Kidney fat and marrow fat indices of the sika deer population at Mount Goyo, northern Japan

Fat deposits are effective indicators of the nutritional status of wild populations of ungulates. Three fat indices (kidney fat, femur marrow fat and mandible marrow fat) of sika deer (Cervus nippon) at Mount Goyo, northern Japan, were compared. The kidney fat index (KFI) was suitable for good and intermediate nutritional status, but could not precisely reflect poor conditions. Bone marrow fat indices (MFI) were not good indicators because samples with high MFI values did not distinguish between samples whose KFI values were different, and samples collected in non-winter seasons did not cover the range of poor conditions. It is therefore recommended to use both the KFI and the femur-MFI complementarily.     

Validating Predictive Models of Nutritional Condition for Mule Deer

Abstract: We developed new, and validated existing, indices of nutritional condition for live and dead mule deer (Odocoileus hemionus). Live animal indices included a body condition score (BCS), thickness of subcutaneous fat and selected muscles using ultrasonography, and body mass. Dead animal indices included femur, metatarsal, and mandible marrow fat, 3 kidney fat indices, and 2 carcass scoring methods. We used 21 female deer and 4 castrates (1-11 yr old) varying widely in nutritional condition (2-28% ingesta-free body fat). Deer were euthanized and homogenized for chemical analysis of fat, protein, water, and ash content. Estimates of fat and gross energy (GE) were regressed against each condition indicator using regression. Subcutaneous fat thickness, a rump BCS, and rLIVINDEX (an arithmetic combination of subcutaneous fat thickness and the rump BCS) were most related to condition for live animals (r² ≥ 0.87, P < 0.001) whereas the Kistner score and kidney fat were most related to fat and GE for dead animals (r² ≥ 0.77, P < 0.001). We also evaluated range of usefulness and sensitivity to small changes in body condition for all models. In general, indices with moderate or highly curvilinear statistical relations to body fat or those based on only one fat depot or a small number of ranking scores will have limitations in their use. Our results identify robust tools for a variety of research and monitoring designs useful for evaluating nutrition's effect on mule deer populations.     

Effects of density,season, and food intake on sika deer nutrition on Yakushima Island,Japan

Sika deer (Cervus nippon) suffer severe winter food limitation in northern Japan; however, plant food resources are available during winter in southern Japan and, consequently, deer nutritional status may not decrease there. To test this hypothesis, we measured seasonal changes in Riney’s kidney fat index (RKFI) and stomach intake in 74 culled deer individuals from five areas with different deer densities on Yakushima Island, Japan. The average RKFI differed significantly among populations and ranged from 22.91 ± 11.91 to 76.23 ± 15.99. There was no significant correlation between RKFI and deer density. The total fresh weight of rumen contents also differed significantly among populations, ranging from 0.51 to 3.51 kg. Food intake and RKFI exhibited an L-shaped distribution in the vicinity of a town ranch. However, we found that food intake had a significantly positive effect in populations at the other four locations, suggesting that changes in nutritional status were related to the quantity of deer rumen contents. Neither deer density nor season were significantly correlated with RKFI values. The average RKFI values exceeded 20 in all five locations. These findings indicate that the deer were not in a poor nutritional condition even in high density areas of >70 head/km², which supports the above hypothesis. Notably, food intake varied among individuals in the same area, but was independent of body weight and age, which suggests that food selectivity differs between deer individuals.     

