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.