Live body weight estimation in small ruminants - a review

2017

This review paper would highlight different methods used in estimating live body weights of small ruminants and serves as a weight-taking guide to village farmers, extension agents, researchers as well as the small ruminant clinicians. Body weight of animals varied as a function of breed, feeding, health, sex, age and management situation under which the animals were kept. Knowing the live bodyweight of small ruminants is important for a number of reasons, such as for breeding, correct feeding medication, marketing and replacement of male and female animals in the herd. Under Ethiopian condition most of small ruminant were reared under smallholder and traditional production systems. Under such situation, it is difficult to measure body weight of animals because of lack of weighing balance and its difficulties during measurements. Under such situation, the animal live body weight of small ruminant can be predicted from different linear body measurements, which have high correlation w...

Tropical Animal Health and Production, 2008

The relationships between live weight and eight body measurements of West African Dwarf (WAD) sheep were studied using 210 animals under on farm condition. Data obtained on height at withers (HW), heart girth (HG), body length (BL), head length (HL), head width (HDW), loin girth (LG), length of hindquarter (LHQ) and width of hindquarter (WHQ) were fitted into linear, allometric and multiple regression models to predict live weight from the body measurements. Results revealed that body measurements of WAD sheep were generally higher in the rams than in the ewes. Coefficient of determination (R 2 ) values computed for the body measurements were generally higher (0.87-0.99) using allometric regression model than linear regression model (0.44-0.94). Heart girth (HG) and WHQ depicted the highest relationship to live weight in linear and allometric models compared to other body measurements. Based on stepwise elimination procedure, HG, HL and WHQ were better in predicting live weight in multiple linear regres-sion models. The magnitude of correlation coefficient (r) indicate that WHQ shows the highest correlation with live weight (r=0.96) compared to HG (r=0.94).

International Journal of Morphology, 2009

Journal of Applied Animal Research, 2017

Five different techniques of estimating the live cattle body weight were evaluated with the objective to identify the most reliable technique for use in the field. Weighbridge was used as the reference for other techniques. The measurement techniques evaluated were Weighbridge, Weigh tape, Rondo tape, Schaeffer's formula, Agarwal's formula, and calculator method. The body weights of 89 Brown Swiss and 34 Jersey Cross cattle were estimated by each technique. Compared with Weighbridge, the body weight estimates in Brown Swiss cattle exceeded by about 70 and 66 kg for Agarwal's formula and Rondo tape, respectively. In Jersey Cross cattle, the estimates exceeded by about 122 and 84 kg for Agarwal's formula and Rondo tape, respectively. In both breeds, the estimates of Schaeffer's formula were not significantly different from the Weighbridge. The estimates of weight tape were also not significantly different from the Weighbridge although the estimates exceeded by over 21 kg in Brown Swiss cattle and over 44 kg in Jersey Cross cattle. The study concluded that Schaeffer's formula is the most reliable of all techniques to estimate live body weight of cattle, followed by weigh tape. Agarwal's formula and Rondo tape are less reliable and their use in the field must be discontinued.

Online Journal of Animal …, 2012

Non-linear, simple linear and multiple linear regression models were developed using Statistical Package for Social Sciences (SPSS version 12.0). For the multiple linear regressions, step-wise regression procedures were used. Predicting models were developed for different age, sex and for the pool. Positive and significant (P<0.01) correlations were observed between body weight and linear body measurements for all sex and age groups. Among the four linear body measurements, heart girth had the highest correlation coefficient (except ear length) in all age and sex groups which is followed by body length, height at wither and pelvic width. Heart girth was the first variable to explain more variation than other variables in both sex and age groups. The models developed had a coefficient of determination of 0.26 to 0.89; the highest coefficient of determination was depicted for male while the lowest was for dentition groups having two permanent incisors. Regression models in general were poor in explaining weight for the dentition groups above one pair of permanent incisors. Heart girth alone was able to estimate weight with a coefficient of determination of 0.77, for both sexes and the pool. The coefficient of determination of the fitted equations (in general) decreased as the age of sheep advances indicating that the fitted equations can predict weight for younger sheep with better accuracy than for older ones. In general, much of the variation in weight was explained when many traits were included in the model. However, for ease of use and to avoid complexity at field condition, it is possible to use heart girth alone as a predicting tool. As a method to estimate weight using linear body measurements, it is possible to use these linear body measurements for selection in an effort to improve body weight of Farta sheep. In addition, the difference in the correlation coefficients between weight and other linear measurements for different age groups indicates the possibility of using different body measurements at different ages to predict weight and use for selection as well.

