Effects of mother versus artificial rearing during the first 12 weeks of life on challenge responses of dairy cows

Early-life contact with non-maternal adult cows and a pasture-based rearing environment influence behavioural responses of dairy heifers to novelty

The complexity experienced in early life can affect trait development of individuals, including sociability and fearfulness. The modern dairy calf's rearing environment often lacks environmental and social complexity. This study examined the effects of early-life, non-maternal adult contact and access to a physically complex environment on the responses of dairy heifers to several stressors, including restraint, social isolation, and novelty at 18 months of age. From the age of 2-13 weeks, 60 dairy heifers (Bos taurus) were reared according to one of three treatments applied to 20 calves each: (1) Hand-reared at pasture in groups of ten, with three unrelated dry cows (+S); (2) Hand-reared at pasture in groups of ten (-S); or (3) Hand-reared in sheds in groups of 10-12 as a commercial control (CC). At 13 weeks, all treatment groups were mixed and managed at pasture as a single herd. At 18 months, the responses of 50 heifers to restraint in a crush, social isolation and a novel object were observed (+S = 16, -S = 17, CC = 17). Treatment did not influence responses to restraint or social isolation, but influenced some indicators of fearfulness during exposure to a novel object. Six +S heifers interacted with the novel object compared to 0 -S and one CC, and CC heifers spent around 50% more time in vigilance than +S or -S heifers. Dairy heifers provided with early-life social enrichment in the form of non-maternal adult contact may have reduced fear of novelty. The implications for lifelong ability to adapt to novel situations, such as entry into the milking herd, should be assessed.

Three years of situated social learning and development of diverse cow-calf contact systems in Danish organic dairy farms

This study had 2 aims: first, to describe the intent of a learning process among farmers about cow-calf contact (CCC) systems using a so-called Stable School approach, where farmers advise farmers. The second aim was to identify the main themes that arose from the conversations held throughout the 21 meetings that focused on the topic of CCC. The meetings were hosted by 10 host farmers. In total, 32 farmers, farm managers, employees, and calf caregivers who collectively represented 16 farms participated. Characteristics of participating farms varied widely, including herd sizes, which ranged from 7 to 600 cows. At each of the 21 meetings, a written summary was recorded and uploaded to a common data storage site. Using an inductive approach, words, phrases, topics, and suggestions were coded into themes relevant to CCC systems and processes of learning and change. The longitudinal nature of this study allowed for the capturing of how farmers changed their views on how to care for the animals and the concept of keeping cows and calves together. A central theme was how they identified particular challenges associated with a CCC system, such as space requirements or pasture access, and then collectively identified potential solutions for implementing cow-calf contact on their farms, increasingly using experience from their own farms. In addition to raising questions regarding the practical aspects of implementing a CCC system, many participants also raised ethical questions, and many acknowledged their pleasure and joy in seeing the system work and the animals thriving (e.g., when calves were playing or seemed to learn very quickly from the cows). Steps that led to an increased understanding among farmers on this topic included developing a shared language, for instance, referring to the "sharing of milk with the calf" rather than the "loss of milk." Despite the diversity of farms represented by the participants, there was an overall acceptance that they were colleagues and thus were highly supportive of each other. Many participants viewed foster cow systems as a more feasible option for providing CCC than dam-rearing systems, but some also viewed the foster cow system as a stepping stone to their long-term goal of implementing a dam-rearing system. This study provided evidence that socially situated learning and communities of practice can facilitate learning by farmers interested in developing, implementing, and improving CCC systems in different dairy farming contexts.

A Pilot Study on the Feasibility of an Extended Suckling System for Pasture-Based Dairies

This study investigated cow-calf productivity in a 10-week, pasture-based, extended suckling system featuring part-time cow-calf contact and once-a-day milking. A total of 30 dairy cows and their calves were assigned to two treatments: (1) cow and calf managed in an extended suckling system; or (2) cow and calf separated at birth and managed as usual. Cow-calf pairs grazed together during the day and spent the night separated by fence-line contact. The dams were reunited with the calves after once-a-day milking every morning. The commercial treatment pairs were separated after birth, and cows were milked twice a day and managed within the farm herd. Commercial calves were reared and managed as per commercial Australian practices. Cow-calf dams yielded 9 L/cow/day less saleable milk (p < 0.001), and their milk had lower fat (p = 0.04) but a higher protein percentage (p < 0.001) than commercial cows during pre-weaning. However, milk yield and composition were comparable post-weaning. Dam-suckled calves gained weight faster and were therefore weaned 2 weeks earlier than commercial calves, which were offered 8 L/day milk. This study has demonstrated a novel system of extended cow-calf suckling that could be practical to implement in pasture-based dairies. The long-term effects and scalability of the extended suckling system described here require further validation.

