Research Reports

Improving the Reproduction of local pigs in Northern Lao PDR by crossing with Vietnamese Mong Cai pigs.

Most pigs in rural areas of Northern Laos are raised in traditional, low input, free and semi-free scavenging systems, where the pigs are allowed to scavenge freely for feed all the year round or after the main crops have been harvested. Local pigs are the main breed raised, and their food usually comprises vegetation collected from the forest, root crops such as: cassava, maize, wild root crops and household refuse. The main constraints of current pig raising practices are disease, and feed supply, both in terms of quality and quantity.Another pig breed of potential interest in Laos is the Lon Mong Cai (Mong Cai pig) from Vietnam, an indigenous breed that originates from Quang Ninh province in northern Vietnam. The breed is regarded as being very well adapted to the harsh conditions in the region and is known for its early puberty, good litter size and ability. In Vietnam there are about 1 million Mong Cai sows, which account for about 50% of the total sow population. The breed is particularly popular in north and central Vietnam it is used as parent stock for the maternal production of crossbred fatteners.This project undertook on an examination of the relative performance of the progeny of crosses between local Lao pigs and imported Mong Cai pigs (both male and female) from Vietnam (2 x 1.5 year old sows and boars were imported from Vietnam and crossed with selected local Lao pigs of the same age). The study was done with farmer collaborators in Mueng Kai village of Luang Prabang district in Luang Prabang province. The experiment was conducted between June and November 2016.Two breeds of Lao local sow pigs and Mong Cai sow pigs weighting 40.5±3kg at service were used in two treatments: treatment T1 - local sow pig (LS) x Mong Cai boar pig (MB); treatment (T2) - Mong Cai sow pigs (MS) x local boar pig (LB). The feeding level was at 4% of live weight (DM basis) until pregnancy was confirmed,after which it was restricted to 1.5% of live weight. In the lactation period the gilts were fed increasing amounts until five days after farrowing; feed was then offered ad libitum. Chemicalcomposition of crude protein in the rice bran was very low (5.5%) but relatively high in the taro silage (15.4%). The dry matter of rice bran was high (86.2%) compared with maize and taro silage which 78.5% and 25.4%, respectively. The gilts were weighed at intervals of 2 weeks during pregnancy. They were weighed after farrowing and then every 2 weeks until the end of lactation (28 days). Piglets were weighed at birth and then every 2 weeks to weaning. Feed intake and live weight gain were recorded during the gestation and lactation periods. Litter size at birth and at weaning, birth weight and weaning weight, mortality of the piglets at birth, live weight changes of the sows during lactation, and interval from weaning to estrus were also calculated.The daily DM intake during pregnancy was high in the treatment 2 (954 g/day) when compared with treatment 1 (803 g/day). During lactation periods daily DM intake and CP intakes were higher than during pregnancy because the sows produce nutrient for the piglets but there were similar trends to during pregnancy, with DM and CP intake in treatment 2 being higher than in treatment 1 (P<0.05).Live weight were increased during pregnancy periods by T2 higher than T1 (T2 = 37.3 kg; T1 = 32.1 kg) or average daily gain (ADG) was high in T2 (T2=327g/day; T2=284g/day) and difference among treatments P<0.05. The feed conversion ratios (FCR) for the T1 and T2 were 2.8 and 2.9 kg feed/kg, Live weight loss and percentage live weight loss in lactation were not affected by sows (T1=11 kg and T2=13 kg) P>0.05. The total mean number of piglets born per litter was 7 and 9 heads in treatments T1, T2, respectively (P>0.05). The number of piglets born alive was not different (P>0.05) between the treatments. Percentage mortality at birth was numerically higher for T1 but the difference was not significant. The total number of piglets and percentage mortality at 28 days were not significant difference between the treatments (P>0.05). Piglet live weight at 28 days was high T2 (2.6 kg) than T1 (2.2 kg) P<0.05.All experiments sow returned to estrus within about 6 days after weaning, and the  mean weaning to estrus interval did not significant difference among the treatments (P>0.05). Overall, based on breeding between native pigs of Laos and Vietnam was improved the growth performance (average dairy gain, feed conversion ratios) and good litter size, particularly it was better to use female Vietnamese pigs with male Lao pigs (T2). Therefore, utilizing female Vietnamese pigs with male Lao pigs would be good option or potential for smallholder producers.

Fulltext

Nouphone MANIVANH, Sangkhom INTHAPANYA, Sianouvong SAVATHVONG and John M. SCHILLER