Repeatability of traits for characterizing feed intake patterns in dairy goats: a basis for phenotyping in the precision farming context

International audienceIn ruminants, feeding behaviour variables are parameters involved in feed efficiency that show variation among individuals. This study aimed to evaluate during the first two production cycles in ruminants the repeatability of feed intake pattern, which is an important aspect of feeding behaviour. Thirty-five dairy goats from Alpine or Saanen breeds were housed in individual pens at four periods (end of first gestation, middle of first and second lactations and middle of second gestation which is also the end of first lactation) and fed a total mixed ration (TMR) ad libitum. Individual cumulative dry matter intake (DMI) was automatically measured every 2 min during the last 4 days of each period. Feed intake pattern was characterized by several measures related to the quantity of feed eaten or to the rate of intake during the 15 h following the afternoon feed delivery. Two main methods were used: modelling cumulative DMI evolution by an exponential model or by a segmentation-clustering method. The goat ability to sort against dietary fibre was also evaluated. There was a very good repeatability of the aggregate measures between days within a period for a given goat estimated by the day effect within breed and goat, tested on the residual variance (P > 0.95). The correlations between periods were the highest between the second and either the third or fourth periods. With increasing age, goats sorted more against the fibrous part of the TMR and increased their initial rate of intake. Alpine goats ate more slowly than Saanen goats but ate during a longer duration. Principal component analysis (PCA) was performed on all the aggregate measures of feed intake patterns. The factor score plots generated by the PCA highlighted the opposition between the different measures of feed intake patterns and the sorting behaviour. The projection of the animals on the scoring plots showed a breed effect and that there was a continuum for the feed intake pattern of goats. In conclusion, this study showed that the feed intake pattern was highly repeatable for an animal in a given period and between periods. This means that phenotyping goats in a younger age might be of interest, either to select them on feeding behaviour and choose preferentially the slow eaters or to adapt the quantity offered and restrict feed delivery to the fast eaters in order to increase feed efficiency and welfare by limiting the occurrence of acidosis, for example

Intestinal motility and weaning in the dairy calf

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Soya protein antigenicity and small intestinal motility in preruminant calves

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The response to an oral drench of propylene glycol is modified in dairy goats previously fed straw for two days compared to control fed goats

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Feed intake pattern did not explain individual variation of feed efficiency in dairy goats fed a Total Mixed Ration

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Effects of repeated stress during pregnancy in ewes on the behavioural and physiological responses to stressful events and birth weight of their offspring.

Stressors are frequently encountered during the pregnancies of farm animals. However, very few studies have investigated the effects of repeated stress in pregnant females on their offspring. Forty-eight ewes at 2.5 months of pregnancy were selected for their high or low cortisol response to isolation. Half of the ewes were subjected, twice a week during the last 5 weeks of gestation, to isolation. The first isolation bout of each week consisted only of isolation from conspecifics, while the second bout of each week consisted of isolation in the presence of a dog. The cortisol responses of ewes were measured during the treatment. The other half of the ewes was drafted and released without further disturbance. The emotional reactivity of the lambs to a light contrast test, a startling stimulus test and a social isolation test were studied at 25 days of age. The lambs were retested at 8 months of age in the same tests and also in a novel arena and a novel object tests. Cardiac responses to the startling stimulus were studied at 8 months of age. Basal cortisol concentrations and cortisol response after the isolation test were studied at both ages and cortisol response to ACTH was studied at 25 days of age. Ewes repeatedly exposed to the treatment of isolation plus presence of a dog habituated to the treatment. Moreover, the initial differences between the high and low reactivity ewes were not apparent when the stress treatment was subsequently imposed. Lambs prenatally stressed were heavier at birth than control lambs. The prenatally stressed lambs showed more exploration and locomotion in the behavioural tests at 8 months of age but not at 25 days of age. At 25 days of age, the basal cortisol concentrations were higher in the prenatally stressed lambs compared to the control lambs. Whereas these results suggest that mild prenatal stress of lambs has no adverse effect on the behavioural and cortisol responses to a range of stressors, there is evidence that this treaIn: Applied Animal Behaviour Science, vol. 85, nr. 3-4, pp. 259-276, 3/25/2004Stressors are frequently encountered during the pregnancies of farm animals. However, very few studies have investigated the effects of repeated stress in pregnant females on their offspring. Forty-eight ewes at 2.5 months of pregnancy were selected for their high or low cortisol response to isolation. Half of the ewes were subjected, twice a week during the last 5 weeks of gestation, to isolation. The first isolation bout of each week consisted only of isolation from conspecifics, while the second bout of each week consisted of isolation in the presence of a dog. The cortisol responses of ewes were measured during the treatment. The other half of the ewes was drafted and released without further disturbance. The emotional reactivity of the lambs to a light contrast test, a startling stimulus test and a social isolation test were studied at 25 days of age. The lambs were retested at 8 months of age in the same tests and also in a novel arena and a novel object tests. Cardiac responses to the startling stimulus were studied at 8 months of age. Basal cortisol concentrations and cortisol response after the isolation test were studied at both ages and cortisol response to ACTH was studied at 25 days of age. Ewes repeatedly exposed to the treatment of isolation plus presence of a dog habituated to the treatment. Moreover, the initial differences between the high and low reactivity ewes were not apparent when the stress treatment was subsequently imposed. Lambs prenatally stressed were heavier at birth than control lambs. The prenatally stressed lambs showed more exploration and locomotion in the behavioural tests at 8 months of age but not at 25 days of age. At 25 days of age, the basal cortisol concentrations were higher in the prenatally stressed lambs compared to the control lambs. Whereas these results suggest that mild prenatal stress of lambs has no adverse effect on the behavioural and cortisol responses to a range of stressors, there is evidence that this treaOnderzoeksbibliografie Frank OdbergHerkomst: Onderzoeksbibliografie van em. prof. dr. Frank O. Ödberg, verbonden aan de Vakgroep Voeding, Genetica en Ethologie van de Faculteit Diergeneeskund

Effect of the site of infusion of para-aminohippuric acid (PAH) on portal blood flow

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