A comparison of certified and noncertified pet foods.

The market presents the buyer with a wide array of pet food choices. Marketing pet foods has changed in the last decade and today foods may be bought at a variety of outlets. The present study compares nutrient composition, digestibility, and effect on urine pH (cat foods only) of selected certified and noncertified pet foods from different outlets. The selected foods were considered analogous in terms of declared ingredients and macronutrient profiles. The analytical methods used were those of the Association of Official Analytical Chemists as described in the Pet Food Certification Protocol of the Canadian Veterinary Medical Association. The test foods were sampled 4 times from August 1994 to July 1995. Both certified and noncertified products met the nutritional requirements on a consistent basis, although 1 of the noncertified dog foods consistently failed to meet the zinc requirements. This same product also failed to meet the Canadian Veterinary Medical Association's standards for concentrations of protein, calcium, and phosphorus. One of the noncertified cat foods failed to meet the recommended calcium level. With the exception of fat digestion in 1 noncertified food, there were no statistically significant differences in major nutrient digestibility between certified and noncertified pet foods. There were some statistically significant differences in digestibility within both the certified and noncertified groups of foods. The practical significance of any of the statistical differences in digestibility is uncertain. Urine pH observed in cats fed noncertified test diets was variable, with some values greater than 7.0 as a maximum or 6.5 as an average. The general conclusion of this study was that the commonly available certified products were the nutritional equal of those foods that position themselves as "premium."     

Evaluation of vegetable protein in canine diets: Assessment of performance and apparent ileal amino acid digestibility using a broiler model

Recent technological advances in the human food industry with respect to meat processing have decreased the availability of animal proteins to the pet food industry which typically formulates diets with an excess of animal protein. In the long term, this is not sustainable; thus, alternative protein sources need to be investigated. This study examined three canine diets, comparing a typical animal protein‐based diet (control) with two experimental diets where the animal protein was substituted in part with vegetable protein (formulated based either on total protein or amino acid content) using a broiler model. Each diet was fed to six cages each containing two birds from day 15, 18 cages in total (36 birds). Excreta were collected from days 19 to 21. On day 23, birds were euthanized and weighed, and their ileal digesta were collected and pooled for each cage. In addition, one leg per cage was collected for evaluation of muscle mass. Results showed no significant difference in animal performance (feed intake or live weight gain) or muscle to leg proportion across the diets. Birds fed the control diet and the diet balanced for amino acid content exhibited the greatest coefficients of apparent metabolizability for nitrogen (p < .001). Birds fed the diets that contained partial replacement of animal with vegetable protein generally had greater ileal digestibility of amino acids compared to birds fed the control (animal protein) diet. Analysis of excreta showed no dietary difference in terms of dry matter content; however, birds fed the diet balanced for total protein and the diet balanced for amino acid content had significantly greater excreta nitrogen than the control (p = .038). Overall, the study suggests vegetable proteins when formulated based on amino acid content are a viable alternative to animal proteins in canine diets.     

Trialling nutrient recommendations for slow lorises (Nycticebus spp.) based on wild feeding ecology

Slow loris (Nycticebus spp.) captive diets have been based on routine and anecdotes rather than scientific fact. The growing body of evidence contradicts the high fruit diet supported by such anecdotes. Non‐human primate nutrient requirements are grouped into new (based on the common marmoset Callithrix jacchus) or old world (based on rhesus macaques Macaca mulatta) primates. Slow lorises are known to suffer from many health ailments in captivity such as dental disease, obesity, wasting and kidney issues all of which have been linked to diet. This study aimed to estimate nutrient intake from free‐ranging slow lorises and to determine whether this intake can be used as nutrient recommendations. We collected data of nutrient intake, food passage rate and digestibility of captive slow lorises on three diet treatments 1: current captive type diet which is mostly fruits, 2: wild‐type diet made only of food items from their natural diet, 3: new diet made to reflect wild slow loris nutrient intake. In order to validate our nutrient recommendations, diets 2 and 3 would have to be significantly different to Diet 1 in terms of nutrients, but not different from each other. Captive diets were significantly higher in soluble carbohydrates and lower in minerals and fibre fractions than both diets 2 and 3. Diets 2 and 3 led to a significantly increased food passage time and to more effective fibre and calcium digestion compared to Diet 1. We also observed obese individuals lost weight and underweight individuals gained weight. Our nutrient recommendations have been validated by our trials, and new or old world monkey nutrient recommendations are not consistent with our results. Diets should be high in protein and fibre and low in soluble carbohydrates and fats.     

