Invited review: The effect of weaning practices on dairy calf performance, behavior, and health-A systematic review.

The aim of this systematic review was to summarize the literature assessing the effects of weaning practices on performance, behavior, and health of dairy calves. Only published, peer-reviewed articles written in English and specifically assessing the effects of weaning treatments on dairy calves were eligible for inclusion. Studies had to include 2 or more treatment groups that addressed at least one of 4 interventions: weaning age (i.e., when milk was fully removed), weaning duration (i.e., number of days from start of milk reduction to when milk was fully removed), weaning criteria (e.g., age vs. intake), or alternative weaning methods (e.g., water dilution). Outcome measures could include starter intake, growth (BW or ADG), behaviors (5 specific sucking behaviors; play behavior; lying behavior; vocalizations; unrewarded visits to an automated milk feeder), and health (mortality rate, diarrhea, and respiratory illness). We conducted 3 targeted searches using Web of Science and PubMed. The articles underwent a 2-step screening process, resulting in a final sample of 44 studies. The majority of studies investigated weaning age (n = 22), followed by weaning duration (n = 13), weaning criteria (n = 9), and other weaning methods such as dilution, linear versus step-down milk reduction, or meal-based approaches (n = 6). There was consensus for positive effects (or at least no negative effects) on overall growth of calves weaned at later ages, over longer durations, based on starter intake, or weaned using step-down or meal-based milk removal approaches. This is despite reduced starter intake in calves weaned at later ages; most studies found improved starter intake in calves weaned over longer durations. Weaning based on starter intake had superior growth and feed intakes compared with calves weaned at a fixed earlier age. Few studies assessed interactive effects of weaning method and milk allowance. However, weaning after 8 wk appears to support superior weight gain, provided preweaning milk allowances are adequate (above 6 L/d). Weaning can lead to hunger-related behaviors and reduced welfare, yet only half of the studies assessed the effects of weaning method on calf behavior. Weaning at later ages can reduce signs of hunger (based on unrewarded visits to the milk feeder), but it is unclear if weaning over longer durations or weaning by starter intake reduces or prolongs hunger. There was little consensus among the few studies that measured oral behaviors of calves. Positive welfare indicators, such as play behavior, were rarely measured, yet are crucial to understanding the emotional states of calves during this potentially stressful diet transition. Health was rarely the primary objective of the study, with low sample sizes to conduct statistical comparisons. Overall, there remains significant knowledge gaps in our understanding of how best to wean calves. A successful weaning program must minimize signs of hunger while promoting high growth and feed intakes, so we encourage future work to include behavioral indicators of hunger and positive welfare to evaluate how weaning methods are experienced by the calf.

Behavioral responses of dairy cows and their calves to gradual or abrupt weaning and separation when managed in full- or part-time cow-calf contact systems.

There is growing interest in managing cow and calf together for a prolonged period, but concerns remain about how best to wean and separate the cow and calf to minimize stress. One approach is to progressively reduce suckling opportunity over time, as in nature. There is also interest in part-time contact (suckling for part of the day) to improve milk yield for the farmer and potentially reduce stress at weaning and separation. The primary objective of this study was to compare the behavioral responses of dairy cows to gradual or abrupt weaning and separation, when managed either full or part time with their calves; a secondary focus was the vocal responses of calves under these management conditions. In a 3 × 2 factorial design (n = 14/ treatment), dairy cows and their calves (n = 84 in 7 blocks of 12 cow-calf pairs) were assigned to one of 3 dam-contact treatments at birth: (1) full-time contact between the dam and calf, apart from milking times (total 23 h/d) (2) part-time contact between the dam and calf, between morning and afternoon milking only (total 10 h/d); (3) no contact, where the dam and calf were separated after leaving the maternity pen and had no further contact. At wk 8, one of 2 weaning treatments was assigned: (1) gradual weaning by reduced contact time (50%, then 25% of original dam-contact time in wk 8 and 9, respectively), or gradually reduced milk allowance for no-contact calves (50%, then 25% of estimated 12-L milk intake in wk 8 and 9, respectively) until complete milk removal and dam-calf separation at wk 10; (2) abrupt weaning where milk removal occurred simultaneously with dam-calf separation at wk 10, or only milk removal for no-contact calves. Overall, part-time contact did not reduce weaning and separation distress for cows or calves for either weaning method. Part-time cows showed reduced behavioral responses to separation (greater lying time and less searching behavior), especially on the day of and 24 h after separation, but they showed a similarly strong vocal response to separation as full-time cows. Part-time calves made substantially more high-pitched vocalizations than full-time calves at 24 h after separation. Furthermore, gradual weaning by reducing contact time did not seem to better prepare cows or calves for complete milk removal and separation; most behavioral and vocal responses occurred on the day of separation for gradual-weaning cows and calves, but 24 h later, the reverse occurred for abrupt-weaning cows and there was no difference between gradual- and abrupt-weaning calves. Our results suggest that part-time contact and gradual-weaning conditions likely resulted in hunger and expectation for reunion, which together may have exaggerated behavioral responses at separation. Temporary daily separations may not have increased independence of cow and calf, and the gradual-weaning method here may not have reduced milk intake by calves. These elements are important criteria to facilitate the weaning process, so future work should explore ways to gradually reduce milk intake and promote social independence of cow and calf to minimize weaning distress.

