Unravelling variation in feeding, social interaction and growth patterns among pigs using an agent-based model

Domesticated pigs, Sus scrofa, vary considerably in feeding, social interaction and growth patterns. This variation originates partly from genetic variation that affects physiological factors and partly from behavioural strategies (avoid or approach) in competitive food resource situations. Currently, it is unknown how variation in physiological factors and in behavioural strategies among animals contributes to variation in feeding, social interaction and growth patterns in animals. The aim of this study was to unravel causation of variation in these patterns among pigs. We used an agent-based model to explore the effects of physiological factors and behavioural strategies in pigs on variation in feeding, social interaction and growth patterns. Model results show that variation in feeding, social interaction and growth patterns are caused partly by chance, such as time effects and coincidence of conflicts. Furthermore, results show that seemingly contradictory empirical findings in literature can be explained by variation in pig characteristics (i.e. growth potential, positive feedback, dominance, and coping style). Growth potential mainly affected feeding and growth patterns, whereas positive feedback, dominance and coping style affected feeding patterns, social interaction patterns, as well as growth patterns. Variation in behavioural strategies among pigs can reduce aggression at group level, but also make some pigs more susceptible to social constraints inhibiting them from feeding when they want to, especially low-ranking pigs and pigs with a passive coping style. Variation in feeding patterns, such as feeding rate or meal frequency, can indicate social constraints. Feeding patterns, however, can say something different about social constraints at group versus individual level. A combination of feeding patterns, such as a decreased feed intake, an increased feeding rate, and an increased meal frequency might, therefore, be needed to measure social constraints at individual level

Associations between colostrum management, passive immunity, calf-related hygiene practices, and rates of mortality in preweaning dairy calves

peer-reviewedCalves are particularly vulnerable to health issues before weaning and experience high rates of mortality. Poor colostrum quality or substandard colostrum management, combined with poor hygiene, can increase disease susceptibility, contributing to elevated mortality rates. This study aimed to assess colostrum and calf management together with subsequent mortality rates in preweaning calves. Forty-seven Irish spring-calving, pasture-based dairy herds were enrolled in the study. To investigate whether colostrum and hygiene practices change as the calving season progresses, each farm was visited in both the first and last 6 wk of the calving season. The concentration of IgG in 250 colostrum samples and 580 calf serum samples was determined by radial immunodiffusion assay. Mean colostrum IgG concentration was 85 mg/mL, and mean calf serum IgG concentration was 30.9 and 27.1 mg/mL, respectively, in the first and last 6 wk of the calving season. Smaller herd size and younger age at sampling were associated with higher calf serum IgG concentration. Dairy breed calves were associated with higher serum IgG concentrations compared with beef breed calves; no association was detected based on sex. For feeding equipment hygiene, we assessed the presence of protein residues and found that hygiene levels tended to worsen from the first to the final 6 wk of the calving season. We found no association between feeding equipment hygiene and herd size or 28-d calf mortality rate. Colostrum and calf management practices were not associated with either calf serum IgG concentration or 28-d calf mortality rate. We found that IgG concentration in colostrum produced in Irish dairy herds was generally good, although large variation existed, emphasizing the need for assessment of colostrum before feeding. Results also suggested that hygiene practices associated with calf rearing can be improved, particularly in the latter half of the calving season

Comparing gradual debonding strategies after prolonged cow-calf contact: Stress responses, performance, and health of dairy cow and calf