Long-term effects of early maternal deprivation on goat social behaviour

Early maternal deprivation has been shown to disrupt goat kids' social behaviour and stress-coping strategy, and has long-term effects in other species like cattle. We studied the long-term effects of early maternal deprivation on 18-month-old goats. Seventeen goats were raised together with their dams (DR kids) and other lactating goats and kids, while 18 goats were separated from their dams three days after birth and artificially reared together (AR kids). Kids of both treatments were weaned around two to three months of age, grouped and raised together until this study 15 months later. Affiliative, playful, and agonistic behaviour was recorded by focal sampling in the home pen, when the focal goat had rejoined the herd after being physically isolated for 3 minutes, and after the focal goat was restrained and manipulated for 3 minutes. Behavioural observations were also conducted after the goats were introduced in groups of four in a herd of 77 unknown, lactating multiparous goats. Avoidance distance tests were performed in the home pen to assess the human-animal relationship. Salivary cortisol was measured before and after physical isolation, and faecal glucocorticoid metabolites were measured before and 24 hours after introduction in the lactating herd. In the home pen, AR goats were involved in less head nudging than DR goats, but other social behaviours or their behavioural and physiological response to the various stressful situations were not affected by their rearing treatment. Upon introduction in a DR lactating herd, most of the agonistic interactions observed were initiated by multiparous goats towards the introduced AR and DR goats alike. AR goats received more threats from the multiparous goats than DR goats, but were involved in less clashing than DR goats. AR goats showed less avoidance of familiar and unfamiliar humans than DR goats. Overall, previously AR and DR goats showed only a few differences in affiliative and agonistic behaviours in their home pen or after being exposed to different stressors 15 months later. Nonetheless, after being introduced into a multiparous goat herd, AR goats were still threatened more often than DR goats, and DR goats clashed more than AR goats, suggesting some persistent differences in their social abilities observed at an early age before and after weaning. As predicted, AR goats remained less fearful of humans than DR goats.

Welfare of calves

This Scientific Opinion addresses a European Commission request on the welfare of calves as part of the Farm to Fork strategy. EFSA was asked to provide a description of common husbandry systems and related welfare consequences, as well as measures to prevent or mitigate the hazards leading to them. In addition, recommendations on three specific issues were requested: welfare of calves reared for white veal (space, group housing, requirements of iron and fibre); risk of limited cow–calf contact; and animal‐based measures (ABMs) to monitor on‐farm welfare in slaughterhouses. The methodology developed by EFSA to address similar requests was followed. Fifteen highly relevant welfare consequences were identified, with respiratory disorders, inability to perform exploratory or foraging behaviour, gastroenteric disorders and group stress being the most frequent across husbandry systems. Recommendations to improve the welfare of calves include increasing space allowance, keeping calves in stable groups from an early age, ensuring good colostrum management and increasing the amounts of milk fed to dairy calves. In addition, calves should be provided with deformable lying surfaces, water via an open surface and long‐cut roughage in racks. Regarding specific recommendations for veal systems, calves should be kept in small groups (2–7 animals) within the first week of life, provided with ~ 20 m²/calf and fed on average 1 kg neutral detergent fibre (NDF) per day, preferably using long‐cut hay. Recommendations on cow–calf contact include keeping the calf with the dam for a minimum of 1 day post‐partum. Longer contact should progressively be implemented, but research is needed to guide this implementation in practice. The ABMs body condition, carcass condemnations, abomasal lesions, lung lesions, carcass colour and bursa swelling may be collected in slaughterhouses to monitor on‐farm welfare but should be complemented with behavioural ABMs collected on farm.