Maternal behavior of dairy cows and suckling behavior of dairy calves in different cow-calf contact conditions.

Cow-calf contact has been suggested as an alternative to the common practice of early separation of dairy cow and calf. Increasing cow-calf contact poses challenges by reducing the machine milk yield and increasing separation stress. Part-time cow-calf contact may prove more feasible than full-time contact for farmers but may affect the maternal behavior of the cows. Gradually reducing the daily contact could gradually wean the calf off milk, preparing it for separation. This study aims to investigate (1) how cows' maternal behaviors toward their own calf are affected by part-time contact, and (2) whether calves' suckling behavior is reduced by reducing daily cow contact. Fifty-six dairy cows and their calves were assigned to either full-time (23 h/d) or part-time (10 h/d) cow-calf contact for 7 wk (main rearing period). This was followed by 2 wk of either reduced contact (50% in wk 8, then 25% of original contact time in wk 9) or unchanged contact. First, the maternal behavior of full- and part-time cows was observed for 24 h in the third week of the main rearing period. Part-time cows spent less time nursing and grooming their own calf than full-time cows did. However, the amount of nursing in the inverse parallel position and the probability of a cow nursing a calf other than her own did not differ between the 2 treatments. Second, calf suckling behavior was observed for 24 h in both weeks of the reduced contact period. Averaged across both observations, total suckling time (i.e., time spent suckling any cow) was lower in part-time calves that experienced reduced contact compared with part-time calves with unchanged contact. In wk 9, time spent suckling only the dam was lower for full-time calves with reduced contact compared with part-time calves with unchanged contact. In conclusion, although we found a lower nursing and grooming time in part-time cows compared with full-time, we found no difference between treatments with regard to nursing in the inverse parallel position and nursing a calf other than the cow's own. The effect of gradually reducing cow-calf contact on calves' suckling time requires more research.

Comparing weaning methods in dairy calves with different dam contact levels.

Allowing the dam to rear her calf is an alternative practice in the dairy industry where cow and calf may gain welfare benefits from performing natural and highly motivated behaviors. However, this system has been linked to an increased separation and weaning response. Reducing the daily dam-calf contact time may be a way to prepare the calf for weaning and separation. The first aim of the present study was to investigate the effect of 8 wk of half-day dam-calf contact on calf response to weaning and separation, compared with calves reared with whole-day dam-calf contact and an artificially reared, group-housed control with unrestricted access to milk for 20 min twice daily. Weaning off milk and separation from the dam can be viewed as 2 independent stressors. By introducing each stressor separately, it may be possible to reduce the overall behavioral response. The second aim of the present study was to investigate the effect of 1-wk fence-line weaning before permanent separation. The study was conducted with a 3 × 2 factorial design with dam contact treatments (whole-day, half-day, and control) and weaning treatments (simultaneous, and stepwise). Whole-day calves were separated twice daily from their dams during milking, whereas half-day calves were separated daily from the afternoon milking and until next morning milking. Simultaneous weaning and separation were done in wk 9, and stepwise weaning and separation started in wk 8 with calves being fence-line weaned before permanent separation in wk 9. Data were collected on 69 dairy calves in wk 8 and wk 9, and data were summarized over the 2 weeks for analysis. Stepwise weaning and separation reduced the number of high-pitched vocalizations and activity of dam-reared dairy calves but had little effect on control calves. There was no difference between whole-day and half-day calves in their response to separation, but as expected, dam-reared calves reacted more strongly than the control group. This was also reflected in the average daily BW gain the week after weaning, with control calves having higher average daily gains than whole-day, while half-day calves were intermediate. However, the behavioral response did not fully wane within the observation period (0-48 h of interventions). In conclusion, 1-wk fence-line weaning reduced the summed weaning and separation response in dam-reared calves. However, no difference between half-day dam-calf contact and whole-day dam contact was detected in the behavioral response to weaning and separation.

Behavior of calves reared with half-day contact with their dams.