We assessed effects of two-step debonding strategies in calf rearing systems with different types of prolonged cow-calf contact (CCC) on stress responses, health and performance of dairy cows and calves. Forty-eight Holstein Friesian cow-calf pairs had either: 1) full contact including suckling, where contact was reduced before weaning via fence-line separation at day 49 (FC-FS) (n = 10); 2) full contact, where contact was reduced at day 56 by fitting calves with a nose-flap (FC-NF) (n = 10); 3) partial contact (calves were housed in a pen adjacent to the cow area allowing physical contact on initiative of the dam but no suckling), where contact was reduced before weaning by moving the calf box from the wall to prevent physical contact at day 49 (PC-BW) (n = 6); 4) partial contact, where contact was reduced the week after weaning by moving the calf box away from the wall at day 63 (PC-AW) (n = 12); 5) no contact (calves were removed from dam directly after birth and housed in a calf barn), calves were weaned at day 56 (NC) (n = 10). Between weeks 7–10, we assessed physiological stress parameters, weight gain, and the health status of calves, plus general activity patterns based on accelerometer sensor data of cow-calf pairs before, during and after the debonding interventions. Additionally, calves were subjected to four consecutive behavioural tests (i.e. open field, novel object, voluntary human approach and involuntary human approach test) prior to permanent separation at day 70 and their behavioural responses were assessed via video recordings to assess fearfulness. Machine-harvested milk yields of cows were evaluated during weeks 6–12. Data were analyzed with (generalized) linear mixed models. Throughout the debonding period, FC-NF calves had an impaired growth rate (P = 0.02). In weeks 6–9, FC-FS and FC-NF cows had lower machine-harvested milk yields than PC-BW, PC-AW, and NC cows (P ≤ 0.01). We found no differences in responsiveness of calves to behavioural tests, except that NC calves exhibited more solitary play events compared to PC and FC calves in the novel object test (P = 0.002). Overall, our results imply that calves with partial CCC showed low stress responses to debonding, whereas abrupt weaning with a nose-flap during full contact seemed most stressful. Machine-harvested milk yield of FC cows seemed to recover once calves were weaned. More research into strategies to improve the process of debonding is warranted

The effects of manual and automated milk feeding methods on group-housed calf health, behaviour, growth and labour

It has been suggested that the integration of automatic feeding systems into calf rearing programmes has the potential to improve calf behaviour, growth and the associated labour. Thus, the objective of this study was to compare the effects of automatic and manual feeding systems on calf health, behaviour, growth and labour. A population of 60 dairy heifer calves was used: 44 Holstein-Friesian (HF) and 16 HF x Jersey (JE), balanced for birth weight (33 ± 4.1 kg), birth date (26 January ± 3.2 days) and breed. The experiment was a randomised block design including two treatments; i) automated calf feeding system (AFS) and ii) manual calf feeding system (MFS). Each treatment was replicated once, so a total of four balanced groups of 15 heifer calves were created. Milk replacer was offered at a rate of 6 L per calf/day (reconstitution rate 15%), with fresh water, ad-libitum concentrates and hay offered from three days old. Calves were weaned based on weight (90 kg for HF and 85 kg for HF x JE). Total labour input/day was consistently less for AFS compared to MFS (-00:01:06 per calf/day). Automatic feeding systems had a higher labour requirement for health inspections and training to the system (+00:00:15 per calf/day and +00:02:06 per calf/day, respectively), on a per calf basis, compared to MFS. The MFS-calves had an increased likelihood of experiencing faecal scores > 0 (Odds Ratio (OR) = 2.009; Confidence Interval (CI) = 1.463 – 2.759). The MFS-calves were also more likely to defecate and urinate (OR= 1.450; CI = 1.080-1.945), eat (OR= 1.281; CI = 1.140 – 1.439) and socially interact (OR= 1.300; CI = 1.111 – 1.521), compared to standing. There was no difference in number of days from birth to weaning (80.8 days) and weight at weaning (92.9 kg); average daily gain in both the pre (81 days) and post weaning (79 days) periods was similar between the two treatments (0.74 and 0.70 kg/day, respectively). Patterns for behaviours such as lying and playing were similar and low levels of abnormal behaviours were found in both treatments. Calves in both treatments exhibited good health and normal behavioural patterns as well as similar growth rates. Thus, when managed appropriately, the saving of labour is a distinct advantage automated feeding systems have over their manual counterparts when rearing group-housed calves.</p

