Vitamins E and A, and proximate composition of whole mice and rats used as feed

THE IMPACT OF SUPPLEMENTARY FEEDING OF PIG CARCASSES ON PLASMA VITAMIN E CONCENTRATIONS IN CAPTIVE CAPE VULTURES (GYPS COPROTHERES)

With vulture population numbers on the decline globally, many countries resort to supplementary feeding to maintain colony health. Despite what is perceived as adequate feeding in South Africa, colonies are still characterized by poor breeding success. One reason could be that supplementary sites fail to meet micronutrient needs of birds. With results from zoological gardens indicating that some carcasses are low in their vitamin E concentrations, vitamin deficiencies may be an underlying problem. For this study it was determined if the feeding of whole pig carcasses, a common food item, could have a negative effect on plasma vitamin E concentrations in a captive colony. Plasma vitamin E concentrations were 7.38 ± 2.92 and 4.51 ± 1.24 after feeding whole pig carcasses (n = 14). Behaviorally, the birds also avoided the viscera and fat when feeding. Reasons for their low vitamin E concentrations could have resulted from the birds consuming only the pork meat, which is known to be low in vitamin E, or from natural peroxidation because of the high fat content of the carcasses. The study thus highlights the need for further research to ascertain the impact of feeding pig carcasses on wild vultures feeding routinely at supplementary feeding sites and also for considerations towards vitamin E supplementation.

HEALTH AND NUTRITIONAL ASSESSMENT OF FREE-RANGING EASTERN INDIGO SNAKES (DRYMARCHON COUPERI) IN GEORGIA, UNITED STATES

Clinical pathology and nutritional parameters are useful in evaluating and monitoring threatened and endangered wildlife populations, but reference ranges for most snake species are lacking. From 2001 to 2005, health assessments were performed on 58 eastern indigo snakes (EIS) (Drymarchon couperi) captured in the wild in southeastern Georgia, United States. Health and nutritional assessments performed included hematology, serum biochemistry, fat-soluble vitamins, heavy metals, pesticide contaminants, parasitology, and surveys of other pathogens. Significant differences in total solids, packed cell volume, glucose, blood urea nitrogen, albumin : globulin ratio, amylase, triglycerides, and bile acids between males and females were observed. Additionally, there was a significant difference between liver and kidney concentrations for vitamins A and E. As previously noted in captive EIS, total Ca was elevated in comparison to concentrations reported in other snake species. Parasitism was a common finding in sampled EIS, but the overall health status of this free-ranging population appeared good. A winter-time dermatitis was found in most snakes, which resolved in the summer months. This study represents the first health and nutritional assessment of free-ranging EIS, and provides needed data to guide monitoring and conservation efforts.

Circulating Fat-Soluble Vitamin Concentrations and Nutrient Composition of Aquatic Prey Eaten by American Oystercatchers (Haematopus palliatus palliatus) in the Southeastern United States

The American oystercatcher (Haematopus palliatus palliatus) is currently listed as a species of high concern by the United States Shorebird Conservation Plan. Because nutritional status directly impacts overall health and reproduction of individuals and populations, adequate management of a wildlife population requires intimate knowledge of a species' diet and nutrient requirements. Fat-soluble vitamin concentrations in blood plasma obtained from American oystercatchers and proximate, vitamin, and mineral composition of various oystercatcher prey species were determined as baseline data to assess nutritional status and nutrient supply. Bird and prey species samples were collected from the Cape Romain region, South Carolina, USA, and the Altamaha River delta islands, Georgia, USA, where breeding populations appear relatively stable in recent years. Vitamin A levels in blood samples were higher than ranges reported as normal for domestic avian species, and vitamin D concentrations were lower than anticipated based on values observed in poultry. Vitamin E levels were within ranges previously reported for avian groups with broadly similar feeding niches such as herons, gulls, and terns (eg, aquatic/estuarine/marine). Prey species (oysters, mussels, clams, blood arks [Anadara ovalis], whelks [ Busycon carica ], false angel wings [ Petricola pholadiformis ]) were similar in water content to vertebrate prey, moderate to high in protein, and moderate to low in crude fat. Ash and macronutrient concentrations in prey species were high compared with requirements of carnivores or avian species. Prey items analyzed appear to meet nutritional requirements for oystercatchers, as estimated by extrapolation from domestic carnivores and poultry species; excesses, imbalances, and toxicities-particularly of minerals and fat-soluble vitamins-may warrant further investigation.