Dam-calf contact has been suggested to improve animal welfare in dairy calves, but practical and economical concerns have led to interest in half-day contact between cows and their calves. However, little is known about the behavioral effects of half-day contact compared with whole-day contact. The present study investigated the behavior of 45 dairy calves housed with their dams in either a whole-day system (cows only away twice daily for milking) or a half-day system (cows away from afternoon milking until after morning milking the next day). Data were video recorded during 24 h when calves were on average 3, 5, and 7 wk old. Half-day calves spent less time suckling and received less grooming compared with whole-day calves, indicating that they received less maternal care. Half-day calves were quicker to reunite with their dam when the cows returned from morning milking compared with whole-day calves. Half-day calves also suckled alien cows more often, although mainly shortly after the cows returned to the pen in the morning. This may indicate that they were hungrier than whole-day calves at this time of day. Half-day calves spent more time eating solid feeds, which may prepare them better for separation from the dam and weaning off milk. In conclusion, half-day dam-calf contact may affect calf welfare both positively and negatively, and further research focusing more directly on assessing affective states is encouraged.

Effects of feed energy density, daily milking frequency, and a single injection of cabergoline on behavior and welfare in dairy cows at dry-off.

Drying off dairy cows may challenge animal welfare due to high milk yields. A total of 111 loose-housed Holstein cows yielding >15 kg/d of milk were included in a 2 × 2 × 2 factorial design during dry-off to investigate the effects of reduced feeding level (normal vs. reduced energy density), reduced milking frequency (twice vs. once daily), and administration of a dopamine agonist (saline i.m. injection vs. cabergoline i.m. injection) on behavior in the home pen. During the 7 d before dry-off, cows were fed and milked according to 1 of the 4 feeding level and milking frequency combinations. Within 3 h after the last milking, cows were injected i.m. with 5 mL of either saline or a dopamine agonist (5.6 mg of cabergoline; Velactis, Ceva Santé Animale, Libourne, France; labeled for use only with abrupt dry-off, i.e., no preceding reduction in feeding level or milking frequency before last milking). Cows' behavior during d -1, 0, and +1 relative to the last milking was recorded via video and leg-attached sensors. Cows on the reduced energy density diet spent more time feeding and showed more attempts to feed from other cows' bins on d -1. Throughout the period of observations, cows on the reduced diet spent a lower percentage of lying time with their head raised, a higher percentage of lying time with their legs bent, and less time standing in a vigilant posture than did cows on the normal lactation diet. Reducing the daily milking frequency from 2 to 1 did not result in any clear behavioral signs of discomfort. On d 0, cows injected with cabergoline lay down longer but had their head raised for a shorter percentage of time while lying, compared with cows injected with saline. Cows injected with cabergoline also spent less time feeding than cows injected with saline on d 0, and reduced the time spent drinking from d -1 to d 0. Finally, fewer cabergoline-injected cows used the brush for self-grooming, and, among cows that did use the brush, the cows injected with cabergoline reduced the time spent using the brush from d -1 to d 0. In conclusion, cows injected with cabergoline showed several behavioral changes compared with control cows injected with saline. The behavioral changes shown by cows injected with cabergoline may be indicative of malaise during the first 24 h after injection, raising concern for animal welfare. No behavioral evidence for reduced udder pain in cows injected with cabergoline compared with control cows injected with saline was found. Drying off by reducing the energy density of the diet caused behavioral changes indicative of hunger before dry-off, whereas reducing the milking frequency had no clear effects on behavior.

Effects of feeding level and milking frequency on behavior of dairy cows before dry-off.

Drying-off may challenge the welfare of especially high-yielding dairy cows. In this study, 119 loose-housed Holstein cows yielding ≥20 kg milk/d were enrolled in a 2 × 2 factorial design aiming to investigate effects of changes in diet energy density and daily milking frequency on behavior. The last 7 d before the dry-off day, cows were milked either twice or once daily, and were fed either a lactation diet or the same diet diluted with 30% barley straw, both offered in individual bins for ad libitum intake. All cows were fitted with sensors to record lying time and activity, and data from 109 of these cows were used together with behavioral observations obtained from video recordings of 52 of the cows. Data from activity sensors and video recordings were obtained during 24 h on d -6, -3, and -1 relative to the dry-off day (i.e., the day of the last milking). Across all days of observation, cows milked once daily spent more time feeding (149 vs. 130 min/d) than cows milked twice daily. Cows on the reduced diet and milked twice daily had a shorter lying time compared with cows on the normal diet and milked twice (759 vs. 837 min/d), whereas lying times of cows on the remaining 2 treatments were intermediate. Among cows on the lactation diet, reduced milking frequency increased time spent perching (from 11.1 to 28.7 min/d). Cows fed the energy-reduced diet spent more time feeding (154 vs. 124 min/d), showed more attempts to feed from unassigned feed bins (31.7 vs. 15.4 attempts daily), and spent less time using a mechanical brush (6.5 vs. 9.2 min/d) than cows fed the lactation diet. These results show that several aspects of cows' behavior, including main activities such as lying and feeding, but also behaviors of low resilience such as brush use, and to some extent more subtle and complex behaviors such as perching and attempts to feed from unassigned feed bins, are sensitive to management changes typically applied during the days before dry-off. The behavioral effects of the reduced feed energy level support earlier findings suggesting that qualitative feed restriction renders cows hungry. The effects of the reduced milking frequency on behavior were generally less pronounced, but 2 noteworthy interactions between milking frequency and diet were seen. First, cows milked twice daily and fed the energy-reduced diet spent less time lying, which is possibly related to increased energy demand and hunger. Second, cows milked once daily and fed the lactation diet spent more time perching, which may be related to udder discomfort. However, these more complex findings warrant further study. Taken together, the results of this study show that a dry-off procedure involving reduced energy supply induces behavioral changes indicating a higher degree of compromised welfare compared with reduced milking frequency.