Annual foods of the Red deer (Cervus elaphus) and the Roe deer (Capreolus capreolus) in the east of England

There have been few studies on the foods of Red deer (Cervus elaphus L.) and Roe deer (Capreolus capreolus L.) in British forests. Notable exceptions are the work of Prior (1968), Henry (1978) and Hosey (1981) on Roe deer. British work on the food of Red deer seems to have been confined to studies of animals on upland swards (Charles, McCowan & East, 1977; Staines ∓ Crisp, 1978). However, a more abundant supply of data on the food and feeding of both Red and Roe deer comes from the Continent (Dragoev, 1964; Gabuzov, 1960; Kolev, 1966; Novikov & Timofeeva, 1964; Siuda, Zorowski & Suida, 1969; Dzieciolowski, 1967 a , b , 1969). Even so the data available were obtained from studies made on individual species of deer. This paper reports the results of an investigation into seasonal changes in the diet of Red and Roe deer coexisting in a conifer forest in the east of England.     

Seasonal fluctuations of body condition in northern sika deer on Hokkaido Island, Japan

We analyzed seasonal and sexual fluctuations in kidney mass (KM) and kidney fat mass (KFM) as indices of condition in Hokkaido sika deerCervus nippon yesoensis Heude, 1884. For 76 male and 132 female sika deer, seasonal fluctuations in KM and KFM were given by fitted sine wave growth curves. Although the kidney fat index (KFI) is used frequently to evaluate animal condition, we reject it because it is based on the assumption that kidney mass is proportional to body mass in all seasons. Our data did not support this assumption. KFM is a better indicator of Hokkaido sika deer condition than KFI. Although sex-based differences in cervid KFM are said to reflect differences in reproductive cycles, the seasonal similarities in sika deer KFM levels may represent adaptations to the long severe Hokkaido winter. Because in our study deer populations were at low densities and had high pregnancy rates, our sine wave growth models can be regarded as reference for fat level fluctuations in Hokkaido sika deer.     

Condition and related mortality of nyala Tragelaphus angasi in Zululand, South Africa

The kidney fat index (KFI) was used to examine the condition of nyala over a 27-m-onth period. From a sample in which both marrow fat and KFI were examined, it was noted that, as has been found in other bovid, kidney fat was mobilized before marrow fat. Seasonal changes in condition were observed and correlated with the rainfall in the previous month. Following periods of less than 50 mm of rain, the larger adult males were in significantly poorer condition than other animals.
The sexual difference in condition is attributed to the differences in body size, where males of asymptotic body mass required 62% more kcal/day than asymptotic mass females. When die-offs occurred during periods of nutritional stress, significantly more old adults died than would be expected. Further, significantly more males died than females.     

Effect of domestic cattle on the condition of female white-tailed deer in southern pine-bluestem forests,USA

Effect of domestic cattle stocking on the nutritional condition of white-tailed deerOdocoileus virginianus (Zimmermann, 1780) was assessed using physiological indices of collected specimens. Three study areas were delineated in McCurtain County, Oklahoma (heavy cattle stocking), and Howard (moderate to light cattle stocking) and Pike (no cattle stocking) counties, Arkansas that were similar with respect to soils and vegetation but differed with respect to cattle stocking rate. Female white-tailed deer were collected from study areas in February and August 1987–1988 to assess nutritional condition. Deer collected from study areas exposed to cattle grazing in February had lower carcass weights, fat attributes (femur marrow and kidney fat), and reproductive rates (fetuses/doe) than deer that were not exposed to cattle grazing. In August, deer collected from the moderate cattle area had heavier eviscerated carcass weights, serum glucose, albumin, and albumin/globulin ratios than deer collected from the heavy cattle area. Results suggest that if cattle are removed from managed forests in winter, nutritional condition of deer would be improved because of reduced competition for food.     