Commercially available avian and mammalian whole prey diet items targeted for consumption by managed exotic and domestic pet felines: macronutrient, mineral, and long-chain fatty acid composition

Whole prey diets encourage species-typical behaviors making them popular in the zoo and home setting for captive exotic and domestic felids, respectively. We evaluated macronutrient, mineral, and long-chain fatty acid composition of 20 whole prey items: mice (1-2, 10-13, 21-25, 30-40, and 150-180 days of age); rats (1-4, 10-13, 21-25, 33-42, and >60 days of age); rabbits (still born, 30-45 days, >65 days with skin, and >65 days of age with skin removed); chicken (1-3 days of age, ground adult); duck (ground adult); and quail (1-3, 21-40, and >60 days of age). Composition of whole prey was highly variable (15-40% DM, 34-75% CP, 10-60% fat, and 8-18% ash). A majority of whole prey samples (15/20) had at least one mineral or fatty acid below AAFCO [] or NRC [] minimum recommended concentrations for domestic cats (K, Na, Cl, Mg, Cu, Mn, and/or Zn; total fat, linolenic acid, arachidonic acid and/or EPA and DHA). These data identify potential nutrient deficiencies allowing for alterations in dietary formulation prior to long-term feeding.

Raptor gastroenterology

Free-living raptors are frequently presented to wildlife rehabilitation centers. Conditions affecting the gastrointestinal tract can be the primary reason for presentation. The gastrointestinal tract can also be affected secondary to debilitation from other injuries or from the stress of the rehabilitation process. A thorough understanding of the anatomy, physiology, and natural history of these species is crucial to successful treatment and rehabilitation. This article addresses raptor gastroenterology with an emphasis on conditions affecting free-living birds.

Blood values of adult captive cheetahs (Acinonyx jubatus) fed either supplemented beef or whole rabbit carcasses

This study evaluated nutrient intake and relevant blood parameters of 14 captive cheetahs, randomly assigned to a meat-only diet (supplemented beef, SB) or a whole prey diet (whole rabbit, WR) for 4 weeks each. Despite a higher food intake, daily metabolizable energy intake was lower when fed WR (308 kJ BW(-1) ) compared with SB (347 kJ BW(-1) ) (P = 0.002). The ratio of protein to fat was markedly lower for WR (2.3:1) compared with SB (8.8:1), which was reflected in higher serum urea levels when fed SB (P = 0.033), and a tendency for elevated cholesterol levels when fed WR (P = 0.055). Taurine intake of cheetahs fed WR was low (0.06% on DM basis); however, analytical error during taurine analysis cannot be ruled out. Feeding WR resulted in a well-balanced mineral intake, in contrast to SB. The latter provided a low calcium:phosphorus ratio (1:2.3), thereby increasing the risk of metabolic bone disease. The high zinc content of SB (200 mg/kg DM), compared with WR (94 mg/kg DM), was reflected in higher serum zinc concentrations (P = 0.011). Feeding WR resulted in an increase in serum vitamin A (P = 0.011). Therefore, the risk of hypervitaminosis A in captive cheetahs when fed WR exclusively on a long-term basis should be evaluated. Our findings suggest that neither diet is likely to provide appropriate nutrition to captive cheetahs when fed exclusively.

Estimation of the dietary nutrient profile of free-roaming feral cats: possible implications for nutrition of domestic cats

Cats are strict carnivores and in the wild rely on a diet solely based on animal tissues to meet their specific and unique nutritional requirements. Although the feeding ecology of cats in the wild has been well documented in the literature, there is no information on the precise nutrient profile to which the cat's metabolism has adapted. The present study aimed to derive the dietary nutrient profile of free-living cats. Studies reporting the feeding habits of cats in the wild were reviewed and data on the nutrient composition of the consumed prey items obtained from the literature. Fifty-five studies reported feeding strategy data of cats in the wild. After specific exclusion criteria, twenty-seven studies were used to derive thirty individual dietary nutrient profiles. The results show that feral cats are obligatory carnivores, with their daily energy intake from crude protein being 52 %, from crude fat 46 % and from N-free extract only 2 %. Minerals and trace elements are consumed in relatively high concentrations compared with recommended allowances determined using empirical methods. The calculated nutrient profile may be considered the nutrient intake to which the cat's metabolic system has adapted. The present study provides insight into the nutritive, as well as possible non-nutritive aspects of a natural diet of whole prey for cats and provides novel ways to further improve feline diets to increase health and longevity.

