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Further studies on the nutritional requirements of Colpoda duodenaria
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Anaerobic biodegradation of methyl esters by Acetobacterium woodii and Eubacterium limosum
The ability of Acetobacterium woodii and Eubacterium limosum to degrade methyl esters of acetate, propionate, butyrate, and isobutyrate was examined under growing and resting-cell conditions. Both bacteria hydrolyzed the esters to the corresponding carboxylates and methanol under either condition. Methanol was further oxidized to formate under growing but not resting conditions. Unlike the metabolism of phenylmethylethers, no H 2 requirement was evident for ester biotransformation. The hydrolysis of methyl carboxylates is thermodynamically favorable under standard conditions and the mixotrophic metabolism of ester/CO 2 allowed for bacterial growth. These results suggest that the degradation of methyl carboxylates may be a heretofore unrecognized nutritional option for acetogenic bacteria.
Effects of maternal and grandmaternal nutrition on deer mass and vulnerability to wolf predation
In a Minnesota ecosystem, mass of female white-tailed deer ( Odocoileus virginianus ) fawns and adults, and survival of adult females in the face of wolf ( Canis lupus ) predation, were directly related to maternal nutrition during gestation. Mass of single male fawns produced by 2-year-old females, and survival of yearlings to 2 years of age were related directly to the nutrition of their grandmothers.
Use of urine in snow to indicate condition of wolves
Urine deposited in snow by wild gray wolves ( Canis lupus ) and by fed and fasted captive wolves was analyzed for urea nitrogen, calcium, sodium, potassium, and creatinine. Ratios of the elements with creatinine were considerably higher for fed than for fasted animals, and ratios for fed wolves compared favorably with ratios from wolf urine in snow along trails leading from kills. Thus, wolf urine in the snow can indicate whether wolves have fed recently, and a series of such urine collections from any given pack can indicate relative nutritional state.
Diet differences in Redheads from nearshore and offshore zones in Louisiana
Habitat management decisions for diving ducks in winter are limited by the lack of information concerning their use of nearshore and offshore zones. Therefore, we compared diets of redheads ( Aythya americana ) collected from nearshore (n = 206) and offshore (n = 72) zones during winters at the Chandeleur Islands, Louisiana, 1987-89. A greater (P < 0.05) proportion of redheads from nearshore had food in their esophagus and proventriculus than redheads from offshore. Feeding redheads in the offshore zone consumed more (P < 0.05) animal matter (42% in esophagus) and less plant material (58%) than conspecifics feeding nearshore (13% animal, 87% plant). Contents of proventriculi showed the same trend (P < 0.05). Zone-related diet differences occurred in both sexes and in early and late winter. Food availability and nutritional needs may affect these differences.
Changes in nutritive value of browse plants following forest fires
No abstract available.
Effects of winter undernutrition on body composition and physiological profiles of white-tailed deer
We examined the effects of undernutrition and recovery on body composition and blood and urinary profiles of 6 captive white-tailed deer ( Odocoileus virginianus ) between 18 December 1984 and 3 May 1985. Deer were weighed, and blood and urine were collected every 2 weeks from 10 January to 3 May. At Weeks 2, 8, and 14, body composition was estimated by the dilution of tritiated water technique and standard predictive equations. Feed intake decreased and cumulative mass loss increased during nutritional restriction. Baseline body composition included 62.1 ± 0.9 (SE)% water, 11.9 ± 1.0% fat, 20.5 ± 0.7% protein, and 4.5 ± 0.0% ash. Percent protein loss was linearly related (r 2 = 0.91, P < 0.001) to percent mass loss. Peak mass loss from the beginning of the study (12.8 ± 2.0%) occurred at Week 12; estimated protein loss was 12.5%. Fat reserves were 85% depleted from Week 2 to Week 14. Elevated packed cell volume (PCV), serum calcium (Ca), cholesterol, triglycerides, and cortisol; and diminished serum urea nitrogen, thyroxine (T4), urinary urea nitrogen: creatinine and potassium: creatinine were associated with reduced food intake, mass loss, and decreases in body water, fat, and protein. Altered values of most of these blood and urinary characteristics reflected initiation of nutritional recovery after nutrition improved. Sequential data collection and the use of a combination of indices in blood or urine will yield the most useful assessments of animal nutrition and condition.
