The correlation of chemical and physical corn kernel traits with growth performance and carcass characteristics in pigs1

Abstract

Corn kernel composition may affect its nutritive value and, thus, pig growth performance and carcass characteristics. The objective of this study was to determine the influence of the chemical and physical traits of corn kernels from different hybrids on the growth performance and carcass characteristics of pigs. A total of 288 crossbred pigs were grown in a 3-phase program from 21 kg of BW until slaughter at 113 kg of BW with 12 pens (4 pigs/pen) per dietary treatment. Target BW for each phase were 20 to 40 kg (grower 1), 40 to 80 kg (grower 2), and 80 to 120 kg (finisher). In each phase, diets were formulated to be marginally deficient in Lys, TSAA, Ca, Na, and nonphytate P to improve the likelihood of detecting differences in performance due to corn hybrid. Each of 6 corn hybrids represented a wide range of kernel chemical and physical traits and was substituted for corn in a common diet formulation on an equal weight basis to make the 6 dietary treatments. Physical and chemical composition of the kernels were analyzed and correlated with performance measures by multivariate ANOVA. Kernel density was correlated with i.m. fat (IMF) content in LM (r = -.35, P < 0.05). Stenvert grinding time was correlated (P < 0.05) with ADG during the grower 1 phase (r = 0.26), ADFI during the grower 2 phase (r = 0.27), final BW (r = 0.27), and IMF (r = -0.36). The amylose content of the cornstarch was correlated (P < 0.05) with ADG during the grower 2 phase (r = -0.28) and with BW at the end of the grower 2 phase (r = -0.27). The NDF content of the kernels was correlated (P < 0.05) with ADG during the finisher phase (r = -0.30), final BW (r = -0.33), and number of days to market (r = 0.31). The ADF content of the kernels was correlated (P < 0.05) with ADG during the grower 1 phase (r = -0.26), final BW (r = -0.26), and IMF (r = 0.31). The correlations of performance measure variation with individual kernel hybrid physical and chemical traits were statistically significant yet not large enough to base corn hybrid selection for feeding pigs on any single kernel chemical or physical trait.