Researchers at Meiji University in Japan and PigCHAMP Pro Europa S.L. have compared reproductive performance across parity and lifetime performance in sow groups categorised by the number of pigs born alive (PBA) in parity 1 and then examined the factors associated with more PBA in parity 1.

In a paper published in Journal of Animal Science, R. Iida and co-authors describe how they analysed 476,816 parity records and 109,373 lifetime records of sows entered into 125 herds from 2008 to 2010.

Sows were categorised into four groups based on the 10th, 50th and 90th percentiles of PBA in parity 1 as follows:

• seven pigs or fewer
• eight to 11 pigs
• 12 to 14 pigs, and
• 15 pigs or more.

Generalised linear models were applied to the data.

For reproductive performance across parity, sows that had 15 or more PBA in parity 1 had 0.5 to 1.8 more PBA in any subsequent parity than the other three PBA groups (P<0.05). In addition, they had 2.8 to 5.4 per cent higher farrowing rates in parities 1 to 3 than sows that had seven or fewer PBA (P<0.05).

However, there were no differences between the sow PBA groups for weaning-to-first-mating interval in any parity (P≥0.37).

For lifetime performance, sows that had 15 or more PBA in parity 1 had 4.4 to 26.1 more lifetime PBA than sows that had 14 or fewer PBA (P<0.05).

Also, for sows that had 14 or fewer PBA in parity 1, those that were first mated at 229 days of age (25th percentile) or earlier had 2.9 to 3.3 more lifetime PBA than those first mated at 278 days old (75th percentile) or later (P<0.05).

Factors associated with fewer PBA in parity 1 were summer mating and lower age of gilts at first mating (AFM; P<0.05) but not re-service occurrences (P=0.34).

Additionally, there was a two-way interaction between mated month groups and AFM for PBA in parity 1 (P<0.05). PBA in parity 1 sows mated from July to December increased non-linearly by 0.3 to 0.4 pigs when AFM increased from 200 to 310 days old (P<0.05). However, the same rise in AFM had no significant effect on the PBA of sows mated between January and June (P≥0.17).

Iida and co-authors concluded that high PBA in parity 1 can be used to predict that a sow will have high reproductive performance and lifetime performance.

They add that the data suggest the upper limit of AFM for mating between July and December to be 278 days of age.

Reference

Iida I., C. Piñeiro and Y. Koketsu. 2015. High lifetime and reproductive performance of sows on southern European Union commercial farms can be predicted by high numbers of pigs born alive in parity one. J. Anim. Sci. 93:2501-2508.

Further Reading

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August 2015