Prediction of some carcass components of fattened barki lambs using principal components techniques

Abstract EN

The present study examined the use of principal components techniques for some live body measurements to predict some carcass components of fattened Barki male lambs.

The study was carried out during 1997 at Borg El-Arab Experimental Station, which belongs to the Agricultural Research Center, Ministry of Agriculture and is located some 40 km west of Alexandria, Egypt.

Fifty Barki male lambs with an average initial live body weight of 26 kg were included in the study.

Eight linear live body measurements were taken before slaughtering.

Carcass traits were carcass weight (CWT), total weight of the prime cuts (TPC), total weight of secondary cuts (TSC), percentages of prime cuts and secondary cuts TPC and TSC as a percentage from CWT (PCP and SCP) and logs of TPC and TSC (LogP and LogS).

Principal components (PC) techniques were used to summarize the variations between different eight live body measurements into one measurement called body size (BZ).

BZ was calculated by multiplying the elements of the first eigenvector of the first PC by each body measurement.

Simple regression analysis of different carcass traits on BZ was done.

The eight studied variables used presented significant statistical correlation (p < 0.05) and the first two PC’s of them explained 70 % of the total variance.

The regression coefficients of CWT, TPC, TSC, PCP, SCP, LogP and LogS were 0.11 kg, 0.06 kg, 0.05 kg, -0.005 %, 0.06 %, -0.00005 Log and 0.0007 Log, respectively.

It could be concluded that, principal components techniques summarized the variation in body measurements into two principal components that accounted for 70% of variation in the dependency structure.

The first principal component provided a measure of the general body size.

The increases of TPC and TSC contributed 55% (60 g) and 45% (50 g), respectively, to the increase of CWT (110 g).

The regression coefficients of the TPC and TSC after transformed data to Log10 were almost zero.