Relationships between body weight and some linear morphometric traits in Nigerian Nsukka ecotype local hens

Body weight (BW) and linear body measurements of 120 Nigerian Nsukka ecotype local hens in terms of body length (BL), chest girth (CG), thigh circumference (TC), thigh length (TL), and shank length (SL) were taken and subjected to Pearson correlation analysis to obtain the relationship between these growth traits. Multiple Linear Stepwise Regression procedure was used to find the best linear combination of the linear body measurements that can best predict BW. The findings showed that linear body measurement traits of Nigerian heavy ecotype local hens were strongly (p < 0.01) and positively correlated (0.5 < r) except thigh length which recorded a moderate value (0.3 < r > 0.5). The regression equations of linear body measurement traits with BW were positive with coefficient of determination ranging from 60.5-74.6%. The stepwise analyses showed shank length as best single measurement with R2 = 0.605, while inclusion of our five predictors in an equation resulted in R2 = 0.746. Thus, the following equation was generated: BW = – 1485.70 + 82.06 SL + 58.34 BL + 38.70 TC + 8.39 CG + 3.85 TL. This showed that they accounted for 74.6% of the variations in the BW of Nigerian heavy ecotype local hens. The prediction equations generated from linear body measurement traits are positive and strong, therefore can accurately be employed to predict the relative BW of Nigerian heavy ecotype local hens during selection programs as well as in the market with the use of measuring tape.

COMPARISON OF SOME LINEAR BODY MEASUREMENT TRAITS OF LOCAL AND COMMERCIAL CHICKEN BREEDS OF SOUTH AFRICA

Linear body measurement traits are used for the estimation of body weight in animal breeding to aid livestock farmers where the weighing scale is not available. The objective of the work was to determine the effect of breed on body weight (BW) and linear body measurement traits such as wing length (WL), keel length (KL), shank circumference (SC), chest circumference (CC) and beak length (BL) of two (Hy-line Silver Brown and Potchefstroom Koekoek) layer chicken layer breeds. A total of 100 layers with 50 for each breed were randomly selected for the study at the age of 22 weeks. Pearson’s correlation and Student T-Test were used for data analysis. Correlation was employed to examine the relationship between measured traits in each breed. Correlation findings showed that BW had a highly positive statistical significant correlation (p < 0.01) with WL (r = 0.76) in Potchefstroom Koekoek breed, while BW had a negative statistical significant correlation (p < 0.05) with WL (r = -0.27) in Hy-line Silver Brown chicken layer breed. Student T-Test results indicated that Potchefstroom Koekoek chicken layer breed was statistically (P<0.05) heavier than Hy-line Silver Brown chicken layer breed. Potchefstroom Koekoek had longer wing length and chest circumference than Hy-line Silver Brown while Hy-line Silver Brown had longer (P<0.05) keel length, shank circumference and beak length than Potchefstroom Koekoek. It is concluded that the results suggest that Potchefstroom Koekoek chicken layer breed is a weightier indigenous layer but keel length, shank circumference and beak length might require improvement. It also suggests that improvement of WL might improve BW of Potchefstroom Koekoek breed while improvement of WL might decrease BW of Hy-line Silver Brown chicken layer breed.

Shared variability in body shape characters at growing phase of indigenous piglets

Body measurement traits, body length (BL) , rump height (RH), rump length (RL), rump width (RW), shoulder width (SW), wither height (WH), heart girth (HG), and flank length (FL) of 52 piglets of indigenous breed, managed under traditional system were obtained at birth and at weaning, to evaluate the sources of shared variability and efficiency of weight determination. Factor analysis reveals four factors accounting for 89.53% at birth and three factors accounting for 73.52% at weaning. Most common variability in body dimension at birth and at weaning could be accounted for by factors representing general size and RL in both cases. Body conformation “shape” was controlled by common and unique factors at both ages. Amount of variation associated with shape characters increased with advancing age and accuracy of weight estimation decreased with increase in age.

Nonlinear Prediction Models for Estimation of Pre-weaning Body Weight of Pigs using Morphometric Traits

Background: In the present study, a set of non-linear prediction equation was developed using records of body measurement traits, namely heart girth, punch girth, height at shoulder, height at back, height at fore leg, height at back leg and body length of pigs. Repeated measurement of traits at birth, 15 d, 30 d and weaning (42 d) of 394 piglets were used. Methods: The regression of body weight on body measurement traits showed non-linear relationship based on equation, Y = aXb. Correlation of heart girth with body weight (r2 = 0.968 for male and 0.969 for females; P less than 0.01) was highest among the traits studied. Result: Heart girth was found to be most suited among the traits to predict body weight in an exponential equation, Y = 0.00058 H2.49 and Y = 0.00061 H2.47 for male and females, respectively, explaining 96 percent of variation.

Improving the accuracy of genomic evaluation for linear body measurement traits using single-step genomic best linear unbiased prediction in Hanwoo beef cattle

Background Recently, there has been a growing interest in the genetic improvement of body measurement traits in farm animals. They are widely used as predictors of performance, longevity, and production traits, and it is worthwhile to investigate the prediction accuracies of genomic selection for these traits. In genomic prediction, the single-step genomic best linear unbiased prediction (ssGBLUP) method allows the inclusion of information from genotyped and non-genotyped relatives in the analysis. Hence, we aimed to compare the prediction accuracy obtained from a pedigree-based BLUP only on genotyped animals (PBLUP-G), a traditional pedigree-based BLUP (PBLUP), a genomic BLUP (GBLUP), and a single-step genomic BLUP (ssGBLUP) method for the following 10 body measurement traits at yearling age of Hanwoo cattle: body height (BH), body length (BL), chest depth (CD), chest girth (CG), chest width (CW), hip height (HH), hip width (HW), rump length (RL), rump width (RW), and thurl width (TW). The data set comprised 13,067 phenotypic records for body measurement traits and 1523 genotyped animals with 34,460 single-nucleotide polymorphisms. The accuracy for each trait and model was estimated only for genotyped animals using five-fold cross-validations. Results The accuracies ranged from 0.02 to 0.19, 0.22 to 0.42, 0.21 to 0.44, and from 0.36 to 0.55 as assessed using the PBLUP-G, PBLUP, GBLUP, and ssGBLUP methods, respectively. The average predictive accuracies across traits were 0.13 for PBLUP-G, 0.34 for PBLUP, 0.33 for GBLUP, and 0.45 for ssGBLUP methods. Our results demonstrated that averaged across all traits, ssGBLUP outperformed PBLUP and GBLUP by 33 and 43%, respectively, in terms of prediction accuracy. Moreover, the least root of mean square error was obtained by ssGBLUP method. Conclusions Our findings suggest that considering the ssGBLUP model may be a promising way to ensure acceptable accuracy of predictions for body measurement traits, especially for improving the prediction accuracy of selection candidates in ongoing Hanwoo breeding programs.