The impact of herd age structure on the performance of commercial sow-breeding farms

Table 2 Descriptive statistics for the sow distribution and prolificacy for piglets born alive and weaned at each parity according to the groups of herd age structures (N = 623)

		Parity 1	Parity 2	Parity 3	Parity 4	Parity 5	Parity 6	Parity 7	Parity ≥ 8
Herd Structure Type 1 (a25%) (N = 156)	Percentage of sows (mean)	17.55	16.57	16.25	15.44	13.85	10.99	6.80	2.56
	Accumulative percentage of sows	-	34.12	50.36	65.80	79.65	90.64	97.44	100
	Percentage of sows (median)	17.73	16.78	15.93	14.74	13.60	11.12	7.16	1.98
	Number of piglets total born	15.30	15.65	16.53	16.70	16.56	16.31	15.43	14.06
	Number of piglets born alive	14.24	14.69	15.35	15.31	15.00	14.59	14.12	13.71
	Number of piglets weaned	12.94	13.06	12.90	12.79	12.57	12.41	12.37	12.32
Herd Structure Type 2 (a50%) (N = 311)	Percentage of sows (mean)	19.30	17.03	15.06	13.21	11.37	9.45	7.47	7.11
	Accumulative percentage of sows	-	36.33	51.39	64.61	75.97	85.42	92.89	100
	Percentage of sows (median)	19.22	17.00	15.03	13.21	11.37	9.45	7.47	7.11
	Number of piglets total born	14.80	15.18	15.96	16.20	16.10	15.85	15.43	14.87
	Number of piglets born alive	13.70	14.21	14.81	14.85	14.59	14.18	13.69	13.16
	Number of piglets weaned	12.34	12.40	12.28	12.14	11.98	11.79	11.63	11.53
Herd Structure Type 3 (a75%) (N = 156)	Percentage of sows (mean)	22.17	17.42	13.45	10.78	9.05	8.12	7.00	12.01
	Accumulative percentage of sows	-	39.58	53.04	63.82	72.87	80.99	87.99	100
	Percentage of sows (median)	21.40	16.91	13.43	10.95	9.34	8.15	6.87	12.13
	Number of piglets total born	14.66	15.13	15.87	16.03	15.91	15.81	15.39	14.46
	Number of piglets born alive	13.57	14.12	14.66	14.76	14.47	14.11	13.57	12.86
	Number of piglets weaned	12.01	12.17	12.03	11.99	11.88	11.81	11.70	11.37

ISSN: 2055-5660