The effect of hides and parity on behavior of periparturient dairy cows at pasture.

Under natural conditions, most parturient cows seek visual cover or seclude themselves from the herd when calving becomes imminent. Studies on calving site selection of dairy cows housed indoors show that predominantly older and dominant cows calve in secluded areas. This study aimed to investigate whether cows distance themselves further from herd members under spacious outdoor conditions and whether artificial hides on a pasture motivate cows to seek visual isolation from the herd. One hundred eighty-two Danish Holstein cows were allocated to 1 of 13 groups of 14 cows according to expected calving date. In 2 paddocks (each 75 × 150 m), 5 zones (75 m × 30 m) were defined; zone 0 contained the feeding and shade area, and zone 4 bordered an area with trees. Weekly and according to calving date, a group of 14 cows was moved either to a paddock that had 12 hides distributed evenly throughout zones 1 to 4 (7 groups) or to a paddock without hides (6 groups). The hides were wooden structures (3.3 m long × 1.0 m wide × 1.2 m high) that the cows could hide behind. One hundred seven cows calved within 14 d of having been moved to the paddock, and 82 of these (38 primiparous and 44 multiparous), and their calves, were included in the study. From 3 h before until 3 h after calving, the location, posture, and behavior of cows were recorded continuously from video recordings. In addition, location, posture, and behavior of the calves were recorded for the first 3 h after birth. Continuous variables were analyzed by linear mixed effects models, whereas binary data were analyzed using mixed effects logistic regression. The presence of hides did not affect selection of calving location in the paddock, but more primiparous than multiparous cows calved in zone 4; that is, furthest away from the feeding area. Before calving, primiparous cows were more likely to be positioned in zone 4 and less likely to approach and contact herd members. After calving, primiparous cows and their calves tended to be more likely to be positioned in zone 4. The more cows present in the paddock, the less likely the cows were to isolate (i.e., be further than 30 m away from any other cow) at the time of calving. In addition, the more cows in the paddock when a calf was born, the less time these calves spent in a lying posture. The results show that primiparous cows move further away from herd members at calving than multiparous cows and suggest that primiparous cows prefer to isolate themselves through distance rather than seeking artificial cover. Contrary to expectation, the hides did not make more cows select a calving site away from the feeding area.

Invited review: Freedom from thirst-Do dairy cows and calves have sufficient access to drinking water?

The importance of drinking water for production and animal welfare is widely recognized, but surveys and animal welfare assessment schemes suggest that many dairy calves and dairy cows do not have sufficient access. Limit milk-fed calves drink more water than calves fed milk ad libitum, but ad libitum milk-fed calves also require access to drinking water, as milk does not meet the animal's requirement for water. At hot ambient temperatures and when calves are sick, access to water is especially important and should be provided at all times. Many young calves do not have access to water throughout 24 h, and whether healthy young calves require free access to water at all times, or from which age, is not clear and requires further study. Dairy cow free water intake (FWI) is largely determined by milk yield, and high-yielding dairy cows may drink up 100 L of water per day. Dry matter, crude protein, and salt content of feed, as well as ambient temperature, have considerable effects on dairy cow water intake. Deprivation of water affects meal patterning for the cow, as well as increased subsequent rate of drinking and compensatory water intake. Although dairy cow ad libitum water intake may exceed the water provision necessary to maintain production, offering water for ad libitum intake may be necessary to safe guard animal welfare. Cattle are suction drinkers that prefer to drink from large open water surfaces, and Holstein dairy cows can drink at a rate of up to 24 L/min. Research on the effect of design and placement of water troughs for indoor-housed dairy cows on their drinking behavior and water intake is limited. Access to a water source at pasture increases the time cows spend there, and access to shade reduces water requirements during periods of warm weather. In both indoor and pastured cattle, there is a lack of knowledge about the effect of stocking of water troughs on competition, drinking behavior, and intake in dairy cows. Studies on the effect of available water trough length and placement, and of the number of cows being able to drink from the same trough of a given dimension, are needed to evaluate current recommendations.

