The effect of tail paint formulation and heifer behavior on estrus detection

Peer review under responsibility of Faculty of Veterinary Medicine, Cairo University.

Figures & data

Fig. 1 Tail paint removed (TPR) score.

Table 1 Definitions of all behaviors observed in the study.

Classification	Behavior	Explanation
Social interactions	Paint lick	Initiator licks the tail paint of the receiver
	Social lick	Initiator licks the head, flank, or neck of the receiver
	Rump lick	Initiator licks the rump region of the receiver
	Play rub^†	Rubs head against another cow, except chin resting
Antagonistic interactions	Body butt	Initiator pushes forehead against part of body of the receiver, other than the head
	Head butt	Initiator bows head and pushes forehead firmly against forehead of the receiver
	Push	Initiator pushes the receiver with her head, resulting in the receiver moving away or changing position
	Winner	Initiator wins in an antagonistic interaction over feed or resources or an interaction in which the behavior cannot be defined, where the receiver moves away or changes position
	Chase up	Initiator touches or butts a lying receiver, and the receiver stands up
Estrus interactions	Chin rest	Initiator rests her chin on the rump of the receiver
	Anogenital sniff	Initiator licks or sniffs the anogenital region of the receiver
	Mount	Initiator mounts and succeeds in resting both legs on rump with or without a standing response from the receiver
	Attempt to mount	Initiator tries to mount the receiver by raising front limbs, but does not succeed

† Behavior in which an initiator and receiver could not be clearly defined.

Fig. 2 Frequency of observations for behaviors related to the tail paint treatments. A: Paint lick received; B: Rump lick received; C: Social lick received; D: Anogenital sniff received. The X-axis shows how many times in a single 30-min period the behavior was observed. The Y-axis shows the percentage of the total observation each count makes up. There were 756 total observations for all 18 heifers in the trial. The number of observations is shown directly above each bar.

Table 2 Least squares means and associated standard errors of the mean (SEM) for the degree of tail paint removal (TPR) and behaviors related to the tail paint treatments for 18 dairy heifers.

Trait	Treatment^† means			SEM	P-value^‡
	CON	SPRAY	CHALK+
TPR, sum for week^§	6.78^a	1.80^b	5.65^a	0.25	<0.001
Behaviors initiated
Paint lick	1.88^a	1.84^a	1.62^a	0.35	0.77
Social lick	12.79^a	13.70^a	11.20^a	1.44	0.25
Rump lick	1.08^a	0.93^a	0.71^a	0.18	0.45
Anogenital sniff	5.46^a	5.99^a	4.01^a	0.68	0.12
Behaviors received
Paint lick	2.50^a	1.18^b	2.33^a	0.18	<0.001
Social lick	13.54^a	13.30^a	12.40^a	0.91	0.56
Rump lick	0.70^a	0.95^a	0.94^a	0.17	0.59
Anogenital sniff	4.34^b	5.96^a	4.91^a,b	0.51	0.04

^a,bValues with the same letter are not significantly different as determined by a Tukey’s adjustment.

† CON: control. SPRAY: spray formulation. CHALK+: test product.

‡ Treatment by week interaction was not significant for any trait (P > 0.29).

§ TPR score: 0 = no paint removed; 1 = less than half of the paint removed; 2 = more than half of the paint was removed.

Table 3 Incident ratio from Poisson regression for traits with treatment differences by comparison of tail paint treatments for 18 dairy heifers.

Trait	Coefficient	SE^†	IRR^‡	95% CI^§	P-Value^¶
Tail paint removal (TPR)^††
CON-SPRAY	1.315	0.14	3.72	2.83–4.90	<0.001
CON-CHALK+	0.180	0.09	1.20	0.99–1.45	0.06
SPRAY-CHALK+	−1.135	0.14	0.32	0.24–2.34	<0.001
Paint lick received
CON-SPRAY	0.750	0.18	2.12	1.49–3.06	<0.001
CON-CHALK+	0.071	0.15	1.07	0.80–1.43	0.63
SPRAY-CHALK+	−0.679	0.18	0.51	0.35–1.37	<0.01
Anogenital sniff received
CON-SPRAY	−0.316	0.12	0.73	0.57–2.03	0.01
CON-CHALK+	−0.123	0.13	0.88	0.69–1.14	0.34
SPRAY-CHALK+	0.193	0.12	1.21	0.96–1.54	0.11

† SE = standard error.

