Effect of age of suckler beef calves on stress indicators and growth performance in response to Burdizzo castration

Figures & data

Table 1. Calves and age per treatment.

Age	Treatment	Number of calves	Age (SD), days (d)	Weight (SD), kg
2.5 mo old	Control (sham^1)	n=10	80 (23)	121.3 (28.9)
2.5 mo old	Castrated	n=10	80 (21)	120.3 (29.6)
5.0 mo old	Control (sham)	n=10	153 (19)	213.5 (31.7)
5.0 mo old	Castrated	n=10	157 (17)	222.6 (29.9)

¹ Sham handled by holding the testes to the side of the scrotum.

Table 2. Description of experimental procedures and timing pre- and post-treatment.

Procedures	Hours relative to treatment (0 h)
	−48	−24	0	24	48
Acclimatization of calf-dam pairs in the housing facility	X	X
Calf-dam tethered	X	X	X
Calf weights		X
Scrotal measurements		X		X	X
Jugular vein catheterization		X
Treatment (castration or control)			X
Blood samplings			X	X	X
Video recording (continuously)		X	X	X	X

Table 3. Blood samples sampling time for each variable collected relative to castration (0 h (h)).

Time, h	−0.5	−0.25	0	0.25	0.5	0.75	1.25	2	3	4	5	7	9	24	48
Bleed n^o	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15
Cortisol	X	X	X	X	X	X	X	X	X	X	X	X	X
Non-esterified fatty acids	X		X		X				X		X		X	X	X
Beta-hydroxybutyrate	X		X		X				X		X		X	X	X
Haptoglobin	X		X		X				X		X		X	X	X
Haematology profiles*	X		X		X	X	X		X		X			X	X

* Haematology profiles = white blood cell, lymphocytes, monocytes, neutrophils, basophils, and red blood cell numbers, haemoglobin concentration, haematocrit percentage and platelet number.

Figure 1. Scrotal latitudinal (A) and longitudinal (B) circumferences.

Table 4. Ethogram used for categorizing behavioural observations of suckled beef calves after castration.

Behaviour	Description
States
Eating	Sucking the teat for milk or eating grass
Ruminating	Chewing when not eating
Standing	Standing in any style
Lying	Lying down completely on the ground in any style
Allo-grooming	The muzzle meets any part of another animal (ex. dam)
Self-grooming	The muzzle meets any part of the animal
Events
Foot stamping	When hindleg was lifted and forcefully placed on the ground
Tail wagging	Tail movement from side to side, except during suckling or blood collection
Head turning	The head turned to a point on the body beyond the shoulder
Kicking	Kicking backward or towards the belly with a hind limb
Postures
Standing
Normal	Standing eating, playing or walking with no obvious abnormality
Abnormal	Standing or walking with obviously abnormal gait (e.g. swaying, walking on knees, stamping feet)
Lying
Normal Ventral	Lying in ventral or sternal recumbency with all legs folded under the body with its head held up or down
Abnormal Ventral	Lying in sternal recumbency with full extension of one or both hind legs or lying on the sternum with the scrotum kept off the ground
Lateral	Lying with one shoulder and hindquarter on the ground with two or more legs extended

(Adapted from Robertson et al. 1994; Molony et al. 1995; Thüer et al. 2007; Boesch et al. 2008; Pieler et al. 2013; Lambertz et al. 2014).

Figure 2. Diagram of bodyweight sampling time points and average daily gain (ADG) intervals.

Figure 3. Effect of Burdizzo castration at 2.5- and 5.0-mo-old on the difference in AUC (dAUC) plasma cortisol concentrations in calves. The area under the cortisol response curve (area under the curve; AUC) was calculated from 0 to 4 h (primary response; AUC₁), and from 4 to 9 h after treatment (secondary response; AUC₂) using the linear trapezoidal rule as described by Ting et al. (2003a). The difference in cortisol AUC was expressed as the difference between the AUC of the treatment group and the respective control from 0 to 4 h (dAUC₁) and from 4 to 9 h (dAUC₂).

Table 5. Effect of Burdizzo castration at 2.5- and 5.0-mo-old on changes in plasma cortisol concentrations in calves during primary response, from 0 to 4 h post treatment.

