culled cows of dairy productivity in the farms of the Republic of Kazakhstan to determine its norm. The object of research were cows of Simmental (18,462 heads) and Holstein (17,862 heads) breeds in various regions of the republic. The research was carried out according to generally accepted zootechnical methods using statistical data processing using RStudio. The results of the studies showed that the percentage of culling increases in cows of the Simmental and Holstein breeds and amounts to 19.7 and 22.9%, respectively. The analysis of the retirement of full-aged cows of the Simmental breed showed that the main causes are hoof diseases (up to 26%), low reproductive function (up to 21%), low productivity (up to 18%). Holstein cows had an increase in disposals in all categories except for disposals for various reasons, for problems with reproduction, the disposal is up to 21%. The determination of the relationship between productivity and retirement in the Simmental breed cows showed that with age and increased lactation, the proportion of retired cows also increases, in the Holstein breed, with increased productivity, the percentage of culled animals also increases.

A survey of practices and attitudes around cull cow management by bovine veterinarians in Ontario, Canada.

The removal (culling) of dairy cows from the farm is a regular and required management practice. The main objectives of this study were to describe the involvement of bovine veterinarians in Ontario, Canada, in dairy cull cow management decisions, their expectations of current producer practices, and their perspectives on welfare issues and best management practices for cull dairy cows. Between February and May 2021, a province-wide survey was conducted among all members of the Ontario Association of Bovine Practitioners (OABP), with questions addressing veterinarians' background and demographics, veterinary clinic characteristics, cull cow management, down cow management, and learning preferences. The response rate for the survey was 25.1%, with 45 responses meeting all eligibility criteria. Dairy veterinarians would like to have greater involvement in cull cow management; when asked for desired involvement in culling decisions, 57.5% of veterinarians would like to be involved in culling decisions most of the time or always. Most (70.0%) veterinarians believed that cull cow welfare has improved over the last decade. However, most respondents also identified at least one area of management (farm of origin, transportation, auction, slaughter) as currently being a high risk to cull cow welfare. Given the frequency of their visits, trust by dairy producers, and knowledge, herd veterinarians are among those in the best position to improve the care of cull dairy cows. Information generated from this survey can be used to inform the development of improved decision-making tools for culling cows, and this, along with increased veterinarians' involvement in cull cow management, could improve the economic and welfare outcomes of culling decisions for dairy producers.