Multivariate analysis of zoometric indicators of sexual maturity of breeding hens Campero INTA

Abstract

The aim of the present study was to evaluate the behavior of the zoometric indicators involved in the biological process of sexual maturity through multivariate analysis to explain their joint behavior and characterize their development. We worked with 400 pullets belonging to 2 genotypes (synthetic E and the hybrid ES*A) that received two nutritional levels (control and treated) between weeks 5 and 22. Canonical analysis was performed to represent the linear association of the variables obtaining equations that allow explaining a portion of the total variance of the data independent of the remaining canonical components. Four canonical components were generated from week 22 and 24. The results of the week 22 showed that the first two components explain 94.87% of the observed variation. The first component (PCC) explains 81.86% of the variance and is positively and significantly correlated with comb index (ICr) (r=0.787; p<0.0001), hip width (ACa) (r=0.626; p<0.0001), abdominal length (LAb) (r=0.527; p=0.0001) and shows no significant association with cloacal width (ACl, r=-0.072; p=0.268), correlating mainly with comb index. The second component (SCC) explains 13.01% of the variance and is positively and significantly correlated with the four variables, but to a greater extent with ACl (r=0.921; p=0.0001) and to a lesser extent with ICr (r=0.233; p=0.0003), ACa (r=0.572; p<0.0001) and LAb (r=0.515; p<0.0001). The results for week 24 for the PCC explain 70.41% of the variance and correlate in a positive and significant way with the ICr (r=0.982; p<0.0001), the ACl (r=0.615; p<0.0001), ACa (r=0.423; p<0.0001) and LAb (r=0.459; p<0.0001, doing it mainly with the comb index. The SCC explains 26.98% of the variance and correlates , in a positive and significant way with the ACl (r=0.525; p<0.0001), ACa (r=0.887; p<0.0001) and LAb (r=0.671; p<0.0001), mainly correlating with hip width and does not show an association with the ICr (r=-0.017; p=0.799). This implies that, the higher the CCP value, the birds have essentially a higher comb index, cloacal width, hip width and abdominal length It is concluded that the increase in the allocation of nutrients produces a significant increase in the average value of the canonical component, which suggests an advance of sexual maturity in both E and ES*A of greater magnitude in hybrids.