This study investigated the productive adaptability of pig breeds under different smallholder production conditions in Vietnam, comparing an indigenous with a Vietnamese improved breed. Fieldwork was conducted in four villages with different remoteness in North Vietnam from 2001 to 2002, in 64 households keeping the improved Mong Cai or indigenous Ban as sow breeds and progeny for fattening. Four visits per farm yielded 234 structured interviews. Reproductive performances were derived from 135 litters. Individual weights of pigs (n = 755) were obtained. Data were analysed by regression, linear and generalised linear, especially loglinear models.
Two distinct pig production systems were identified, that differed in remoteness, market access, resource availability, distribution of pig breeds and pig production intensity. Higher performances of 1.4 and 1.5 litters year− 1, 8.4 and 8.4 piglets weaned litter− 1, 66.6 and 93.0 kg piglets weaned sow− 1 year− 1, and 136 and 177 g day− 1 ADG were found in two villages near town with semi-intensive production conditions and a high rate of improved Mong Cai sows and MC and LW × MC offspring in the observed population. Lower performances of 1.1 and 1.1 litters year− 1, 4.6 and 5.5 piglets weaned litter− 1, 20.5 and 30.9 kg piglets weaned sow− 1 year− 1, and 66 and 85 g day− 1 ADG were observed in parallel to higher incidences of indigenous Ban pigs away from town under extensive conditions. Total live weight offtake per household per year was higher near town and in one village distant to town. MC and LW × MC remained even under demand-driven conditions below the performance potential reported for improved genotypes. Under resource-driven conditions with a saving-oriented production pattern, the higher-yielding but more demanding Mong Cai might not be an efficient production alternative as a further performance reduction can be assumed. A considerable live weight output was observed under resource-driven conditions and with a higher percentage of crossbred LW × Ban offspring in the population, possibly representing a promising production alternative. Factors influencing the performance expression of pigs, and the suitability of different methods for the assessment of performance parameters on-farm are discussed. 相似文献
Fetal bovine serum (FBS) has been widely used as a supplement in the maturation medium of bovine oocytes in
vitro. However, serum contains many undefined factors and is potentially infectious to humans and animals. As a serum
replacement, we evaluated the feasibility of using the silk protein, sericin, derived from the cocoons of silkworm. To examine the
rates of oocyte maturation and fertilization, cumulus-oocyte complexes were cultured in TCM-199 supplemented with 0.01%, 0.05%,
0.1% or 0.15% sericin or 5% FBS. The sizes of the perivitelline space that might relate to polyspermy, the expressions of
Has2 and CD44 mRNA, the amount of hyaluronan (hyaluronic acid: HA) contained in the oocytes
and the rates of blastocyst formation following insemination were then compared between the oocytes cultured with 0.05% sericin
and 5% FBS, because the polyspermy rates in oocytes cultured with 0.05% sericin were significantly lower than in those cultured
with 5% FBS. After in vitro maturation (IVM), the mean size of the perivitelline space was significantly greater
in oocytes cultured with sericin than in those cultured with FBS, although the rates of nuclear maturation, fertilization and
blastocyst formation of oocytes under both IVM conditions were not significantly different. The expression of HAS2 and
CD44 mRNA and the amount of HA in the denuded oocytes cultured with 0.05% sericin were significantly greater than in
those cultured with FBS. These results indicate the feasibility of sericin as an alternative protein supplement for IVM in bovine
oocytes. 相似文献
Village breeding programmes are being developed by an integrated long-term project for smallholders in Northwest Vietnam to improve pig production in different production systems. In total, 120 smallholders with 169 sows in 5 of the 9 project villages were approached in single person interviews, using a structured questionnaire. Frequency analysis of data on breeding management and ranking of smallholders' trait preferences and selection criteria used for pigs were performed with SAS 9.1, using the FREQ procedure. Survey results indicate that both improved local breeds and exotic genotypes should be incorporated in future village breeding programmes for market-oriented smallholder pig production, improving the reproductive and growth performance as well as the carcass quality. In a next step, a model reflecting the status quo at farms with market-oriented pig production was developed integrating data from farmers' survey and information from the project's current recording scheme. A deterministic approach was used to assess the profitability and genetic merit of the current recording scheme. Modelling results show that the current recording scheme is unprofitable (− 33.90 € sow− 1). As continued success of village breeding programmes depends on the profitability of breeding measures, the long-term sustainability of the current recording scheme seems unlikely. Genetic gains are achieved in production and carcass quality traits, while a small reduction in reproduction traits can be observed. In a last step, possible effects of increased pig performances on the profitability and genetic merit of the current recording scheme were evaluated. Effects of increased pig performances on the genetic and economic success of the recording scheme are generally limited. Further model calculations are necessary for finding possibilities to improve smallholder pig breeding in a profitable way. 相似文献