‡ IRR = incidence rate ratio.

§ CI = confidence interval.

¶ Treatment by week interaction was not significant for any trait (P > 0.29).

†† TPR Score: 0 = no paint removed; 1 = less than half of the paint removed; 2 = more than half of the paint was removed. Scores for dairy heifers were summed by week^. CON: control. SPRAY: spray formulation. CHALK+: test product.

Table 4 Least squares means of initiated behaviors by comparison of expected low activity in wk 1 and high activity in wk 2.

Trait	Week 1 – low activity^†		Week 2 – high activity		P-Value
	Mean	95% CI^‡	Mean	95% CI
Play rub	1.67	1.24–2.25	1.55	1.15–2.10	0.64
Behaviors initiated
Paint lick	2.11	1.46–3.03	1.50	1.02–2.21	0.05
Social lick	14.35	11.36–18.12	11.06	8.68–14.08	0.01
Rump lick	1.19	0.85–1.66	0.71	0.47–1.09	0.05
Body butt	2.34	1.76–3.12	3.46	2.64–4.55	<0.001
Head butt	3.68	2.84–4.76	4.15	3.22–5.35	0.29
Push	4.01	2.95–5.44	3.88	2.85–5.27	0.77
Winner	4.22	2.86–6.21	4.23	2.87–6.24	0.97
Chase up	0.41	0.24–0.72	0.61	0.37–1.01	0.20
Chin rest	1.88	1.23–2.87	3.72	2.63–5.27	<0.01
Anogenital sniff	4.89	3.72–6.41	5.58	4.30–7.24	0.41
Mount	0.35	0.17–0.75	1.20	0.73–1.95	<0.01
Attempt to mount	0.60	0.34–1.09	0.66	0.38–1.17	0.77

† Low activity is expected in wk 1 of each period and high activity is expected in wk 2 of each period due to the application of the Ovsynch protocol.

‡ CI = confidence interval.

Table 5 Least squares means of received behaviors and tail paint removed (TPR) by comparison of expected low activity in wk 1 and high activity in wk 2.

Trait	Week 1 – low activity^†		Week 2 – high activity		P-Value
	Mean	95% CI^‡	Mean	95% CI
TPR^§	5.82	4.89–6.92	4.01	3.28–4.91	<0.01
Behaviors received
Paint lick	2.42	2.00–2.93	1.66	1.33–2.09	0.01
Social lick	14.96	13.21–16.93	11.50	10.07–13.14	<0.001
Rump lick	1.16	0.86–1.57	0.66	0.44–0.99	0.03
Body butt	2.21	1.57–3.11	3.29	2.37–4.57	<0.01
Head butt	3.67	2.81–4.78	4.09	3.14–5.32	0.29
Push	4.12	3.16–5.38	4.02	3.08–5.25	0.82
Winner (loser)	4.93	4.04–6.02	4.91	4.02–6.00	0.97
Chase up	0.33	0.17–0.64	0.50	0.27–0.94	0.11
Chin rest	1.88	1.25–2.84	3.78	2.71–5.28	<0.01
Anogenital sniff	4.74	3.85–5.85	5.48	4.48–6.71	0.16
Mount	0.30	0.14–0.62	1.09	0.66–1.78	<0.001
Attempt to mount	0.61	0.37–1.01	0.54	0.32–0.91	0.69

† Low activity is expected in wk 1 of each period and high activity is expected in wk 2 of each period due to the application of the Ovsynch protocol.

‡ CI = confidence interval.

§ TPR Score: 0 = no paint removed; 1 = less than half of the paint removed; 2 = more than half of the paint was removed. Scores for 18 dairy heifers were summed by week.

Table 6 Estimates of initiated behaviors by follicle size for 18 dairy heifers on day 7 and day 9 of 3 periods, as determined by ovarian ultrasound.

