Intensity of Oestrus Signalling Is the Most Relevant Indicator for Animal Well-Being in High-Producing Dairy Cows

Table 3

Percentages of pregnancy (animal ratios in parentheses) at day 50 (transrectal manual examination) and of calving, disclosed by relative P₄ level in blood serum on day 0 and by intensity of oestrus (day 0) for dairy Heifers (𝑛=37) or first parity cows (C1 cows, 𝑛=30).

Animal category	P4 at day 0	Oestrous intensity at day 0			Pregnancy rates		Calving rates
		Low	Medium	High
Heifers	Low	71 (5/7)	50 (1/2)	100 (6/6)	80^a (12/15)		60 (9/15)
	Medium	67 (2/3)	0 (0/1)	75 (6/8)	67^ab (8/12)	72^a (26/36)	58 (7/12)	64^a (23/36)
	High	60 (3/5)	100 (1/1)	67 2/3	67^ab (6/9)		78 (7/9)
C1 cows	Low	14 (1/7)	33 (2/6)	67 (2/3)	31^b (5/16)		25 (4/16)
	Medium	33 (2/6)	50 (1/2)	—	38^ab (3/8)	37^b (11/30)	38 (3/8)	33^b (10/30)
	High	40 (2/5)	100 (1/1)	—	50^ab (3/6)		50 (3/6)
Pregnancy rates		45^a (15/33)	46^ab (6/13)	80^b (16/20)	56 (37/66)
Calving rates		39^a (13/33)	38^a (5/13)	75^b (15/20)			50 (33/66)

^{a, b}different superscripts differ significantly between animal categories (𝑃<0.01 on PR column and 𝑃<0.05 on CR column, PR row and CR row).