Abstract: Devices used to measure cardiac activity (elasticized belt, electrodes, etc.) in standardised behavioural tests could be stressful for the animals, and therefore affect their responses. Preliminary habituation to the device is not always possible. To date, the impact of carrying such devices has been poorly evaluated. In the present experiment, we examined the impact of a device used to measure cardiac activity on the behavioural responses of handled and non-handled lambs in a standard human test. We also studied variations in heart rate in response to human presence and separation. Twenty-one lambs were separated from their dam 12 h after birth: 11 received no additional human contact (non-handled) and 10 received additional contact for 1 week and then 1 day a week until 6 weeks. They consisted of stroking and milk-feeding (handled). At 6.5 weeks of age, each lamb was submitted twice to a behavioural test. The procedure comprised three phases: the lamb stayed alone for 2 min, then for 2 min with the familiar stockperson, and then alone for 2 min again. The tested lambs were equipped or not with a cardiac device in a cross-over design. The device used to measure cardiac activity led to a decrease in vocalisations and locomotion (P < 0.05). It had only a limited impact on the behavioural differences between handled and non-handled lambs. It reduced slightly the time spent near the stockperson for the non-handled lambs (mean +/- S.E. 0.1 +/- 0.1 s with cardiac device versus 3 1 s without; P < 0.05) but had no effect on the handled lambs (35 +/- 15 s versus 23 +/- 10 s; P > 0.1). In handled lambs, the frequency of vocalisations and the heart rate decreased as the stockperson entered (P < 0.05). When he left, we observed an increase in frequency of vocalisations but no change in heart rate (P > 0.1). No change in heart rate was observed for the non-handled lambs. We conclude that the device used to measure cardiac activity led to a general decrease in activity but did not affect the difference between handled and non-handled lambs. Consequently, this method seems to be appropriate for further exploring artificially reared lambs' perception of humans, with few risks of behavioural alterations. However, the absolute values of locomotor and vocal activities should be taken with caution. Behavioural and physiological measures were not totally consistent, which questions then-respective emotional significance. (c) 2005 Elsevier B.V. All rights reserved.
Abstract: The present study investigated the rewarding effects of nonnutritive sucking oil the development of a filial preference. Two experiments were conducted to test whether nonnutritive visceral and oral stimuli have reinforcing properties independent from each other or act in synergy. Lambs could interact freely with their dam but were deprived of suckling by covering the udder for the first 12 hr. In Experiment 1, suckling was prevented and replaced by human giving, in the presence of the mother, either a bottle of water (B-5 and B-2.5: 5% or 2.5% birth weight, BW, divided into seven portions over 12 hr) or water via tube-feeding (I-5 and I-2.5: 5% or 2.5% BW also divided into seven portions over 12 hr). During a two-choice test performed at 12 hr after birth, only B-5 and I-5 lambs preferred their mother to all alien ewe however, B-5 were faster at choosing their mother at the beginning of the test. B-2.5 and I-2.5 lambs made a random choice. In Experiment 2, suckling was prevented and replaced by human giving, in the presence of the mother; either a bottle of water (B-2.5: 2.5% BW divided into seven portions over 12 hr) or water via tube-feeding (I-10 and I-2.5: 10% or 2.5% BW, also divided into seven portions over 12 hr). During a two-choice test at 12 hr, tube-fed lambs (I-10 and I-2.5) preferred their mother to a human. B-2.5 lambs were equally attracted to both partners and spent more time near the human than lambs from the other groups. In a test of reactivity to a human performed on neonates isolated from their mother, B-2.5 lambs explored the human much more than the other lambs. The presence of the human had soothing properties in B-2.5 lambs and once the human left, they were the only lambs displaying enhanced vocal and locomotor activity. In these experiments, nonnutritive gastrointestinal stimuli induced a preference for the mother whereas nonnutritive sucking led to a strong positive relationship with the human. These results suggest that when lambs suckle their dam, the development of filial bonding is facilitated through the combined effects of oral and gastrointestinal stimuli. (c) 2006 Wiley Periodicals, Inc.
Abstract: Understanding how farm animals perceive their stockperson is a major challenge, especially for artificially reared animals which are known to show strong attraction to humans. Replacing the stockperson by its photograph in an arena test could be a useful method for standardising human stimuli. Such an approach requires individual consistency in young lambs' responses to their stockperson, which has not yet been demonstrated. Our objective was to test this consistency and to determine whether the responses of lambs to a photograph of a stockperson in an arena test are linked in a specific way to their responses to the real stockperson in that same test. Thirty-six female lambs were bucket-fed by two men. The individual responses of the lambs to the person feeding them were assessed when the lambs were 4, 5 and 10 weeks of age, in a test pen where the lambs were first alone for 2 min, then left with their stockperson for 2 min, and then left alone again for a further 2 min. At I I weeks of age, a similar test was run with photographs (object and stockperson). Responses to the real stockperson were positively correlated between tests (r(s) > 0.44, P < 0.01). The lambs spent more time near the photograph of their stockperson than a photograph of an object (40 +/- 15s versus 29 +/- 4s, P = 0.02). The time spent near the two photographs was statistically linked (P < 0.02) to the time spent near the real stockperson in the previous test. We observed an increase of the frequency of vocalisations and locomotion when the stockperson left the pen (P < 0.001), but not when the photographs were removed. In conclusion, individual lambs' give consistent responses to the presence or disappearance of a stockperson in an arena test. This suggests an early individual behavioural trait in lambs, and therefore the possibility of early selection for this trait. Our results do not support the use of photographs of humans in arena tests, due to an absence of specific link. (c) 2005 Elsevier B.V. All rights reserved.