Nutritional restriction and acid-base balance in white-tailed deer
We examined the effect of progressive nutritional restriction on acid-base balance in seven captive, adult white-tailed deer ( Odocoileus virginianus ) from 4 February to 5 May 1988 in north central Minnesota (USA). Metabolic acidosis was indicated by low mean blood pH (7.25 to 7.33) in deer throughout the study. Mean urinary pH values declined ( P = 0.020) from a mean (±SE) baseline of 8.3 ± 0.1 to 6.7 ± 0.3 as restriction progressed. Acidemia and aciduria were associated with significant variations in mean blood CO 2 ( P = 0.006) and pO 2 ( P = 0.032), serum potassium ( P = 0.004) concentrations, and with a significant ( P = 0.104) handling date × group interaction in urinary potassium : creatinine values. Mean bicarbonate : carbonic acid ratios were consistently below 20:1 during nutritional restriction. Mean packed cell volume increased ( P = 0.019) and serum total protein decreased ( P = 0.001); thus there was evidence for progressive dehydration and net protein catabolism, respectively. Blood pCO 2 , serum sodium, and urinary sodium : creatinine were stable throughout the study. We propose that acidosis and aciduria are metabolic complications associated with nutritional restriction of white-tailed deer.
Naturally occurring secondary nutritional hyperparathyroidism in cattle egrets ( Bubulcus ibis ) from Central Texas
Naturally occurring secondary nutritional hyperparathyroidism is described in the nestlings of two colonies of cattle egrets ( Bubulcus ibis ) from Central Texas (Bryan and San Antonio, Texas, USA). Nestlings from a third colony (Waco, Texas, USA) were collected in a subsequent year for comparison. Birds from the first two colonies consistently had severe osteopenia and associated curving deformities and folding fractures of their long bones. These birds also had reduced bone ash, increased osteoclasia, a marked decrease in osteoblast activity, variable lengthening and shortening of the hypertrophic zone of the epiphyseal cartilage, decreased and disorganized formation of new bone, and a marked hypertrophy and hyperplasia of the parathyroid glands as compared to birds collected from the third colony. Fibrous osteodystrophy was found in all of the birds from San Antonio and Bryan. Evidence of moderate to severe calcium deficiency was also identified in 33% of the cattle egrets collected from Waco. Gut contents of affected chicks contained predominately grasshoppers and crickets; vertebrate prey items were absent from the Bryan birds. Grasshoppers and crickets collected from fields frequented by the adult egrets in 1994 had 0.12–0.28% calcium and 0.76–0.81% phosphorus. Pooled grasshoppers and crickets collected during a subsequent wet early spring averaged 0.24% calcium and 0.65% phosphorus. Although the phosphorus content of the insect prey was adequate for growth, calcium was approximately one-third the minimum calcium requirement needed for growth for other species of birds. It was postulated that cattle egrets breeding in Central Texas have expanded their range into habitat that contains less vertebrate prey, and as a result, many nestling egrets are being fed diets that contain suboptimal calcium. Therefore, in years where vertebrate prey is scarce and forage for insect prey is reduced in calcium, nestling egrets are at risk for developing secondary nutritional hyperparathyroidism.
Lack of surface-associated microorganisms in a mixed species community of freshwater Unionidae
To determine whether unionids contain surface-attached endosymbiotic bacteria, ciliates, or fungi, we used scanning electron microscopy to examine the epithelial surface of various organs within the digestive systems and mantle cavity of temperate river and lake unionids on a seasonal basis. We also cultured material removed from the lumen of these same organs and from the mantle cavity to detect cellobiose-, cellulose-, and chitin- degrading microbes. No true endosymbiotic fauna were observed attached to the surface of the digestive or mantle tissues of any species of unionid. Microbial growth on cellulose or chitin bacteriological media varied by season and habitat, but not by unionid species or source of the isolate. Lake unionids did not contain microbes capable of digesting cellulose or chitin, whereas unionids from the river site did in March and August, but not in December. Since these cultured cellulose- and chitin-degrading bacteria were never found attached to any unionid tissues, they appeared to be transient forms, not true endosymbionts. Microbes capable of digesting cellobiose were found in every unionid collected in all seasons and habitats, but again, no microbes were directly observed attached to unionid tissues. If unionids, like most other vertebrates, lack digestive enzymes required to initiate primary bond breakage, then the lack of cellulolytic and chitinolytic endosymbionts would affect the ability to utilize cellulose or chitin foods. Thus, in captivity dry feeds based on corn, soybeans, or nauplii should be pre-digested to ensure maximum absorption of nutrients by unionids. The lack of celluloytic or chitinolytic endosymbionts should not affect relocation success, though the seasonal role of transient microbes in unionid nutrition requires further investigation.
