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Repeated handling of pigs during rearing. I. Refusal of contact by the handler and reactivity to familiar and unfamiliar humans.
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Pigs housed in groups received different handling treatments for 40 d until slaughter age. Pigs of the human interaction (HI) and refusal of contact (RC) groups were individually introduced into a pen each day, where they remained for 3 min in the presence of a squatted handler. The handler tried to increase progressively physical reciprocal interactions with the HI pigs using eye and body contact and voice. The handler remained immobile and avoided eye contact and used of voice with RC pigs. These pigs were pushed away when they touched the handler. Control pigs remained in their home pens. Over seasons, HI pigs progressively increased physical interactions with the handler, up to 35% of their time. The RC pigs were motivated to interact with the handler as they tried to establish physical contact with the handler throughout the experiment. They increased levels of locomotion, rubbing, immobility, and snout contact with the wall, suggesting that they were frustrated by the refusal of contact. At the end of the experimental period, all pigs were subjected to three human exposure tests, where pigs were exposed to the handler and two other persons, one of which was unfamiliar, in a Latin square design. During this test, behavior of the humans was the same as for the RC treatment. The HI pigs discriminated between the handler and the other persons as indicated by their increased approach behavior toward the handler. Part of the prior handling experience was generalized to other humans as indicated by higher levels of proximity of HI and RC pigs with the different persons compared with controls. Physical contact with the human was associated with increased heart rates. Two possibilities are that these two characteristics are part of a general behavioral/physiological reactive profile or that contact with humans provokes an arousal or emotional response. Despite this, behavioral data show that pigs are motivated to be in physical contact with a handler, even when the handler consistently refuses contact.
Inference in disease transmission experiments by using stochastic epidemic models
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The paper extends the susceptible–exposed–infective–removed model to handle
heterogeneity introduced by spatially arranged populations, biologically plausible distributional
assumptions and incorporation of observations from additional diagnostic tests. These extensions
are motivated by a desire to analyse disease transmission experiments in a more detailed
fashion than before. Such experiments are performed by veterinarians to gain knowledge about
the dynamics of an infectious disease. By fitting our spatial susceptible–exposed–infective–
removed with diagnostic testing model to data for a specific disease and production environment
a valuable decision support tool is obtained, e.g. when evaluating on-farm control measures.
Partial observability of the epidemic process is an inherent problem when trying to estimate
model parameters from experimental data.We therefore extend existing work on Markov chain
Monte Carlo estimation in partially observable epidemics to the multitype epidemic set-up of
our model. Throughout the paper, data from a Belgian classical swine fever virus transmission
experiment are used as a motivating example.
Effects of dietary magnesium and short-duration transportation on stress response, postmortem muscle metabolism, and meat quality of finishing swine.
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Supplementing swine diets with Mg has been shown to have beneficial effects on pork color and to decrease the incidence of PSE pork. Research has demonstrated that supplementing swine diets with Mg decreases blood cortisol and catecholamine concentrations and produces visibly calmer pigs after long-distance transportation. This study was to determine the effects of long-term dietary supplementation of magnesium and short-duration transportation on performance, stress response, postmortem metabolism, and pork quality. Thirty-six pigs in 6 pens were fed either control diet or control diet supplemented with 2.5% magnesium mica (MM) during early-finisher (44 to 68 kg of body weight), and late-finisher (68 to 103 kg) periods. At the end of 71-d feeding trial, 12 pigs from each dietary treatment were selected randomly and subjected wither to no stress (NS) or 3 h of transportation stress (TS). Dietary MM had no effect on average daily gain or feed intake; however, feed efficiency was improved during the early-finisher period when pigs were fed MM-supplemented diets. Plasma glucose concentrations were increased in TS pigs fed control diet, but transportation did not affect plasma glucose in pigs fed 2.5% MM. Transportation increased lactate, cortisol, and glucose concentrations, which were not affected by dietary MM. The LM from TS pigs fed MM had higher initial and 45-min pH values than the LM from NS fed control diet. Neither MM nor TS altered the color or water-holding capacity of the LM and semimembranosus. The transportation model elicited the expected changes in endocrine and blood metabolites, but dietary MM did not alter the stress response in pigs.
Genetics of fear in ruminant livestock.
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This article reviews research that has shown consistency in fear responses in ruminant livestock. The authors also provide evidence that there is a genetic basis for fear responsiveness, and discuss the problems with genetic evaluation and selection. Some of the problems include the absence of validation in experimental designs, the complexity of fear-related responses, and the inconsistency of fear-related responses due to the interaction between genetic and environmental factors. The following topics are discussed: the possible welfare consequences of selection programs currently used, the possibility of including fear criteria in selection programs, and recent evidence on how genes control fearfulness. The ability to select animals that easily adapt and are less fearful has potential to improve their welfare.
Human-mare relationships and behaviour of foals toward humans.
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Recent studies have addressed the ease of handling and other aspects of a foal’s interaction with humans. Most of these have attempted to modify the foal’s response by a program of intensive human interaction and handling of the foal early in their life. In this study the experimenters directed their handling toward the mare, with the hypothesis that mare’s would transfer their response to humans to their foal. Fourty-one mares and foals were involved in the study. Half of the group involved brushing of the mare, with the foal present, for 15 min a day during the first five days of the foal’s life. The other mares and foals received no handling other than a cleaning of the foal at birth and assistance in finding a teat. The foals were tested at several points during the subsequent 15 months for their response in various handling and approach tests. Foals from the treated group, whose mothers had been brushed frequently during the foal’s first five days of life, approached or remained closer to humans in subsequent tests, and accepted handling procedures, such as saddle-pads, more readily than the control foals. It would appear that a foal’s response to humans can be fairly easily influenced by regular handling of the mare in the presence of the foal.