Barren diets increase wakeful inactivity in calves

Inactivity is a vastly understudied behavioural category, which may reflect positive or negative affective states in captive or domesticated animals. Increased inactivity in barren-housed animals, in combination with an increased or decreased interest in stimuli, e.g. novel objects, can indicate boredom or apathy. Another theory is that inactivity is an alternative strategy to stereotypies to cope with sub-optimal conditions. The aim of this study was to further our understanding of inactive behaviours and possible associated negative affective states in intensively raised calves fed different diets. In two separate experiments, Holstein-Friesian veal calves (N = 40 + 160) were fed barren or enriched diets: 1) imposed/restricted diet versus free dietary choice (experiment 1); 2) no additional straw versus ad libitum provision of straw (experiment 2); 3) low versus high solid feed provision (experiment 2); 4) bucket versus automated milk dispenser for milk replacer feeding, with high or low solid feed provision (experiment 2). Inactive behaviours, i.e. experiment 1: lie, idle and sleep; experiment 2: lie idle, stand idle, and sleep, were recorded at two ages (experiment 1: 12 and 26. wk; experiment 2: 15 and 24. wk) using instantaneous scan sampling. In experiment 2, latency to touch two novel objects was recorded at 15 and 24. wk. No differences in inactivity were found between calves with a restricted or free choice diet (experiment 1). However, calves fed the more barren diets in experiment 2 showed more lying idle at 24. wk of age, and calves with no ad libitum straw in particular, showed more standing idle at 24. wk of age (P. <. 0.05). No differences in latency to touch the novel objects were found. Therefore, although barren diets were generally associated with higher levels of inactivity, we found no support that this inactivity reflected boredom or apathy. Only weak associations were found between inactivity and stereotypies, providing only limited support for the idea that these constitute alternative strategies to cope with sub-optimal conditions.</p

A Survey of Calf Housing Facilities Pre-Weaning, Management Practices and Farmer Perceptions of Calf Welfare on Irish Dairy Farms

It is unknown whether calf rearing facilities in the Republic of Ireland are fit for purpose, or if facilities sufficiently consider calf and farmer welfare. The aim of this study was to review current calf housing facilities and management practices on Irish farms to determine if calves are reared in structurally appropriate facilities with management decisions that safeguard calf and farmer welfare. Fifty-one farms located in the Munster region in the Republic of Ireland were visited twice: (1) Pre-calving (December–January) and (2) During peak calving (January–March). During visit one, herd owners completed a questionnaire regarding calf housing and management practices on-farm and each facility used to rear calves was measured (measurement of cubic air capacity, ventilation, pen area, drainage etc.) without calves being present. Visit two consisted of a short interview with the principal calf manager to validate previously asked questions and environmental based measurements of each calf house that had been recorded, with any deviation from the first visit noted (measurements of temperature, wind speed, light intensity, facility provisions in-house and in-pen; calves present). Average herd size was 254, operating a spring calving system with a median calving season length of 11.6 weeks. While most farms expanded (88%; N = 51), this did not appear to have negatively affected calf space allowances (9.9% houses overcrowded at a space allowance of 1.5 m2/calf; N = 121). Calves were most commonly housed in group sizes of <12 (71.6% of all groupings; N = 394), with farmers moving away from individual housing for a period immediately post-birth, to grouping them immediately instead (58.8%; N = 51). The number of farmers testing colostrum was 31.4% (N = 51). Although the calving season was compact, most farmers were unconcerned about the upcoming spring workload (58.8%; N = 51). Farms appeared sufficiently prepared for spring, with most using the same number or less sheds during visit two than declared in visit one (76.5%; N = 51). To conclude, farmers made sufficient provision for calf housing and space allowances for calves that facilitated group housing post-birth. While structural and management components of rearing systems appear in line with sectoral recommendations, certain areas require attention on many farms (e.g., colostrum testing) to safeguard calf welfare and reduce the workload associated with calf rearing for farmers

