Nigel B. Cook

Efforts to improve efficiency and profitability on dairy farms have renewed focus on how culling practices affect herd sustainability and economic outcomes. This study surveyed decision-makers on 60 high-producing, freestall-housed dairy farms in Wisconsin, with a mean (SD) turnover rate of 36.0 (8.0)%. Using a structured questionnaire, we examined herd management, culling criteria, and motivations. Most farms (93%) used on-farm management systems to guide culling, yet only 48% used designated reports, relying instead on individual cow records. Milk production, infertility, and somatic cell count were the top culling criteria, with high milk yield cited as the most difficult factor in removal decisions. While 54% recorded the most obvious reason for culling, only 7% documented multiple causes. Cull cows were typically transported by third parties; 80% farms sent cows directly to slaughter, while 52% sent them to auction. One-third of farms sold cows for continued dairy use. Euthanasia was performed on 93% of farms, mostly by employees, with minimal veterinary input. The study aimed to investigate producer perspectives on the culling decision-making process on commercial dairy farms. The findings highlight opportunities for improved veterinary involvement and the use of structured herd-level reports to support more strategic culling decisions.

Appropriate handling of dairy cows improves animal welfare and milk production and reduces the risk of injury to cows and people. However, interacting with cows safely requires training to understand their natural behavior. Our objective was to develop, in collaboration with Wisconsin dairy farming stakeholders, an innovative tool for dairy farm staff to practice appropriate cow handling. We created and evaluated a prototype of Mooving Cows, a digital touchscreen game in which players practice moving cows in simulated dairy farm environments. The learning objectives were to understand how human actions affect safety and cow behavior, stress, and productivity. We conducted focus groups with dairy farm staff (3 groups in Spanish, n = 16; 2 groups in English, n = 4) and 3 English focus groups with decision-makers (n = 10) such as farm owners and managers, bilingual consultants, and veterinarians. First, the focus group participants completed questionnaires about their experiences with and perceptions of cow handling and professional training and then they played the game prototype individually. On average, participants indicated they felt fairly comfortable using mobile applications (scale: 1 = very comfortable, 5 = very uncomfortable; farm staff: 1.9 ± 1.2, mean ± SD, range = 1 to 5; decision-makers: 1.8 ± 1.0, range = 1 to 4). After playing the game prototype, participants engaged in recorded, facilitated discussions about their qualitative impressions of the game. The research team reviewed the transcriptions to identify action items for improving the final version of the game, then conducted an inductive codebook thematic analysis to summarize themes relating to the participants' impressions of the game. We incorporated participants' feedback into version 1.0 of the game and compiled their ideas for future versions of the game. Overall, participants indicated the game was entertaining and would be useful for job training, particularly for new hires with little cow-handling experience. The results from the qualitative evaluation of the game prototype by dairy farming stakeholders suggest that the game could be a relevant way for farm staff, especially new hires, to remain current with national standards and expectations for continuing education.

Despite hoof trimming (HT) being a recommended procedure for hoof lesion and lameness prevention, there is limited data on the efficacy of different HT methods. Our objective was to compare the effects of HT cows at dry-off with the functional method that uses a little model (LIT) to an adaptation with bigger modeling (BIGM) of the higher load-bearing hoof on the occurrence of new hoof lesions and the risk for lameness in the next lactation. Cows scheduled for their regular HT at dry off were enrolled weekly from 3 sand bedded free-stall housed herds located in Wisconsin (n = 2) and Minnesota (n = 1). Cows were eligible for enrollment if they did not have hoof horn lesions at their dry-off HT. Cows were allocated to either LIT or BIGM weekly. Locomotion scores were collected on a biweekly basis from 2 herds once before enrollment and until their subsequent HT or up to 165 DIM. Two trained hoof trimmers collected hoof lesion data either during the cow's scheduled mid-lactation HT between 100 and 165 DIM or during an HT prompted by identification as a lame cow by farm personnel. Data were analyzed using multivariable logistic regression with the presence of any hoof lesion as the outcome of interest and multivariable Cox proportional hazards models with the presence of lameness as the outcome of interest. A total of 1,556 cows were enrolled, with 790 (51%) cows in the LIT treatment and 766 (49%) cows in the BIGM treatment. The average DIM at the cow's next HT was 113 (95% CI: 111-114). A total of 205 (16.2%) of the 1265 cows were identified with a lesion before 165 DIM. A total of 501 (43%) of the 1167 cows were identified as lame following enrollment. There was no evidence of a difference between the LIT and BIGM groups overall when presence of any hoof lesion was considered as the outcome. The median time to lameness was 193 d for LIT and 203 d for BIGM. For the hazard of lameness outcome there was no evidence of a difference between the LIT and BIGM groups overall. However, for both the presence of any hoof lesion and lameness outcomes, a cow's lactation group modified the effect of BIGM. First lactation cows trimmed with BIGM had reduced risk of any hoof lesion and specifically reduced risk for hoof horn lesions (risk difference 6.1% (95% CI: 9.6 - 2.5) and odds 76% (OR 0.24, 95% CI: 0.10 - 0.58). In addition, first lactation cows and cows with an enrollment locomotion score < 3 had a lower hazard of becoming lame in the following lactation if they were allocated to the BIGM treatment, compared with cows trimmed with LIT. In summary, the effect of the BIGM trimming method was modified by factors related to parity and prior lameness status, possibly influenced by bone exostosis on P3. Therefore, the BIGM HT method should be considered to prevent lameness and hoof lesions when animals are trimmed at their 1st lactation dry-off trim.

