Brigitta Wichert

Overweight and impaired insulin sensitivity present in growing cats

Obesity is a growing problem in pets as well as in humans. Overweight and obesity are linked to insulin sensitivity and subsequently in older cats, to an increased risk of developing diabetes mellitus. In the experimental cat population of the Institute of Animal Nutrition of the Vetsuisse Faculty, University of Zurich, an overweight phenotype in intact cats younger than 1 year became evident. The aims of the present study were to determine whether an association between insulin sensitivity and body condition score (BCS) or feline body mass index (FBMI) is already present during young adulthood in these cats and to test the hypothesis that the phenotype lean/overweight is significantly associated with monthly body weight during the growing period. Therefore, 41 kittens from the mentioned cat breeding colony were studied. They were weighed weekly and checked monthly (third to eighth month after birth) for BCS and FBMI. At the age of 8 months, they were classified into an overweight and lean phenotype based on BCS on a scale of 9 (median; maximum and minimum: overweight male (6.4; 6.8; 6.0); overweight female (6.1; 6.2; 6.0); lean male (5.4; 5.7; 5.0); lean female (5.2; 5.6; 5.0). A significant association between the phenotype and body weight was obvious during the growing period from the third to the 8 months (p = 0.0001). At month 8, body fat content was measured by dual energy X-ray absorptiometry and a glucose tolerance test to determine the insulin sensitivity index was performed. Insulin sensitivity was significantly associated with BCS (p = 0.0007) and body fat content (p < 0.0001) but not with sex (p = 0.61). Our data provide evidence that already in young intact cats; insulin insensitivity is significantly associated with BCS or a presumed phenotype lean/overweight.

Energy and protein needs of cats for maintenance, gestation and lactation

In the present investigation, data on the energy intakes and energy needs, as well as protein and fat accretion, of queens during pregnancy, during lactation and after lactation are given. Eleven adult cats were used as experimental animals. Data were collected during the fourth and seventh week of pregnancy, the second and sixth week of lactation and the second and sixth week after lactation. The cats were fed dry kitten food. During gestation and after lactation, all measurements were performed with respiration chambers. During lactation, balance trials without respiration chambers were performed. Body weight was measured and nitrogen, carbon and energy balances were calculated. From these, protein and fat accretion, as well as the metabolisable energy intake, was calculated. The weight gain during gestation was linearly independent of the number of kittens. During lactation, all cats lost weight; nevertheless, all cats except one were heavier 2 weeks after lactation than at mating. The energy intake of the cats during gestation was 1.8 times the maintenance requirement in the fourth week and two times maintenance requirement in the seventh week, and these energy intakes differed greatly among individuals. The energy intake of the cats during lactation was clearly higher than that recommended by National Research Council (NRC)1, whereas the recommended protein intake in the second week of lactation was met. As the calculated protein balance was negative, the NRC recommendation for protein intake seems to be too low. In comparison to previous data, the cats showed a higher energy intake during lactation (median 502 kJ/kgBW/d, second week lactation), and the weight loss was much lower. Further investigations on pregnant and lactating cats are necessary to complete the database.

Judgement of hygienic quality of roughage in horse stables in Switzerland.

In 46 horse farms all over Switzerland, the hygienic quality of the roughage (including silages) was investigated. Therefore, a macroscopic examination as well as the microbial counts (bacteria, yeasts and moulds) was carried out. Further, the contents of lipopolysaccharides (LPS) and the contamination with deoxynivalenol (DON) were determined. In all roughages, the dry matter (DM) content was measured and in silages additionally the pH was measured. Predominantly, the straw showed a lower hygienic quality than hay and silages. The LPS contents were significantly higher in straw than those in hay samples. The macroscopic examination and the microbial counts showed a tendency in the same direction. Eight straw samples and one hay sample with DON contamination were found. The silages showed a DM content with a median of 65.8%. The pH of those silages was between 4.3 and 5.9. Despite the high values of DM and pH, the silages showed mainly a high hygienic quality. In total, the hygienic standard of straw was worse than that of hay. This should be taken into account also in straw used as bedding as much as the hygienic quality of hay.