Physiological assessment of deer populations by analysis of urine in snow
We compared the nutritional status of free-ranging white-tailed deer ( Odocoileus virginianus ) in 3 natural yards and 1 yard where deer were supplementally fed from 1 January to 31 March 1985 in northeastern Minnesota. We monitored deer nutritonal status by sequential collection and chemical analysis of urine in snow (snow-urine) for urea nitrogen (U), sodium (Na), potassium (K), calcium (Ca), and phosphorus (P). Dilution of urine by snow was corrected by comparing these data as ratios to creatinine (C). All deer remained in an early phase of undernutrition; however, declining trends of U:C, Na:C, and K:C in 2 natural yards indicated increasingly inadequate nutrition as winter progressed. Unaltered values of these ratios and P.C in snow-urine collected from the third natural yard reflected stable levels of nutrient availability. Significant (P < 0.05) elevations of Na:C, K:C, and P:C in 2 natural yards with similar snow regimes suggested initiation of nutritional recovery in deer during late March. In contrast, deep snow in the third natural yard restricted feeding activity and was associated with ratios that remained diminished. Elevated U:C, Na:C, and K:C provided physiological evidence of the higher nutritional status of supplementally fed deer throughout winter and their ability to increase nutrient intake during late March despite prolonged deep snow cover. Frequent and quantitative assessments of the physiological status of deer by snow-urine analysis provided an improved understanding of the relationship between snow cover and the nutritional well-being of these deer.
Age-class separation of blue-winged ducks
Accurate determination of age is of fundamental importance to population and life history studies of waterfowl and their management. Therefore, we developed quantitative methods that separate adult and immature blue-winged teal ( Anas discors ), cinnamon teal ( A. cyanoptera ), and northern shovelers ( A. clypeata ) during spring and summer. To assess suitability of discriminant models using 9 remigial measurements, we compared model performance (% agreement between predicted age and age assigned to birds on the basis of definitive cloacal or rectral feather characteristics) in different flyways (Mississippi and Pacific) and between years (1990-91 and 1991-92). We also applied age-classification models to wings obtained from U.S. Fish and Wildlife Service harvest surveys in the Mississippi and Central-Pacific flyways (wing-bees) for which age had been determined using qualitative characteristics (i.e., remigial markings, shape, or wear). Except for male northern shovelers, models correctly aged lt 90% (range 70-86%) of blue-winged ducks. Model performance varied among species and differed between sexes and years. Proportions of individuals that were correctly aged were greater for males (range 63-86%) than females (range 39-69%). Models for northern shovelers performed better in flyway comparisons within year (1991-92, La. model applied to Calif. birds, and Calif. model applied to La. birds: 90 and 94% for M, and 89 and 76% for F, respectively) than in annual comparisons within the Mississippi Flyway (1991-92 model applied to 1990-91 data: 79% for M, 50% for F). Exclusion of measurements that varied by flyway or year did not improve model performance. Quantitative methods appear to be of limited value for age separation of female blue-winged ducks. Close agreement between predicted age and age assigned to wings from the wing-bees suggests that qualitative and quantitative methods may be equally accurate for age separation of male blue-winged ducks. We interpret annual and flyway differences in remigial measurements and reduced performance of age classification models as evidence of high variability in size of blue-winged ducks' remiges. Variability in remigial size of these and other small-bodied waterfowl may be related to nutrition during molt.
