An evaluation of over-wintering feeding strategies prior to finishing at pasture for cull dairy cows on live animal performance, carcass and meat quality characteristics.
Fifty-six spring calving Holstein-Friesian dairy cows (body weight=607 kg and body condition score=2.75), destined for culling, were randomly assigned to one of four experimental treatments. Cows were confirmed non-pregnant by rectal palpation. The experiment was split into two periods: over-wintering period (OWP) and spring finishing period (SFP). Animals were assigned to one of four treatments: a control group (C) was slaughtered after am milking on day 0; three dietary treatments, two of which were dried pre-experiment; ad libitum grass silage (GS+G); 75% grass silage and 25% straw (GS+S); and one with the extended lactation concept applied, cows were offered grass silage plus 6 kg concentrate DM/cow/day and milked twice daily (EXTLAC). EXTLAC cows were dried-off 1 week prior to turnout. The OWP lasted 84 days. Subsequent to the OWP cows were turned out to pasture (SFP). All cows were finished to a pre-defined carcass specification; >272 kg cold carcass weight, P+carcass conformation class and 3 carcass fat class. Over the entire experimental period, average daily gain (ADG) was lower (P<0.001) for the EXTLAC treatment compared with the two other dietary treatments. The GS+G treatment finished 33 and 38 days (P<0.001) earlier than the GS+S and EXTLAC treatments, respectively. Total feed utilized on a DM basis was 1.9, 2.0 and 2.5 tonnes/cow for the GS+G, GS+S and EXTLAC dietary treatments, respectively. All finishing treatments resulted in a significant improvement in carcass weight, as well as carcass quality traits, compared to the C group. A significant improvement occurred in muscle redness between the C group and treatments offered a finishing period prior to slaughter.
Minchin
W
W
Moorepark Dairy Production Research Centre, Teagasc, Moorepark, Fermoy, Co. Cork, Ireland.
Buckley
F
F
Kenny
D A
DA
Monahan
F J
FJ
Shalloo
L
L
O'Donovan
M
M
D000821:Animal Feed; D000818:Animals; D001835:Body Weight; D002102:Cadaver; D002417:Cattle; D003612:Dairying; D004041:Dietary Fats; D002149:Energy Intake; D005260:Female; D005524:Food Technology; D007774:Lactation; D008460:Meat / Q000592:standards*; D018482:Muscle, Skeletal / Q000737:chemistry; D006109:Poaceae; D012621:Seasons; D012820:Silage
D004041:Dietary Fats