Optimizing the sampling effort to evaluate body condition in ungulates: A case study on red deer

Body condition is a useful measure of the nutritional status and performance in ungulates. The most widely used indicators of body condition are based on fat reserves, mainly those surrounding the kidneys. To estimate the body condition in large herbivores, researchers often collect and pool the data from both kidneys and their perirenal fat in order to compensate for potential differences between the body condition indicators obtained from the left and right kidneys. Since these differences do not seem to be properly established in wildlife, we checked for the potential differences between the body condition indicators, derived from both kidneys, in wild ungulates. In the present study, we used red deer Cervus elaphus, both under experimental and field conditions, as a model to analyse the patterns of response of the body condition indicators, calculated from left and right kidneys, to supplementary feeding, sex, age class and season. By considering two analytical approaches – kidney fat index and fat weight (including kidney weight as a covariate) – we consistently obtained similar statistical results and the same ecological interpretations by using left, right and average indicators for all the factors tested. In the experimental study, supplementary feeding had a significant effect on all the body condition indicators of red deer hinds. Under field circumstances, the condition indicators were statistically higher in females than in males and they increased with age. Sex related differences were significant in the winter. Taking into account our results, we hypothesize that information from only one kidney will be enough to assess the body condition in red deer and probably in other wild ungulates. However, a standardized sample (i.e. always using the same kidney and associated fat) should be used, while a better understanding regarding possible asymmetries in the amount of the energy reserves on each side of the animals’ bodies has not been reached. Our study has clear implications concerning wildlife monitoring since it represents a considerable reduction of time and effort, both in the field (collecting the samples) and in the laboratory (processing and weighing the samples) when evaluating the body condition of individuals and populations.     

Differential effects of ruminally protected amino acids on fattening of fallow deer in two culling periods

A well-balanced amino acid profile in the feedstuffs for livestock is essential to support adequate growth. This is well studied for monogastric species but still not well understood for ruminants and especially for the most unconventional species, like cervids. This study investigated the influence of ruminally protected lysine (Lys) and methionine (Met) supplementation during the fattening period, as well as two slaughter seasons (late autumn (LA) v. late winter (LW)), on the growth, carcass traits, body condition and blood plasma metabolites of fallow deer (Dama dama). Forty-five yearlings of fallow deer bucks were allocated into three groups, balanced by weight (40.2 ± 2.7 kg). The deer were pasture-fed and supplemented with barley, free-choice mineral premix, silage during the winter period, and varying levels of ruminally protected Lys and Met: no amino acids (Control), 9 g/day of Lys, and 9 g/day of Lys plus 3 g/day of Met (Lys+Met). Animals were slaughtered in two separate seasons, LA (six animals per group), and LW (nine animals per group). Animals culled in LA had higher average daily weight gain than LW (P = 0.002), due to the reduced growth during winter typical for seasonal cervids in temperate zone, mediated by the photoperiod. Dressing percentage was significantly higher in LW and in the Lys+Met group (P = 0.002). Body condition score (P = 0.024), kidney fat index (KFI) (P = 0.005), and internal fat (P < 0.001) increased significantly with Lys+Met supplementation. During LW, KFI (P = 0.004) and kidney fat (P = 0.001) were also significantly higher than in LA. Blood creatinine concentration increased significantly for deer receiving Lys (P = 0.002) and Lys+Met (P < 0.001). Also, triglycerides level increased in Lys group (P < 0.001). These findings highlight the effects of Lys and Met supplementation on the growth and internal fat storage for winter survival, suggesting a different use of the supplemented resource according to the season. Also, the observed effects on protein and fat metabolism of fallow deer may influence the production of farmed animals, and offer interesting insights about the physiology of the species.     

Femur-Marrow Fat of White-Tailed Deer Fawns Killed by Wolves

Abstract: I present marrow fat (MF) data from a large sample of white-tailed deer fawns killed by wolves and a sample of fawns that died by accident in a single area, and I use these data to explore the extent that poor nutritional condition may have predisposed fawns to wolf predation. Percent MF of 110 5-10-month-old white-tailed deer (Odocoileus virginianus) fawns killed by wolves (Canis lupus) from November through April 1984-2002 in northeastern Minnesota, USA, was lower than MF for 23 fawns killed by accidents in the same area and period. The MF of both male and female wolf-killed fawns decreased over winter. The MF of male fawns decreased as a snow-depth index increased, but MF of females showed little relationship to the snow-depth index and was higher than that of males. Poor nutritional condition is one factor that predisposes deer fawns to wolf predation during winter and spring. This information expands our knowledge of wolf-prey relations by documenting that, even with younger prey animals that might be thought vulnerable because of youth alone, poor nutritional condition also is an important factor predisposing them to wolf predation.     

