Effect of teasing by the ram on the onset of puberty in Romney ewe lambs

Figures & data

Table 1  Live weights of ewe lambs at D1 based on ewe lamb treatment (Unteased vs Teased) and occurrence of puberty (No vs Yes) during the period D1 to D17.

	Live weight (kg)
	2008		2009
	n		n
Treatment
Unteased	50	34.55±0.33	50	36.67±0.20
Teased	50	34.24±0.28	49	36.85±0.26
Puberty^1
No	38	34.32±0.25	24	36.79±0.31
Yes	62	34.49±0.35	75	37.03±0.17
^1 It was deemed that lambs reached puberty when progesterone concentrations were greater than 1 ng/ml on two consecutive occasions during the period D1 to D17 in the 2008 and 2009 studies, respectively.

Table 2  The effect of ewe lamb treatment (Unteased vs Teased) on the proportion of ewe lambs achieving puberty¹, during D1 to D17 and D1 to D28 periods. Within years and day-intervals, means of treatments followed by different letters are significantly different (P<0.05).

	Proportion that achieved puberty^1
	2008			2009
	n	D1–17	D1–28	n	D1–17	D1–28
Treatment
Unteased	50	−1.15^a ± 0.33 (24.0)^2	0.32 ± 0.29 (58.0)	50	−1.52^a ± 0.37 (18.0)	0.32^a ± 0.29 (58.0)
Teased	50	−0.08^b ± 0.28 (48.0)	0.66 ± 0.30 (66.0)	49	1.36^b ± 0.35 (79.6)	2.73^b ± 0.60 (93.9)
^1 It was deemed that lambs reached puberty when progesterone concentrations were greater than 1 ng/ml (Wells et al. 2003; Valasi et al. 2006) on two consecutive occasions during the period D1 to D28 in the 2008 and 2009 studies, respectively.
^2 Data are presented as logit transformations with back-transformed percentages in parentheses.

Table 3  The effect of ewe lamb treatment (Unteased vs Teased) and corpus luteum number on progesterone concentrations in ewe lambs at D5, D9 and D12 in 2009 study. Within treatments and days means followed by different letters are significantly different (P < 0.05).

	Progesterone concentration ng/ml
	n ^1	D5	n ^1	D9	n ^1	D12
Treatment
Unteased	50	0.37^b±0.19	50	0.62±0.14	49	0.67±0.13
Teased	48	0.67^a±0.12	47	0.81±0.08	39	1.06±0.09
CL Number
0	90	0.28^a±0.06	73	0.33^a±0.06	63	0.45^a±0.07
1	8	0.76^b±0.22	24	1.10^b±0.15	25	1.30^b±0.13
Treat×CL num^2
Unteased×0	48	0.24^a±0.08	46	0.28^a±0.08	44	0.44^a±0.08
Unteased×1	2	0.50^ab±0.38	4	0.95^b±0.27	5	0.91^b±0.24
Teased×0	42	0.31^a±0.08	27	0.37^a±0.10	19	0.47^a±0.12
Teased×1	6	1.02^b±0.22	20	1.24^b±0.12	20	1.66^b±0.12
^1 Table includes only ewe lambs with 0 or 1 CL. Ewe lambs with more CLs are excluded at each time point analysis.
^2 Ewe lamb treatment by CL number interaction.

Table 4  The effect of ewe lamb treatment (Unteased vs Teased) on the proportion of ewe lambs that displayed oestrus during D18 to D28 regardless of whether they reached puberty or not during D1 to D17. Within years, means followed by different letters are significantly different (P < 0.05).

	Proportion displaying oestrus during D18–28
		2008		2009
	n		n
Treatment
Unteased	50	−1.51^1 ± 0.37^a (18.0)	50	−0.95 ± 0.32^a (28.0)
Teased	50	−0.24 ± 0.28^b (44.0)	49	0.63 ± 0.30^b (65.3)
^1 Data are presented as logit transformations with back-transformed percentages in brackets.