Predicting nutritional condition in black bears and polar bears on the basis of morphological and physiological measurements

1990 ◽  
Vol 68 (1) ◽  
pp. 32-39 ◽  
Author(s):  
Marc Cattet
Keyword(s):  
Body Weight ◽  
Body Size ◽  
Multiple Regression ◽  
Lipid Content ◽  
Ursus Americanus ◽  
Nutritional Condition ◽  
Black Bears ◽  
Polar Bears ◽  
Regression Equations ◽  
Age Classes

Thirty-eight black bears (Ursus americanus) and 43 polar bears (Ursus maritimus) were dissected to determine equations for predicting body weight (BW) and nonfat body weight (NFBW). Nutritional condition was estimated by calculating a fat to nonfat (FNF) ratio, equalling (BW – NFBW)/NFBW. For each species, BW and NFBW were accurately predicted by multiple regression equations based on morphological measurements. The FNF ratio was independent of body size and thus comparable between sexes and among age-classes. The accuracy of predicting the FNF ratio is limited, and reliable comparisons of nutritional condition among individual bears will require the development of more accurate techniques. Physiological measurements of marrow and intramuscular percent lipid content were also evaluated as potential indicators of nutritional condition, but were determined to be unreliable.

scholarly journals Phenotypic Variation in Skull Size and Shape Between Newfoundland and Mainland Populations of North American Black Bears, Ursus americanus

2003 ◽  
Vol 117 (2) ◽  
pp. 236 ◽  
Author(s):  
John A. Virgl ◽  
Shane P. Mahoney ◽  
Kim Mawhinney
Keyword(s):  
Body Size ◽  
Sexual Dimorphism ◽  
Ursus Americanus ◽  
Population Variation ◽  
Black Bears ◽  
Selection Pressures ◽  
Skull Shape ◽  
Skull Size ◽  
Environmental Selection ◽  
Gape Size

It is well recognized that differences in environmental selection pressures among populations can generate phenotypic divergence in a suite of morphological characteristics and associated life history traits. Previous analysis of mitochondrial DNA and body size have suggested that Black Bears (Ursus americanus) inhabiting the island of Newfoundland represent a different subspecies or ecotype from mainland populations. Assuming that body size covaries positively with skull size, we predicted that skull size would be greater for bears on the island than the mainland, and the distribution of size-related shape components in multivariate space should show a distinct separation between Newfoundland and mainland populations. Measurements of 1080 specimens from Newfoundland, Alberta, New York, and Quebec did not provide unequivocal support for our prediction that skull size in Newfoundland bears would be larger than bears from the mainland populations. After removing ontogenetic effects of skull size, between-population variation in skull shape was greater in females than males, and the analysis significantly separated Newfoundland bears from mainland populations. Explanations for this pattern are numerous, but currently remain hypothetical. Limited covariation between skull size and body size suggests that genetic traits regulating the size of Black Bear skulls are more heritable (i.e., less influenced by environmental selection pressures) than characteristics affecting body size. We hypothesize that if gape size does not limit prey size in solitary terrestrial carnivores, large degrees of among-population variation in body size should be coupled with little covariation in skull size. In general, sexual dimorphism in skull size and shape was marginal for the phenotypic characters measured in our study. We believe that sexual dimorphism in skull size in Black Bears is primarily driven by intrasexual selection in males for increased gape size display, while similarity in skull shape between sexes is associated with the constraints of a temporally-selective, but similar diet.

The Appetite Potential of Jersey Cows

1984 ◽  
Vol 1984 ◽  
pp. 125-125
Author(s):  
T. D. A. Brigstocke ◽  
M. A. Lindeman
Keyword(s):  
Body Size ◽  
Multiple Regression ◽  
Dry Matter ◽  
Regression Equations ◽  
Previous Trial ◽  
Jersey Cows

A previous trial (Brigstocke et al., 1982) had indicated that mature Jersey cows ate considerably more dry matter (DM) in relation to their body size than was currently projected from the multiple regression equations used for appetite prediction. However this trial was run on one large high-yielding herd with only a small number of animals and it was not known whether the results were applicable to the more average Jersey producer.

scholarly journals Growth Rate and Body Size at Maturity of Florida Black Bears

2019 ◽  
Vol 10 (2) ◽  
pp. 458-467
Author(s):  
Tad M. Bartareau
Keyword(s):  
Growth Rate ◽  
Body Weight ◽  
Body Size ◽  
Maximum Growth ◽  
Black Bears ◽  
Size At Maturity ◽  
Natural Diet ◽  
Human Food ◽  
Younger Age ◽  
Chest Girth