Body condition and ruminal morphology responses of free-ranging impala (Aepyceros melampus) to changes in diet

Variation of the intraruminal papillation pattern with diet quality has been described in many ruminant species, but the use of papillation measures as a proxy for habitat quality and nutritional status of animals has not been evaluated. We compared various measures of body condition (body mass, body condition score, kidney fat index, bone marrow fat index, adrenal mass, kidney to adrenal mass ratio), diet quality (%browse, protein and fibre content) and rumen papillation in 106 impalas (Aepyceros melampus) from four different locations in Zimbabwe. The various condition proxies indicated that periods of low diet quality are characterised by a high proportion of browse in the diet of this species. Animals with a high proportion of browse had more voluminous rumens, suggesting a compensation for lower diet quality by increased intake. Macroscopic papillation indices did not yield meaningful significant correlations with diet quality or body condition proxies, and hence, their use for estimating habitat or body condition cannot be advocated. In contrast to previous histological reports, ballooning cells of the Stratum corneum of the ruminal mucosa were more prominent in animals on lower-quality diets. There were significant correlations of the kidney to adrenal mass ratio with other body conditions and with diet quality indices, suggesting that poor body condition and low diet quality represent stressful situations.     

A half a century of measuring ungulate body condition using indices: is it time for a change?

From a literature review of five wildlife ecology journals since 1937, we document how using indices to monitor ungulate body condition is common practice, with the kidney fat index (KFI = weight of fat around the kidneys/weight of kidneys without fat × 100) as the favoured tool (82% of studies). In this context, we highlight the problems of using indices when underlying statistical assumptions are not met (isometry, parallel slopes between treatments). We show, with real and simulated data for two cervids with contrasting fat storage strategies, how results from analysis of variance of KFI values differ from analysis of covariance (ANCOVA) of raw data. We conclude that the KFI is affected by the restrictions typically associated with derived index values, and as a consequence, statistical analysis of the KFI could generate spurious results leading to erroneous interpretations concerning variation in body condition of ungulate populations. Thus, we recommend analysing fat weight as an untransformed variable in ANCOVA (kidney weight as covariate) to describe body condition variation in ungulates. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Indices of condition in tropical ruminants*

Bone marrow dry weight expressed as a percentage of its fresh weight was found to be a good indication of its fat content in wildebeest, kongoni, and buffalo. The calculated regression equations were similar enough to suggest a more general formula for the larger ruminants. Bone marrow fat is mobilized after the kidney fat and hence is a better measure of condition when an animal is under more extreme stresses. Fluctuations in kidney fat reflect physiological events related to reproduction. Visual estimates of bone marrow were found to reflect true differences in fat content, and the method is useful when marrow samples cannot be collected readily. It is pointed out that estimates of condition of naturally dying wild animals must be obtained before primary and secondary causes can be identified.     

Seasonal variations in physiological indices of adult female white-tailed deer in Texas

Seasonal variations in blood chemistry, urine chemistry, fat reserves, and crude protein levels of rumen contents were determined for free-ranging adult female white-tailed deer (Odocoileus virginianus Zimmermann) in central Texas. Seasonal variations (P less than 0.05) existed for serum total protein, albumin, globulin, albumin/globulin ratios, blood urea nitrogen (BUN), cholesterol, alkaline phosphatase, creatinine, phosphorus, and sodium; and urinary urea/creatinine (U/C) ratios, rumen crude protein, the kidney fat index (KFI), femur marrow fat (FMF), and dressed weights. Variations in BUN, urinary U/C ratios, dressed weights, KFI, and FMF were attributed partially to the nutritional demands of late gestation and lactation.     

