Using heart girth to determine weight in finishing pigs (2002)

Abstract

Heart girth and body weight were measured on 100 growing-finishing pigs (50 to 273 lb) at the KSU Swine Teaching and Research Center. Heart girth, in inches, was measured using a cloth measuring tape. The tape was placed directly behind the front legs and then wrapped around the heart girth and read directly behind the shoulders. Heart girth was strongly correlated (R2=0 .98) with body weight, with the following regression equation: pig weight = 10.1709 Ã-Heart girth-205.7492. The 95% confidence interval shows the projected weight to be ±10 lb of the actual weight of the pig. To validate our equation we weighed and measured heart girth on 40 pigs from a commercial breeding farm and a group of 165 pigs at the 2002 Swine Classic Youth Exposition. At the commercial breeding farm, the actual measured body weights fit within the 95% confidence interval from their projected weights, based on the regression equation. The average residual (difference between predicted and actual weight) of the 40 pigs was-0.70 lb with a range of ± 4 lb. The actual weights of pigs at the Swine Classic averaged 16 lb greater than their predicted body weights with a range of ±8.5 lb. The actual weights failed to fall within the 95% confidence interval for the developed regression equation. This was probably due to shrink during transportation to the show and limited feed and water. Heart girth as a means of determining body weight is a viable device for 4-Hers and producers, but it is important to use only on pigs with continuous access to feed and water.; Swine Day, Manhattan, KS,

Path analysis of body weight in grower and finisher pigs

“…The overall path analysis of these traits on body weight of pigs showed that heart girth is the major contributor to the body weight of the pig with a higher amount of direct effect of 0.6539 (R 2 = 95.25). This agrees with the findings of Groesbeck et al (2003) and Walugembe et al (2014) who recommended the use of heart girth in estimating the weight of finishing gilts. A high correlation coefficient was observed between other traits and body weight.…”

“…This is an indication of the expected physiological increase in the growth of muscles, bones, tissues and other structures as the pigs advanced in age. Phenotypic correlations of body weight and linear body measurements of the pigs at both phases of production and their overall observations are shown in Table 2. A high positive and significant correlation coefficient (P < 0.01) between these biometric traits and body weight was witnessed at all phases of production supporting earlier documented findings for pigs (Groesbeck et al, 2003;Banik et al, 2012). At both production phases, overall observation showed that heart girth recorded high correlation coefficient (r = 0.9761; P < 0.01) with body weight compared to other biometric traits determined.…”

“…The body weight of pigs was taken using a weighing balance. In order to reduce variations due to measurements, three separate measurements for each trait were taken on each pig during grower (8 to 15 weeks of age) and finisher (16 to 30 weeks of age) stages of production as recommended by Groesbeck et al (2003) and computed average of the three measurements on each animal was used as a representative data for a particular trait during analysis. Thus, a mean record of 1150 measurements for each biometric trait was used in the analysis.…”

Evaluation of pig and cattle performance under small scale farmers’ management conditions

“…Research conducted to develop prediction equations for Kenya and Philippine native pigs using external body measurements indicated that heart girth explained 91% and 88% of the total body weight variation, respectively . These results were consistent with findings from a study conducted at Kansas State University where a body weight prediction equation was determined using heart girth for finishing pigs (Groesbeck et al, 2004). Heart girth was strongly correlated (R 2 = .98) with body weight, and a 95% confidence interval showed the projected weight to be approximately ± 5 kg of the pig actual weight.…”

“…These relationships between body weight and linear measurements could be used to estimate body weights when scales are not available and if the measurements are easily obtained (Alade et al, 2008). Although this weight prediction approach could be used in both developed and developing countries (Groesbeck et al, 2004;, it would be more useful in developing countries where most farmers operate on a small scale, do not own scales, and market pigs primarily based on live weight. Using linear measurements to predict animal live weights empowers farmers with knowledge about the animal's market weight and value.…”