Abstract Growth rate and body size at maturity are important life-history traits of interest because they represent a potential source of fitness variance within a species and provide information for understanding the nutritional condition, fecundity, and dynamics of populations. My objective here was to examine the growth rate and body size at maturity of Florida black bears Ursus americanus floridanus using body length, chest girth, and body weight measurements fitted to the nonlinear von Bertalanffy, Gompertz, and logistic size-at-age growth functions. The von Bertalanffy model had the largest Akaike weight, indicating the best fit for all measurements of both sexes. Growth models showed that females grew more slowly, with a younger age at maximum growth, faster rate at which maturity was reached, and attained significantly smaller asymptotic body length, chest girth, and weight than males. A more conservative growth strategy by females to invest available energy resources to costs of reproduction, together with intrasexual selection among males for larger body size to enhance intimidating and fighting ability to increase reproductive and survival success, are implicated as determinants of the male-biased direction and degree of sexual size dimorphism. In both sexes, the presence of human food in the diet increased the asymptotic body weight from the estimate for bears consuming a natural diet, but differences were insignificant. Females consuming human food had a slightly younger age at maximum growth and continued growth in body weight for a somewhat longer duration than did conspecifics that consumed a natural diet. In contrast, males that consumed human food had a slightly older age at maximum growth and decreased body weight growth somewhat earlier than did conspecifics consuming a natural diet. Florida black bears exhibited a larger asymptotic body size, faster growth rate, and younger age at maximum growth and maturity when compared with conspecifics in other mainland populations. Recognition of Florida black bear growth rate and adult body size provides wildlife managers a foundation for implementing measurable criteria to assess trends in population health.

Hibernating black bears ( Ursus americanus ) maintain muscle to body weight ratio in unloaded soleus muscle

2007 ◽  
Vol 21 (5) ◽  
Author(s):  
Jonathan M Van Dyke ◽  
David V Baewer ◽  
Brian D Curry ◽  
Sandya R Govindaraju ◽  
James W Bain ◽  
...  
Keyword(s):  
Body Weight ◽  
Soleus Muscle ◽  
Ursus Americanus ◽  
Weight Ratio ◽  
Black Bears ◽  
Body Weight Ratio

Variation in the chemical composition of adipose tissue of three species of ursids

2001 ◽  
Vol 79 (8) ◽  
pp. 1512-1517 ◽  
Author(s):  
Marc R.L Cattet ◽  
Paul D Watts ◽  
Jeong S Sim
Keyword(s):  
Adipose Tissue ◽  
Water Content ◽  
Lipid Content ◽  
Species Differences ◽  
Body Water ◽  
The Body ◽  
Black Bears ◽  
Polar Bears ◽  
Lipid Contents ◽  
The Relationship

The relationship between the water content and lipid content of adipose tissue was compared between 25 polar bears (Ursus maritimus) and 25 black bears (Ursus americanus) to determine if it was affected by species differences in the fatty-acid composition of adipose tissue. The adipose tissue of polar bears had a lower water content and a higher proportion of long-chain fatty acids than did the adipose tissue of black bears, when compared at equal lipid content. The relationship between the body water and lipid contents was also compared among 11 polar bears, 18 black bears, and 6 brown bears (Ursus arctos) to determine if this relationship could be affected by species differences in the relationship between the water and lipid contents of adipose tissue. The body-water content in marine (polar) bears was less than that in terrestrial (black and brown) bears, and the differences in body-water content between the two groups became more apparent as the body-lipid content increased. These results suggest that the fatty-acid composition of adipose tissue can affect the body-water content, especially in fat bears. These findings have implications for the use of isotope-dilution models to predict body composition in bears.

scholarly journals Pre- and Post-Slaughter Methodologies to Estimate Body Fat Reserves in Lactating Saanen Goats

Animals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1440
Author(s):  
Leonardo Sidney Knupp ◽  
Mondina Francesca Lunesu ◽  
Roberto Germano Costa ◽  
Mauro Ledda ◽  
Sheila Nogueira Ribeiro Knupp ◽  
...  
Keyword(s):  
Body Weight ◽  
Multiple Regression ◽  
Body Fat ◽  
Body Condition Score ◽  
Regression Equations ◽  
Dairy Goats ◽  
Fat Reserves ◽  
Fat Thickness ◽  
Total Fat