Tuberculosis in children: getting started on the road to zero [Editorial]

The declining number of yak farming families is perceived as a socio-political and economic concern in Bhutan. However, there is limited understanding of what influences herders' plans and decisions on yak farming. We studied factors determining future perspectives of yak farming by interviewing yak herders and livestock professionals. We analysed relationships between herders' characteristics and level of concerns, and future plans related to yak farming. Furthermore, relationships between level of concern and future plans were analysed. Most of the herder characteristics did not influence their future plans with yak farming. Age and level of perceived concern of the herders was associated with their wish for their children to continue yak farming in the future. Nevertheless, they expect that the number of yak farming families will decline in the next ten years. Additionally, most of the livestock professionals believe that the number of yak farming families will decline in the future. No differences were observed between the aggregated score of concern of herders and livestock professionals. The most important factors threatening the future of yak farming in Bhutan according to herders and livestock professionals are forage shortage, predation and no successor to take up yak farming.</p

Transition towards sustainable yak farming in Bhutan : stakeholders’ viewpoints and recommendations for future steps

The Bhutanese government initiated a highland development programme in the year 2016 to promote yak farming because the number of yak farming families is declining. However, there are several cross-cutting policies and issues that affect successful implementation of interventions to support yak farming in transition. We studied the challenges and opportunities to sustain yak farming and related trade-offs around problems and solutions through individual and focus group interviews with six stakeholder groups (i.e. herders from two regions, extensionists, park rangers, livestock officials, and forest officials). Overall the herders rated forage availability and yak mortality as the main threats to yak farming, while government officials rated labour availability as the main threats. Most problems and solutions that were identified in the focus group interviews had diverging views among the stakeholder groups. There is clearly a need for a multi-stakeholder dialogue aiming to discuss problems and solutions together. This should take away misleading and disputed claims, and provide understanding about the approach to cope with risks and uncertainty around transhumance yak-based communities. A strong collaboration should lead to appropriate policy, which would reduce challenges and barriers, and simultaneously give opportunities to herders and their children to stay in yak farming in future.</p

Barren diets increase wakeful inactivity in calves

Inactivity is a vastly understudied behavioural category, which may reflect positive or negative affective states in captive or domesticated animals. Increased inactivity in barren-housed animals, in combination with an increased or decreased interest in stimuli, e.g. novel objects, can indicate boredom or apathy. Another theory is that inactivity is an alternative strategy to stereotypies to cope with sub-optimal conditions. The aim of this study was to further our understanding of inactive behaviours and possible associated negative affective states in intensively raised calves fed different diets. In two separate experiments, Holstein-Friesian veal calves (N = 40 + 160) were fed barren or enriched diets: 1) imposed/restricted diet versus free dietary choice (experiment 1); 2) no additional straw versus ad libitum provision of straw (experiment 2); 3) low versus high solid feed provision (experiment 2); 4) bucket versus automated milk dispenser for milk replacer feeding, with high or low solid feed provision (experiment 2). Inactive behaviours, i.e. experiment 1: lie, idle and sleep; experiment 2: lie idle, stand idle, and sleep, were recorded at two ages (experiment 1: 12 and 26. wk; experiment 2: 15 and 24. wk) using instantaneous scan sampling. In experiment 2, latency to touch two novel objects was recorded at 15 and 24. wk. No differences in inactivity were found between calves with a restricted or free choice diet (experiment 1). However, calves fed the more barren diets in experiment 2 showed more lying idle at 24. wk of age, and calves with no ad libitum straw in particular, showed more standing idle at 24. wk of age (P. <. 0.05). No differences in latency to touch the novel objects were found. Therefore, although barren diets were generally associated with higher levels of inactivity, we found no support that this inactivity reflected boredom or apathy. Only weak associations were found between inactivity and stereotypies, providing only limited support for the idea that these constitute alternative strategies to cope with sub-optimal conditions.</p