A survey on the feeding of eventing horses during competition

This study aims at the comparison of the actual feeding of horses with the recommendations from the literature, and it studies the effects of feeding and exercise on several blood metabolic parameters before and after exercise. Blood samples were collected from 25 horses during one-star eventing competitions and evaluated for blood glucose, insulin, lactate, free fatty acids and triglyceride levels. Questionnaires on the feeding practices of the horses were evaluated. The questionnaires revealed that during training, and on tournament days, horses received on average 4.3 kg of concentrate per day (min. 1.54 kg, max. 8 kg). The statistical analysis showed no significant effect of the amount of concentrate fed before exercise on the measured blood values. Oil was supplied as a supplementary energy source to 30% of the horses, but most of them only received very small quantities (0.02-0.4 l/day). Five horses (20%) had no access to salt supplements at all, and eleven horses (45%) had no access to salt on tournament days. Fifteen horses (60%) were supplied with mineral feed. Twenty-one horses (84%) had daily access to pasture during the training period. During competition, 55% of the horses received roughage ad libitum, compared with 37% during training. The majority of the horses received less roughage on days before the cross-country competition. It could not be ascertained whether feeding a large amounts of roughage had a beneficial effect on performance, because only a few horses in this study were fed with very restrictive roughage. Feeding of most of the horses was in agreement with the recommendations from the literature, except the need for sodium and chloride. The sodium and chloride need for sport horses may be overestimated in literature and needs to be re-evaluated.

Effect of vitamin E supplementation of sheep and goats fed diets supplemented with polyunsaturated fatty acids and low in Se.

Vitamin E (VitE) and selenium (Se) are an essential part of the antioxidative functions of metabolism. There are situations of low supply of both micronutrients. As VitE is involved in ruminal biohydrogenation of polyunsaturated fatty acids (PUFA) and their protection against oxidation in metabolism, diets supplemented with PUFA may challenge VitE to an extent making recommended supplies insufficient. Twelve goats and sheep each were fed a diet supplemented with PUFA and characterised by low Se and limited VitE contents during the last 2 months of gestation and the first 2 months of lactation. The basal diet consisted of hay and concentrate. Six goats and sheep received extra VitE, while the control groups received no extra VitE. Blood and milk samples were taken. In addition, liver, heart muscle and spleen samples were obtained from the offspring after slaughtering at an age of 8 weeks. No significant changes were observed in serum Se and VitE. A significant increase in serum VitE concentrations between 2 and 4 weeks postpartum (pp) was evident in the supplemented kids. In 4, 6 and 8 weeks pp, the serum concentrations of VitE in the supplemented kids were significantly higher compared to the unsupplemented group. In the kids, VitE was higher in liver of the supplemented groups. There were no significant differences in response to extra VitE between sheep and goat. The kids responded to serum VitE different from that of lambs, as a significant difference was observed between supplemented and unsupplemented animals in the goat kids, but not the lambs. In conclusion, goats and sheep have to be viewed differently and may not be considered alike relating to VitE/Se metabolism and requirements, especially in young animals.

Mineral content of hay harvested in Bavarian and Swiss horse farms. Predictive value of cutting time, number of cut, botanical composition, origin and fertilization.

Hay samples from 29 horse farms in Southern Upper Bavaria and 31 horse farms in Switzerland were taken and analysed for minerals such as calcium, magnesium, phosphorus and potassium. The content of herbs and legumes in the hay was determined and the Weende analysis was performed. Comparison between Bavaria and Switzerland resulted in comparable calcium contents of approximately 4 g Ca/kg dry matter (DM) in grass hay. Hay with more than 10% of herbs and legumes found only in Switzerland showed higher Ca contents of >7 g Ca/kg DM in hay. The mineral contents of phosphorus and potassium were lower in hay from Switzerland (P: 1.8 +/- 0.7 g/kg DM, K: 15.4 +/- 5.1 g/kg DM) than from Bavaria (P: 3.8 +/- 0.6 g/kg DM, K: 20.0 +/- 6.0 DM), whereas the magnesium content of the hay showed no difference between the regions ( approximately 1.5 g Mg/kg DM). Very late first grass hay cuts showed low magnesium and calcium (<4 g/kg DM) contents. Further minerals in the hay for horses differed from those in dairy cattle in the same region. Fertilization showed only small effects on the mineral contents of the hay produced for horses. Therefore, in calculation of ration and production of supplements for horses, these differences should be taken into account.

Nährstoffgehalte und Eignung des Grundfutters zur Pferdefütterung: Eine Erhebung unter schweizerischen Bedingungen

For horses no special tables related to nutrients for Swiss roughage exist. For this reason samples of hay, straw, silage/haylage and green forage were taken from 46 horse keeping farms in 22 cantons. The samples were judged by sense and following the nutrient--and macromineral--content as well as the content of fructans were analysed. Regarding its quality no sample was totally inadequate for horses. The mean contents of crude protein in Swiss hay for horses were clearly lower than in hay for ruminants and in German hay for horses. The mineral contents (calcium, magnesium, phosphorus) showed a wide range. On average they were also lower than the values provided in tables for ruminants. Except for one sample the silages/haylages showed a dry matter content of more than 40 %. No nutrient tables for silage or haylage, which are such high in dry matter contents, were found in the literature. The contents offructans in silage/haylage and green forage also showed a wide range with a maximum of 94 g/kg DM fructan.