This work aimed to compare pre- and post-slaughter methodologies to estimate body fat reserves in dairy goats. Twenty-six lactating Saanen goats ranging from 43.6 to 69.4 kg of body weight (BW) and from 1.84 to 2.96 of body condition score (BCS; 0–5 range) were used. Fifteen pre-slaughter and four post-slaughter measurement values were used to estimate the weight of fat in the omental (OM), mesenteric (MES), perirenal (PR), organ (ORG), carcass (CARC), and non-carcass components (NC) and total (TOT, calculated as the sum of CARC and NC) depots in goats. The pre-slaughter measurements were withers height; rump height; rump length; pelvis width; chest depth; shoulder width; heart girth; body length; sternum height; BW; BCS assessed in the lumbar (BCSl) and sternal (BCSs) regions; and fat thickness measured by ultrasound in the lumbar (FTUSl), sternal (FTUSs), and perirenal (FTUSpr) regions. The post-slaughter measurements were hot carcass weight (HCW), empty body weight (EBW), and fat thickness measured by digital caliper in the lumbar (FTDCl) and sternal (FTDCs) regions. Linear and multiple regressions were fit to data collected. BW, BCS (from lumbar and sternal regions), all somatic measurements, and fat thickness measured by ultrasound in the lumbar and sternal regions were not adequate to estimate the weight of total fat in lactating Saanen goats (R2 ≤ 0.55). The best pre-slaughter and post-slaughter estimators of OM, MES, PR, ORG, NC, and TOT fat were FTUSpr and EBW, respectively. Among pre- and post-slaughter measurements, BCSl (R2 = 0.63) and HCW (R2 = 0.82) provided the most accurate predictions of CARC fat, respectively. Multiple regression using the pre-slaughter variables FTUSpr, BW, and BCSl yielded estimates of TOT fat with an R2 = 0.92 (RSD = 1.14 kg). On the other hand, TOT fat predicted using the post-slaughter variables HCW and FTDCs had an R2 = 0.83 (RSD = 1.41 kg). These results confirm that fat reserves can be predicted in lactating Saanen goats with high precision using multiple regression equations combining in vivo measurements.

scholarly journals Predicting Body Weight of Ethiopian Indigenous Chicken Populations from Morphometric Measurements

2021 ◽  
Vol 9 (6) ◽  
pp. 1138-1143
Author(s):  
Fikrineh Negash
Keyword(s):  
Body Weight ◽  
Multiple Regression ◽  
Correlation Coefficients ◽  
Stepwise Multiple Regression ◽  
Regression Equations ◽  
Body Measurements ◽  
Indigenous Chicken ◽  
Morphometric Measurements ◽  
Measuring Tape ◽  
The Relationship

The purpose of this study was to estimate the relationship between body weight (BW) and morphometric measurements of Ethiopian indigenous chicken populations and to develop prediction equations used to estimate BW from body measurements. A total of 621 chickens comprising 134 males and 487 females reared under smallholder management conditions were used for the study. Body weight and morphometric measurements including body length (BL), chest circumference (CC), shank length (SL), and shank circumference (SC) were taken using a hanging scale and a textile measuring tape, respectively. The relationship between BW and morphometric measurements was determined using Pearson’s correlation coefficients (r) and stepwise multiple regression analyses. Descriptive statistics indicated that male birds were heavier than female birds. Correlation results revealed that body weight was significantly and strongly correlated with SL (r = 0.76) in both sexes, and moderately correlated with SC (r = 0.69), BL (r = 0.67), and CC (r = 0.52) in male birds, BL (r=0.68) and SC (r = 0.59) in female birds. Compared to other measurements, SL best predicted BW in both male and female birds, with coefficients of determination (R2) = 0.58. Combining SL with other body measurements (BL, CC, and SC) generally improved the predictive power of the equation. Thus, multiple regression equations that included a combination of the four linear body measurements are more suitable for predicting BW of Ethiopian indigenous chicken populations.

A body-condition index for ursids

2002 ◽  
Vol 80 (7) ◽  
pp. 1156-1161 ◽  
Author(s):  
Marc R.L Cattet ◽  
Nigel A Caulkett ◽  
Martyn E Obbard ◽  
Gordon B Stenhouse
Keyword(s):  
Body Size ◽  
Body Condition ◽  
Positive Relationship ◽  
Condition Index ◽  
Black Bears ◽  
Grizzly Bears ◽  
Polar Bears ◽  
Body Condition Index ◽  
Total Body Mass ◽  
Total Body

In this investigation a body-condition index (BCI) was developed for polar bears (Ursus maritimus), black bears (Ursus americanus), and grizzly bears (Ursus arctos), based on residuals from the regression of total body mass against a linear measure of size, straight-line body length (SLBL). Transformation of mass–length data from 1198 polar bears, 595 black bears, and 126 grizzly bears to natural logarithms resulted in a linear relationship between mass and length. However, the relationship in polar bears differed from that in black and grizzly bears. SLBL had a close positive relationship with skeletal (bone) mass in polar bears (n = 31) and black bears (n = 33), validating the use of SLBL as an accurate index of body size. There was no correlation between SLBL and BCI for polar bears (r = 0.005, p = 0.87, n = 1198) or for black bears and grizzly bears (r = 0.04, p = 0.30, n = 721), indicating that the BCI was independent of body size. The BCI had a close positive relationship with true body condition, measured as the standardized residual of the combined mass of fat and skeletal muscle against SLBL, in polar and black bears that were dissected to determine individual tissue masses. The BCI also had a close positive relationship with the standardized residual of fat mass against SLBL. Estimation of BCI values for polar bears, or for black bears and grizzly bears, is facilitated by prediction equations that require measurement of total body mass and SLBL for individual animals.