Relationship between a plant-based ‘vegan’ pet food and clinical manifestation of multiple nutrient deficiencies in two cats

A topical subject in human nutrition is the steadily growing number of people choosing to limit or completely avoid all animal-derived food products either for moral dilemma, health concerns or both. To meet people's will of applying their dietary choices to their domestic animals, the pet food industry answered by launching on the market some plant-based diets. This leads to concerns about whether these diets are adequately formulated to satisfy the target species nutritional requirements, especially for cats which are still considered strict carnivores. This case report follows a 2-year-old male neutered Main Coon and a 1-year-old female spayed Domestic Shorthair cat, presented to the nutrition service of the University of Toulouse, France. Reason for consultation was lethargy with in anamnesis a recent dietary transition to a plant-based pet food. Dysorexia, lethargy and muscle waste were present at first consultation. Progressive weight loss developed during follow-ups. A macrocytic, non-regenerative anaemia with serum folates below reference were the main clinical features. Analysis of pet food showed multiple nutrients below minimum recommendation at the average daily intake of both cats. Folic acid supplementation improved dysorexia, and subsequent reintroduction of animal-derived ingredients in the diet restored appetite, weight and a normal mentation in both cases.     

Availability, brands, labelling and salmonella contamination of raw pet food in the minneapolis/st. Paul area

The purpose of the study was to characterize the commercially available raw meat pet food diets in the Minneapolis/St. Paul area by (i) determining the number and types of available diets; (ii) assessing pet food stores and brand labels for the provision of precautionary statements regarding the risk of foodborne illness from raw meat; (ii) assessing the labels for Food and Drug Administration (FDA)/American Association of Feed Control Officials (AAFCO) required content and nutrient-related information; and (iv) culturing purchased diets for the presence of Salmonella. Sixty raw meat diets were purchased, representing 11 different brands from eight different stores. Diets were readily available in the form of raw-frozen, dehydrated or freeze-dried varieties from different protein sources, such as lamb, beef, chicken or duck. All stores promoted raw meat diets; however, none provided foodborne illness warnings. Brands varied greatly in their precautionary statements; none of the diets underwent feeding trials; and nutritional adequacy substantiation was through formulation only. The first five ingredients tended to consist of meat, organ meat (by-products), vegetables, grains and ground bones. Currently, it is required that pet foods have an AAFCO nutritional adequacy statement and provide a guaranteed analysis table. Three brands did not meet these FDA requirements. Thirty-one (51.7%) of the 60 raw meat diets underwent some degree of processing including dehydration, freeze-drying or high-pressure pasteurization. Four of the 60 raw diets (7%) tested positive for Salmonella. Analysis of raw meat pet food labels indicated a lack of foodborne illness warnings. Based on these findings, we recommend that warning statements similar to those required by the United States Department of Agriculture and placed on labels of raw meat intended for human consumption be provided on the labels of raw meat pet food diets.     

Effects of raw and heat-treated bambara groundnut (Vigna subterranea) on the performance and body composition of growing broiler chicks.