Spawning salmon and the fitness of stream-dwelling fishes: Marine-derived nutrients show saturating effects on growth and energy storage in juvenile salmonids
We examined how marine-derived nutrients (MDN), in the form of spawning Pacific salmon, influenced the nutritional status and d15N of stream-dwelling fishes. We sampled juvenile coho salmon (Oncorhynchus kisutch) and Dolly Varden (Salvelinus malma) during spring and fall from 11 south-central Alaskan streams that ranged widely in spawning salmon biomass (0.1–4.7 kg•m–2). Growth rate (as indexed by RNA–DNA ratios), energy density, and d15N enrichment in spring-sampled fishes increased with spawner biomass, indicating the persistence of spawner effects more than 6 months after salmon spawning. Point estimates suggest that spawner effects on nutrition were substantially greater for coho salmon than Dolly Varden (268% and 175% greater for growth and energy, respectively), indicating that both species benefitted physiologically, but that juvenile coho salmon accrued more benefits than Dolly Varden. Although the data were less conclusive for fall- than spring-sampled fish, they do suggest spawner effects were also generally positive during fall, soon after salmon spawned. In a follow-up analysis where growth rate and energy density were modeled as a function of d15N enrichment, results suggested that both increased with MDN assimilation, especially in juvenile coho salmon. Our results support the importance of salmon runs to the nutritional ecology of stream-dwelling fishes.
Effects of feeding and fasting on wolf blood and urine characteristics
Feeding and fasting trials were conducted with 2 groups (A and B) of 4 gray wolves ( Canis lupus ) each during January 1980. The groups were fed for 9 days and fasted for 10 days in a cross-over design. Blood and urine samples and weight data were collected every 2-3 days during each trial. Hemoglobin (Hb) concentrations, red blood cell (RBC) counts, and hematocrits (HCT) were elevated in both groups during fasting. White blood cell (WBC) counts, serum urea nitrogen (SUN), triiodothyronine (T3), and insulin concentrations decreased during fasting in Groups A and B. Mean corpuscular hemoglobin concentration (MCHC), serum cholesterol, triglyceride, and iron (Fe) concentrations were diminished in fasted Group A wolves compared to fed Group B. Creatine phosphokinase (CPK) concentrations were elevated in fed Group A wolves. Serum creatinine (C) concentrations were reduced in both groups during feeding. Urinary urea: creatinine (U:C), potassium:creatine (K:C), and sodium:creatinine (Na:C, pooled Group A and B data) ratios decreased in fasted wolves. Differences were not found between fed and fasted wolves for mean corpuscular volume (MCV), serum cortisol, glucose, calcium (Ca), bilirubin, serum glutamate-oxaloacetate transaminase (SGOT), serum glutamate-pyruvate transaminase (SGOT), serum glutamate-pyruvate transaminase (SGPT), alkaline phosphatase, and luteinizing hormone (LH) concentrations, total iron binding capacity (TIBC), and urinary calcium: creatine (Ca:C) ratios. Analysis of multiple blood or urine samples collected from free-ranging wolves would be useful in enabling researches and managers to identify the nutritional status and general health of wolves over time.
Diseases of amphibians
The development and refinement of amphibian medicine comprise an ongoing science that reflects the unique life history of these animals and our growing knowledge of amphibian diseases. Amphibians are notoriously fastidious in terms of captive care requirements, and the majority of diseases of amphibians maintained in captivity will relate directly or indirectly to husbandry and management. Investigators have described many infectious and noninfectious diseases that occur among various species of captive and wild amphibians, and there is considerable overlap in the diseases of captive versus free-ranging populations. In this article, some of the more commonly reported infectious and noninfectious diseases as well as their etiological agents and causative factors are reviewed. Some of the more common amphibian diseases with bacterial etiologies include bacterial dermatosepticemia or “red leg syndrome,” flavobacteriosis, mycobacteriosis, and chlamydiosis. The most common viral diseases of amphibians are caused by the ranaviruses, which have an impact on many species of anurans and caudates. Mycotic and mycotic-like organisms cause a number of diseases among amphibians, including chytridiomycosis, zygomycoses, chromomycoses, saprolegniasis, and ichthyophoniasis. Protozoan parasites of amphibians include a variety of amoeba, ciliates, flagellates, and sporozoans Common metazoan parasites include various myxozoans, helminths (particularly trematodes and nematodes), and arthropods. Commonly encountered non-infectious disease etiologies for amphibians include neoplasia, absolute or specific nutritional deficiencies or overloads, chemical toxicities, and inadequate husbandry or environmental management.
Nutritional levels and growth rates of hand-reared coyote pups
No abstract available.
Evidence for nutritional disease a Lake Victoria cichlid, Haplochromis (Prognathochromis) perrieri (Pellegrin): a clinical assessment
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