Abstract: Nineteen young horses that had recently started to perform the stereotypy of crib-biting were compared with 16 non-stereotypic horses for 14 weeks. After initial observations of their behaviour and an endoscopic examination of the condition of their stomachs, the horses were randomly allocated to a control or an antacid diet At the start of the trial, the stomachs of the crib-biting foals were significantly more ulcerated and inflamed than the stomachs of the normal foals. In addition, the faecal pH of the crib-biting foals (6.05) was significantly lower than that of the normal foals (6.58). The antacid diet resulted in a significant improvement in the condition of the horses' stomachs. The crib-biting behaviour declined in most of the foals, regardless of their diet, but tended to decline to a greater extent in the foals on the antacid diet.

Abstract: High carbohydrate diets can affect the health and behaviour of foals, but the mechanisms are not always fully understood. The objective of this study was to compare the effects of feeding a starch and sugar (SS), or a fat (oil) and fibre (FF) rich diet to two groups of eight foals. Diets were fed from 4 to 42 weeks of age, alongside ad libitum forage. Faecal pH levels did not differ significantly between groups and endoscopic examination showed that the gastric mucosa was healthy in both groups at 25 and 42 weeks of age. At 40 weeks of age, SS foals had significantly higher total blood glucose and lower total blood gastrin than FF foals during the 6h period following ingestion of their respective diets, but insulin levels did not differ significantly. The ratio between serum tryptophan and other large neutral amino acids showed a trend towards an interaction between diet and sampling time. The results provide preliminary information about the effects of diet on the physiology of young horses.

Abstract: In order to determine if horses will increase their intake in response to caloric dilution, four pony geldings were fed ad lib a mixed grain diet either undiluted (3.4 Mcal/kg of digestible energy) or diluted (wt/wt) with 25% sawdust (2.6 Mcal/kg) or with 50% sawdust (1.7 Mcal/kg). The mean daily caloric intake was 17,457 kcal (3.4 Mcal diet), 17,546 kcal (2.6 Mcal diet) and 12,844 kcal (1.7 Mcal). The mean time spent eating was 246 (3.4 Mcal), 351 (2.6 Mcal), and 408 (1.7 Mcal) minutes/day. Meal size increased and meal frequency decreased with increasing dilution. The median long survivorships of intermeal intervals were 6.4 min (3.4 Mcal), 3.95 min (2.6 Mcal) and 4.91 min (1.7 Mcal). Ponies responded to caloric dilution by increasing the volume of intake to maintain caloric intake when the diet had 25% diluent. When the diet was diluted by 50%, intake was increased, but not at a rate adequate to maintain caloric intake. However, the ponies were able to maintain body weight.

Abstract: The landmark discrimination learning test can be used to assess the ability to utilize allocentric spatial information to locate targets. The present experiments examined the role of various factors on performance of a landmark discrimination learning task in beagle dogs. Experiments 1 and 2 looked at the effects of age and food composition. Experiments 3 and 4 were aimed at characterizing the cognitive strategies used in performance on this task and in long-term retention. Cognitively equivalent groups of old and young dogs were placed into either a test group maintained on food enriched with a broad-spectrum of antioxidants and mitochondrial cofactors, or a control group maintained on a complete and balanced food formulated for adult dogs. Following a wash-in period, the dogs were tested on a series of problems, in which reward was obtained when the animal responded selectively to the object closest to a thin wooden block, which served as a landmark. In Experiment 1, dogs were first trained to respond to a landmark placed directly on top of coaster, landmark 0 (L0). In the next phase of testing, the landmark was moved at successively greater distances (1, 4 or 10 cm) away from the reward object. Learning varied as a function of age group, food group, and task. The young dogs learned all of the tasks more quickly than the old dogs. The aged dogs on the enriched food learned L0 significantly more rapidly than aged dogs on control food. A higher proportion of dogs on the enriched food learned the task, when the distance was increased to 1cm. Experiment 2 showed that accuracy decreased with increased distance between the reward object and landmark, and this effect was greater in old animals. Experiment 3 showed stability of performance, despite using a novel landmark, and new locations, indicating that dogs learned the landmark concept. Experiment 4 found age impaired long-term retention of the landmark task. These results indicate that allocentric spatial learning is impaired in an age-dependent manner in dogs, and that age also affects performance when the distance between the landmark and target is increased. In addition, these results both support a role of oxidative damage in the development of age-associated cognitive dysfunction and indicate that short-term administration of a food enriched with supplemental antioxidants and mitochondrial cofactors can partially reverse the deleterious effects of aging on cognition.

Abstract: Our previous study suggested that fenofibrate affects obesity and lipid metabolism in a sexually dimorphic manner in part through the differential activation of hepatic peroxisome proliferator-activated receptor alpha (PPARalpha) in male and female C57BL/6J mice. To determine whether fenofibrate reduces body weight gain and adiposity in female sham-operated (Sham) and ovariectomized (OVX) C57BL/6J mice, the effects of fenofibrate on not only body weight, white adipose tissue (WAT) mass, and food intake, but also the expression of both leptin and PPARalpha target genes were measured. Compared to their respective low-fat diet-fed controls, both Sham and OVX mice exhibited increases in body weight and WAT mass when fed a high-fat diet. Fenofibrate treatment decreased body weight gain and WAT mass in OVX, but not in Sham mice. Furthermore, fenofibrate increased the mRNA levels of PPARalpha target genes encoding peroxisomal enzymes involved in fatty acid beta-oxidation, and reduced apolipoprotein C-III (apo C-III) mRNA, all of which were expressed at higher levels in OVX compared to Sham mice. However, leptin mRNA levels were found to positively correlate with WAT mass, and food intake was not changed in either OVX or Sham mice following fenofibrate treatment. These results suggest that fenofibrate differentially regulates body weight and adiposity due in part to differences in PPARalpha activation, but not to differences in leptin production, between female OVX and Sham mice.