Impact of early dam contact on veal calf welfare

Dairy calves, including surplus calves, are typically separated from their dam within hours of birth. The aim of this study was to assess the welfare impacts of raising surplus calves destined for veal with their dam for 2 or 4 weeks until transport. Surplus calves from one dairy farm were separated from their dam at birth (n = 39) or kept with the dam (n = 37) until transport to the veal farm at either 2 (n = 50) or 4 (n = 26) weeks of age, with abrupt separation for dam-reared calves. Calf measures of body weight, health, immunity, haematology and behaviour were recorded at the dairy and veal farms. Dam-reared calves had higher body weights in weeks 3, 4 and 5 at the DF, as well as at arrival at the veal farm, but by slaughter this advantage was lost. More dam-reared calves had fever in week 3 and showed signs of disease in week 5 at the dairy farm. Dam-reared calves did not differ in IgG, IgA or IgM levels but had higher counts of white blood cells, which could reflect a higher pathogen exposure rather than improved immunity. Dam-reared calves displayed more fear towards humans in a human approach test at 5 and 7 weeks after arrival at the veal farm, and more frequent social behaviours at the veal farm at 9 and 16 weeks of age. In conclusion, it seems that there may be both advantages and disadvantages to keeping veal calves with the dam in terms of welfare in the current system.

Probiotication of Nutritious Fruit and Vegetable Juices: An Alternative to Dairy-Based Probiotic Functional Products

Fruits and vegetables are widely known to be rich in nutrients, antioxidants, vitamins, dietary fiber, minerals, and a bioactive molecule, making them an essential component of a balanced diet with multiple documented positive effects on human health. The probiotication of plant-based juices for the production of functional and nutraceutical food serves as a healthy alternative to dairy probiotics. They are cholesterol free, lack several dairy allergens, and also encourage ingestion for people with lactose intolerance. This review highlights valuable claims regarding the efficacy of different probiotic strains on various diseases. A comprehensive nutrition comparison and the preference of plant-based over dairy probiotic drinks is also discussed, supported with updated market trends of probiotic drinks (dairy and non-dairy based). An extensive compilation of current plant-based probiotic drinks that are available in markets around the world is listed as a reference. The fermentability of carbon sources by probiotic microorganisms is crucial in addressing the development of plant-based drinks. Therefore, the pathway involved in metabolism of sucrose, glucose, fructose, and galactose in fruit and vegetable juice was also underlined. Finally, the key factors in monitoring the quality of probiotic products such as total soluble solids, sugar consumption, titratable acidity, pH, and stability at low storage temperatures were outlined.

Social behavior in farm animals: Applying fundamental theory to improve animal welfare

A fundamental understanding of behavior is essential to improving the welfare of billions of farm animals around the world. Despite living in an environment managed by humans, farm animals are still capable of making important behavioral decisions that influence welfare. In this review, we focus on social interactions as perhaps the most dynamic and challenging aspects of the lives of farm animals. Social stress is a leading welfare concern in livestock, and substantial variation in social behavior is seen at the individual and group level. Here, we consider how a fundamental understanding of social behavior can be used to: (i) understand agonistic and affiliative interactions in farm animals; (ii) identify how artificial environments influence social behavior and impact welfare; and (iii) provide insights into the mechanisms and development of social behavior. We conclude by highlighting opportunities to build on previous work and suggest potential fundamental hypotheses of applied relevance. Key areas for further research could include identifying the welfare benefits of socio–positive interactions, the potential impacts of disrupting important social bonds, and the role of skill in allowing farm animals to navigate competitive and positive social interactions. Such studies should provide insights to improve the welfare of farm animals, while also being applicable to other contexts, such as zoos and laboratories.

Maternal deprivation affects goat kids’ social behavior before and after weaning

Maternal deprivation has been shown to disrupt the development of neonates. Nevertheless, separating the young animals from their dams soon after birth is a common practice in dairy farming. We investigated the effects of maternal deprivation on goat kids’ (Capra hircus) social behavior and social ontogeny before and after weaning. Twenty female kids were raised together with their dams (DR kids) and other lactating goats and kids, whereas 20 female kids were separated from their dams 3 days after birth and artificially reared together (AR kids). At weaning, each treatment group was split in half and moved into two new pens where they were mixed with the other treatment group. Social behaviors were recorded before and after weaning. Before weaning, AR kids were observed performing more play‐fighting, racing, stepping on each other, and standing in contact with each other than DR kids, but AR allogroomed less and spent less time resting alone than DR kids. After weaning and mixing of the treatments, DR kids initiated more and received less agonistic interactions than AR kids, but this difference reduced across the 5 weeks of observations as AR kids appeared to progressively change their social behavior after interacting with DR kids.