	Age (A)			Treatment (Trt)			Time (T), h									P-values
Variables	2.5 mo old	5.0 mo old	SEM	Control	Castrated	SEM	0	0.25	0.5	0.75	1.25	2	3	4	SEM	A	Trt	T	I
Plasma cortisol, ng/mL	6.5^a	10.7^b	1.10	6.0^a	11.6^b	1.10	8.3^a	14.0^b	13.1^b	10.7^a	8.1^a	6.4^a	5.2^b	5.1^b	1.10	***	***	***	^1

^a.b Within rows, Lsmeans differ from pre-castration baseline (0 h) (P < 0.05).

A = age, Trt = treatment, I = interactions, NS = not significant (P > 0.05). * P < 0.05, ** P < 0.01, *** P < 0.001. NS = not significant (P > 0.05).

¹ Trt × T (P < 0.001). SEM = pooled standard error.

Table 6. Effect of Burdizzo castration at 2.5- and 5.0-mo-old on changes in plasma cortisol concentrations in calves during secondary response, from 4 to 9 h post treatment.

	Age (A)			Treatment (Trt)			Time (T), h				P-values
Variables	2.5 mo old	5.0 mo old	SEM	Control	Castrated	SEM	4	5	7	9	SEM	A	Trt	T	I
Plasma cortisol, ng/mL	4.1^a	9.5^b	1.13	5.1^a	7.6^b	1.13	5.1^a	5.9^a	7.1^b	7.1^b	1.13	***	*	**	NS

^a,b Within rows, Lsmeans differ from secondary response baseline (4 h) (P < 0.05).

A = age, Trt = treatment, I = interactions, NS = not significant (P > 0.05). * P < 0.05, ** P < 0.01, *** P < 0.001. NS = not significant (P > 0.05).

SEM = pooled standard error.

Table 7. Effect of Burdizzo castration at 2.5- and 5.0-mo-old on changes in plasma cortisol concentrations in calves.

	2.5 mo old		5.0 mo old			P-values
	Control	Castrated	Control	Castrated	SEM	A	Trt	A × Trt
Cortisol baseline (0 h), ng/mL	8.9	9.3	9.0	9.2	1.13	NS	NS	NS
Interval to peak, h	0.4	0.5	0.5	0.7	0.09	NS	*	NS
Peak cortisol concentration, ng/mL	10.4^a	26.1^b	21.7^b	33.9^b	3.04	**	***	NS
Increase to peak, ng/mL	5.7^a	19.8^b	16.7^b	27.7^b	3.26	***	***	NS

^a,b Lsmeans differ within rows (P < 0.05).

A = age, Trt = treatment, NS = not significant (P > 0.05). * P < 0.05, ** P < 0.01, *** P < 0.001.

SEM = pooled standard error.

Table 8. Effect of Burdizzo castration of 2.5- and 5.0-mo-old calves on the adjusted area under the curve from 0 to 4 h (AUC₁) and from 4 to 9 h (AUC₂) for plasma cortisol concentration.

	2.5-mo-old		5.0-mo-old		SEM
	Control	Castrated	Control	Castrated
AUC1	15.5^a	34.3^b	31.2^bc	60.9^d	4.97
AUC2	21.7^a	26.5^ab	45.3^b	77.1^c	8.29

^{a,b, c, d} Within rows, Lsmeans differ between treatment group, within age group (P < 0.05).

AUC1= 0–4 h, AUC₂= 4–9 h.

SEM = pooled standard error.

Table 9. Effect of Burdizzo castration at 2.5- and 5.0-mo-old in difference in the area under the curve (AUC) of cortisol concentration in calves.

	2.5 mo old	5.0 mo old	SEM	P-values
dAUC1, ng/mL/h	23.5	32.2	5.81	NS
dAUC2, ng/mL/h	21.9^a	40.4^b	6.10	*

^a,b Within rows, Lsmeans differ between treatment group, within age group (P < 0.05). * P < 0.05.

dAUC1= 0–4 h, dAUC₂= 4–9 h, NS = not significant (P > 0.05).

SEM = pooled standard error.