Trait	Day 7			Day 9			P-Value^‡
	Follicle ≥ 12.4 mm	Follicle < 12.4 mm	SE^†	Follicle ≥ 12.4 mm	Follicle < 12.4 mm	SE	Follicle size	Day
Play rub	0.83	0.54	0.16	0.67	0.56	0.17	0.27	0.69
Behaviors initiated
Paint lick	0.68	0.72	0.20	1.03	0.44	0.21	0.20	0.86
Social lick	4.63	6.67	0.89	4.58	4.74	0.91	0.21	0.24
Rump lick	0.40	0.48	0.15	0.43	0.36	0.16	0.97	0.79
Body butt	1.88	1.80	0.32	1.71	1.37	0.33	0.52	0.33
Head butt	1.95	1.68	0.33	1.89	1.13	0.34	0.12	0.32
Push	2.48	2.13	0.38	1.76	1.46	0.39	0.36	0.04
Winner	2.03	2.05	0.39	2.73	1.58	0.40	0.07	0.67
Chase up	0.15	0.02	0.15	0.52	0.39	0.15	0.43	0.03
Chin rest	1.52	0.94	0.51	2.46	1.80	0.52	0.23	0.07
Anogenital sniff	2.25	1.78	0.49	3.69	2.55	0.51	0.14	0.04
Mount	0.29	0.17	0.23	1.26	0.49	0.27	0.08	0.008
Attempt to mount	0.84	0.21	0.19	0.51	0.26	0.20	0.03	0.45

† SE = standard error.

‡ Follicle size by day interaction was not significant in for any trait (P > 0.13), with the exception of winner initiated (P > 0.06).

Table 7 Estimates of received behaviors and tail paint removed (TPR) by follicle size for 18 dairy heifers on day 7 and day 9 of 3 periods, as determined by ovarian ultrasound.

Trait	Day 7			Day 9			P-Value^‡
	Follicle ≥ 12.4 mm	Follicle < 12.4 mm	SE^†	Follicle ≥ 12.4 mm	Follicle < 12.4 mm	SE	Follicle size	Day
TPR^§	15.77	15.62	2.22	16.49	13.17	2.27	0.48	0.72
Behaviors received
Paint lick	0.93	0.66	0.15	0.65	0.75	0.15	0.61	0.56
Social lick	6.13	5.55	0.60	4.44	4.75	0.62	0.84	0.07
Rump lick	0.66	0.19	0.14	0.59	0.23	0.14	<0.01	0.92
Body butt	1.76	1.86	0.41	2.03	1.11	0.42	0.29	0.51
Head butt	1.91	1.71	0.33	1.54	1.40	0.33	0.61	0.27
Push	2.29	2.27	0.35	1.49	1.71	0.36	0.78	0.04
Winner (loser)	1.97	2.06	0.33	2.25	1.97	0.34	0.78	0.76
Chase up	0.20	0	0.14	0.35	0.52	0.14	0.86	0.02
Chin rest	1.70	0.838	0.55	3.36	1.08	0.56	<0.01	0.09
Anogenital sniff	2.24	1.79	0.47	4.18	2.15	0.48	0.02	0.02
Mount	0.47	0.04	0.21	1.22	0.36	0.22	<0.01	0.03
Attempt to mount	0.75	0.12	0.16	0.58	0.07	0.17	<0.01	0.53

† SE = standard error.

‡ Follicle size by day interaction was not significant in for any trait (P > 0.13), with the exception of winner initiated (P > 0.06).

§ TPR Score: 0 = no paint removed; 1 = less than half of the paint removed; 2 = more than half of the paint was removed. Scores for dairy heifers were summed for each respective day, for all 3 periods of the trial.

Fig. 3 Estimate of tail paint removal (TPR) for effects of treatment, day of ultrasound, and interactions. Treatment: (P < 0.001). All other effects and interactions were not different (P < 0.20). Treatments with different letters were different for d 7 (P < 0.02) and d 9 (P < 0.08).

Fig. 4 Estimate of tail paint removed (TPR) for effects of treatment, follicle size, and interactions. Treatment by follicle size: (P = 0.09); treatment: (P < 0.001). All other effects and interactions were not different (P < 0.20). Treatments with different letters were different (P < 0.02) for small follicle size (<12.4 mm; letters a, b) or large follicle size (>12.4 mm; letters x, y).