The present study aimed to determine the relationship between circulating progesterone (P4) concentrations and milk yield during the ovulatory follicular wave on the proportion of multiple ovulation (MOV) in multiparous high-producing Holstein cows (n = 1,345). The study used first-service multiparous cows submitted to a Double-Ovsynch program (GnRH; 7 d later, PGF_2α; 3 d later, GnRH; 7 d later, GnRH [G1]; 7 d later, PGF_2α [PG1]; 1 d later, PGF_2α; ∼32 h later, GnRH [G2]; ∼16 h later, timed AI [TAI]). To assess ovulatory response and proportion of MOV, ovarian ultrasonography examinations were performed at G1 (n = 1,215) and G2 (n = 1,345) and from 40 to 48 h after each GnRH. Average milk yield (kg/d) for the weeks before G1 and PG1 were recorded. Blood samples were collected at G1 (n = 1,242) and PG1 (n = 1,333) to measure serum P4 concentrations. Milk yield for the 2 weeks before PG1 was 56.0 ± 0.2 kg/d. Overall, ovulation to G1 was 71.5%, and MOV to G1 was 16.6%. Circulating P4 concentration at G1 was higher in cows with single ovulation (SOV) at G1 than in cows with MOV (4.31 ± 0.08 vs. 3.70 ± 0.20 ng/mL, respectively). Overall, ovulation to G2 was 90.2%, and MOV to G2 was 13.7%. Cows with MOV to G2 also had lower P4 concentration at PG1 than cows with SOV (7.24 ± 0.28 vs. 8.91 ± 0.11 ng/mL, respectively). The interaction of serum P4 tertiles at PG1 × milk yield tertiles was not significant for MOV to G2. Nevertheless, independent of each other, MOV to G2 was positively associated with milk yield and negatively associated with serum P4 at PG1. The proportion of cows with MOV to G2 was greater for cows with previous MOV to G1 (32.9%) than for cows with SOV to G1 (9.8%). In summary, MOV in multiparous high-producing Holstein cows was highly associated with serum P4 concentrations, milk yield, and previous MOV. In addition, an increased proportion of MOV was associated with high milk yield tertile (≥58.5 kg/d) regardless of the serum P4 concentrations during the growth of the ovulatory follicle.

The contentious issue of cow calf separation at birth is incongruent with many views on acceptable farming practices, and carries the risk of eroding public trust in the dairy industry if it is not addressed. The available evidence provides little support for the practice, but research on best practices for maintaining cow calf contact in a way that enhances animal welfare, while preserving farm profitability is nascent. In this article, the authors address the research questions that require answers to better inform producers and facilitate their decision making, and prepare the dairy industry to take another evolutionary step forward.

