Theme 3-2: Livestock Production Systems--Poster Sessions
Description
The inclusion of herbage in the diet of medium yielding dairy cows offered a total mixed ration (TMR) may be beneficial. This study, which involved mid lactation dairy cows, examined the effect of partial replacement of a TMR with annual temperate pasture. Treatments were ad libitum TMR (TMR100), 75% ad libitum TMR + ryegrass (Lolium multiflorum ‘Maximus’) (TMR75), and 50% ad libitum TMR + ryegrass (TMR50). Twelve multiparous Holstein and F1 Jersey × Holstein cows were divided into six homogeneous groups, taking account of milk production (26.6 ± 4.5 kg/day), days in milk (128 ± 50) and body weight (546 ± 31 kg). Treatments were compared in a replicated 3×3 Latin square design, comprising three 21-day periods (measurements during final 5 days). Cows on TMR75 and TMR50 strip grazed between morning and afternoon milking (7 h/day), with a target pre- and post-grazing sward height of 24 and 12 cm, respectively. Herbage DM intake was estimated as the difference between pre- and post-grazing herbage mass. The TMR and herbage had a crude protein content of 150 and 303 g/kg DM, and a NDF content of 366 and 495 g/kg DM, respectively. Herbage DM intake increased from 4.8 kg/day in TMR75 to 6.7 kg/day on TMR50. Total DM intake decreased from 19.4 kg/day (TMR100), to 18.1 and 15.9 kg/day (TMR75 and TMR50, respectively). Milk production, milk fat and milk protein content were similar between treatments, averaging 25.6 kg/day, 44.6 g/kg and 33.7 g/kg, respectively. The net energy for lactation (NEL) supply was 113, 104 and 92% of NEL requirements, for cows receiving TMR100, TMR75 and TMR50, respectively. Ryegrass pastures were able to replace up to 50% of TMR offered to mid lactation dairy cows without any adverse effects on milk production and milk composition.
Included in
Annual Ryegrass Pasture for Dairy Cows Receiving Total Mixed Ration
The inclusion of herbage in the diet of medium yielding dairy cows offered a total mixed ration (TMR) may be beneficial. This study, which involved mid lactation dairy cows, examined the effect of partial replacement of a TMR with annual temperate pasture. Treatments were ad libitum TMR (TMR100), 75% ad libitum TMR + ryegrass (Lolium multiflorum ‘Maximus’) (TMR75), and 50% ad libitum TMR + ryegrass (TMR50). Twelve multiparous Holstein and F1 Jersey × Holstein cows were divided into six homogeneous groups, taking account of milk production (26.6 ± 4.5 kg/day), days in milk (128 ± 50) and body weight (546 ± 31 kg). Treatments were compared in a replicated 3×3 Latin square design, comprising three 21-day periods (measurements during final 5 days). Cows on TMR75 and TMR50 strip grazed between morning and afternoon milking (7 h/day), with a target pre- and post-grazing sward height of 24 and 12 cm, respectively. Herbage DM intake was estimated as the difference between pre- and post-grazing herbage mass. The TMR and herbage had a crude protein content of 150 and 303 g/kg DM, and a NDF content of 366 and 495 g/kg DM, respectively. Herbage DM intake increased from 4.8 kg/day in TMR75 to 6.7 kg/day on TMR50. Total DM intake decreased from 19.4 kg/day (TMR100), to 18.1 and 15.9 kg/day (TMR75 and TMR50, respectively). Milk production, milk fat and milk protein content were similar between treatments, averaging 25.6 kg/day, 44.6 g/kg and 33.7 g/kg, respectively. The net energy for lactation (NEL) supply was 113, 104 and 92% of NEL requirements, for cows receiving TMR100, TMR75 and TMR50, respectively. Ryegrass pastures were able to replace up to 50% of TMR offered to mid lactation dairy cows without any adverse effects on milk production and milk composition.