PSVI-8 Meta-regression Analysis to Determine the Relationship Between Growing Pig Body Weight and Variation

2021 ◽  
Vol 99 (Supplement_1) ◽  
pp. 218-219
Author(s):  
Andres Fernando T Russi ◽  
Mike D Tokach ◽  
Jason C Woodworth ◽  
Joel M DeRouchey ◽  
Robert D Goodband ◽  
...  
Keyword(s):  
Body Weight ◽  
Regression Analysis ◽  
Sample Size ◽  
Polynomial Regression ◽  
Data Sets ◽  
Regression Equations ◽  
Prediction Equations ◽  
Data Set ◽  
Rate Of Increase ◽  
The Relationship

Abstract The swine industry has been constantly evolving to select animals with improved performance traits and to minimize variation in body weight (BW) in order to meet packer specifications. Therefore, understanding variation presents an opportunity for producers to find strategies that could help reduce, manage, or deal with variation of pigs in a barn. A systematic review and meta-analysis was conducted by collecting data from multiple studies and available data sets in order to develop prediction equations for coefficient of variation (CV) and standard deviation (SD) as a function of BW. Information regarding BW variation from 16 papers was recorded to provide approximately 204 data points. Together, these data included 117,268 individually weighed pigs with a sample size that ranged from 104 to 4,108 pigs. A random-effects model with study used as a random effect was developed. Observations were weighted using sample size as an estimate for precision on the analysis, where larger data sets accounted for increased accuracy in the model. Regression equations were developed using the nlme package of R to determine the relationship between BW and its variation. Polynomial regression analysis was conducted separately for each variation measurement. When CV was reported in the data set, SD was calculated and vice versa. The resulting prediction equations were: CV (%) = 20.04 – 0.135 × (BW) + 0.00043 × (BW)2, R2=0.79; SD = 0.41 + 0.150 × (BW) - 0.00041 × (BW)2, R2 = 0.95. These equations suggest that there is evidence for a decreasing quadratic relationship between mean CV of a population and BW of pigs whereby the rate of decrease is smaller as mean pig BW increases from birth to market. Conversely, the rate of increase of SD of a population of pigs is smaller as mean pig BW increases from birth to market.

scholarly journals ASAS-NANP SYMPOSIUM: Applications of machine learning for livestock body weight prediction from digital images

2021 ◽  
Vol 99 (2) ◽  
Author(s):  
Zhuoyi Wang ◽  
Saeed Shadpour ◽  
Esther Chan ◽  
Vanessa Rotondo ◽  
Katharine M Wood ◽  
...  
Keyword(s):  
Machine Learning ◽  
Body Weight ◽  
Optical Sensors ◽  
Genetic Selection ◽  
Medium Size ◽  
Regression Equations ◽  
Infrared Cameras ◽  
Applications Of Machine Learning ◽  
Corrosive Environments ◽  
Partial Weight

Abstract Monitoring, recording, and predicting livestock body weight (BW) allows for timely intervention in diets and health, greater efficiency in genetic selection, and identification of optimal times to market animals because animals that have already reached the point of slaughter represent a burden for the feedlot. There are currently two main approaches (direct and indirect) to measure the BW in livestock. Direct approaches include partial-weight or full-weight industrial scales placed in designated locations on large farms that measure passively or dynamically the weight of livestock. While these devices are very accurate, their acquisition, intended purpose and operation size, repeated calibration and maintenance costs associated with their placement in high-temperature variability, and corrosive environments are significant and beyond the affordability and sustainability limits of small and medium size farms and even of commercial operators. As a more affordable alternative to direct weighing approaches, indirect approaches have been developed based on observed or inferred relationships between biometric and morphometric measurements of livestock and their BW. Initial indirect approaches involved manual measurements of animals using measuring tapes and tubes and the use of regression equations able to correlate such measurements with BW. While such approaches have good BW prediction accuracies, they are time consuming, require trained and skilled farm laborers, and can be stressful for both animals and handlers especially when repeated daily. With the concomitant advancement of contactless electro-optical sensors (e.g., 2D, 3D, infrared cameras), computer vision (CV) technologies, and artificial intelligence fields such as machine learning (ML) and deep learning (DL), 2D and 3D images have started to be used as biometric and morphometric proxies for BW estimations. This manuscript provides a review of CV-based and ML/DL-based BW prediction methods and discusses their strengths, weaknesses, and industry applicability potential.

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