Associations between Feeding Behaviors Collected from an Automated Milk Feeder and Neonatal Calf Diarrhea in Group Housed Dairy Calves: A Case-Control Study.

The objective of this case-control study was to determine if feeding behavior data collected from an automated milk feeder (AMF) could be used to predict neonatal calf diarrhea (NCD) in the days surrounding diagnosis in pre-weaned group housed dairy calves. Data were collected from two research farms in Ontario between 2017 and 2020 where calves fed using an AMF were health scored daily and feeding behavior data (milk intake (mL/d), drinking speed (mL/min), number of rewarded or unrewarded visits) was collected. Calves with NCD were pair matched to healthy controls (31 pairs) by farm, gender, and age at case diagnosis to assess for differences in feeding behavior between case and control calves. Calves were first diagnosed with NCD on day 0, and a NCD case was defined as calves with a fecal score of ≥2 for 2 consecutive days, where control calves remained healthy. Repeated measure mixed linear regression models were used to determine if there were differences between case and control calves in their daily AMF feeding behavior data in the days surrounding diagnosis of NCD (-3 to +5 days). Calves with NCD consumed less milk on day 0, day 1, day 3, day 4 and day 5 following diagnosis compared to control calves. Calves with NCD also had fewer rewarded visits to the AMF on day -1, and day 0 compared to control calves. However, while there was a NCD status x day interaction for unrewarded visits, there was only a tendency for differences between NCD and control calves on day 0. In this study, feeding behaviors were not clinically useful to make diagnosis of NCD due to insufficient diagnostic ability. However, feeding behaviors are a useful screening tool for producers to identify calves requiring further attention.

Symposium review: Precision technologies for dairy calves and management applications.

There is an increasing interest in using precision dairy technologies (PDT) to monitor real-time animal behavior and physiology in livestock systems around the world. Although PDT in adult cattle is extensively reviewed, PDT use for the management of preweaned dairy calves has not been reviewed. We systematically reviewed research on the use and application of precision technologies in calves. Accelerometers have the potential to be used to monitor lying behavior, step activity, and rumination, which are useful to detect changes in behavior that may be indicative of disease, responses to painful procedures, or positive welfare behaviors such as play. Automated calf feeding systems can control delivery of nutritional plans to individualize feeding and weaning of calves; changes in feeding behaviors (such as milk intake, drinking speed, and unrewarded visits) may also be used to identify early onset of disease. The PDT devices also measure physiological and physical attributes in dairy calves. For instance, temperature monitoring devices such as infrared thermography, ruminal boluses, and implanted microchips have been assessed in calves, but no herd management-based commercial system is available. Many other PDT are in development with potential to be used in dairy calf management, such as image and acoustic-based monitoring, real-time location, and use of enrichment items for monitoring positive emotional states. We conclude that PDT have great potential for application in dairy calf management, enabling precise behavioral and physiological monitoring, targeted feeding programs, and identification of calves with poor health or behavioral impairments. We strongly encourage further development and validation of commercially available technologies for on-farm application of the monitoring of dairy calf welfare, performance, and health.

Technical note: Estimating body weight of dairy calves with a partial-weight scale attached to an automated milk feeder.

Monitoring early growth in neonatal dairy calves provides insight into the effectiveness of a producer's nutrition program and helps monitor for sickness. The objective of this study was to validate whether a partial-weight scale attached to an automated milk feeder (Combi; DeLaval, Tumba, Sweden) could precisely and accurately estimate calf weights compared with twice-weekly weights of a calibrated electronic scale (gold standard; Brecknell PS1000; Avery Weigh-Tronix LLC, Fairmont, MN). Holstein heifers (n = 20) were enrolled in this study from birth until 84 d of age. All heifers were eligible to receive 10 L of milk replacer/d for 56 d and were subsequently weaned using a step-down strategy across 14 d. The automated milk feeder had a radio frequency identification panel placed directly above the scale such that calves had to stand with both front hooves on the scale platform to access milk from the nipple. An algorithm was created to summarize and clean the scale measurements of any non-biologically relevant data points. The relationship between the daily weight average from the partial scale and the electronic scale was analyzed using Pearson correlations, linear regressions, and Bland-Altman plots. Data from the partial weight scale were considered precise if the correlation coefficient and coefficient of determination were very high (>0.90) and the mean bias from the Bland-Altman plots included zero with the 95% interval of agreement. The partial-weight scale was considered accurate if the slope from the linear regression did not differ significantly from 1. We found a very high Pearson correlation coefficient (0.99) and coefficient of determination (0.99). Bland-Altman plots were deemed acceptable and nonbiased; the Bland-Altman difference (feeder weight - scale weight) was 0.45 ± 2.33 kg (mean ± standard deviation). The slope of the linear regression was not different from 1 (slope = 1.01; 95% confidence interval = 1.00-1.03), suggesting that the partial-weight scale was accurate. In summary, the partial-weight scale was validated, with a high precision and accurate estimate of weight in calves compared with the gold standard electronic scale. The partial-weight scale may be a useful tool for producers to estimate calf weight if a data cleaning algorithm is used.

Effect of milk feeding strategy and lactic acid probiotics on growth and behavior of dairy calves fed using an automated feeding system1.

