BCG对妊娠母猪血清及初乳免疫球蛋白含量影响的研究

本试验给妊娠后期的法国大白母猪接种卡介苗（ＢａｃｉｌｌｉＣａｌｍｅｔｔｅ－Ｇｕｅｒｉｎ；ＢＣＧ），以研究ＢＣＧ对母猪血清及初乳中ＩｇＧ、ＩｇＭ、ＩｓＡ含量的影响。试验结果表明：一、活或灭活ＢＣＧ均可显著地提高妊娠母猪血清中ＩｇＧ、ＩｇＭ的含量，但对血清ＩｇＡ的含量影响不大。二、分娩前２个月及皮内多点注射活或灭活ＢＣＧ均可显著地提高分娩后２４小时内初乳中ＩｇＭ、ＩｇＧ的含量，但对初乳ＩｇＡ的影响甚微。三、对照组母猪在妊娠后期血清ＩｇＧ、ＩｇＭ呈下降趋势，而血清ＩｇＡ呈上升趋势。     

Assessment of post-farrowing performance in sows having a high number of pigs born dead on commercial farms

The objectives of the present study were to investigate the relationship between number of pigs born dead (PBD) and both post-farrowing performance and culling risk in sows, and to determine the repeatability of PBD within sow. The present study used 256,527 parity records of 51,907 sows on 110 commercial farms. Five groups for PBD were categorized: PBD 0, 1, 2, 3 and ≥ 4 pigs. Linear mixed-effects models were used to analyze the data. Variance components analysis was separately conducted for three groups based on parity at culling. Mean value (± SEM) of PBD was 1.1 ± 0.01 pigs. Relative frequency of PBD 0, 1, 2, 3 and ≥ 4 pigs were 44.7, 24.8, 14.6, 7.5 and 8.4%, respectively. The relative frequency of PBD ≥ 4 pigs increased from 4.2 to 14.4% as parity increased from 2 to ≥ 6, whereas the frequency of PBD ≥ 4 pigs in parity 1 was 6.0%. Sows with PBD ≥ 4 pigs had 3.4% lower subsequent farrowing rate than those with PBD 0 pigs (P < 0.01). In parities ≥ 3, sows with PBD ≥ 4 pigs had fewer pigs born alive at subsequent parity than those with PBD 1 pigs (P < 0.01). However, in parities 1 and 2, no differences were found between the PBD groups in number of pigs born alive at subsequent parity. No difference was also found between the PBD groups in their subsequent weaning-to-first-mating interval. At each farrowed parity, culling risk for sows increased as PBD increased (P < 0.01). Furthermore, the values of the repeatability of PBD in sows culled in parities 2–5, 6–7 and ≥ 8 were relatively low, 0.14, 0.16 and 0.15, respectively. In conclusion, culling for low-parity sows based on PBD is not justified as the value of repeatability of PBD is low. Additionally, assisted farrowing is recommended for high-parity sows and parity-1 sows to reduce the PBD.