Reproductive Performances of Three Group Breeders of Replacement Gilts for Backyard Pig Farms in Thailand

Abstract

Most of pig production in countryside of Thailand is backyard farm. Almost all of farmers manage it as the second source of their income. As a result, the production costs are quite low. The production in each farm has been emanated from insufficient costs to cover all management. Especially, an essential basis of reproductive management; for instance, almost all of owners have been using female fatteners as replacement gilts. Both factors contribute to low litter size. Therefore, all of the problems are conduced to this study. The replacement gilts were classified by mating strategies and were divided into 3 groups: group 1 (Gr1: 30 crossbred gilts; produced by crossbred boar (Landrace (L) x Yorkshire (Y): LY 50/50) and crossbred sow (LY 50/50)), group 2 (Gr2: 30 crossbred gilts; produced by purebred boar (Yorkshire) and purebred sow (Landrace)) and group 3 (Gr3: 30 hybrid gilts; (Landrace x Yorkshire x Duroc: 25/25/50)). The average age at first observed estrus of replacement gilts in all 3 groups was 229.94±15.77 days of age and the gilts were mated at age 253.84±15.62 days of age. An average age at first farrowing was 368±15.57 days of age. There was not different between each group. Body weight at first service was 121.06±9.16 kg. In addition, backfat thickness at first observed estrus and at first service was approximately 13 and 18 mm respectively, in all groups. There was no significant difference (P>0.05) in all traits. TB, BA and mean birth weight of piglets in group 2 was the highest mean that equaled 12.73±3.13, 11.63±2.79 (piglets/litter) and 1.56±1.22 kg, respectively. There were significantly different between each of three groups (P<0.05) in average numbers of piglets in both total and alive sections. There was no significant difference (P>0.05) in average birth weight between group 1 and 2. According to the results of this observation, mean of weaning weight of piglets in group 1 was the highest (6.83±0.93 kg). There was significant difference (P<0.05) between group 1 and the other two groups. Percentage of pre-weaning mortality in group 1 was the lowest (2.90%). There was significantly different (P<0.05) of this amount between group 1 and group 2. The result of health condition screening of replacement found that three kinds of parasite eggs were found in feces samples including Strongyle, Ascaris suum and Trichuris suis. The results of serum antibodies to PRRS and PPV were reported that all serum samples were negative for PRRSV antibody; PPV antibody present in all serum samples. The average of feces P4 metabolite concentration on day 1 was the lowest and the highest on day 12 after standing heat. In conclusion, overall results suggested that the crossbred (LY) provides a higher reproductive performance than fattener female breeder. The appropriate model of gilt replacement can be successfully developed in order to produce the good production in backyard farm.