This study aimed to determine if 200 μg of GnRH (gonadorelin hydrochloride) would increase ovulatory response and pregnancies per AI (P/AI) compared with 100 μg at the first GnRH of the breeding-Ovsynch of a Double-Ovsynch program (DO) in lactating Holstein cows. Weekly cohorts of primiparous (n = 719) and multiparous (n = 1,191) cows submitted to DO [GnRH - 7 d - PGF_2α - 3 d - GnRH - 7 d - GnRH (G1) - 7 d - PGF_2α (PG1) - 1 d - PGF_2α - ~32 h - GnRH (G2) - ~16 h - TAI] for first timed-artificial insemination (TAI), randomly received either 100 μg or 200 μg of GnRH (gonadorelin hydrochloride) at G1 (primiparous, 64-75 DIM; multiparous, 59-70 DIM). Ovulation was determined by ultrasound 2 d after G1 (n = 1,294) and 2 d after G2 (n = 1,020). Blood samples were collected at G1 and at PG1 d to evaluate serum progesterone (P4) concentrations. Conventional (n = 314, Angus; n = 1,084, Holstein) and Holstein sexed-semen (n = 276) were used. Pregnancy was diagnosed on d 32, 46, 88, and 200 post-TAI. The high dose of GnRH (200 μg) increased overall ovulatory response to G1 compared with 100 μg (81.3% vs. 65.1%), being similar between parities (primiparous, 72.2%; multiparous, 73.9%). Mean serum P4 concentrations at PG1 did not differ between treatments (100 µg: 9.59 ± 0.15 ng/mL vs. 200 µg: 9.43 ± 0.15 ng/mL). Cows with no ovulation to G1 had higher serum P4 concentrations at G1 than cows with ovulation to G1 (6.27 ± 0.19 ng/mL vs. 4.66 ± 0.07 ng/mL). At PG1, the proportion of cows with functional CL (98.7% vs. 89.7%) and serum P4 concentrations (9.68 ± 0.12 ng/mL vs. 9.14 ± 0.22 ng/mL) were greater in cows that ovulated to G1 compared with cows that did not ovulate. Also, cows that ovulated to G1 had a greater increase in serum P4 concentrations from G1 to PG1 than cows with no ovulation (5.26 ± 0.12 ng/mL vs. 3.32 ± 0.25 ng/mL). The high dose of GnRH improved overall P/AI at 32 d post-TAI in cows inseminated with conventional semen (54.6% vs. 48.2%) and tended to improve P/AI on 46 (48.8% vs. 44.9%), 88 (47.6% vs. 43.4%) and 200 (45.3% vs. 41.2%) d post-TAI. Primiparous cows inseminated with conventional semen had better P/AI than multiparous cows at d 32 (58.2% vs. 49.4%), 46 (55.1% vs. 44.4%), 88 (53.2% vs. 43.2%) and 200 (51.6% vs. 40.7%) post-TAI. Primiparous cows treated with 200 µg GnRH had lower P/AI on d 32, 46, 88, and 200 post-TAI when inseminated with sexed semen than with conventional semen. In summary, the higher dose of GnRH at G1 improved ovulatory response and P/AI at d 32 post-TAI and tended to improve P/AI at d 46, 88, and 200 post-TAI in cows inseminated with conventional semen. Moreover, the effect of treatment on P/AI in primiparous cows depended on semen type (conventional vs. sexed semen).

Summary: It is assumed that cows spend little time waiting for milking in free-flow automated milking systems (AMS), but this has not been assessed. We evaluated cows' (n = 40) milking time behavior and identified factors that influenced the time waiting to be milked in a free-flow AMS herd using video analysis over 2 days. Visit frequency and waiting time to access the robot to be milked were influenced by cows' stage of lactation and parity along with the robot's layout and design. In addition, longer waiting time was associated with shorter lying times. This study highlights the importance of minimizing waiting time to enhance cow comfort by reducing the risk for lameness.

This symposium review examines the association between comfort and cow longevity, with a particular emphasis on optimizing resting behavior in confinement-housed systems. Housed dairy cattle demonstrate a variety of negative behavioral and physiological effects when lying time is restricted, with cows prioritizing the recovery of rest over feeding when both are deprived. There is, however, wide individual-cow variation in daily lying times, influenced by an array of cow-, housing-, and management-related factors. Cow-related factors include individual preference, parity, stage of lactation cycle, milk yield, ill health, and lameness. Lying time tends to increase with age and days in milk and during periods of ill health, whereas milk yield is negatively correlated with lying time. The effect of lameness is complicated by severity and by interactions with bedding type, which modifies the cows' ability to rise and lie down. Generally, lame cows suffer prolonged lying bouts of greater variability in length and take fewer bouts per day. Often this results in an overall increase in lying time. Thus, higher standards of cow comfort and improved cow health are not always reflected by longer lying times. Housing and management factors that influence resting behavior include the design of the resting area, access to the resting space, and the thermal microenvironment of the lying area. Provision of dry, deep loose bedding, stocking cows to allow each animal access to a resting space, allowing sufficient time to access the resting area, and providing heat abatement to reduce heat load optimize resting behavior. Because lameness and poor body condition are commonly found in culled dairy cattle, the link between cow comfort and culling is likely mediated through lameness onset and management. Optimal comfort helps prevent the onset of lameness and facilitates recovery once cows become lame, which limits the effect of lameness on feeding behavior and reduces the risk for other health-related disorders, poor reproductive performance, and early herd removal. Cow comfort cannot be assessed by measuring the duration of lying time alone. Rather, comfort is reflected by the optimization of resting behavior, providing facilities and management to allow cows to lie down when they choose to do so for as long as they need to.