Pier Paolo Mussa

Influence of cellulose fibre length on faecal quality, mineral excretion and nutrient digestibility in cat

In dogs, faeces quality and nutrients digestibility were affected by different types of cellulose (Wichert et al., 2002). In this study, it was investigated whether there are comparable effects of cellulose type in cats. Seven adult, healthy cats were fed a moist commercial complete cat food with three different cellulose type added at a level of 4% for a 1 week period. Faeces quality was between 1 and 3 on the scale used from 1 to 5. The addition of long fibre cellulose resulted in significantly firmer faeces. Addition of cellulose decreased the digestibility of dry matter and energy, whereas the impact on protein and fat digestibility was not significant. The type of cellulose affected faecal bulk and faecal water excretion. Faecal excretion of sodium and potassium was exponentially correlated to faecal water, faecal bulk and to a lesser extent to faecal dry matter excretion. Faecal calcium, magnesium and phosphorus excretion showed an exponential correlation to faecal dry matter excretion. A weaker correlation existed in all three elements to faecal bulk, whereas the effect of faecal water excretion was small. Results suggest a remarkable likeness between cats and dogs with regard to the digestive physiology of major minerals.

Use of injectable transponders for the identification and traceability of pigs

Individual identification in pigs is a key point for management, traceability and trade control. The aim of this experiment was to study retention rate and functionality of electronic identification systems in pigs, injected in different sites, evaluate traceability of animals and highlight histopathological alterations of tissues in different inoculation sites. A total of 60 crossbred piglets were used to compare different transponder inoculation sites. One group (15 piglets) was identified only by plastic ear-tags, while three groups were identified by passive injectable transponders (PIT), with different inoculation sites. Pigs were slaughtered in two different moments, in order to evaluate injection sites, macroscopically and histologically, either 50 days after injection or at a normal slaughtering weight. In general, no apparent animal health problems were observed the day after the injection or during the control readings performed during the experiment. Intraperitoneal localization gave excellent results in term of readability until the slaughter time. Transponders at the slaughter line were always recovered in the viscera tray, as they were found loose in the peritoneal cavity. In some cases, they were found on the carcasses, attached to the peritoneum. In those cases a sample of peritoneal tissue was collected for histological examination. A reparative chronic reaction with moderate and multifocal fibrosis and neoformed vessels associated to multifocal and mild lymphoplasmacytic infiltrate were detected. In one case (6.7%) the transponder was found on the visceral side of the liver and the histological examination highlighted a localized superficial hepatic atrophy by compression. Retroauricolar site of injection gave lower readability results, as 2 transponders (13.3%) were no more readable during the first month after injection. No lesions were found with this inoculation site. PIT injected in the perineal region were operative until slaughter time. Recovery procedures at the slaughterhouse were simple for animals slaughtered at a low weight, but much more difficult in the case of heavy pigs. Moreover, in three cases (20%), PITs were no more in the subcutaneous tissue but had an intramuscular localization. The histological examination of the muscles revealed a chronic reparative process. In our experiment, injectable transponders in the intraperitoneal position provided the best identification system for pigs. Histo -pathological examination revealed only local reparative processes in the tissues interested by PIT contact, and no other pathological changes.

Fresh meat quality of pigs fed diets with different fatty acid profiles and supplemented with red wine solids

Three groups of pigs were fed three different diets, namely a diet rich in saturated fatty acids (palm oil-based, PO), a polyunsaturated fatty acid (PUFA)-rich diet (corn oil-based, CO), and a PUFA-rich diet (corn oil-based) supplemented with red wine solids (RWS), which was added to the diet (CO+RWS) in order to assess the protective effect on the oxidative status of the pork meat. The addition of corn oil favourably modulates the FAs profile of the backfat, and to a lesser extent of the intramuscular fat of semimembranosus muscle, without causing adverse effects on the meat quality or on its oxidative stability. Moreover, these parameters were not affected by the addition of the RWS in the CO+RWS diet.

Dog Nutrient Requirements: New Knowledge

Dog nutrition was based on anecdotal knowledge from domestication until the beginning of last century. In 1943, McCay, in his book “Nutrition of the dog” quoted published studies and underlined that there was a real lack of information on this topic; more so than for other species. The result of this was that many animals grew old quickly and died early. The last 30 years have been characterised by a substantial increase in research into dog nutrition, particularly concerning nutritional requirements. The National Research Council (NRC) of the United States, considering this new information, has developed a new edition of Nutrient Requirements of the dog and cat. When comparing the four editions of this book (issued in 1972, 1974, 1985 and 2003), several differences, both in form and in substance, are noticed. The earlier editions supplied general advice, while the 1985 edition specified minimum requirements of essential nutrients. Both these systems have advantages and disadvantages: improvements in the new edition include determination of minimum levels (to avoid lacks) and maximum levels (to avoid toxicity) of different nutrients and energy and providing a safety range. This concept is already being applied by pet food companies, but misunderstandings are still common about energy requirements. The main doubt is related to maintenance energy requirements (energy consumed by an adult animal with moderate physical activity in thermic neutrality conditions). Different results have been found by authors in this area. These differences are due, in part, to the extraordinary heterogeneity among canine breeds; only horses are almost comparable. For example, weight can vary between 1 and 100 kg; the coat can be very long or almost nonexistent; and character and spontaneous physical activity are highly variable. Finally, it is important to consider the life style imposed on the animal by the owner. The aim of this paper is to compare the different systems for evaluating nutrient requirements, to obtain general rules useful for practical feeding and nutrition of dogs.

Effect of dietary supplementation with lysozyme on coat quality and composition, haematological parameters and faecal quality in dogs

The objective of this study was to determine whether: (1) lysozyme supplementation would influence coat quality in dog and (2) coat quality improvement would be related with haematological parameters, fur composition and faecal quality. Eight dogs were divided into two groups and fed a diet supplemented with 0.2% lysozyme. Blood samples were analysed for haematological and haematochemical parameters. Coat quality was assessed using near infrared spectrometry (NIRS) and through a three-point scoring system. Fur copper and zinc concentrations were analysed. Faeces were scored using a five-point scale, and faecal concentration of short-chain fatty acids was analysed. Coat quality changed significantly with lysozyme treatment as assessed by NIRS analysis and was improved according to a three-point visual scale. Plasma total protein, creatinine, blood urea and plasma chloride were lower after a two-month lysozyme dietary supplementation period. Faecal valerate was higher after the supplementation period. Lysozyme supplementation would lead to an improvement of coat quality, which could be related to modification of gut microflora in dogs.