A review of factors affecting the welfare of dairy calves in pasture-based production systems

Current research on factors affecting the welfare of dairy calves is predominantly based on indoor, year-round calving systems. Calf rearing in these systems differs from that in more seasonal, pasture-based dairy production, meaning that risks to the welfare of dairy calves may not always be comparable between the two systems. The aim of this review was to consolidate the scientific literature relating to calf welfare in pasture-based dairy systems from birth until weaning, allowing for (1) the identification of current and emerging risks to calf welfare and (2) the formation of recommendations to mitigate these risks. Many of the risks to calf welfare discussed in this review are not exclusive to pasture-based dairies. This includes a global trend for increasing perinatal mortalities, a significant number of calves failing to achieve effective passive transfer of immunity, the low uptake of best practice pain relief when calves are disbudded, and the feeding of restricted milk volumes. In addition to these persisting welfare risks, two factors discussed in this review pose an immediate threat to the social license of dairy farming; the separation of cow and calf soon after birth and the management of surplus calves (i.e. calves not needed by the dairy industry). Several recommendations are made to improve the uptake of best-practice calf rearing and progress the development of alternative pasture-based rearing systems that accommodate changing community expectations. These include communication strategies that strengthen farmer beliefs regarding the welfare and productivity benefits achieved by best practice calf rearing and challenge beliefs regarding the associated costs. Farmers should also be encouraged to benchmark their rearing practices through improved record keeping of key rearing inputs and outcomes. Biological research is needed to advise the development of new calf rearing recommendations and the evolution of existing recommendations. Research priorities identified by this review include the effects of dystocia on the neonate and strategies to mitigate these effects, relationships between features of pen design and calf health and welfare, feasibility of dam rearing in large pasture-based dairy systems, and strategies that increase the value of the surplus calf.

Short- and long-term effects of rearing dairy calves with contact to their mother on their reactions towards humans

In this Research Communication we address the hypotheses that reduced contact with humans during the first week of life would impair the relationship of dairy calves reared in dam-calf-contact systems to humans in comparison with artificially reared animals, but that this difference would vanish over time. Artificially reared calves (Artificial) that had been separated from their mother within 12 h after birth were bottle-fed with colostrum for 5 d and thereafter sucked milk from an automatic milk feeder. Animals reared with dam-calf contact (Dam-contact) were kept in the calving pen with their dam for 5 d, and then had permanent access to the cow barn and thus to their dam. Calves were weaned at an age of 12 weeks and kept in young stock groups mixed of both treatments until integration into the cow herd. We tested the animals' relationship with humans by assessing the animals' responses towards an unfamiliar person in an avoidance distance (AD) test in the home environment at 4 weeks of age, at 15 months and at 33 months. In calves, we additionally measured AD in a novel arena after a stationary person test. Artificial animals had lower AD, i.e. showed lower level of fear, than Dam-contact calves. However, the AD in Dam-contact calves decreased with increasing number of days they experienced assistance for suckling. Further, there was no significant difference in later ages. In conclusion, gentle human contact in combination with feeding during the first 5 d of life improved calves' relationship to humans leading to differences between the two treatments as well as within the Dam-contact calves. Potential effects under different conditions regarding quantity and quality of human-animal interactions need further research.

Maternal deprivation affects goat kids' stress coping behaviour

Maternal deprivation early in life has been shown to disrupt neonates' development. Nevertheless, separating the young animals from their dams soon after birth remains a common practice in dairy farm husbandry. This study investigated the effects of different rearing conditions on goat kids' stress coping abilities. Twenty female kids were raised together with their dams ('dam-reared') in a herd composed of other lactating goats and kids, while twenty female kids were separated from their dams three days after birth and reared together with same-age peers ('artificially-reared') and visually separated from the lactating herd. All kids shared the same father and two thirds of the kids were twins allocated to each treatment. At one month of age, kids were individually submitted to a series of tests: a novel arena test, a novel goat test, and a novel object test. These tests happened consecutively in this order, and lasted 180 s each. The kids' behaviour was video-recorded and analysed post-hoc by an observer blind to treatments. Five weeks after weaning, the kids were also subjected to human-animal relationship tests. During the three behavioural tests, artificially-reared kids vocalized more (P < 0.001), reared more (P < 0.001), ran more (P = 0.002) and jumped more (P < 0.001) than dam-reared kids, but self-groomed less (P = 0.01) and urinated less (P = 0.05) than dam-reared kids. During the novel goat test and the novel object test, artificially-reared kids gazed less at the novel goat and the novel object (P = 0.02) and initiated contact more quickly (P = 0.05) with the novel goat and the novel object than dam-reared kids. The treatments however did not differ significantly in salivary cortisol response to the tests (P = 0.96). Artificially-reared kids showed significantly less avoidance of humans than dam-reared kids during the human-animal relationship tests after weaning (P < 0.001). The higher intensity of their behavioural reaction showed that artificially-reared kids react to stressful situations more actively than dam-reared kids. The difference between the three tests were only minor, suggesting a general change in the kids' response to stressful situations rather than a specific change in their social response tested with an unfamiliar adult. Hence, artificial rearing affects goat kids' behavioural response to challenges, probably maternal deprivation being the main factor.