Bambara groundnut (Vigna subterannea)--a leguminous root nut, which grows in the tropics and subtropics--was used in an experiment to test its effect on the performance of growing broiler chicks. Performance was measured by monitoring growth, measuring nutrients and energy balances and also by determining nutrient accretion. Twelve-day old broiler chicks, kept in individual metabolic cages, were used in an experiment in which birds were equally allotted (n = 10) into a control (fed high performance diet made up principally of wheat and soybean meal) and 6 test groups fed diets containing 19, 76 and 95% raw or autoclaved bambara groundnuts. All diets were similar in energy, nitrogen and total lipid contents. Diets were also balanced for amino acids, vitamins and minerals in accordance to the specific requirements of the birds. Feed and water were provided ad libitum. Growth performance was monitored over 15 days. Nutrient and energy balances were measured by use of TiO2 as marker. The comparative slaughter technique was implored for the determination of energy and nutrient accretion. The results showed that the level of raw or autoclaved bambara had no significant influence on feed intake. Increasing the bambara level in the diets caused a general linear drop in the performance of the broilers. However, with up to 95% bambara in the diet, the general performance was still above 75% compared to the control. Increasing levels of bambara groundnut caused a decrease in the metabolizability of energy and efficiency of utilisation of ME for BWG. The animals retained more water with increasing levels of raw bambara in the diets while autoclaving increased their DM content to levels comparable to the control. The protein composition of gain was comparable at all levels of inclusion. In general autoclaving improved the performance of bambara.     

Homemade diets: attributes, pitfalls, and a call for action

At one time, it was estimated that the majority of dogs and cats in the United States received 90% or more of their nutrition from complete and balanced commercially prepared foods, and this estimate was reaffirmed in a 2004 survey. However, 4 years and several pet food and treat recalls later, fewer pet owners are feeding commercial pet food products exclusively and more are asking questions and looking for alternatives. As in any market-driven economy, there are many more alternative diets and food products available today from which pet owners may select. A difficult to measure but growing number of clients are feeding homemade diets that provide 100% of their pet's nutrition, while a larger number are feeding a combination of products, treats, and home prepared meals. Most practitioners can attest to this increase in their client's interest in homemade meals and to having insufficient knowledge to assist them. At a time when motivated clients are considering homemade for their pets as an alternative, veterinarians are less than adequately versed in canine and feline nutrition and dietary options. The article addresses the two most important health issues concerning pet owners and veterinarians about homemade diets: nutritional integrity and food safety.     

Pet birds as potential reservoirs of virulent and antibiotic resistant zoonotic bacteria

Bacterial pathogens carried by pet birds are considered a risk for birds, workers, and pet owners. This study investigated the potential of pet birds as reservoirs for virulent multidrug-resistant (MDR) zoonotic bacteria and assessed the genetic relatedness and diversity of bacterial isolates from pet birds and human contacts. Cloacal and tracheal swabs from 125 pet birds and 70 hand swabs from human contacts were collected. The results revealed that the pet birds were reservoirs for Escherichia coli, Klebsiella pneumoniae (17.6 %, each), and Staphylococcus aureus (15.2 %). These isolates were also identified in their human contacts, at percentages of 14.3 %, 12.9 %, and 24.3 %, respectively. Virulence associated genes were identified from E. coli (stx2, stx2f, eaeA, and hlyA), K. pneumoniae (fimH, TraT, and magA), and S. aureus (PVL, hly, sea, sed genes) isolates. Multidrug-resistant E. coli, K. pneumoniae, and S. aureus were highly prevalent (81.3 %, 90.3 %, and 61.1 %, respectively). The genetic relationship between the E. coli and K. pneumoniae isolates from the pet birds and human contacts were determined by ERIC-PCR, while, RAPD-PCR was used for the S. aureus isolates. ERIC-PCR was found to have the highest discriminatory power. The clustering of the isolates from the pet birds and human contacts indicated potential transmission between the birds and workers. In conclusion, pet birds could act as potential reservoirs for zoonotic bacterial pathogens; thus, posing a risk to their human contacts.     