Invited review: Lying time and the welfare of dairy cows.

Adequate time lying down is often considered an important aspect of dairy cow welfare. We examine what is known about cows' motivation to lie down and the consequences for health and other indicators of biological function when this behavior is thwarted. We review the environmental and animal-based factors that affect lying time in the context of animal welfare. Our objective is to review the research into the time that dairy cows spend lying down and to critically examine the evidence for the link with animal welfare. Cows can be highly motivated to lie down. They show rebound lying behavior after periods of forced standing and will sacrifice other activities, such as feeding, to lie down for an adequate amount of time. They will work, by pushing levers or weighted gates, to lie down and show possible indicators of frustration when lying behavior is thwarted. Some evidence suggests that risk of lameness is increased in environments that provide unfavorable conditions for cows to lie down and where cows are forced to stand. Lameness itself can result in longer lying times, whereas mastitis reduces it. Cow-based factors such as reproductive status, age, and milk production influence lying time, but the welfare implications of these differences are unknown. Lower lying times are reported in pasture-based systems, dry lots, and bedded packs (9 h/d) compared with tiestalls and freestalls (10 to 12 h/d) in cross-farm research. Unfavorable conditions, including too few lying stalls for the number of cows, hard or wet lying surfaces, inadequate bedding, stalls that are too small or poorly designed, heat, and rain all reduce lying time. Time constraints, such as feeding or milking, can influence lying time. However, more information is needed about the implications of mediating factors such as the effect of the standing surface (concrete, pasture, or other surfaces) and cow behavior while standing (e.g., being restrained, walking, grazing) to understand the effect of low lying times on animal welfare. Many factors contribute to the difficulty of finding a valid threshold for daily lying time to use in the assessment of animal welfare. Although higher lying times often correspond with cow comfort, and lower lying times are seen in unfavorable conditions, exceptions occur, namely when cows lie down for longer because of disease or when they spend more time standing because of estrus or parturition, or to engage in other behaviors. In conclusion, lying behavior is important to dairy cattle, but caution and a full understanding of the context and the character of the animals in question is needed before drawing firm conclusions about animal welfare from measures of lying time.

The effect of milk feeding strategy and restriction of meal patterning on behavior, solid feed intake, and growth performance of male dairy calves fed via computer-controlled milk feeders.

Dairy calves are often offered milk allowance at a flat rate during the first 6 wk of life, although an initial high allowance followed by a stepwise reduction (step-down strategy) may correspond better to the calves' nutritional needs. The amount of milk offered per feeding is typically constant. However, during natural suckling, the daily number of milk meals (suckling frequency) declines with age, which may reflect increased consumption of solid feeds. Thus, allowing calves to pattern their meals on a computer-controlled feeder by placing less restriction on meal frequency may stimulate dairy calves' ingestion of solid feeds. This experiment investigated the effects of milk feeding strategy and milk feeding frequency on calves' feeding behavior, intake, and growth. Sixty-four male Holstein Friesian calves, purchased from conventional dairy farms, were housed in groups of 8 and fed milk replacer (MR) via computer-controlled milk feeders. From 14 d old, calves were assigned to either a conventional flat-rate milk allowance (CON: 6.5 L/d of MR from d 14 to 42; 4 L/d from d 43 to 49; 2 L/d from d 50 to 56 of age) or to stepwise reduction in milk allowance (STEP: 8 L/d of MR from d 14 to 28; 5 L/d from d 29 to 42; 4 L/d from d 43 to 49; 2 L/d from d 50 to 56 of age). Within each group of 8, 4 calves were randomly allocated to each of 2 milk feeding frequencies, either restricted portion size (RES: maximum milk portion size of 2.3 L/portion) or unrestricted portion size (UNRES). Concentrates, hay, and water were available ad libitum. Feeding behavior was recorded via video for 24 h on 26 and 40 d of age. On d 26, where STEP calves were offered 1.5 L/d more milk than CON calves, no difference was seen regarding the time spent eating concentrate (16.9 vs. 20.3 min/d). However, STEP calves spent more time eating concentrate on d 40, where these calves had 1.5 L/d less milk than CON (36.1 vs. 27.2 min/d). Thus, a lower daily milk allowance stimulated feeding on concentrate d 40, but not d 26. As predicted, UNRES calves spent more time eating concentrate (27.6 vs. 21.9 min/d) and more time eating hay (38.4 vs. 30.0 min/d) than RES calves. However, higher appetite for solid feeds by UNRES calves may not be explained by milk intake per se. Rather, this is likely due to their opportunity to have larger milk meals, which appeared to increase their appetite for milk (as indicated by longer time spent in the milk feeder; 64.0 vs. 48.8 min/d) as well as for solid feeds. Among CON calves, the UNRES treatment resulted in higher ADG 2 wk postweaning, but not among STEP calves. These findings partially support that relaxing restriction on milk portions helps calves to transition from milk to solid feeds before weaning off milk. However, more research is needed to determine how restriction on milk portions interacts with milk feeding strategy when a higher total milk allowance is offered.