The effect of rearing conditions during the milk-fed period on milk yield, growth, and maze behaviour of dairy cows during their first lactation

The objective was to find whether cow growth, milk performance, and behaviour are affected by (1) rearing conditions until weaning after a milk-fed period of 84 d and (2) the sire lineage. Thirty-five Holstein heifers were assigned to one of three treatments: SM, n=13, pen with mother to 21st day, then group pen (they received a maximum of 6 kg of milk daily); SN, n=9, after 3 d with own mother in pen with nursing cow (they received a maximum of 6 kg of milk daily); H, n=13, in hutch from the 2nd to 56th day (6 kg of milk replacer daily), then loose housing pen to weaning (6 kg of milk replacer daily). After weaning at the 84th day, all heifers were kept in pens with the same ration as during calving. During lactation, live body weight (LBW) was measured each month and milk yield each day. Maze learning was evaluated in the fifth month of lactation. The data were analysed using a general linear model ANOVA. At the 30th day, the LBW tended to be the highest in SN (SM 528.2 ± 11.4 kg, SN 571.7 ± 15.3 kg, H 533.2 ± 12.3 kg). When lactation ended, the highest LBW was in SN and the lowest in H (SM 612.6 ± 12.2 kg, SN 623.1 ± 16.4 kg, H 569.8 ± 13.2 kg; P<0.05). The SN tended to have the highest production of milk (SM 7143.9 ± 241.5 kg, SN 7345.1 ± 319.0 kg, H 7146.7 ± 234 kg), and the H for FCM (SM 6290.3 ± 203.2 kg, SN 6307.6 ± 268.4 kg, H 6399.3 ± 197.1 kg) for 305 d lactation. Group SN crossed the maze fastest (SM 1141.4 ± 120.5 s, SN 810.3 ± 160.5 s, H 1120.8 ± 118.6 s). The vocalization number differed significantly (SM 32.3 ± 5.7, SN 20.8 ± 4.4, H 9.9 ± 2.6; P<0.01). The results indicated that the rearing method up to weaning may have an impact on dairy cows' performance and behaviour.

Early-Life Dam-Calf Contact and Grazing Experience Influence Post-Weaning Behavior and Herbage Selection of Dairy Calves in the Short Term

Rearing dairy calves with their mothers could teach them how to graze, optimizing grass use, and improving their welfare and performance. We tested the short-term effects of dam-calf contact experience on grazing and social behavior of weaned calves, monitored over seven days for their first post-weaning grazing experience. “Dam” (D) calves were reared and grazed with their mothers until weaning. “Mixed” calves (M) were separated from their mothers after 4 ± 0.5 weeks, they experienced dam-calf contact, but not grazing. “Standard” (S) calves had never experienced either dam-calf contact (separated at birth) or grazing. Each group grazed an equivalent pasture plot offering heterogeneous herbage. Scan sampling of calves' activities was performed every 5 min, 6 h per day, on Days 0, 1, 2, 3, and 7. Daily, the time when calves started grazing after introduction to pasture, and the number and duration of their grazing cycles were measured. Daily activities were differentiated into ingestion, rumination, and idling. The proportion of time that calves spent grouped with other individuals or isolated, and standing or lying were recorded. When grazing, their bites were characterized by botanical family group, height of the selected bite and vegetation status. Individual average daily gains from the 2-week periods before and after grazing were calculated, and were equivalent between groups (313 ± 71 g/d). On Day 0, D-calves started grazing immediately (1 ± 4.1 min), unlike M- and S-calves (39 ± 4.1 and 23 ± 4.1 min), and D-calves grazed patches of dry grass 21.7 times less than M-calves and 16.9 times less than S-calves. Dry herbage patch preference and grazing start time differences disappeared on Day 1. Calves spent the same time ingesting and idling, but M-calves spent on average 1.6 times less ruminating than D- or S-calves. The D-calves showed grazing behavior similar to that of adult cows, selecting grasses throughout pasture utilization, although legumes and forbs were present in the grazed layer. On the contrary, M- and S-calves did not express any specific preference. The S-calves spent more time isolated but had more positive reciprocal interactions than the calves in the other groups.

