Increased age at first-mating interacting with herd size or herd productivity decreases longevity and lifetime reproductive efficiency of sows in breeding herds

Table 2 Comparisons of performance measurements (Means and SEM) between two herd size and between two productivity groups¹

	Herd size groups		Herd productivity groups
Measurements	Small-to-mid herds	Large herds	Ordinary herds	High productivity herds
n	102,528	44,666	99,680	47,514
Age at first-mating	264 ± 4	241 ± 8	241 ± 6	264 ± 7
Longevity
Number of parity at removal	5.17 ± 0.10	4.88 ± 0.12	5.01 ± 0.09	5.03 ± 0.13
Sow life days	1056 ± 14 ^a	998 ± 19 ^b	1038 ± 14	1017 ± 19
Sow herd-life days	801 ± 14 ^a	743 ± 18 ^b	783 ± 14	762 ± 19
n	83,600	52,265	79,594	56,271
Prolificacy
Herd-life piglets born alive	69.2 ± 1.2	66.0 ± 1.5	65.0 ± 1.2 ^b	70.2 ± 1.6 ^a
Herd-life piglets weaned	60.0 ± 1.0	58.0 ± 1.2	56.5 ± 0.9 ^b	61.5 ± 1.3 ^a
Reproductive efficiency
Sow life annualized piglet weaned	18.8 ± 0.2	18.7 ± 0.2	17.7 ± 0.1 ^b	19.8 ± 0.2^a

¹Means and SEs were estimated by the models
^a,bDifferent superscripts within a row represent significant differences in means (P < 0.05)

ISSN: 2055-5660