Tropical Animal Health and Production, 1996

Czech Journal of Animal Science

Live body measurements of weight, height, length, girth, stifle- and hip-width and a measure of muscularity (ratio of stifle to hip width) were monitored on 258 Yankasa sheep stratified into age categories of 1 to over 3 years determined mostly from records and partly by dentition. These animals are from purebred Yankasa sheep kept as a part of the open nucleus-breeding scheme of the National Animal Production Research Institute, Shika, Zaria, Nigeria. The effect of sex, type of birth and age group of lambs on live measurements and muscularity were analyzed by least-squares procedures. All variables examined, except sex, had significant (P &lt; 0.001) effects on all body measurements. At birth, male and single-born lambs were significantly heavier than female and twin-born lambs. At early age, most factors significantly (P &lt; 0.01) influenced the body weight, body dimensions and muscularity traits with single-born lambs being 31% heavier, 10% taller and 11% bigger in girth; more h...

Italian Journal of Animal Science, 2010

The aim of this study was to assess, for two Italian meat sheep breeds (Appenninica and Merinizzata italiana), the relationship between an easily recorded measurement (girth of chest) and the character used for selection purposes (weight), and to define the most appropriate mathematical methods to infer the second from the first. For the Appenninica 1392 lambs were measured, for the Merinizzata italiana 1559 lambs were measured. The possibility of estimating weight through chest girth (CG) measurement was evaluated, separately for each breed, by taking the most suitable model between those including different kinds of regression effect. The model was chosen in relation to the value of the determination coefficient and the sum of square residuals. The prediction accuracy of the model was assessed by comparing the expected values with the observed ones through a number of statistical tests. A further prediction analysis was carried out using the mean values of the observed weights that fell in each 1 cm class of girth, in order to reduce the error derived by the varying numbers of observations per unit of chest girth. The model including the square regression nested within the sex effect and the flock random effect nested within the sex effect was observed to be the most suitable one to predict the weight from the chest girth; the determination coefficients ranged between 0.944 (Appenninica) and 0.955 (Merinizzata). The prediction parameters were: -10.458+ 0.241 (CG) + 0.004 (CG 2 ) for the Appenninica males; -6.121 + 0.093 (CG) + 0.005 (CG 2 ) for the Appenninica females; -6.325 + 0.189 (CG) + 0.004 (CG 2 ) for the Merinizzata males; -4.676 + 0.078 (CG) + 0.005 (CG 2 ) for the Merinizzata females. The correlation between the observed and expected values was always higher than 0.97. The equations estimated using the mean weights for each girth showed extremely high determination coefficients (= 0.99) due to the reduction of variability implied by this method. Choosing between the equations calculated on the entire data set or on the mean weights will only be possible after a period of field tests.

The reflections of heart girth measurement to live body weight of Sudanese Shogur sheep under field conditions have been studied. Ninety males(90) of each three age groups were randomly selected( With a total population number of 270) in herds from different native areas where the animals were reared and evaluated using live body weight(kg) and heart girth measurement(cm). Means of live body weight and heart girth for the three age groups were calculated (P≤0.05). There were positive correlation coefficients (0.54, 0.66 and 0.81) between live body weight and heart girth. A predictive indices of (W= -4.62 + 0.45(HG), W= -23.78 + 0.73(HG) and W= -55.14 + 1.17(HG)) where more than (55%, 66% and 65%) of the population falls in respectively for the three studied age groups. It was therefore conclude that heart girth measurement is a useful tool in reflecting live body weight of Sudanese Shogur sheep under field conditions.