Calves' management conditions affect sperm count in adult bulls

Background

Early maternal separation may have long-lasting physiological effects on different organ systems. Although long-lasting effects of early maternal separation are mostly studied in connection with the development and function of the central nervous system hypothalamic–pituitary–adrenal axis, animal health, behaviour and productivity, there is a lack of information about its impacts on the reproductive system. In the dairy industry, calves are often separated from mothers 1 or 2 days after birth and are not nursed. In the present retrospective study based on data from an artificial insemination (AI) centre, we compared semen parameters and fertility in bulls that were separated from their mothers one day after birth with the semen parameters of bulls that remained with their mothers and were nursed for approximately 2 months. Semen parameters were followed in 3 consecutive years in 52 maternally separated and 22 nursed bulls.

Results

Ejaculate volume and total sperm count in ejaculate were significantly higher in nursed bulls in comparison to maternally separated bulls at the age 25–36 and 37–48 months, but interestingly, not at the age 12–24 months, during the first year in the AI centre. Non-return rates did not differ between separated and nursed bulls.

Conclusion

The results suggest that early maternal separation causes long-lasting effects on the functioning of the male reproductive system, evident by reduced production of semen in adult bulls. The data suggest that with a standard of 20 million sperms per straw of frozen semen, 27–78 fewer straws can be obtained from one ejaculate of maternally separated bulls in comparison to the nursed bulls.

The influence of maternal contact on activity, emotionality and social competence in young dairy calves

The study reported in this research communication aimed to assess the influence of maternal contact on calves' activity, fearfulness, and social competence. Calves were either dam-reared for their first 14 d of age (Maternal Contact, n = 12) or were separated from their dams within 12 h after birth (Motherless, n = 12). Calves of both treatments and the dams of Maternal Contact calves were group-housed and suckling was prevented with udder nets. The general activity (lying, locomotion, swapping between lying and standing) was measured using pedometers in eight Maternal Contact and eight Motherless calves within a 24-d period. Since general activity might be affected by calves' age or the separation of Maternal Contact calves from the dams the 24-d period was additionally divided into two groups (period A: 3rd–13th day of age, period B: 14th–27th day of age). Emotionality and social competence were assessed in the open field, novel object, and confrontation test with an unknown cow at 14, 21, and 28 d of age, respectively. Mann–Whitney-U-tests were performed for statistical analysis. Locomotion was greater in Motherless calves than Maternal Contact calves during the 24-d period (A + B combined, P < 0.001) and period B (14th to 27th day of age, P < 0.001). There was no treatment difference in duration of lying or in the amount of swapping in any of the periods. After a Bonferroni correction, which we used due to the exploratory character of the study, there were no treatment differences in behaviours indicating emotionality. Compared to Motherless calves, Maternal Contact calves showed increased vigilance (P < 0.01) during the confrontation test. The results of this study indicate that mother-reared calves likely searched less for social contact and developed greater social skills than calves that were separated from their mothers soon after birth.

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.

Play and social behaviour of calves with or without access to their dam and other cows

The aim of the study reported in this Research Communication was to compare play behaviour and social interactions of dairy calves either separated from their mother and reared in a calf group (Artificial) or with access to their mother and the cow herd (cow-calf contact: Contact). Contact calves had access to a calf area and also to the cow barn where they could suckle their dam. Artificial calves were fed whole milk up to 16 kg per day via an automatic milk feeder and were only kept in the calf area. We observed the animals on 3 d during the first three months of life. Contact calves showed solitary play, consisting predominantly of locomotor play, for longer than Artificial calves and mainly in the cow barn. This indicates higher welfare in Contact calves. In addition, Artificial calves hardly experienced any agonistic interaction, while Contact calves both initiated and received agonistic interactions, which might contribute to the development of higher social competence.