Methodology for experimental and observational animal studies in cow-calf contact systems.

In this Research Reflection we describe a common standpoint on suitable methodology for controlled and observational studies in cow-calf contact systems in dairy production. Different methods to assess behaviour, health and production in cow-calf contact systems are outlined. Knowledge and experience from researchers working in this field supplement scientific literature whenever relevant. Specific methods including study design, early behaviour of cow and calf, social behaviour relevant to cow-calf contact systems, human-animal relationships and aspects related to management (milking, weaning and separation, health) are reviewed, and recommendations formed. We expect that this paper can contribute to a better understanding of the complexity of cow-calf contact systems and help to advance research in this area of dairy production.

Methodological terminology and definitions for research and discussion of cow-calf contact systems.

Due to increasing public concern regarding separation of the dairy cow and calf within the first days after birth, alternative systems, where cows and calves stay in contact for an extended period, are receiving increasing interest from a broad array of researchers and other stakeholders. With more research in the area, there is a risk of inconsistencies emerging in the use of terminology. To create a better consensus in further discussions, the aim of this Research Reflection is to provide definitions and propose a common terminology for cow-calf contact in dairy production. We also suggest definitions for various systems allowing cow-calf contact and describe the distinct phases of cow-calf contact systems.

Assessing response to dry-off in dairy cows kept outdoors using spontaneous behaviours and infrared thermography-a pilot study.

We used spontaneous behaviours to assess response to dry-off involving abrupt dietary and milking frequency changes, followed by regrouping, after the last milking in 15 clinically healthy Holstein-Frisian cows kept outdoors. Moreover, we explored the potential of infrared thermography to detect eye temperature variations possibly induced by dry-off. On days - 1, 0, 1 and 2 relative to dry-off, we recorded whether cows vocalised during feed delivery; ate fresh feed within 5 min; and mean maximum eye temperature at approximately 1 h after feed delivery. On days 1 and 2, cows were more likely to eat fresh feed compared to days - 1 and 0. No difference in likelihood of vocalising was found. Compared to day - 1, eye temperature was substantially higher on days 0 and 2. Collectively, the results suggest that cows responded, both behaviourally and physiologically, to the abrupt dry-off management. The interpretation of the current findings deserves further investigation using larger sample sizes, more controlled environments and further behavioural, physiological, cognitive and clinical measures.

Secluded maternity areas for parturient dairy cows offer protection from herd members.

Use of individual maternity pens for dairy cows is recommended to ensure undisturbed calving and postpartum transfer of colostrum to calves, but management of these pens is a challenge due to difficulty predicting the time of calving. If group-housed cows, however, have the opportunity to calve in a secluded area of a group pen, this may limit disturbance of the dam and her newborn, especially if this area is fitted with a gate preventing other cows from entering. The aims of this study were to assess effects of cows calving inside a secluded area versus cows calving in the group area on maternal behavior and social interaction between dam and herd members during the first postpartum hour, calf's latency to stand, number of calves suckling an alien cow, and the dam's acute response to separation from the calf. This was investigated in pens consisting of a central group area with access to 6 secluded areas with or without a mechanical push gate allowing only 1 cow access at a time. At least 2 wk before expected calving, 60 Danish Holstein multiparous cows were assigned alternately, in groups of 6, to a group pen with 6 gated secluded areas or a group pen with 6 ungated secluded areas. The effects of treatment (gated, ungated) and calving place chosen within treatment (secluded area, group area) on maternal behavior, interactions with herd members, maternal response to separation, and calf latency to stand were investigated. Irrespective of whether cows calved in a secluded area or not and whether the secluded area was gated or not, cows spent, on average, 39 (±7.9) min of the first hour after calving licking their calves. When calving in a gated secluded area, the cows interacted less with herd members than when calving in the group area (0.5, 28, 18, and 33 min/h for gated/secluded, gated/group, ungated/secluded, and ungated/group areas, respectively), and no calves suckled an alien cow within the first hour after birth. In addition, the longer the calf stayed with the dam, the longer the dam stood with her head out of the pen after removal of the calf. Calf's latency to stand after calving was unaffected by treatment and calving place (mean = 39 min; range = 8-243 min). The results show that dam and calf can be protected from disturbances when cows calve in a secluded maternity area, especially if the secluded maternity area is fitted with a gate preventing other cows form entering.

Better recovery from lameness among dairy cows housed in hospital pens.