Rapid disappearance of small fat bodies during the early stage of imbibition of lettuce seeds

It was found that small fat bodies disappeared from New Yorklettuce seeds during the early stage of imbibition at 20?C.The disappearance began about 4 hr after the start of imbibitionand ended before the start of the radicle elongation. It wascompletely suppressed under thermodormancy at 35?C. Red lightand GA treatment promoted the disappearance, and far-red lightand ABA treatment inhibited it. These results suggest that thedisappearance of the small fat bodies may be closely relatedto the control mechanism of lettuce seed germination. (Received April 23, 1977; )     

Evaluating Mule Deer Body Condition Using Serum Thyroid Hormone Concentrations

ABSTRACT Body condition of ungulates is a determinant of fecundity and survival rates. Ultrasonography and body condition scoring techniques allow reliable estimation of body fat but may not be feasible to employ in some circumstances. A reliable blood chemistry index for assessing relative condition of different ungulate populations or groups would be useful in ongoing population monitoring programs. We provided a nutrition supplement (treatment) to a group of free-ranging mule deer (Odocoileus hemionus) during 2 consecutive winters in southwest Colorado. In late February each year, we evaluated whether percent body fat and serum concentrations of total thyroxine (T4), total triiodothyronine (T3), free thyroxine (FT4), and free triiodothyronine (FT3) were higher among treatment deer than an adjacent group of deer that did not receive treatment (control). As a corroborative analysis, we modeled body fat as a function of thyroid hormone concentrations and morphometric variables. Estimated body fat of treatment deer averaged 12.3% (SE = 0.327), whereas estimated body fat of control deer averaged 7.0% (SE = 0.333) during the 2 winters of study. Concentrations of T4 and FT4 averaged 48.07 nanomole/L (SE = 3.80) and 12.61 picomole/L (SE = 1.04) higher, respectively, in treatment deer than control deer. Our optimal model of estimated body fat included T4, T4², FT4, and deer chest girth (%FAT = −4.8015 − 0.0946 × T4 + 0.000603 × T4² + 0.1474 × FT4 + 0.1426 × chest girth, R² = 0.609). Serum thyroid hormones effectively discerned treatment deer from control deer and were related to estimated body fat. Ultrasound and body condition scoring should be used to estimate body fat whenever possible. However, in cases where only a blood sample can be obtained, we documented potential utility of T4 and FT4 during late winter for evaluating relative body condition of mule deer.     

Revisions of Rump Fat and Body Scoring Indices for Deer,Elk, and Moose

Abstract: Because they do not require sacrificing animals, body condition scores (BCS), thickness of rump fat (MAXFAT), and other similar predictors of body fat have advanced estimating nutritional condition of ungulates and their use has proliferated in North America in the last decade. However, initial testing of these predictors was too limited to assess their reliability among diverse habitats, ecotypes, subspecies, and populations across the continent. With data collected from mule deer (Odocoileus hemionus), elk (Cervus elaphus), and moose (Alces alces) during initial model development and data collected subsequently from free-ranging mule deer and elk herds across much of the western United States, we evaluated reliability across a broader range of conditions than were initially available. First, to more rigorously test reliability of the MAXFAT index, we evaluated its robustness across the 3 species, using an allometric scaling function to adjust for differences in animal size. We then evaluated MAXFAT, rump body condition score (rBCS), rLIVINDEX (an arithmetic combination of MAXFAT and rBCS), and our new allometrically scaled rump-fat thickness index using data from 815 free-ranging female Roosevelt and Rocky Mountain elk (C. e. roosevelti and C. e. nelsoni) from 19 populations encompassing 4 geographic regions and 250 free-ranging female mule deer from 7 populations and 2 regions. We tested for effects of subspecies, geographic region, and captive versus free-ranging existence. Rump-fat thickness, when scaled allometrically with body mass, was related to ingesta-free body fat over a 38–522-kg range of body mass (r² = 0.87; P < 0.001), indicating the technique is remarkably robust among at least the 3 cervid species of our analysis. However, we found an underscoring bias with the rBCS for elk that had >12% body fat. This bias translated into a difference between subspecies, because Rocky Mountain elk tended to be fatter than Roosevelt elk in our sample. Effects of observer error with the rBCS also existed for mule deer with moderate to high levels of body fat, and deer body size significantly affected accuracy of the MAXFAT predictor. Our analyses confirm robustness of the rump-fat index for these 3 species but highlight the potential for bias due to differences in body size and to observer error with BCS scoring. We present alternative LIVINDEX equations where potential bias from rBCS and bias due to body size are eliminated or reduced. These modifications improve the accuracy of estimating body fat for projects intended to monitor nutritional status of herds or to evaluate nutrition's influence on population demographics.     