Exacerbative effect of vitamin A on malabsorption syndrome in chicks

The interaction between malabsorption syndrome (MAS) and dietary vitamins A and D was studied in broiler chicks reared in floor pens for 4 weeks. The chicks were naturally infected with MAS, whereas hatchmates fed the same diets but in a separate facility (battery brooder) did not exhibit signs of MAS and, therefore, were considered controls. MAS significantly reduced body weights, bone ash, serum calcium and phosphorus concentrations, and liver lipids and increased the incidence of skeletal abnormalities (tibial dyschondroplasia and rickets). Rather than ameliorating the effects of MAS, vitamin A caused a further reduction in body weight and bone ash. A possible nutrient interaction between vitamin A and vitamin D or vitamin E in birds with MAS may account for the exacerbative effect of vitamin A.     

Understanding regulations affecting pet foods

In the United States, pet foods are subject to regulation at both the federal and the state levels. The US Food and Drug Administration has jurisdiction over all animal feeds (including pet foods, treats, chews, supplements, and ingredients) in interstate commerce, which includes imported products. Many states adopt and enforce at least in part the Association of American Feed Control Officials Model Bill and Model Regulations for Pet Food and Specialty Pet Food. Thus, all pet foods in multi-state distribution are subject to a host of labeling requirements covering aspects such as product names, ingredient lists, nutrient content guarantees, and nutritional adequacy statements. Ingredients must be GRAS (generally recognized as safe) substances, approved food additives, or defined by Association of American Feed Control Officials for their intended use. Pet food labels may not bear claims that are false or misleading or that state or imply use for the treatment or prevention of disease. Pet foods that are found to be adulterated or misbranded may be subject to seizure or other enforcement actions.     

Ingredients: where pet food starts

Every clinician is asked "What should I feed my pet?" Understanding the ingredients in pet food is an important part of making the best recommendation. Pet food can be as simple as one ingredient or as complicated as containing more than 60 ingredients. Pet food and its ingredients are regulated by the Food and Drug Administration and state feed officials. Part of that regulation is the review and definition of ingredients. Existing ingredients change and new ingredients become available so the need for ingredient definitions grows. Ingredients for product formulations are chosen based on their nutrient content, digestibility, palatability, functionality, availability, and cost. As an example, a typical, nutritionally complete dry dog food with 42 ingredients is examined and the ingredients are discussed here. Safe, healthy pet food starts with safe ingredients sourced from well-monitored suppliers. The ultimate goal of both veterinarians and pet food manufacturers is the same--long healthy lives for dogs and cats.     

Comparison of the guaranteed analysis with the measured nutrient composition of commercial pet foods

The purpose of this study was to compare the guaranteed analysis of commercial pet foods to their measured nutrient concentrations. Data were collected regarding the guaranteed and measured concentrations of crude protein, crude fat, crude fibre, moisture and ash of pet foods from annual feed inspection reports from South Dakota (2003–2005), Indiana (2004–2005), Rhode Island, New York and New Jersey (2005–2006). The difference for each nutrient was compared among types of food (dry, canned or treat), intended species, target life‐stages, manufacturers and reporting laboratories. Significant differences between the guaranteed and measured nutrient concentrations were found. For all foods, the mean ± one standard deviation of the difference was 1.5 ± 2.0% for crude protein, 1.0 ± 1.7% for crude fat, ‐0.7 ± 1.3% for crude fibre, ‐4.0 ± 3.3% for moisture, and ‐0.5 ± 1.0% for ash. The difference in crude protein was significantly greater for treats than for other food types. The difference in crude fat was significantly less for dry foods than for other food types. The differences in crude fibre and moisture were significantly less for canned foods than for other food types. Only the differences in crude fibre differed significantly among target species, life‐stages, manufacturers or laboratories. More accurate estimations of the nutrient composition and calculated metabolizable energy content of commercial pet foods can be obtained by making adjustments to the guaranteed analysis. This includes adding 1.5% and 1% to the guaranteed minimums for crude protein and crude fat, respectively, and subtracting 0.7%, 4% and 0.5% from the guaranteed maximums for crude fibre, moisture and ash, respectively.     

