Characterisation of the Repeat Breeding Syndrome in Swedish Dairy Cattle

Table 2 Descriptive statistics (frequencies (%), or medians with inter-quartile ranges within parenthesis) for cows classified as repeat breeder (RB+) and not repeat breeder (RB-)^a.

Variable	RB+ (n = 3,436)	RB- (n = 34,051)
Breed:
Swedish Red and White Cattle	1,973	18,976
Swedish Fresian Cattle	1,299	13,179
Other or cross-bred	164	1,896
FCM23^b	28.4 (24.7–32.8)	28.0 (24.1–32.2)
Lactation number:
1	1,299	12,420
2	892	9,300
3+	1,245	12,331
Parturition :
Normal or not known	3,211	32,357
Difficult or dystocia	159	1,065
Twins (normal parturition)	66	629
Stillbirth:
No	3,261	32,677
Yes	175	1374
Season at 1^st service:
January	439	3,293
February-March	666	6,263
April-September	701	9,282
October-December	1,630	15,213
RB in previous lactation:
No	2,916	28,802
Yes	194	1,255
not known	326	3,994
Days in milk at 1^st service	68 (58–83)	75 (63–93)
Veterinary treated^c cases of:
Clinical mastitis	5.5	7.1
Reproductive disorder	4.5	3.8
Digestive disorder	6.7	6.6
Other disorder	0.9	0.8

^a The sum of number of cows is less than the total (57,616) since only cows with at least one AI were at risk for RB and some had missing information on explanatory variables
^b Average of daily fat-corrected milk yield recorded at 2^nd and 3^rd official test-month after calving
^c Only treatments occurring before 1^st service

ISSN: 1751-0147