Table 3. The effect of dietary supplementation of marine derived Ca-Mg complex on reproduction performance in gilts/sows in four successive parities¹⁾

Items	Parity 1			Parity 2			Parity 3			Parity 4			SEM	p-value
Items	CON²⁾	CM1	CM2	CON	CM1	CM2	CON	CM1	CM2	CON	CM1	CM2	SEM	Parity	Treatment	P × T
Litter size
Total birth piglet (head)	14.2^bB	15.1^a	14.9^a	14.4^bB	15.2^a	15.1^a	15.2^a	15.8	15.5	15.4^a	15.8	15.7	0.212	***	***	NS
Live piglet (head)	13.7^bB	14.8^a	14.6^a	13.8^bB	14.8^a	14.7^a	14.7^bA	15.4^a	14.9^a	14.8^a	15.3	15.3	0.242	***	***	NS
Stillbirth (head)	0.5	0.3	0.3	0.4	0.3	0.3	0.5	0.4	0.6	0.5	0.4	0.4	0.099	NS	NS	NS
Mummification (head)	0.04	0.00	0.00	0.04	0	0	0	0	0	0.04	0	0	0.021	NS	NS	NS
Dead after 3 days of birth (head)	0.04	0.00	0.08	0.1	0.1	0.1	0	0	0	0.1	0	0	0.050	NS	NS	NS
Disorder (head)	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-
Survival rate (%)	96.1	98.4	97.7	96.0	97.5	97.1	96.7	97.6	96.1	95.9	97.1	97.0	0.702	NS	**	NS
Sow body weight (kg)
Initial	181.4^C	181.6	181.3	182.9^C	179.8	181.2	198.8^B	198.3	199.6	218^a	219	219.6	1.28	***	NS	NS
Before farrowing	222.2^D	220.7	221.3	238.3^C	237.7	239.5	257.9^B	258.9	259.8	278.2^a	280.6	280.7	1.401	***	NS	NS
After farrowing	196.7^D	194.1	194.7	213.20^C	211.30	212.60	231.70^B	232.3	233.4	252.1^a	254.4	254.1	1.429	***	NS	NS
Weaning	182.9^D	179.8	181.2	198.8^C	198.3	199.6	218^B	219	219.6	237.6^a	240.9	240.6	1.468	***	NS	NS
Back fat thickness (mm)
Initial	15.37^C	15.41	15.37	15.41^bC	16.12^a	15.75^a	16.33^B	16.95	16.95	18.62^bA	19.25^a	19.70^a	0.242	***	**	NS
Before farrowing	17.95^D	18.16	18.0	18.5^C	18.66	18.83	21.04^B	21.37	21.54	22.70^bA	23.45^a	23.50^a	0.23	***	*	NS
After farrowing	17.41^D	17.75	17.41	17.95^C	18.29	18.41	20.25^B	20.45	20.87	21.83^bA	22.66^a	22.62^a	0.219	***	**	NS
Weaning	15.41^bD	16.12^a	15.79^ab	16.33^C	16.95	16.95	18.62^bB	19.25^ab	19.70^a	19.95^bA	21.08^a	21.20^a	0.236	***	***	NS
Backfat thickness difference 1³⁾	2.58^C	2.75	2.62	3.08^C	2.54	3.08	4.70^a	4.41	4.58	4.08^B	4.20	3.79	0.204	***	NS	NS
Backfat thickness difference 2	0.54	0.41	0.58	0.54	0.37	0.41	0.79	0.91	0.66	0.87	0.79	0.87	0.112	***	NS	NS
Backfat thickness difference 3	2.05	1.62	1.62	1.62	1.33	1.45	1.62^a	1.20^B	1.16^B	1.87^a	1.58^ab	1.41^B	0.130	***	***	NS
Average daily feed intake (kg)
Gestation	2.02^C	2.02	2.02	2.06^B	2.07	2.06	2.16^a	2.17	2.16	2.16^a	2.17	2.16	0.005	***	NS	NS
Lactation	6.14^B	6.17	6.18	6.12^B	6.15	6.15	6.38^a	6.40	6.40	6.38^a	6.41	6.40	0.024	***	NS	NS
Estrus interval (day)	3.8^C	3.4	3.3	3.6^bC	3.3	3.3	4.3^ab	3.9	4.3	4.6^a	4.5	4.5	0.226	***	NS	NS

Values represent the means of 24 sows per treatment.
CON, basal diet; CM1, basal diet – MgO - 0.3% limestone + 0.40% marine derived Ca-Mg complex; CM2, basal diet - MgO - 0.7% limestone + 0.40% marine derived Ca-Mg complex.
Backfat thickness difference: 1, initial to before farrowing; 2, before farrowing to after farrowing; 3, after farrowing to weaning.
Different superscripts within a row indicate a significant difference (p < 0.05) in response to treatment diets CM1 and CM2.
Different superscripts within a row indicate a significant difference (p < 0.05) among parity.
p < 0.05,
p < 0.01,
p < 0.0001.
P × T, interactive effects between parity and dietary treatments; NS, non-significant.