Table 2.

Data collected on the risk factors of perinatal mortality in 1101 calves born from 11 Orkney beef herds during the spring 2016 calving season

Variable	Level	Total calves	Stillborn calves	Neonatal deaths	Perinatal loss (%)
Herd	A	61	0	1	1.6
	B	90	2	0	2.2
	C*	130	2	1	2.3
	D	109	2	1	2.8
	E	87	2	1	3.4
	F	100	4	0	4.0
	G	49	1	1	4.1
	H	115	4	2	5.2
	I	105	6	1	6.7
	J	126	7	2	7.1
	K†	129	13	3	12.4
Calf sex	Female	564	13	3	2.8
	Male	537	30	10	7.4
Plurality	Single	1017	32	11	4.2
	Twin	84	11	2	15.5
Dam BCS	<2.5	164	14	4	11.0
	2.5–3.5	677	21	6	4.0
	>3.5	28	0	0	0
	Not recorded	232	8	3	4.7
Breed of sire	Aberdeen Angus	342	14	6	6
	Simmental	203	8	2	5
	Charolais	191	4	1	3
	Shorthorn†	142	12	3	11
	Saler	100	1	1	2
	Limousin	98	3	0	3
	Stabiliser*	25	1	0	4
Month of birth	February	58	1	1	3.4
	March	282	9	1	3.5
	April	438	15	7	5
	May	284	16	4	7
	June	39	2	0	5.1
Day of the week	Monday–Friday	769	23	10	4.3
	Weekend	332	20	3	6.9
Time of day	00.00–05.59	149	4	2	4
	06.00–11.59	239	21	5	10.9
	12.00–17.59	213	8	5	6.1
	18.00–23.59	181	7	1	4.4
	Not recorded	319	3	0	0.9
Level of calving assistance	Unobserved	201	17	5	10.9
	Observed, unassisted	455	4	2	1.3
	Mild assistance	138	9	1	7.2
	Hard assistance‡	71	11	4	21.1
	Vet assistance‡	4	1	0	25
	Caesarean‡	9	1	1	22.2
	Not recorded	223	0	0	0

*100% of Stabiliser-bred calves were from herd C.

†85% of Shorthorn-bred calves were from herd K.

‡These categories were grouped for statistical analysis (see table 3).

BCS, body condition score.