Housing in hospital pens may be beneficial for lame cows due to soft flooring and less competition for resources. We compared recovery from lameness among dairy cows housed in designated hospital pens, with deep-litter straw, with recovery among cows housed together with the rest of the lactating cows in their home pens, with cubicles and slatted or solid concrete floors. Additionally, we compared lying behavior in the 2 groups of cows. A total of 168 lame dairy cows from 5 herds were included in the study. Each herd was visited once weekly, and lame cows (locomotion score 3 or 4 on a 5-point scale) were examined in a hoof-trimming chute, trimmed, and randomly assigned to 1 of 2 treatments: housing in a hospital pen (termed "treatment"; 72 cows) or housing under the herds' standard conditions together with the rest of the lactating cows in the herd (termed "control"; 96 cows). Cows were locomotion scored weekly until they were no longer lame or until they had been part of the trial for 3 weeks (i.e., 2, 3, or 4 locomotion scorings per cow). We categorized cows to describe the progression of lameness over time: recovery (divided into fast, medium, or slow), improvement without recovery, constant lameness, or worsening of lameness. Lying behavior was recorded in a sample of 60 of the 168 cows for a period of 5 d. Overall, recovery from lameness was significantly different between treatment and control cows. The proportion of cows included in the study with locomotion score 4 and a subsequent improvement was significantly higher among treatment cows than among control cows. Among cows included with locomotion score 4, 40% of treatment cows also had a locomotion score 4 at the fourth locomotion scoring, 46% had improved to a score 3, and 14% were no longer lame. In comparison, 73% of control cows had a locomotion score 4 at the fourth locomotion scoring, 16% had improved to a score 3, and 11% were no longer lame. We found no differences between treatment and control cows for mean daily lying time, number of steps per day, number of daily lying bouts, or mean duration of lying bouts. Housing of lame dairy cows in a hospital pen with a soft surface, easier access to feed and water, a smaller group size, and reduced waiting time for milking may have positive effects on recovery from lameness. Typically, farmers have housed only severely lame cows in hospital pens. However, our results indicate that less severely lame cows may also benefit from a stay in a hospital pen.

The degree of visual cover and location of birth fluids affect dairy cows' choice of calving site.

Under natural conditions, cows seek isolation and visual cover when calving becomes imminent, but the degree of visual cover necessary to provide an attractive calving site is not known. When calving indoors, preparturient cows are attracted to other cows' birth fluids, and this may influence their isolation seeking. Therefore, we aimed to investigate the effect of degree of visual cover of secluded areas and the location of birth fluids on dairy cows' calving site selection. One hundred twenty-four Danish Holstein cows were moved in groups of 8 to 12 to a group pen with access to 6 areas secluded by a barrier of either 3 m (wide barrier) or 1.5 m (narrow barrier). Sixty cows calved within 14 d of having been moved to the group pen and were included in the study. From 3 h before partition and until the cow and calf were removed from the pen within 3 h after parturition, the location and posture of cows were recorded, along with the location of where their birth fluids were discharged. In addition, location and posture of calves were recorded during and up to 3 h after calving. All data were collected from continuous video recordings. Continuous data for location and behavior were analyzed by mixed models, binary data were analyzed by chi-squared analysis, and location of calving relative to where the cow's own or alien birth fluids were discharged was analyzed using logistic regression models. Ten percent of the cows calved in a secluded area, with no effect of barrier width. However, before calving, cows with access to secluded areas with a wide barrier spent more time in a secluded area (22 vs. 7 min/3 h), and more cows were observed lying there (58 vs. 28%) than cows with access to secluded areas with a narrow barrier. Secluded areas with a wide barrier were used by more cows and calves during the first hour after calving (36 vs. 10%). Among the cows that entered a secluded area after calving, the latency to enter correlated with their calf's latency to enter, suggesting that the 2 sought seclusion together. Seventy-nine percent of the cows calved in proximity (within a 1.25-m radius) to their own or an alien cow's birth fluids. There was no effect of barrier width on the probability of calving in proximity to their own or alien birth fluids. However, the probability of calving in proximity to their own or alien birth fluids was higher than the probability of not doing so. The greater use of secluded areas with a 3-m-wide barrier before and after parturition suggests that these are preferred over areas with a 1.5-m-wide barrier. Only a few cows calved in a secluded area, and more research is needed to explore the environmental and social factors affecting parturient cows' use of designated calving areas. The majority of cows calved close to where their own or alien birth fluids were discharged, suggesting that cows are attracted to these before calving. This may have affected the use of secluded areas as calving sites.

Effect of group size and health status on behavior and feed intake of multiparous dairy cows in early lactation.