Invited review: A systematic review of the effects of prolonged cow-calf contact on behavior, welfare, and productivity

Separation of calves from cows within hours or days of birth is common on dairy farms. Stakeholders have conflicting perspectives on whether this practice is harmful or beneficial for the animals' welfare and production. Our objective was to critically evaluate the scientific evidence for both acute and long-term effects of early separation versus an extended period of cow-calf contact. The outcomes investigated were the behavior, welfare (excluding physical health), and performance (milk yield and growth, respectively) of dairy cows and calves. Primary research papers were found through targeted Web of Science searches, the reference lists of recent reviews for each topic, and the reference lists of papers identified from these sources. Studies were included if they were published in English, the full text was accessible, and they compared treatments with and without contact between dairy cows and calves for a specified period. Early separation (within 24 h postpartum) was found to reduce acute distress responses of cows and calves. However, longer cow-calf contact typically had positive longer-term effects on calves, promoting more normal social behavior, reducing abnormal behavior, and sometimes reducing responses to stressors. In terms of productivity, allowing cows to nurse calves generally decreased the volume of milk available for sale during the nursing period, but we found no consistent evidence of reduced milk production over a longer period. Allowing a prolonged period of nursing increased calf weight gains during the milk-feeding period. In summary, extended cow-calf contact aggravates the acute distress responses and reduces the amount of saleable milk while the calves are suckling, but it can have positive effects on behaviors relevant to welfare in the longer term and benefit calf growth. The strength of these conclusions is limited, however, given that relatively few studies address most of these effects and that experimental design including timing of contact and observations are often inconsistent across studies. Few studies presented indicators of long-term welfare effects other than abnormal and social behavior of the calves.

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.

Dairy cows - an opportunity in the research field of non-genetic inheritance?

More than 1 billion cattle are raised annually for meat and milk production. Dairy cows are repeatedly impregnated and separated from their calves, usually within the first 24 h after birth. Here, I suggest that dairy cows undergo a procedure comparable to the 'Maternal separation combined with unpredictable maternal stress' paradigm (MSUS), which is used to study the non-genetic inheritance (NGI) of phenotypes in rodents. I discuss what research on dairy cows may bring to the research field of NGI. The resulting research findings are likely to have benefits to our understanding of MSUS, NGI and consumer safety.

American and German attitudes towards cow-calf separation on dairy farms

Public concerns regarding the quality of life of farm animals are often focused on specific practices such as separating the cow and calf immediately after birth. The available scientific literature provides some evidence in support of this practice (including reduced acute responses to separation when it does occur), as well as evidence of disadvantages (such as increased risk of uterine disease in cows). The aim of this study is to systematically examine public views around this practice. Specifically, this study analyzes the views of American and German citizens to separation of cow and calf at birth using a quantitative segmentation approach. Although the majority of participants opposed early separation, a small proportion of our sample supported the practice. According to participants’ preference for early and later separation and their evaluation of different arguments for both practices, three clusters were identified. US participants were more likely to support early separation compared to German participants. The arguments presented for and against both practices caused different reactions in the three clusters, but did not appear to sway the opinions of most participants. The results show considerable opposition to the practice of early separation in large parts of the sample and suggest that the dairy industry should consider approaches to address this concern.

Invited review: Effects of group housing of dairy calves on behavior, cognition, performance, and health

Standard practice in the dairy industry is to separate the calf and dam immediately after birth and raise calves in individual pens during the milk-feeding period. In nature and in extensive beef systems, the young calf lives in a complex social environment. Social isolation during infancy has been associated with negative effects, including abnormal behavior and developmental problems, in a range of species. Here, we review empirical work on the social development of calves and the effects of social isolation in calves and other species; this evidence indicates that calves reared in isolation have deficient social skills, difficulties in coping with novel situations, as well as specific cognitive deficits. We also review the practices associated with group housing of dairy calves, and discuss problems and suggested solutions, especially related to cross-sucking, competition, aggression, and disease. The studies reviewed indicate that social housing improves solid feed intakes and calf weight gains before and after calves are weaned from milk to solid feed. Evidence regarding the effects of social housing on calf health is mixed, with some studies showing increased risk of disease and other studies showing no difference or even improved health outcomes for grouped calves. We conclude that there is strong and consistent evidence of behavioral and developmental harm associated with individual housing in dairy calves, that social housing improves intakes and weight gains, and that health risks associated with grouping can be mitigated with appropriate management.