Luc Do Duc

Reproductive and productive performances of the stress- negative Piétrain pigs in the tropics: the case of Vietnam

The objective of the present study is to investigate the reproduction, production and semen traits of the stress-negative Pietrain line of pigs in the north of Vietnam, as well as to identify various factors (halothane genotype, generation-origin, parity, sex and month of the year) acting on these traits. The experiment was carried out on a purebred nucleus on Dong Hiep farm, Haiphong province in Vietnam. The reproduction performances and the sperm quality measures were based on 12 sows and 5 boars imported from Belgium as well as on 29 sows and 14 boars born in Vietnam, while the production performances were recorded only from 251 animals born in Vietnam. No significant differences were observed between halothane genotypes of sows for reproduction traits (P > 0.0578). At the age of 7.5 months, bodyweight, backfat thickness and longissimus depth (7.5) of homozygous-dominant pigs were higher (P < 0.05) than in heterozygotes. Homozygous-dominant boars had higher total number of spermatozoa than heterozygote boars (P < 0.05); similarly, Vietnam boars also presented higher total number of spermatozoa values than Belgium boars (P < 0.001). Vietnam sows had longer duration of pregnancy, more piglets born alive and heavier litter weight of weaning than Belgium sows (P < 0.01). Bodyweight at birth, at weaning, at 2, 5.5 and 7.5 months of age increased from the first to third parity (P < 0.05). Gilts had more lean meat than intact boars (P < 0.01). Compared with observations made in temperate countries, the reproduction and production performances, sperm concentration and total number of spermatozoa of stress-negative Pietrain pigs were reduced, whereas lean meat percentage was not affected. This might be due to the different climate, although improving values for animals born in Vietnam might indicate adaptation of the animals and/or of the technicians with that breed. The results support the interest of the use of this new Pietrain line in tropical countries with ecological and climatic conditions similar to Vietnam.

Utilization of Large White x Mong Cai crossbred sows, Duroc and stress negative Piétrain boars for the production of fattening pigs under household conditions in northern Vietnam

The objective of this study was to compare the effects of Duroc (DU) and stress-negative Pietrain (PI) as terminal sires mated to F1(Large White × Mong Cai) sows (F1) on productivity, carcass characteristics, meat quality, and meat chemical composition under household conditions in Hai Duong province, Vietnam. The reproduction performances were based on 74 litters of 42 F1 sows from 12 households and the semen from 11 Duroc and 10 Pietrain boars. Data on production and carcass traits were collected from 76 DU × F1 and 67 PI × F1 crossbred fattening pigs. Longissimus dorsi samples from 55 DU × F1 and 37 PI × F1 were analysed to determine meat quality and meat chemical composition. The results show that household affected production, carcass, and meat quality traits (P 0.06) reproduction traits (except individual weight of pigs born alive and weaned pigs, P < 0.01), production traits, meat chemical composition, or meat quality (except pH at 4 days post mortem, P < 0.05). Lean meat percentage of Pietrain-sired pigs was higher than that of Duroc-sired pigs (P < 0.05). The use of Pietrain boars does not affect reproduction performance, growth rate, or meat quality but does improve lean meat percentage compared with Duroc boars. This suggests that the use of stress-negative Pietrain boars as terminal sires would improve lean meat percentage under household conditions in North Vietnam.