Principal Component Analysis of Conformation and Blood Marker Traits at Pre- and Post-Weaning Stages of Growth in F2 Crossbred Nigerian Indigenous X Landrace Pigs

Abstract

Linear body measurements and blood hematology and biochemistry parameters were taken on 92 and 15 grower pigs, respectively, chosen randomly from a crossbred F2 population of Nigerian Indigenous (NI) x Landrace pigs to evaluate body conformation and blood marker traits using a multivariate approach. For linear body measurements at pre-weaning stage (4 weeks old), two principal components accounted for 91.63% of the total variation in body conformation traits, while at post weaning stage (12 weeks old), one principal component accounted for 73.63% of the total variations in body conformation traits. The first factor (principal component) accounted for 72.34% of the total variance (body weight) while the second factor accounted for 19.29% (ear length) at pre-weaning stage. While at post-weaning stage only one factor contributed to the total variability of the original six traits tested, with 73.63% (body length). For blood parameters, three principal components accounted for 81.85% of the total variation at pre-weaning stage while 89.44% of the total variation at post-weaning stage was accounted for by four principal components. The first factor (principal component) accounted for 38.048% (Packed cell volume), the second accounted for 24.72% (hemoglobin) and the third accounted for 19.08% (aspartate transaminase). While at the post-weaning stage, the first factor was influenced by red blood corpuscles (37.17%), the second factor had its loading for hemoglobin (25.80%), the third factor had loading for white blood corpuscles (13.67%), while the fourth factor had loading for alkaline phosphatase only (12.80%). Using communality extraction factors, ear length best described body conformation at the pre-weaning stage; whereas, at post-weaning stage, body length was the best descriptor. In blood parameters, packed cell volume best described blood marker traits at the pre-weaning stage; whereas, at the post-weaning stage, red blood corpuscles best described it. Hence, the two extracted factors in linear body measurements and in blood parameters could be considered in breeding programs to improve and predict body conformation in crossbred pigs, as well as predict blood marker traits.

Principal component analysis of morphometric and growth traits in crossbred piglets

“…These PCs accounted for 73.7, 73.76 and 75.45% variance, respectively of total variance. Okoro et al (2015) in crossbred pigs of Nigeria extracted two factors of 6 body confirmation traits at pre-weaning stage which accounted for 91.63% of total-variation. They however extracted only one factor at post-weaning stage explaining 73.63% of the total variation.…”

“…principal components, which are linear combination of original variables and has been used to elucidate the structural relationships among different traits. Tolenkhomba et al (2013) in Mizo local pigs and Okoro et al (2015) in crossbred pigs of Nigeria used principal component analysis to study the morphometric traits. Information on interdependence among pre-and postweaning body measurements to reduce dimension of explanatory data set are very scanty in Indian crossbred pigs.…”

Principal Component Analysis (PCA) of the reproductive traits in the Large White sows

“…Отже, існує необхідність зниження вимірності матриці вихідних даних та визначення прихованих (латентних) змінних, що суттєво впливають на характер мінливості, але не можуть бути безпосередньо виміряні. [16].…”

A comparative study of the reproductive traits and clustering analysis among different pig breeds

“…Hu et al (2006) та R. Ros-Freixedes et al (2014). Також АГК активно використовувався при дослідженні лінійних промірів тіла (Van Steenbergen, 1989), краніометричних ознак (Gregory and Whelehan, 1983), ростових процесів на різних етапах відгодівлі (Okoro et al, 2015), етологічних характеристик свиней (Czycholl et al, 2017) та ін. Також є приклади вдалого використання АГК при дослідженні особливостей мінливості відтворювальних ознак свиноматок (Young et al, 1977;1978).…”