Lactobacilli counts in crop,ileum and caecum of growing broiler chickens fed on practical diets containing whole or dehulled sweet lupin (Lupinus angustifolius) seed meal

1. Four experiments with growing broiler chickens were carried out to study the effects of the inclusion in their diets of lupin (Lupinus angustifolius ) seed meal on E. coli and lactobacilli counts in crop, ileum and caeca at 3 or 4 weeks of age. 2. Diets were formulated to contain the same amounts of metabolisable energy (12.55 MJ/kg) and protein (210 g/kg). Raw whole (heat-untreated) or dehulled sweet (low in alkaloids) lupin seed meal (400 and 320 g/kg respectively) were used to prepare the lupin-based diets, whose protein content was completed with either defatted soyabean meal or casein. 3. Final body weight and food intake of chickens fed on whole lupin seed meal diets were lower than controls, but gain: food ratios were not different. However, birds given the diet with dehulled lupin seed meal had similar body weight, food intake and gain: food values as those of controls. 4. While E. coli counts were not affected, lactobacilli numbers were consistently increased compared to controls in all intestinal sections of chickens fed on the whole or dehulled lupin-based diets, irrespective of the age of the birds or the presence of soyabean meal or casein in the diet. The lactobacilli species isolated were: Lactobacillus fermentum, L. acidophilus, L. salivarius and L. brevis 5. The results suggest that the use of whole or dehulled sweet lupin seed meal in diets for growing broilers might enhance the growth of lactic acid-fermenting bacteria in the gut.     

The histamine content of commercial pet foods

The histamine contents of a range of North American commercial pet foods and pet food ingredients were determined by a spectrofluorometric technique. The change in histamine content of open cans of pet food stored in a refrigerator or at room temperature was also investigated. The histamine content of the pet foods examined ranged from a low of 0.16 microg/g in a liquid critical care diet to a high of 65.5 microg/g in a canned fish diet. The amount of histamine in the foods tested was insufficient to cause histamine toxicosis but it cannot be excluded that some of the foods contained sufficient histamine to cause idiosyncratic reactions in histamine-sensitive cats. Storage of opened cans of pet food, either under refrigeration or at room temperature, did not significantly increase the histamine content of most pet foods.     

Nutritional value of raw and autoclaved kabuli and desi chickpeas (Cicer arietinum L.) for growing chickens.

1. Two experiments were carried out to determine the effect of inclusion of raw (kabuli and desi) and autoclaved (desi) chickpea seeds in wheat-based starter diets in chickens grown to 28 d of age on the performance, digestive organ sizes, nitrogen-corrected apparent metabolisable energy (AMEn), ileal apparent protein and starch digestibilities (APD and ASD) and intestinal alpha-amylase and trypsin activities. 2. In the first experiment, diets were formulated to contain 0, 150, 300 and 450 g/kg of raw kabuli chickpea seeds. Increasing the proportion of seed in the diet negatively influenced body weight gain, food intake and food efficiency. The relative weights of the pancreas, liver and gizzard and the relative lengths of duodenum, jejunum, ileum and caeca were increased significantly when the chickpea seeds were included in the diets. Correspondingly, APD, ASD, alpha-amylase and trypsin activities and AMEn were reduced significantly when the chickpea seed was incorporated in the diets. 3. In the 2nd experiment, diets were formulated to contain 75 and 150 g/kg of raw and autoclaved desi chickpea seeds. Weight gain and food intake of the chicks given desi chickpea diets were significantly reduced compared with those fed on the control diet. Increasing the proportion of seed in the diet negatively influenced body weight gain, food intake and food efficiency. Moreover, a significant increment in the relative weights of liver and pancreas, and in the relative lengths of duodenum, ileum and caeca was observed when the concentration of chickpea seeds in the diets was increased. Feeding autoclaved seeds significantly increased the weight gains and the food intakes. However, food efficiency was not modified by the autoclaving. Relative weights of gizzard and liver and relative lengths of ileum were decreased significantly by the inclusion of autoclaved desi chickpea in the diet. 4. We concluded that the inclusion of kabuli (up to 450 g/kg) and desi (up to 150 g/kg) chickpea seeds produced a negative effect on the performance of the birds, and an increment in the relative weights and lengths of the digestive organs. In addition, the incorporation of kabuli chickpea produced a reduction of protein and starch digestibilities, alpha-amylase and trypsin activities, and AMEn of food compared with the birds given the control diet. Autoclaved treatment of desi chickpea improved the performance of the birds.     