Energy Requirement and Food Intake Behaviour in Young Adult Intact Male Cats with and without Predisposition to Overweight

Obesity is a common problem in cats. In the experimental cat family of the institute of animal nutrition besides a “normal” lean phenotype, cats with predisposition to an overweight phenotype are present. To investigate energy requirements and food intake behaviour of intact male cats of different phenotypes, six “normal” lean cats (GL) and six cats disposed to overweight (GO) were used. At the beginning of the experiment, all cats had an ideal body condition score of 5. To reach this the GO cats had to pass a weight-loss program. Energy requirements of the cats were determined using respiration chambers, whereas the amount and frequency of food intake was measured with a feeding station recording the data automatically. Energy requirement at weight constancy of the GO cats was even on fat-free mass (FFM) significantly (P = 0.02) lower (162.6 kJ/kg FFM/d) than that of the “normal” lean cats (246 kJ/kg FFM/d). The GO cats also showed a higher food intake 34.5 ± 1.5 g dry matter/kg body weight0.67 compared to the GL cats (24.0 ± 2.1 g dry matter/kg body weight0.67)(P = 0.001). In conclusion quantifiable differences in food intake and behaviour in cats predisposed to overweight compared to “normal” lean cats were found.

Metabolic response to three different diets in lean cats and cats predisposed to overweight

BackgroundThe existence of a genetic predisposition to obesity is commonly recognized in humans and rodents. Recently, a link between genetics and overweight was shown in cats. The goal of this study was to identify the effect of diet composition on plasma levels of glucose, insulin, free fatty acids and triglycerides in cats receiving different diets (high-carbohydrate, high-fat and high-protein diets).ResultsInsulin and leptin concentrations were significantly correlated with phenotype. Insulin levels were lower, whereas leptin levels were higher in cats predisposed to overweight. The other blood parameters were not correlated with phenotype. Intake of the high-carbohydrate diet resulted in higher insulin concentrations compared with the two other diets. Insulin levels were within the values described for non-obese cats in previous studies.ConclusionsThere was no difference in metabolic response between the two groups. As the high-carbohydrate diet led to the highest insulin blood concentrations, it might be useful to avoid such diets in cats predisposed to overweight. In addition, even cats with genetically linked obesity can regain insulin sensitivity after weight loss.

Puppy feeding in Switzerland

In this study breeders and owners of 8 different dog breeds (Beagle, Bernese Mountain Dog, Cavalier King Charles Spaniel, Great Dane, German Shepherd (GS), Labrador, Papillon, Sheltie) were interviewed to obtain information on puppy feeding in Switzerland. Besides answering a questionnaire (husbandry and feeding of the puppies), the participation in this study included weekly weighing of the animals as well as exact documentation of the amount fed to the animals. Totally 67 dog breeders and 131 new owners of puppies participated. The weight development of the puppies was mostly parallel to the growth curve in the GS, Labradors and Shelties. There were some substantial differences to the ideal growth curve within the other breeds. The daily mean energy requirement was estimated too high, when including the growth curves. 80 - 90 % of the recommendations would be sufficient for most animals. The calcium supply was in the range of tolerance in all breeds. Nearly all breeders used commercially available complete food while raising the puppies. No breed-specific differences could be shown.In this study breeders and owners of 8 different dog breeds (Beagle, Bernese Mountain Dog, Cavalier King Charles Spaniel, Great Dane, German Shepherd (GS), Labrador, Papillon, Sheltie) were interviewed to obtain information on puppy feeding in Switzerland. Besides answering a questionnaire (husbandry and feeding of the puppies), the participation in this study included weekly weighing of the animals as well as exact documentation of the amount fed to the animals. Totally 67 dog breeders and 131 new owners of puppies participated. The weight development of the puppies was mostly parallel to the growth curve in the GS, Labradors and Shelties. There were some substantial differences to the ideal growth curve within the other breeds. The daily mean energy requirement was estimated too high, when including the growth curves. 80 - 90 % of the recommendations would be sufficient for most animals. The calcium supply was in the range of tolerance in all breeds. Nearly all breeders used commercially available complete food while raising the puppies. No breed-specific differences could be shown.