Temporal and sequential structure of behavior and facility usage of laying hens in an enriched environment
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The goal of the study was to gain insight into facility usage and hen behavioral needs throughout a 24-hour period when there were no obvious retraints. Commercial laying hens that had not been beak-trimmed and that were 18 weeks old were allocated to pens providing nest boxes, drinkers, feeders, perches, sand, and wood shavings (also called commodities). Behavior analysis was carried out in order to gain insight into the temporal and sequential structures of behavior. Video analysis was conducted for 10 days and behavior analysis was conducted on 5 birds for 5 days. Hens spent 97 % of the day on nest use, preening, drinking, feeding, still, walking, perching, and resting. Behavior involving a commodity was carried out for 43 % of the day, while non-commodity-oriented behavior was carried out for 57 % of the day. Around 70 % of the behaviors were short, lasting less than two minutes. The behaviors were also frequent, with about 70 % of the inter-event intervals being less than 40 seconds in length. The preferred place for attack, escape, flying, resting, walking, and wing flapping was the pen corridor. Feeding-drinking-feeding, preening-resting-preening, scratching-resting-scratching, dust bathing-resting-preening, or dust bathing-resting-wing stretching-dust bathing were the preferred sequences of behavior. Behavioral events were clustered, even though hens interrupted ongoing behaviors and changed behaviors frequently.
Newborn and 5-week-old calves vocalize in response to milk deprivation.
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Vocalizations by calves are common after they have been separated from the cow and during the weeks they are fed milk. The purpose of this study was to understand the functional and motivational basis for the vocalizations. In the first experiment, some newborn calves were recorded during conventional feeding (twice daily for a total of five liters of milk per day) and some during a feeding regime where the calves were fed every four hours and received eight liters of milk per day. Calves on the conventional feeding regime vocalized more and at a higher fundamental frequency, than those on the revised regime. In a second experiment, calves were found to vocalize more when deprived of milk compared to calves that had ad-libitum access to milk. The results of these experiments indicate that improving milk feeding regimes can significantly decrease the distress associated with weaning. Vocalizations were found to decrease when calves were fed more milk more often. Each calf’s call was determined to be distinctive, through an analysis of call duration, fundamental frequency, and frequency of maximum amplitude.
Effect of granulocyte-macrophage colony-stimulating factor on post-weaning multisystemic wasting syndrome in porcine circovirus type-2-transfected piglets
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Post-weaning multisystemic wasting syndrome (PMWS) is a complex disease syndrome in
swine, affecting nursery and fattening pigs. Although ongoing evidence suggests that
porcine circovirus type-2 (PCV2) is the causal agent of PMWS, the host immune system
appears to have a crucial role in the PMWS pathogenesis of PCV2-affected pigs. Owing to
difficulties in producing a biologically pure form of PCV2 devoid of the other viral agents
commonly present in swine tissues, we decided to use a tandem-cloned PCV2 DNA
providing highly pure grade reagent in order to monitor the virulence of PCV2 alone or
with an immunostimulating co-factor, granulocyte-macrophage colony-stimulating factor
(GM-CSF). A single intramuscular injection of tandem-cloned PCV2 DNA into 5-weekold
piglets produced plasmid to viral genome progeny and infectious particles as early as 8
days post-injection in all the organs tested (the lung, the tonsil and the inguinal, mesenteric,
bronchial and upper-right axial lymph nodes). The initial plasmid load was not
detected with the help of primers designed to specifically detect the acceptor plasmid, thus
confirming the replication of the viral genome. Despite the presence of a high level of
PCV2 genome copies in the lymphoid organs – the tonsil and the lung – and the presence
of infectious particles, no detectable clinical manifestations or pathological lesions were
observed in the transfected pigs over the period of observation, regardless of whether they
had been co-injected with plasmid containing GM-CSF DNA or had received plasmid
containing PCV2 DNA alone. GM-CSF encoding DNA injection had no significant effect
on viral replication or on the production of viral particles and appearance of the disease.
The effect of two teeth resection procedures on the welfare of piglets in farrowing crates. Part 1.
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The objective of this study was to assess piglet welfare following either clipping or grinding of their needle teeth, or leaving the teeth intact. Thus, at birth litters were assigned to treatments of either clipped (C), ground (G), or intact (I) teeth. Grinding the teeth was the longest procedure to perform, which may have increased piglet stress due to being restrained. I piglets had the highest facial lesion scores, but the lowest mouth lesion scores. It was C piglets that had the highest mouth lesion scores due to leftover tooth splinters, and C piglets spent more time chewing when their mouth was empty during the 5 minutes after the teeth clipping procedure. I piglets were more active during many of the observation periods, while G piglets were more inactive (standing/sitting with eyes open or sleeping) during those times and C piglets were sleeping more during those times. A larger number of I piglets than C piglets died due to overlying (being crushed by the sow). In conclusion, findings indicated that all procedures were associated with some welfare problems, but grinding was recommended in preference to clipping or leaving the needle teeth intact.
Effects of age and method of castration on performance and stress response of beef male cattle: A review.
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The effects of the method of castration and the age at which it was performed were evaluated. Weight loss increased quadratically as the age at which castration was carried out increased. This indicated that castration by any method (surgical or rubber banding), at birth or close to birth, drastically reduces weight loss. A detrimental effect on performance extending beyond the first 30 days after castration was caused when surgical castration was the method used. Average daily gain was not affected by the method of castration. The stress response of cattle = 6 months of age tended to be lower than cattle that were over 6 months of age. Rubber banding and surgical castration data was not significantly different. The fact that there was an insignificantly lower stress response of intact cattle compared with banded cattle suggests that rubber banding castration is less stressful than surgical castration.