Marrow fat content, sex and age of red deer killed by wolves in winter in the Carpathian Mountains

Age, sex and legbone marrow fat content of 90 red deer Cervus elaphus killed by wolves Canis lupus in winter in southeastern Poland were examined 1984–1988. The majority of kills were calves (44%) and hinds (40%); stags formed only 16%. The average age of hinds was 7.2 yr compared to 5.3 yr in stags. Animals older than 10 yr comprised only 13% of prey. Adults showed high femoral fat content (> 80%) throughout the winter (76% in early winter and 52% in late winter). Among calves femur marrow fat varied through the winter. In early winter 70% of calves had a high fat content (> 80%), though by late winter only 20% had such a high fat content, whilst 43% had low fat content (< 20%).     

Evaluation of stored body fat in nuisance-killed Japanese black bears (Ursus thibetanus japonicus)

We evaluated the stored body fat of Japanese black bears (Ursus thibetanus japonicus) killed as nuisances in Gifu and Fukushima prefectures, Japan, during 2005-2007. We employed femur marrow fat (FMF), modified kidney fat index (mKFI), and abdominal subcutaneous fat (ASF) as indices for quantitative evaluation. We examined the basic characteristics of these indices, such as seasonality, age and sex dependency, and the quantitative relationship among them. mKFI and ASF increased towards the beginning of the denning period (December), while FMF was relatively stable throughout the sampling period (July-December). In cubs, all indices showed significantly lower values than in the older age classes. There seemed to be a catabolizing order between FMF and mKFI, but not between mKFI and ASF. We also evaluated the yearly change in the indices, and discussed its relevance to the incidence of bear intrusion into human residential areas. Bears nuisance-killed in summer (July-September) 2006 had a significantly larger amount of stored body fat than those killed in summer 2007, although the number of nuisance kills was larger in 2006 than in 2007. This suggests that poor nutritional condition is not a direct cause of bear intrusion.     

Variation in the XKR4 gene was significantly associated with subcutaneous rump fat thickness in indicine and composite cattle

Variation in the XK, Kell blood group complex subunit–related family, member 4 (XKR4) gene on BTA14 was associated with rump fat thickness in a recent genome‐wide association study. This region is also of interest because it is known to show evidence of a signature of population genetic selection. In this study, additional variation in this gene was genotyped in a sample of a total of 1283 animals of the Belmont Red (BEL) and Santa Gertrudis (SGT) breeds. The SNP rs41724387 was significantly (P < 0.001) associated with rump fat thickness and explained 5.9% of the genetic variance for the trait in this sample. Using the 4466 genotypes for the SNP rs42646708 from several data sets to estimate effects in seven breeds, this relatively large quantitative trait locus effect appears to be a result of the variation in indicine and taurine–indicine composite cattle. However, the only DNA variant found in Brahman cattle that altered the predicted amino acid sequence of XKR4 was not associated with rump fat thickness. This suggests that causative mutations lie outside the coding sequence of this gene.