Table 1.

Summary statistics of sows, corpus luteum and litter characteristics

Variables	n	Mean	SD	Min	Max
Experiment 1
Parity	45	7.3	3.2	2	13
TUS pregnancy age, d	45	23.4	2.9	20	28
Slaughter pregnancy age, d	45	29.8	1.9	27	32
Ovulation rate by TUS	45	23.4	5.8	13	34
Ovulation rate after dissection	45	24.1	5.3	13	37
Average CL diameter TUS1, mm	25	10.3	0.73	8.4	11.7
Average CL diameter DISS2, mm	25	10.3	0.64	8.7	11.5
Average CL weight DISS3, g	25	0.40	0.07	0.22	0.56
Total average CL diameter4, mm	25	9.8	0.7	7.8	11.0
Total average CL weight4, g	25	0.38	0.1	0.20	0.51
Total luteal mass5, g	25	7.9	1.5	5.2	10.7
Experiment 2
Parity	100	5.0	1.9	2	9
TUS pregnancy age, d	100	23.8	2.4	21	29
Gestational length, d	100	115	1.7	111	120
Average CL diameter TUS1, mm	100	8.4	0.8	5.5	10.5
Litter size6	100	17.9	3.0	9	26
Number of live born	100	16.3	2.9	6	23
Number of stillborn	100	1.53	1.8	0	9
Number of mummies	100	0.42	0.8	0	5
Average piglet BW7, g	100	1277	165	914	1618
SD BW7, g	100	303	76	161	555
Average live born piglets BW7, g	100	1299	167	933	1674
SD BW live born7, g	100	292	76	115	492
Litter BW, kg	100	23	4.0	15	30

¹Average calculated based on the diameter of the 5 biggest corpora lutea in each ovary (10 per sow) measured by Transrectal ultrasonography (TUS).

²Average calculated based on the diameter of the 5 biggest corpora lutea in each ovary (10 per sow) measured with caliper rule after slaughter of the sows and ovarian dissection.

³Average weight of the 5 corpora lutea in each ovary (10 per sow) that had the highest diameter measured after ovarian dissection.

⁴Average diameter and weight calculated based on the measurement of all corpora lutea dissected from each ovary.

⁵Sum of the weight of all the corpora lutea dissected from the ovaries.

⁶Litter size is the sum of piglets born alive (live born) and stillborn piglets.

⁷Piglets were weighed within 24 h after birth.