Providing social contacts and objects for nibbling moderates reactivity and oral behaviors in veal calves.

The aim of this work was to assess the role of social and physical enrichment in the adaptation of veal calves to their environment. We compared calves housed in individual stalls that varied in the extent of contacts they allowed between neighbors (16 calves: open partitions; 16 calves: solid partitions; 32 calves: solid and extended partitions preventing all contact). All but 16 out of the 32 isolated calves were provided with a piece of tire and a chain, objects they could easily nibble.

Effect of intracerebroventricular administration of vasopressin on stress-induced hyperthermia in rats.

Vasopressin has been reported to be an endogenous antipyretic peptide. The present study assessed whether this peptide has similar effects on stress-induced hyperthermia. Infusion of 3 ng of vasopressin into the lateral ventricle prior to a 40-min restraint stress reduced significantly the hyperthermic response of rats to this stress, compared to saline-injected controls.

[Descriptive epidemiology of placental retention in intensive dairy herds in Brittany].

The influences of several risk factors (temporal, mechanical, zootechnical and nutritional) on the incidence of placental retention (PR) were tested. The study was conducted in Brittany on 5,240 calvings of Black-Pied females belonging to 47 herds surveyed over a period of four consecutive years. For twin births, the PR-incidence levels were only decreased in the case of calves born alive.

Models based on variable fractional digestion rates to describe ruminal in situ digestion.

Using a first-order model to describe ruminal in situ digestion implies that the rate of digestion is affected only by the quantity of potentially digestible substrate remaining. Other factors, like the microbial efficacy for digesting substrate, are assumed to be constant. However, microbes are not only the cause but also the result of digestion, being one of the digestion end-products.

Altered response of protein synthesis to nutritional state and endurance training in old rats.

This study was undertaken to determine whether the loss of muscle protein mass during aging could be explained by a reduced sensitivity of muscle protein synthesis to feeding and exercise. Male Wistar rats aged 12 and 24 mo were exercised by treadmill running for 4 mo. Protein synthesis was measured by the flooding dose method in tibialis anterior, soleus, and liver of conscious rested, trained rats and age-matched controls in the postprandial or in the postabsorptive state.

[Modelling of temporal data and the role of graphics].

The importance of graphics for temporal data modelling, which is often used in ecopathology, is illustrated through 2 examples. The first concerns a univariate time series (tank milk germ measurements). It uses correlograms (choice of the model), plots of residuals of the model (diagnostics) and principal component analysis graphical outputs (comparison of time series).

Learning to suckle from an artificial teat within groups of lambs: Influence of a knowledgeable partner.

This work was aimed at finding evidence of observational learning in sheep. The task to be learned was that of suckling milk from a bucket provided with teats. Lambs were reared in groups of either four neonates and an older lamb accustomed to artificial suckling (14 experimental lambs) or five neonates (16 controls).

Age-related changes in protein synthesis measured in vivo in rat liver and gastrocnemius muscle.

This study analyses in detail the effects of ageing on gastrocnemius muscle and liver protein synthesis measured in vivo at three ages, 1.5 months (young), 12 months (adult) and 24 months (old) in Sprague-Dawley rats. Comparing adult and old rats, muscle protein synthesis was decreased in old rats when expressed per unit of RNA and per day (translational efficiency), was unchanged when expressed in absolute terms and increased when expressed in fractional terms as a result of protein loss due to muscle atrophy.

Effect of amino acids alone or with insulin on muscle and liver protein synthesis in adult and old rats.

This study was carried out to analyze age-related changes on amino acid and insulin effects on muscle and liver protein synthesis. Conscious male rats, aged 12 (adult) and 24 (old) mo, were infused for 90 min with either saline, amino acids, or amino acids with insulin and glucose. Protein synthesis was measured during the last 15 min of infusion (flooding dose of valine with L-[2,3,4-3H]valine).

Effect of insulin in conjunction with glucose, amino acids and potassium on net metabolism of glucose and amino acids in the goat mammary gland.

The hyperinsulinaemic euglycaemic insulin clamp technique was used to study the effect of insulin on the arterio-venous concentration differences of glucose and amino acids across the mammary gland in dairy goats. Insulin was given in conjunction with K to prevent insulin hypokalaemia. Appropriate amino acid infusion was used to blunt insulin-induced hypoaminoacidaemia or to create hyperaminoacidaemia and maintain this state under insulin treatment.

Escherichia coli CS31A fimbriae: molecular cloning, expression and homology with the K88 determinant.

CS31A is a plasmid-encoded K88-related fimbrial antigen. A Sau3AI library was constructed from p31A, a 180 kb CS31A encoding plasmid, in the pSUP202 vector. Bacterial recombinant clones expressing CS31A were isolated.

Establishment of cellulolytic bacteria in the digestive tract of conventionally reared young mice: effect of the dietary cellulose content in the adult.

Cellulolytic bacteria became established 12 days after birth in the caecum and colon of conventionally-reared mice fed a diet containing 5 p. 100 crude cellulose (Weende). Their population reached a level between 10(6) and 10(7) bacteria per gram of digestive contents in 25-day-old animals.