The histamine content of commercial pet foods

The histamine contents of a range of North American commercial pet foods and pet food ingredients were determined by a spectrofluorometric technique. The change in histamine content of open cans of pet food stored in a refrigerator or at room temperature was also investigated. The histamine content of the pet foods examined ranged from a low of 0.16 𝛍g/g in a liquid critical care diet to a high of 65.5 𝛍g/g in a canned fish diet. The amount of histamine in the foods tested was insufficient to cause histamine toxicosis but it cannot be excluded that some of the foods contained sufficient histamine to cause idiosyncratic reactions in histamine-sensitive cats. Storage of opened cans of pet food, either under refrigeration or at room temperature, did not significantly increase the histamine content of most pet foods.     

Prevalence and antimicrobial resistance of Salmonella spp. in pet mammals, reptiles, fish aquarium water, and birds in Trinidad

The prevalence of Salmonella spp. was determined in 970 animals comprising 423 pet birds, 485 fish aquaria water and 62 other pets (40 pet mammals, 14 reptiles, eight others - crustaceans, snail, stingray) from both pet shops and households throughout Trinidad. The serotypes of Salmonella spp. isolated were identified and the resistance to various antimicrobial agents was determined. Overall nine (0.9%) of 970 pet animals were positive for Salmonella spp. Six isolates of Salmonella spp. were recovered from all pet birds with two isolates of serotype Aberdeen and one isolate each of Thompson, Rubislaw, Panama and Newport. The prevalence of Salmonella spp. in birds was 0.9%. Four isolates of Salmonella spp. were recovered from fish aquaria water, serotypes included Panama (two isolates), Newport (one isolate) and Virchow (one isolate). Prevalence of Salmonella spp. from fish aquaria was 0.4%. No isolate of Salmonella spp. was detected in pet mammals sampled while two isolates were recovered from reptiles, S. Enteritidis and S. Montevideo. One isolate of Salmonella spp. was recovered from a stingray, serotype unknown. Antimicrobial resistance was present is all animal types. The highest prevalence of resistance was to streptomycin among isolates from birds (83.3%) and other pets (100.0%) while isolates from fish aquarium water exhibited comparatively high resistance to cephalothin (50.0%). It was concluded that the isolation of Salmonella spp. from apparently healthy birds, fish aquarium water and other pet animals may pose a health risk to their owners and contacts as all serotypes are known to be potentially pathogenic depending on the oral dosage of the organism and the immune status of those in contact. The high prevalence of resistance to antimicrobial agents among Salmonella isolates across pet species may pose chemotherapeutic consequences to their owners and contacts.     

The Effect of Levels of α-Galactosidase Enzyme on Performance of Broilers Fed Diets Based on Corn and Soybean Meal