Abstract: In this paper, we assessed the relative importance of handling and feeding lambs in the development of affinity for their stockperson. We also tested the extent to which this affinity can be linked to feeding motivation and behaviour in a conditioning hypothesis. Lambs were reared in groups of three and artificially fed from a multiple-nipple bucket. From the first day of age, contacts with the stockperson were given in the home pens three times a day for 5 consecutive days, then 2 days a week until the tests. In five groups (Presence), the stockperson sat motionless; in five groups (Handling), he caught the lambs and stroked them; in six groups (Handling & Feeding), he caught and stroked the lambs while placing them at the food bucket. At 3.5 weeks of age, the lambs were individually tested in a 6 m X 1.5 m arena. In Test 1 (Human Test), the lambs stayed 2 min alone, 2 min with the familiar stockperson, then 2 min alone again. In Test 2 (Bucket Test), a milk bucket was added to the arena and the same procedure was followed. For each test, the lambs were observed after 5 h of starvation or ad libitum feeding (cross-over design). In the Human Test, Presence lambs spent less time near the stockperson (27 [plus-or-minus sign] 7 s) than Handling lambs (59 [plus-or-minus sign] 9 s, P = 0.03) or Handling & Feeding lambs (59 [plus-or-minus sign] 6 s, P = 0.03). In the Bucket Test, three lambs suckled from the bucket. Only Handling & Feeding lambs increased their time spent near the bucket when the stockperson entered (treatment x time, P = 0.05). No interaction between the treatments and the hunger state was observed in any test.Handling per se contributed to the development of lambs' affinity for their stockperson during individual tests, and could have calming and rewarding properties for the lambs. Neither feeding from a bucket during handling nor hunger state increased this affinity. Nevertheless, some association of the stockperson with the milk bucket seemed to occur, suggesting a food conditioning. The way of feeding the animals and their perception of the test as an alimentary situation are discussed.
Abstract: Human factors (attitudes, personality traits, self-esteem, job satisfaction) strongly determine our behaviour towards animals, animal production and animal welfare. Recent studies have emphasised positive human contacts as indicators of a stockperson's positive attitude towards animals and towards animal welfare in general. Stockmanship can be improved by careful selection of people and/or by training. However, little is known of the biological basis of the effect of stock handling procedures on the welfare of animals. The animal's perception of the stock-person (based both on emotional responses and cognitive aspects such as anticipation, recognition and categorisation), and the existence of sensitive periods in an animal's life, need to be explored in more depth, especially under farm conditions. We need to consider the complexity of human behaviour (eg husbandry practices, balance between positive and negative interactions, predictability, controllability) and the effect on animal welfare from the animal's point of view, throughout its whole life. This paper identifies the importance of positive human contacts for both animals and stockpeople, and highlights the challenge to maintain such positive contacts despite the trend in modern agriculture to increase the number of animals per stockperson. This requires better knowledge of animal genetics, socialisation to humans during sensitive periods, and management of the social group. We emphasise the ethical importance of the human-animal relationship in the context of farm animal welfare and productivity.
Abstract: The influence of chemosensory perception on weight gain by newly hatched chicks was investigated. One day after hatching, 96 chicks were randomly assigned to 3 treatment conditions (32 chicks per condition) : Both nares blocked with acrylic cement; 1 nare blocked; controls, with unblocked nares. Pairs of chicks in the same treatment condition were housed together with ad lib access to food and water; all chicks were weighed on the treatment day and 1, 2, 3 and 6 days later. Beginning one day post-treatment, and on each of the subsequent test days, chicks with both nares blocked weighed significantly less than those with only one blocked nare, or the controls. No significant differences were observed between chicks with one blocked nare vs. the controls. The relative weight gained between successive measures ( proportion of initial body weight) by chicks with both nares blocked was less than that of the other conditions during the first 2 days following treatment, however, there were no differences between conditions after that time. In tests conducted to assess whether the treatment effectively disrupted chemosensory perception, control chicks and those with one blocked nare displayed overt responses when exposed to the odor of mint, but there was little reaction by chicks with both nares blocked. Reduced weight gain by chicks with olfactory deficits presumably reflects disrupted feeding behavior, however, after 2 days, those chicks compensated for their perceptual impairments. These results further illustrate the salience of chemical stimuli for newly hatched chicks.