Dairy cows in early lactation are often housed in a large group, where they may have to compete for access to feed and space. However, a cow's ability to compete may be impaired due to production disease, and housing in a small group with minimal competition may be beneficial for cow welfare. The aim of this study was to investigate the effect of group size and health on social and feeding behavior of cows during the first 3 d after introduction to a new group. Data included 54 multiparous Holstein-Friesian cows that were moved from an individual maternity pen and individually joined an existing group pen for 6 (N6) or 24 cows (N24) on d 4 after calving. Cows were considered sick if they were diagnosed with and treated for milk fever, mastitis, or retained placenta, diagnosed with subclinical ketosis or metritis within 3 d of calving, or were diagnosed and treated for any other infection (n = 22; balanced across treatments). Stocking density of both pens was 100% at the feeding and lying areas. Behavioral data were collected from video recordings during the 1 d after introduction to the group pen, as well as via electronic feed bins and leg-attached accelerometers during the first 3 d after introduction to the group pen. No interactions between health status and group size were discovered. During the 1 d after introduction, N6 cows displaced other cows from feed less frequently than N24 cows (1.22 vs. 5.76 times/24 h), were less likely to access feed after a displacement (replacement; 0.29 vs. 1.67 times/24 h), and were less frequently being butted by another cow (0.42 vs. 1.69 times/24 h). Second-parity cows received more head butting than later-parity cows. Data obtained from feed bins showed that the number of replacements peaked on d 2 after introduction to the group pen. During the first 3 d we observed no effect of group size on DMI, but sick cows ate less than cows that were not sick (15.2 vs. 16.6 kg of DM/d). However, cows in N6 visited the feeder less often (42.4 vs. 55.6 times/d). Over the 3 d after introduction DMI and feeding time increased, whereas feeding rate decreased. Lying time and the number of lying bouts increased from d 1 to 2. The number of steps decreased over days, but the number of steps was higher among N24 than N6 cows on d 1 and d 2. Results suggest that cows experience less competition when moved to a smaller group after calving regardless of health status. Thus, minimizing competition by housing dairy cows in a small group for the first days after calving may improve cow welfare under commercial conditions.

Effects of level of social contact on dairy calf behavior and health.

Housing preweaned dairy calves in pairs rather than individually has been found to positively affect behavioral responses in novel social and environmental situations, but concerns have been raised that close contact among very young animals may impair their health. In previous studies, the level of social contact permitted in individual housing has been auditory, visual, or physical contact. It is unclear how these various levels of social contact compare with each other and to pair housing, when their effects on behavior and health are considered, and whether the timing of pair housing has an effect. To investigate this, 110 Holstein calves (50 males, 60 females) in 11 blocks were paired according to birth date. Within 60h of birth, each pair of calves was allocated to 1 of 5 treatments: individual housing with auditory contact (I), individual housing with auditory and visual contact (V), individual housing with auditory, visual, and tactile contact (T), pair housing (P), or individual housing with auditory and visual contact the first 2wk followed by pair housing (VP). At 6wk of age, calves were subjected to a social test and a novel environment test. In the social test, all pair-housed calves (P and VP) had a shorter latency to sniff an unfamiliar calf than did individually housed calves (I, V, and T), whereas calves with physical contact (T, P, and VP) sniffed the unfamiliar calf for longer than calves on the remaining treatments (I and V). In the novel environment test, calves with physical contact (T, P, and VP) had a lower heart rate, and more of these calves vocalized during the test compared with calves without physical contact (I and V). No effect of treatment was found for clinical scores, levels of the 5 most common pathogens in feces, or in development of serum antibodies against the 3 most common respiratory pathogens. Calves housed individually are more fearful of unfamiliar calves than are pair-housed calves. Contrary to common belief, the allowance of physical contact and pair housing had no effects on the health of the calves.

Gradual weaning of 3-month-old calves from foster cows in dairy production.

When calves are reared by cows, separation can be stressful, and it is often advised to use gradual weaning to minimize this stress. In foster cow systems, one gradual weaning method is to remove the foster cows, one by one, from the cow-calf group. The response to one-by-one removal of foster cows of 32 calves housed in 5 groups was studied. Calves were fostered to a designated foster cow individually, in pairs, or in trios, at the age of 1 to 2 wk and then housed in groups of 4 to 6 foster cows and 6 to 11 calves until gradual weaning started at 3 mo of age. Calf behavior and aggression received by calves from cows were recorded using video during 18 h before any foster cow was removed, as well as 18 h before and 18 h after the designated foster cow was removed from the group. Before any foster cow was removed, the calves spent a similar amount of time sucking the designated foster cow and other cows (in total 43 ± 5 min/18 h). The total duration of sucking was similar before and after the designated foster was removed, as the duration of sucking other cows increased. The number of aggressive events received from other cows also increased. The results indicate that milk availability for the group of calves decreases as foster cows are gradually removed and that the older and heavier calves increasingly compete with the younger and lighter calves for the available milk. This weaning method may also compromise the welfare of the foster cows that are left to wean off an increasing number of calves, and this warrants further research.