This study evaluated the effect of milking frequency (MF; once a day (OAD) versus twice a day (TAD))
at two nutritional levels (NL) on hoof health, locomotion and lying behaviour of dairy cows. Cows
(n=72)were randomly assigned to one of four treatments from calving in a 2×2 factorial design for
an entire lactation: OAD or TAD milking at a high (30.9 kg DM/c/d) or low(18.8 kg DM/c/d) herbage
allowance NL. Hoof health (sole lesions, heel erosion, digital dermatitis and white line disease) and
locomotory ability (including overall locomotion, ab/adduction, tracking, speed, head carriage and
spine curvature scores) were assessed on 6 occasions between calving in the spring and housing
the following autumn. Udder firmness was recorded in the milking parlour prior to milking at
approximately 57, 93 and 132 days in milk (DIM). Standing/lying behaviour was recorded using
modified voltage dataloggers over 2×24 h periods at approximately 157 and 208 DIM. Cows milked
OAD had lower sole lesion (P<0.05) andwhite line disease (P<0.01) scores, but higher heel erosion
scores (P<0.05) than cows milked TAD. Therewas an interaction between time of examination and
MF (P<0.05) for locomotion scores; although in early lactation cows milked OAD had higher overall
locomotion scores than TAD cows, this was reversed later in lactation. OAD cows had higher ab/
adduction scores in early lactation (P<0.05).On the other hand, speed and head carriage scoreswere
all higher for TAD compared to OAD cows. High NL cows had higher overall ab/adduction (P<0.01)
scores, and at 57 DIM had higher udder tension scores than low NL cows (P<0.001).NeitherMF nor
NL had an effect on total lying times. However cows on the high NL and OAD treatments spent less
time standing after morning milking (P<0.05), and spent more time per hour lying between 0900
and 1200. CowsmilkedOADalso spentmore time than TADcows lying between 1530 and1830. High
abduction scores in the OAD cows in early lactation may be related to discomfort in the udder. In
general however, OAD milking resulted in improvements to hoof health and locomotion ability.
Moreover, cows milked OAD use the extra time at pasture in the afternoon to rest, an option that is
not available to TAD milked cows. Fewer disruptions to the diurnal pattern of OAD cows are an
indication of improved welfare.
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