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Performance, milk fatty acid composition and behaviour of high‐yielding Holstein dairy cows given a limited grazing period
Author(s) -
Atkins Norton E.,
Cianchi Claire,
Rutter S. M.,
Williams Sarah J.,
Gauld Carrie,
Charlton Gemma L.,
Sinclair Liam A.
Publication year - 2020
Publication title -
grass and forage science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.716
H-Index - 56
eISSN - 1365-2494
pISSN - 0142-5242
DOI - 10.1111/gfs.12471
Subject(s) - milking , grazing , morning , zoology , total mixed ration , pasture , biology , dairy cattle , lactation , agronomy , ice calving , pregnancy , botany , genetics
The effects of a limited grazing period on the performance, behaviour and milk composition of high‐yielding dairy cows were examined. A total of 56 Holstein cows yielding 44.7 ± 0.42 kg/day were allocated to one of four treatments in one of two, 4‐week periods. Treatments were as follows: control (C)—cows housed and offered TMR ad libitum; early grazing (EG)—cows grazed for 6 hr after morning milking then housed; delayed grazing (DG)—cows returned to housing for 1 hr after morning milking followed by grazing for 6 hr, then housed; restricted TMR (RT)—cows grazed for 6 hr after morning milking, then housed and fed TMR at 75% of ad libitum. Intake of TMR was highest in cows receiving C, intermediate in EG and DG, and lowest in RT at 26.9, 23.6, 24.7 and 20.3 kg DM/day respectively. Pasture intake was similar in cows receiving EG or DG, but was higher in RT at 2.4, 2.0 and 3.5 kg DM/day respectively. Milk yield was similar between cows receiving C, EG or DG, but lowest in RT at 45.7, 44.2, 44.9 and 41.7 kg/cow, respectively, while milk fat content of C18:3 n‐3 was increased by grazing. Cows in C spent more than 55 min/day longer lying and had three additional lying bouts/day, while lying bouts were shorter than for cows receiving EG, RT or DG. It is concluded that high‐yielding cows can be grazed for 6 hr/day with little impact on performance, provided TMR is available ad libitum when housed.