Specific dynamic action of ambystomatid salamanders and the effects of meal size, meal type, and body temperature

The past decade has witnessed a dramatic increase in studies of amphibian and reptile specific dynamic action (SDA). These studies have demonstrated that SDA, the summed energy expended on meal digestion and assimilation, is affected significantly by meal size, meal type, and body size and to some extent by body temperature. While much of this attention has been directed at anuran and reptile SDA, we investigated the effects of meal size, meal type, and body temperature on the postprandial metabolic responses and the SDA of the tiger salamander (Ambystoma tigrinum tigrinum). We also compared the SDA responses among six species of Ambystoma salamanders representing the breadth of Ambystoma phylogeny. Postprandial peaks in VO(2) and VO(2), duration of elevated metabolism, and SDA of tiger salamanders increased with the size of cricket meals (2.5%-12.5% of body mass). For A. tigrinum, as for other ectotherms, a doubling of meal size results in an approximate doubling of SDA, a function of equal increases in peak VO(2) and duration. For nine meal types of equivalent size (5% of body mass), the digestion of hard-bodied prey (crickets, superworms, mealworms, beetles) generated larger SDA responses than the digestion of soft-bodied prey (redworms, beetle larvae). Body temperature affected the profile of postprandial metabolism, increasing the peak and shortening the duration of the profile as body temperature increased. SDA was equivalent among three body temperatures (20 degrees, 25 degrees, and 30 degrees C) but decreased significantly at 15 degrees C. Comparatively, the postprandial metabolic responses and SDA of Ambystoma jeffersonianum, Ambystoma maculatum, Ambystoma opacum, Ambystoma talpoideum, Ambystoma texanum, and the conspecific Ambystoma tigrinum mavortium digesting cricket meals that were 5% of their body mass were similar (independent of body mass) to those of A. t. tigrinum. Among the six species, standard metabolic rate, peak postprandial VO(2), and SDA scaled with body mass with mass exponents of 0.72, 0.78, and 1.05, respectively.

Effects of prey size, meal size, meal composition, and daily frequency of feeding on the recovery of rodent remains from carnivore scats

Recovery of rodent bone and teeth from coyote (Canis latrans) scats (feces) varied with prey size, meal size, energy content of the meal, and the frequency with which prey were consumed. Mean percentages of mouse and rat teeth recovered ranged from 1% (SE = 0.5%, n = 5) to 24.4% (SE = 3.6%, n = 4) and from 13.8% (SE = 3.8%, n = 5) to 52.5% (SE = 16.6%, n = 5), respectively. A significant portion of this variation resulted from physiological mechanisms affecting how long prey were retained in the digestive acids of the stomach. Recovery of hair did not vary and thus it was considered to be nondigestible. Owing to the variation in the recovery of bone and teeth and the lack of variation in the recovery of hair, we recommend the use of teeth or bone to identify the small rodents present in carnivore scats, and then the use of a visual estimate of hair, or sample of hair, to apportion the scat to the prey items present. We caution against using the numbers of teeth or diagnostic bones to determine the number or amount of a prey item represented by a scat without addressing the variability in their recovery. The effects of gastrointestinal physiology should be considered when planning feeding trials to derive correction factors for scat analysis.

Pharmacokinetics of 2-naphthol following intrapericardial administration, and formation of 2-naphthyl-beta-D-glucoside and 2-naphthyl sulphate in the American lobster, Homarus americanus

1. Following a 0.25-mg/kg intrapericardial dose of the phenolic compound, 2-naphthol, to the American lobster, Homarus americanus, a two-compartment model best described the disposition of parent [14C]-2-naphthol in the haemolymph. Male and female lobsters had similar alpha-phase half lives of 26 +/- 19 min (mean +/- SD, n = 4) and 29 +/- 15 min respectively. The beta-phase half lives were significantly longer in males, 63.9 +/- 30.9 h, than in females, 30.6 +/- 6.8 h (p < 0.05). The total body clearance for females was 26.4 +/- 6.5 ml x h-1 x kg-1 and was higher than that of males, 11.1 +/- 5.9 ml x h-1 x kg-1 (p < 0.05). 2. 2-Naphthol was converted to 2-naphthyl-beta-D-glucoside (major metabolite) and 2-naphthyl sulphate (minor metabolite) such that at 24 h 39-60.6% of the radioactivity in haemolymph was 2-naphthyl-beta-D-glucoside, 38.6-58.9% 2-naphthol and 0.5-4% 2-naphthyl sulphate. 3. The 2-naphthol-derived radioactivity was > 99% bound to haemolymph proteins at 1 min and > 90% bound at 1 day after the dose, indicating that both 2-naphthol and 2-naphthyl-beta-D-glucoside were highly protein bound. 4. 2-Naphthyl-beta-D-glucoside was slowly eliminated from haemolymph in both males and females, with elimination half lives of 34-78 h. 2-Naphthyl-beta-D-glucoside was the major metabolite in urine samples collected at 5 days after the dose. Hepatopancreas and antennal gland contained glucosidase activities, and the long half life of 2-naphthyl-beta-D-glucoside could be explained by conjugation deconjugation cycling. 5. 2-Naphthyl sulphate was eliminated from haemolymph with a half-life < 10 h and was excreted in urine.