Table 10. Effect of Burdizzo castration at 2.5- and 5.0-mo-old on the changes in latitudinal and longitudinal scrotal circumferences relative to pre-treatment baseline.

	2.5-mo-old		5.0-mo-old			P-values
	Control	Castrated	Control	Castrated	SEM	A	Trt	A × Trt
Baseline latitudinal scrotal circumference (cm)
−24 h	18.3	18.5	22.7	23.9	0.76	***	NS	NS
Changes in latitudinal scrotal circumference from baseline (cm)
24 h	−0.1	2.5^a	0.6	4.0^b	0.74	NS	***	NS
48 h	−0.3	1.7^a	0.3	5.1^b	0.72	**	***	*
Baseline longitudinal scrotal circumference (cm)
−24 h	16.0	16.8	28.6	29.2	0.93	***	NS	NS
Changes in longitudinal scrotal circumference from baseline (cm)
24 h	1.1	7.4	0.0	6.1	1.16	NS	***	NS
48 h	−0.4	7.0	1.4	8.7	1.08	NS	***	NS

^a,b Within rows, Lsmeans differ between age groups, within castration treatments (P < 0.05).

A = age, Trt = treatment, NS = not significant (P > 0.05). * P < 0.05, ** P < 0.01, *** P < 0.001.

SEM = pooled standard error.

Table 11. Effect of Burdizzo castration at 2.5- and 5.0-mo-old on behaviour of calves during 3 h of continuous observations post treatment.

	Age (A)			Treatment (Trt)			Time interval (T)				P-value
	2.5 mo old	5.0 mo old	SEM	Control	Castrated	SEM	T1	T2	T3	SEM	A	Trt	T	A × T	A × Trt	Trt × T	A × Trt × T
States
Eating, s	262	424	77.0	396	290	78.7	241	426	363	88.0	NS	NS	NS	NS	NS	NS	NS
Lying, s	1213	1113	178.3	1229	1097	182.2	320^a	1364^b	1805^b	184.6	NS	NS	***	NS	NS	NS	NS
Standing, s	1041	905	75.1	863^a	1082^b	76.5	1469^a	872^b	578^b	136.1	NS	*	***	NS	NS	NS	NS
Ruminating, s	14^a	142^b	43.4	104	52	44.3	27	91	116	45.0	*	NS	NS	NS	NS	NS	NS
Postures
Lying ventral abnormal, s	348^a	69^b	55.4	72^a	345^b	56.5	13^a	189^b	423^b	66.7	**	**	***	NS	NS	**	NS
Lying ventral normal, s	943	1206	124.6	1289^a	860^b	127.2	330^a	1257^b	1636^b	148.4	NS	*	***	NS	NS	*	NS
Standing abnormal, s	127	204	27.8	49^a	282^b	28.4	366^a	70^b	62^b	30.5	NS	***	***	**	**	***	***
Standing normal, s	2244	1999	143.4	2118	2125	146.6	2842^a	2023^b	1499^b	166.0	NS	NS	***	NS	NS	NS	NS
Events
Foot stamping, number	9	10	1.5	5^a	19^b	1.6	18^a	7^b	7^b	2.2	NS	***	**	NS	NS	NS	NS
Tail wagging, number	6^a	65^b	5.5	18	20	8.5	25	19	14	8.9	***	NS	NS	NS	NS	NS	NS

SEM = pooled standard error.

T1 = first 1 h block; T2 = second 1 h block, T3 = third 1 h block, after treatment.

^a,b Within rows, Lsmeans without a common superscript letter differ. NS = not significant (P > 0.05). * P < 0.05, ** P < 0.01, *** P < 0.001.

Table 12. Effect of Burdizzo castration at 2.5- and 5.0-mo-old on behaviour of calves during scan observations (3 h blocks).

