Effects of nutritional cues on the duration of the winter anovulatory phase and on associated hormone levels in adult female Welsh pony horses (Equus caballus)

Table 3 Mean dates ± S.E.M. (in days) of beginning, end and durations of ovulatory inactivity in mares kept under the 3 experimental diets and under natural photoperiod.

		Ovarian inactivity 1^st winter	Ovarian inactivity 2^nd winter	Ovarian inactivity 3^rd winter	Mean duration (days) (2) (3)
WF	Beginning	21 Nov ± 12	31 Dec ± 10	14 Jan ± 25
	End	22 March ± 17	28 March ± 12	26 April ± 23
	Duration (1)	119 ± 37 (4/10)	87 ± 17 (4/9)*	103 ± 13 (3/9)	103.0	40.4
R	Beginning	21 Nov ± 11	22 Sep ± 10	27 Oct ± 4
	End	21 May ± 7	15 May ± 6	21 May ± 4
	Duration (1)	180 ± 15 (8/10)	235 ± 13 (10/10)	206 ± 7 (10/10)	207.3	194.2
V	Beginning	16 Nov ± 5	14 Nov ± 7	03 Nov ± 9
	End	6 May ± 9	2 May ± 10	13 May ± 6
	Duration (1)	171 ± 12 (8/10)	169 ± 15 (8/10)	193 ± 8 (8/10)	178.0	141.0

(1) (Number of mares presenting winter ovarian inactivity/total number of mares).
(2) With only the mares presenting winter inactivity taken into account.
(3) With all the mares in the group taken into account.
* After an accidental fracture, one mare was removed from the experiment.

ISSN: 1477-7827