Automated milk feeders offer flexibility to feed calves high milk allowances, to change the daily quantity of milk offered, and also to dispense additives like probiotics on an individual basis. Our objectives were to test the effects of 2 milk feeding protocols and a lactic acid bacterium probiotic on performance and behavior in calves. Heifer dairy calves (n = 96) were enrolled at birth in a 2 × 2 factorial study design comparing feeding (1) 2 milk feeding protocols and (2) a lactic acid bacterium-based probiotic program, or a placebo, using automated milk feeders. The early milk feeding strategy (EM) offered a maximum of 11 L/d on day 1 and a peak maximum allowance of 15 L/d on day 21. The late milk feeding strategy (LM) offered a maximum of 7 L/d on day 1 and increased slowly to its peak at 13 L/d on day 28. Both feeding strategies gradually weaned the calves after peak milk allowance until complete weaning at day 53, offering a total of 543 liters of milk. Probiotics or placebo were fed orally in a gel once after colostrum, and twice daily in the milk until weaning. Water and calf starter were provided ad libitum. The experimental period was divided into 3 periods: from day 1 on the automated feeder to day 28 (Period 1), from day 29 to day 53 (Period 2), and the week post-weaning (Period 3). For Period 1, the average daily gain (ADG) of the probiotic group was greater than that of the placebo group (0.84 ± 0.10 kg/d vs. 0.74 ± 0.10 kg/d, respectively), but was not different between milk feeding strategies. For Period 2, ADG was not affected by probiotic or milk feeding strategies. For Period 3, ADG was greater for EM compared to LM (1.27 ± 0.10 kg/d vs. 1.02 ± 0.10 kg/d, respectively), but not between probiotic and placebo groups. During the whole experimental period, LM calves consumed significantly more milk than the EM calves (431.84 ± 33.0 liters vs. 378.64 ± 34.2 liters, respectively). During Period 3, probiotics affected the frequency of visits to the calf starter feed bunk (37.72 ± 2.8 vs. 23.27 ± 2.8 visits per day for probiotic and placebo groups, respectively), but did not affect total time spent at the feed bunk. The supplementation of a lactic acid-based probiotic improved ADG during early life and altered some aspects of the feeding behavior of dairy calves. Calves receiving an early accelerated milk allowance had improved growth during post-weaning and consumed less milk in total, which may indicate better use of solid feed.

Current perspectives on the short- and long-term effects of conventional dairy calf raising systems: a comparison with the natural environment.

Although the neonatal and infancy period is short, it is well documented that the early neonatal environment is critical for appropriate physical, behavioral, and cognitive development that lasts into adulthood. Dairy calves are commonly removed from the dam shortly after birth and raised in individual housing and fed limited milk allowances (4 to 6 L/d) in commercial farms around the world (conventional raising). Individual housing was developed to promote health status and facilitate individual animal monitoring. However, it is associated with high labor demand, and early life social isolation is associated with cognitive and behavioral abnormalities. Recently, group housing and enhanced milk-feeding programs are being increasingly adopted by farms; these practices more closely resemble the social and nutritional environments in natural or seminatural environments when the calf is raised with the dam. Conventional raising may lead to short- and long-term effects when compared to calves raised with the dam or peers. Short-term effects of conventional raising include impaired social skills when introduced to novel peers, reduced consumption of novel feeds, increased activity in a novel environment, and signs of hunger associated with limited milk intake and poor growth during the preweaning period. Evidence also suggests that the long-term effects of conventional artificial raising systems include behavioral differences, such as lower social submissiveness, increased heart rate and cortisol when presented with a novel environment, and production differences such as milk yield and reproductive performance. However, research on the long-term effects of maternal, social, physical, and nutritional restrictions in early life is still limited and should be encouraged. More research is needed to determine the long-term effects of artificial raising systems (individual, group housing, dam-raised) on future behavior, cognition, performance, and health parameters in dairy calves.

Impact of Observed and Controlled Water Intake on Reticulorumen Temperature in Lactating Dairy Cattle.

Dairy precision technologies helps producers monitor individual animals. Reticulorumen temperature boluses are a way to monitor core body temperature; however, factors such as water intake affects reticulorumen temperature. This research determined the effect of natural water intake and a controlled water drench on reticulorumen temperature (RT) in dairy cattle. In observational study part 1, tie- stall cows (n = 4) with RT transponders were observed for natural water intake (recorded by in line water meters) for 48 h. In experiment part 2, a randomized Latin square design with cows (n = 12) restricted on feed for 4 h, were drenched daily with a water quantity of 6.7 L, 11.4 L or 22.7 L, and at controlled water temperature of 1.7 °C, 7.2 °C, 15.5 °C, or 29.4 °C. Descriptively, observational study 1 had (Mean ± SD 0.27 ± 0.31 L ingested per drinking event (n = 84) and RT decline from baseline was 2.29 ± 1.82 °C. For the experiment, a 48-h specific rolling baseline temperature range (BTR) was calculated for each cow prior to the experiment to determine time required for RT to reach BTR, and time to return to BTR. In part 2 of the experiment, as water quantity increased, RT had a greater maximum degree drop from baseline. Water temperature and water quantity interaction influenced time required for BTR to reestablish. The coldest water temperature at the highest drench quantity affected time for BTR to reestablish the longest (103 min). Results from this study suggest that an algorithm could be designed to predict water intake events for producers using reticulorumen temperature.