	Age (A)			Treatment (Trt)			Time interval (T)				P-value
	2.5 mo old	5.0 mo old	SEM	Control	Castrated	SEM	T1	T2	T3	SEM	A	Trt	T	A × T	A × Trt	Trt × T	A × Trt × T
States
Eating, number	3^a	4^b	0.3	3	3	0.3	4	3	3	0.3	***	NS	NS	***	NS	NS	NS
Lying, number	10^a	6^b	0.5	7	7	0.5	7	8	8	0.5	***	NS	NS	NS	NS	*	NS
Standing, number	2^a	1^b	0.2	2	2	0.2	1^ab	2^ab	1^a	0.2	*	NS	*	***	NS	NS	NS
Ruminating, number	2^a	4^b	0.3	3	3	0.3	2	3	3	0.4	***	NS	NS	NS	NS	*	NS
Grooming, number	1^a	2^b	0.2	1	1	0.2	1	2	1	0.2	*	NS	NS	*	NS	NS	NS
Postures
Lying abnormal, number	3^a	1^b	0.3	1^a	3^b	0.3	2	1	2	0.4	***	**	NS	NS	NS	NS	NS
Lying ventral normal, number	9	9	0.6	9	8	0.6	8	9	9	0.6	NS	NS	NS	NS	NS	NS	NS
Standing normal, number	5^a	8^b	0.4	6	6	0.4	7	7	6	0.4	***	NS	NS	NS	NS	NS	NS

SEM = pooled standard error

T1 = from 1900 to 2200 h (d 0); T2 = from 0500 to 0800 h (d 1), T3 = from 0500 to 0800 h (d 2), after treatment.

^a,b Within rows, Lsmeans without a common superscript letter differ. NS = not significant (P > 0.05). * P < 0.05, ** P < 0.01, *** P < 0.001.

Table 13. Effect of Burdizzo castration at 2.5- and 5.0-mo-old on changes on haematological profiles of bull calves.

Variables	Age (A)			Treatment (Trt)			Time (T), h										P-values
	2.5-mo-old	5.0-mo-old	SEM	Control	Castrated	SEM	−0.5	0	0.5	0.75	1.25	3	5	24	48	SEM	A	Trt	T	A × T	Trt × T
White blood cell, ×10^3 cells/µL	9.6	10.5	0.51	10.1	10.0	0.49	10.1^a	9.5^a	9.4^a	9.3^b	10.0^a	10.8^a	11.1^b	10.8^a	10.5^a	0.40	NS	NS	***	NS	NS
Neutrophils (N), ×10^3 cells/µL	3.0	3.3	0.23	3.0	3.3	0.23	2.9^a	2.7^a	2.7^a	2.7^a	3.2^a	3.9^b	3.8^b	2.8^a	2.9^a	0.20	NS	NS	***	NS	**
Lymphocytes (L) ×10^3 cells/µL	6.4	7.0	0.40	7.0	6.4	0.40	7.2^a	6.7^b	6.6^b	6.3^b	6.5^b	6.6^b	7.1^a	7.7^a	7.8^b	0.31	NS	NS	***	*	NS
N:L Ratio	0.5	0.5	0.04	0.4	0.5	0.04	0.4	0.4	0.4	0.5	0.5	0.7	0.6	0.4	0.4	0.03	NS	NS	***	NS	*
Monocytes, ×10^3 cells/µL	0.5	0.5	0.02	0.5	0.4	0.02	0.4^a	0.4^a	0.5^a	0.4^a	0.5^a	0.5^a	0.5^b	0.5^a	0.4^a	0.02	NS	NS	***	**	NS
Basophils, ×10^3 cells/µL	0.13	0.12	0.01	0.14	0.12	0.01	0.14^a	0.13^a	0.12^a	0.12^b	0.12^a	0.12^b	0.13^b	0.14^a	0.14^a	0.01	NS	NS	**	NS	NS
Red blood cell, ×10^6 cells/µL	10.2	9.9	0.29	9.8	10.3	0.29	10.5^a	9.9^b	9.9^b	9.8^b	10.0^b	10.1^b	10.1^b	10.7^a	10.7^a	0.21	NS	NS	***	NS	**
Hematocrit, %	33.6^a	30.7^b	0.63	31.2^a	33.2^b	0.62	33.6^a	31.9^b	32.0^b	31.4^b	32.0^b	32.2^b	32.2^b	35.0^b	34.6^a	0.48	**	*	***	NS	**
Hemoglobin, g/dL	11.5	11.4	0.24	11.1	11.7	0.24	11.9^a	11.3^b	11.3^b	11.2^b	11.4^b	11.5^b	11.4^b	12.2^b	12.2^a	0.18	NS	NS	***	NS	NS
Platelets, ×10^3 cells/µL	514.3	524.3	34.02	537.3	501.6	33.55	590.9^a	474.2^b	453.6^b	489.2^b	513.5^b	555.0^a	558.6^a	579.5^a	585.0^a	31.68	NS	NS	***	NS	NS

