Abstract: The aim of this study was to compare the reproductive performance and the early growth performance differences of the binary sows of Duroc ×Guangdong small-ear spotted pig (DH) under two different hybridization modes, namely backcrossing and crossbreeding. It was to provide a reference for the efficient hybrid utilization of Guangdong small-ear spotted pig. Healthy and weight-matched DH sows were selected as the maternal parent. DH sows were crossed with either Duroc boars or DH boars to produce two descendant groups: Duroc×(Duroc×Guangdong small-ear spotted pig) (DDH, 25% Guangdong small-ear spotted pig bloodline) and (Duroc ×Guangdong small-ear spotted pig) ×(Duroc ×Guangdong small-ear spotted pig) (DHDH, 50% Guangdong small-ear spotted pig bloodline). Under the same feed nutrition level and management conditions, the reproductive performance of DH sows and the early growth performance of DDH and DHDH were statistically analyzed. The results showed that the sows in the DDH group had significant advantages in total number born litter size (TNB, 11.67 piglets) and number born alive (NBA, 11.39 piglets), which were significantly higher than those in the DHDH group (10.43 piglets, 10.36 piglets, P＜0.01 or P＜0.05), and litter weight at birth (13.90 kg) and weaning weight of litter at 30 d (69.56 kg) were significantly higher than those in the DHDH group (9.87 kg, 54.54 kg, P＜0.01); however, compared with the DHDH group, the proportion of weak piglets in the DDH group was extremely significantly increased (0.81 piglets, P＜0.01), and the weaning survival rate (86%) was extremely significantly decreased (P＜0.01). The early growth traits indicators such as birth weight (1.33 kg), weaning weight at 30 d (7.03 kg) of DDH were extremely significantly higher than DHDH (1.03 kg, 6.01 kg, P＜0.01), the days to 30 kg body weight (104.06 d) was significantly shorter than that of DHDH (106.59 d, P＜0.05). The average daily gain during the early growth stage (6～30 kg) showed no significant difference (P＞0.05). In terms of trait correlations, TNB and NBA were extremely significantly positively correlated (P＜0.001, r=0.92), and both were extremely significantly or significantly positively correlated with litter weight at birth , weaning live number, and weaning weight of litter at 30 d; at the same time, they were extremely significantly positively correlated with the number of weak piglets (P＜0.001, r=0.67, 0.65); however, TNB, NBA were not significantly correlated with birth weight, weaning weight at 30 d, and average daily gain during the early growth stage. Litter weight at birth, weaning weight at 30 d, and weaning weight of litter at 30 d were all extremely significantly positively correlated with birth weight (P＜0.001, r=0.63, 0.52, 0.32). The results of this study indicated that in the practice of hybrid utilization of Guangdong small-ear spotted pig, the DDH combination had more advantages in production efficiency, such as litter size, birth weight, weaning (litter) weight and the corrected weight at 30 kg of age, but it was necessary to strengthen the feeding and management of sows and piglets. In addition, it was also necessary to comprehensively consider the coat color and muscle quality to achieve the maximum production efficiency and benefits.

Key words: Guangdong small-ear spotted pig, Duroc, hybridization, DH sow, reproductive performance, early growth performance