In vitro formation of metabolic-intermediate cytochrome P450 complexes in rabbit liver microsomes by tiamulin and various macrolides

Tiamulin and a number of macrolides were evaluated as to their ability in forming metabolic-intermediate (MI) complexes with cytochrome P450 in liver microsomes from rabbits bred for meat production. Complex formation, which occurred only in preparations where the expression of P450 3A was increased as the result of rifampicin pre-treatment and with different kinetics, was in the order tiamulin > erythromycin > TAO approximately roxithromycin approximately tylosin and did not take place with tilmicosin and spiramycin. Most of the tested compounds underwent an oxidative N-dealkylation and a good relationship could be found between the rate of N-dealkylase activity in induced preparations and the aptitude in generating MI complexes. Although the results from in vitro studies should be interpreted with caution, it is suggested that the potential for in vivo drug interactions also exists in the rabbit for tiamulin and for four out of the six tested macrolides.     

Nutritional Peculiarities and Diet Palatability in the Cat

Cats have become the most popular companion animal in Western Europe. Unlike other domestic animals, cats are strict carnivores and this influences both their nutritional requirements and food preferences. Cats have very high protein requirements and their diet must contain some nutrients, such as arginine, taurine, niacin, vitamin A and arachidonic acid. Besides its nutritional value, a diet for cats must also be highly palatable. This paper offers a quick overview of feline nutritional peculiarities and the factors that influence food palatability in cats.

     

Nutritional peculiarities and diet palatability in the cat

Cats have become the most popular companion animal in Western Europe. Unlike other domestic animals, cats are strict carnivores and this influences both their nutritional requirements and food preferences. Cats have very high protein requirements and their diet must contain some nutrients, such as arginine, taurine, niacin, vitamin A and arachidonic acid. Besides its nutritional value, a diet for cats must also be highly palatable. This paper offers a quick overview of feline nutritional peculiarities and the factors that influence food palatability in cats.     

The effects of two different light intensities on the production and behavioural traits of Italian heavy pigs

Eighty Italian heavy pigs having an initial body weight of about 75 kg were allotted to two experimental groups: a low light intensity group (LL), in which pigs received the lowest level of illumination mandatory in piggeries (40 lux) and a high light intensity group (HL), in which pigs were exposed to a higher level of illumination (80 lux). For both groups the light phase lasted 12 hours per day. Pigs were slaughtered at about 160 kg body weight. Light intensity showed to have no effects on the growth traits, carcass parameters or neutrophil-to-lymphocyte ratio of heavy. With the exception of drinking (more frequently observed among LL pigs; P < 0.01) and sternal recumbency (more frequently observed among pigs belonging to HL group; P < 0.01), the behavioural observations, carried out on 20 pigs per group, indicated that light intensity did not affect the main behavioural traits of pigs. Agonistic interactions were significantly higher (P < 0.05) among pigs receiving a lower level of illumination (40 lux; LL group) and pigs exposed to the higher level of illumination (80 lux; HL group) showed a tendency (P < 0.1) towards a higher proportion of tactile social interactions. Our results confirm that a proper illumination level can be included among environmental conditions having a positive effect in order to preserve swine welfare.     

Effect of a Lactobacillus animalis strain on composition and metabolism of the intestinal microflora in adult dogs

Probiotics are microorganisms that are added to food to exert beneficial effects on the host. Aim of the present study was the in vitro and in vivo evaluation of the effect of Lactobacillus animalis LA4 (isolated from the faeces of a healthy adult dog) on composition and metabolism of dog intestinal microflora. When added to dog faecal cultures, LA4 reduced enterococci and increased lactobacilli counts throughout the study, whereas C. perfringens counts were significantly reduced at 24 h. After 8 h of incubation, LA4 reduced ammonia and increased lactic acid concentrations. For the in vivo study, nine adult dogs received the freeze-dried preparation of L. animalis LA4 for 10 days. On day 11, faecal lactobacilli were higher than at trial start (6.99 log CFU/g versus 3.35 log CFU/g of faeces) and faecal enterococci showed a trend towards a numerical reduction (P = 0.08). L. animalis LA4 was recovered in all faecal samples collected on day 11 and in four samples at day 15. The present results show that LA4 was able to survive gastrointestinal passage and transitorily colonize the dog intestine where, based on the in vitro results, it could positively influence composition and metabolism of the intestinal microflora. These results suggest that L. animalis LA4 can be considered as a potential probiotic for dogs.     

Water requirements of liquid-fed heavy pigs: Effect of water restriction on growth traits,animal welfare and meat and ham quality

Reducing water waste, and therefore the total volume of manure produced, is one of the ways to lower the environmental impact of intensive pig farming. The aim of this trial was to verify whether the absence of additional fresh drinking water could compromise the production traits or behaviour of liquid-fed heavy pigs. Sixty animals (initial BW 78 kg) were divided into two experimental groups, both fed a liquid diet (water-to-feed ratio 3:1 w/w). All pens were equipped with nipple drinkers; one of the groups had permanent access to fresh water (working drinkers—WD), whereas the other group had no water supply except that delivered with food (dry drinkers—DD). The pigs were housed in temperature- and humidity-controlled rooms. They were brought to a weight of 160 kg and then slaughtered. Hams were dry-cured according to the directives for Parma ham production. No significant differences (P>0.05) were observed between the experimental groups with respect to growth parameters (ADG and FCR), behavioural traits, blood parameters or the qualitative traits of carcasses (dressing out, lean meat yield, backfat thickness), meat (pH, colour, WHC, fatty acid composition of subcutaneous fat and tenderness) and cured hams (weight losses, sensory properties, chemical composition and oxidative status). With respect to drinking behaviour, a low number of visits to the drinker were recorded for both groups and data seem to indicate a high amount of water wasted by pigs provided with additional water delivery by nipple drinkers. Liquid feeding did not suppress drinkers use or drinker manipulation in both groups.     

Investigation of the metabolic activity of a bovine mammary epithelial cell line (BME-UV1)

The metabolic activity of a mammary epithelial cell line (BME-UV1) was evaluated on monolayers exposed, in serum free medium, to different concentrations (2-4-8 muM) of aflatoxin B1 (AFB1), a mycotoxin eliminated into milk especially as hydroxylated metabolite aflatoxin M1 (AFM1). After 4, 8, 12, 24 h of treatment, a dose and time dependent production of AFM1 has been detected. As the enzymes involved in the hydroxylation of AFB1 in bovine hepatocytes are mainly CYP1A and CYP3A, the results suggest that BME-UV1 express CYP450 isoenzymes which metabolize AFB1 thus representing a potential model for the investigation of the metabolic activity of bovine mammary epithelial tissue.