^a,b Within rows, Lsmeans differ from pre-castration baseline (−0.5 h) (P < 0.05). NS = not significant (P > 0.05). * P < 0.05, ** P < 0.01, *** P < 0.001.

N:L = neutrophil:lymphocyte.

SEM = pooled standard error.

Table 14. Effect of Burdizzo castration at 2.5- and 5.0-mo-old on changes on serum haptoglobin, non-esterified fatty acids (NEFA) and beta-hydroxybutyrate (BHB) concentrations in calves.

Variables	Age (A)			Treatment (Trt)			Time relative to castration (0 h) (T), h									P-values
	2.5- mo-old	5.0-mo-old	SEM	Control	Castrated	SEM	−0.5	0	0.5	3	5	9	24	48	SEM	A	Trt	T	I
Haptoglobin, mg/mL	0.09	0.08	0.011	0.08	0.08	0.011	0.09	0.08	0.08	0.08	0.08	0.08	0.08	0.09	0.011	NS	NS	NS	NS
NEFA, mmol/L	0.19	0.19	0.022	0.18	0.20	0.022	0.21^a	0.20^a	0.27^b	0.21^a	0.22^a	0.17^a	0.15^b	0.12^b	0.022	NS	NS	***	NS
BHB, mmol/L	0.12	0.11	0.013	0.12	0.11	0.013	0.12^a	0.12^a	0.13^a	0.13^a	0.13^a	0.11^a	0.11^a	0.09^b	0.011	NS	NS	***	NS

^a,b Within rows, Lsmeans differ from pre-castration baseline (P < 0.05). Pre-castration baseline is −0.5 h.

A = age, Trt = treatment, I = interactions, NS = not significant (P > 0.05). * P < 0.05, ** P < 0.01, *** P < 0.001.

SEM = pooled standard error.

Robertson IS, Kent JE, Molony V. 1994. Effect of different methods of castration on behaviour and plasma cortisol in calves of three ages. Res Vet Sci. 56:8–17.

 PubMed Web of Science ®Google Scholar

Molony V, Kent JE, Robertson IS. 1995. Assessment of acute and chronic pain after different methods of castration of calves. Appl Anim Behav Sci. 46:33–48.

 Web of Science ®Google Scholar

Thüer S, Mellema S, Doherr MG, Wechsle B, Nuss K, Steiner A. 2007. Effect of local anaesthesia on short- and long-term pain induced by two bloodless castration methods in calves. Vet J. 173:333–342.

 PubMed Web of Science ®Google Scholar

Boesch D, Steiner A, Gygax L, Stauffacher M. 2008. Burdizzo castration of calves less than 1-week old with and without local anaesthesia: short-term behavioural responses and plasma cortisol levels. Appl Anim Behav Sci. 114:330–345.

 Web of Science ®Google Scholar

Pieler D, Peinhopf W, Becher AC, Aurich JE, Rose-Meierhöfer S, Erber R, Möstl E, Aurich C. 2013. Physiological and behavioral stress parameters in calves in response to partial scrotal resection, orchidectomy, and Burdizzo castration. J Dairy Sci. 96:6378–6389.

 PubMed Web of Science ®Google Scholar

Lambertz C, Farke-Röver A, Moors E, Gauly M. 2014. Comparison of the effects of weaning and castration when conducted separately or in combination on the behaviour of crossbred beef cattle. Appl Anim Behav Sci. 161:28–33.

 Web of Science ®Google Scholar

Ting STL, Earley B, Crowe MA. 2003a. Effect of repeated ketoprofen administration during surgical castration of bulls on cortisol, immunological function, feed intake, growth, and behavior. J Anim Sci. 81:1253–1264.

 PubMed Web of Science ®Google Scholar