A study was conducted with male chicks of a commercial broiler strain to evaluate the effects of different dosage levels of a commercial α-galactosidase enzyme. Diets were formulated based on corn and soybean meal to meet the nutrient standards of top poultry companies. The positive control diet was formulated with no adjustment in the ME content of the soybean meal associated with enzyme supplementation. The negative control diet was formulated assuming a 10% improvement in the ME of the soybean meal. The negative control diet was supplemented with 0, 1.5, 3.0, 4.5, or 6.0 g of enzyme per kilogram of soybean meal to provide for 0, 45, 90, 135, or 180 galactosidase units (GALU)/kg of soybean meal. Each of the test diets was fed in mash form to 8 replicate pens of 30 birds. Body weight, feed efficiency, mortality, and calorie conversion were determined at 14, 35, and 42 d of age. Body weight, feed efficiency, and mortality were not significantly (P < 0.05) affected by dietary treatment. Birds fed the negative control with no enzyme supplement were numerically reduced in body weight or feed efficiency as compared with the control diet; however, addition of the enzyme was without benefit. When unadjusted energy values were analyzed, birds fed the negative control diet were more efficient in calorie conversion, but this finding was unrelated to enzyme addition, suggesting that diet composition was responsible for the differences in calorie utilization. When adjusted energy values were compared, birds fed the negative control tended to have higher (less efficient) calorie conversion than those fed the positive control with little or no indication of improvement from the addition of the α-galactosidase enzyme. Results of this study show no benefit from the addition of the enzyme used in this trial.     

Estimation of protein requirement for maintenance in adult parrots (Amazona spp.) by determining inevitable N losses in excreta

Especially in older pet birds, an unnecessary overconsumption of protein--presumably occurring in human custody--should be avoided in view of a potential decrease in the excretory organs' (liver, kidney) efficiency. Inevitable nitrogen (N)-losses enable the estimation of protein requirement for maintenance, because these losses have at least to be replaced to maintain N equilibrium. To determine the inevitable N losses in excreta of adult amazons (Amazona spp.), a frugivor-granivorous avian species from South America, adult amazons (n = 8) were fed a synthetic nearly N-free diet (in dry matter; DM: 37.8% starch, 26.6% sugar, 11.0% fat) for 9 days. Throughout the trial, feed and water intake were recorded, the amounts of excreta were measured and analysed for DM and ash content, N (Dumas analysis) and uric acid (enzymatic-photometric analysis) content. Effects of the N-free diet on body weight (BW) and protein-related blood parameters were quantified and compared with data collected during a previous 4-day period in which a commercial seed mixture was offered to the birds. After feeding an almost N-free diet for 9 days, under the conditions of a DM intake (20.1 g DM/bird/day) as in seeds and digestibility of organic matter comparable with those when fed seeds (82% and 76% respectively), it was possible to quantify the inevitable N losses via excrements to be 87.2 mg/bird/day or 172.5 mg/kg BW(0.75)/day. Assuming a utilization coefficient of 0.57 this leads to an estimated protein need of approximately 1.9 g/kg BW(0.75)/day (this value does not consider further N losses via feathers and desquamated cells; with the prerequisite that there is a balanced amino acid pattern).     

The species-specific feeding of rabbits in pet husbandry

To meet nutrient demands as well as the species specific requirements of an animal it is absolutely necessary to know its nutrition physiology (KAMPHUES et al. 1999). Characteristics of the nutrition physiology of rabbits include the anatomy of the intestinal tract (i.e. the teeth, the size of gut as well as the small intestine and colon), the special ingesting behaviour (selection, intensity of gnawing and chewing) and digestive processes within the intestinal tract (digestion by own as well as by microbial enzymes, processes of separation (producing soft faeces) and the excretion of digested or undigested nutrients (excretion via faeces or kidneys, quality of faeces). In feeding pet rabbits it has to be recommended, that these species do not need concentrates, but ingredients with higher crude fiber contents due to their origin and their intestinal tract. Therefore these herbivorous species should be fed with hay, straw or vegetables and not with concentrates exclusively. If these components are not offered (an usual feeding practice in rabbits kept as companion animals), other products rich in crude fibre have to be fed. The offer of a pressed diet in cube form with long fibrous ingredients would be a possibility to upgrade a ration poor in crude fibre. To meet the gnawing requirement of the rabbits this cubes should be pressed intensively. Furthermore it is advisable to exchange ingredients of the mixed feed with a high energy content (i.e. sunflower seeds, nuts) for ingredients of lower energy density (i.e. oat hulls, pelleted ground hay). Finally calcium oversupply has to be avoided because higher calcium intake may result in urolithiasis (calcium stones/concrements).