It was set up to ensure that use of the Economic Breeding Index (EBI) is breeding cows suitable for an Irish grass-based production system; facilitate the monitoring of difficult to measure traits; and enhance the future development of the EBI.
The herd was assembled during 2012, with the purchase of maiden heifers, in-calf heifers and heifer calves from commercial dairy herds around the country, and animals from within Teagasc dairy herds.
The herd is made up of heifers from two distinct genetic groups:
1. Elite (extremely high EBI) – sires represented include SOK, IRP, WHS, BHZ and WGM; average EBI of 2011 born heifers was €234.
2. Control (national average EBI) – sires represented include UPH, RXR, BYJ and WMZ; average EBI of 2011 born heifers was €116.
The Next Generation Herd is being evaluated across three seasonal grass-based management systems. The treatments are: control system with a target post-grazing residual of ~4.5cm, and a concentrate supplementation level of ~350kg/cow; high concentrate system with a similar postgrazing residual and a higher concentrate supplementation level of ~1,200kg/cow; and high stocking rate with a target post-grazing residual of ~3.5cm, with a concentrate supplementation level similar to the control system.
The mean calving date in year one (2013, all animals are in their first lactation) of the study was February 12. Early milk production data indicate differences in performance in line with that predicted by the breeding values.
The indications are that milk volume, lactose concentration and liveweight are similar for both genotypes, while both milk fat and protein concentrations are higher for the Elite animals, resulting in higher milk solids output.
The Elite animals are also exhibiting a definite tendency to maintain higher body condition score.
By Frank Buckley, Teagasc, AGRI Centre, Moorepark, Fermoy, Co Cork
Table 3: Performance of Elite and Control herds for week ending August 18 on the Control management system.
Mean calving date: 15/2 for Elite, 9/2 for Control
Cumulative milk yield: 3,052 for Elite, 3,192 for Control
% fat: 4.19 for Elite 3.93 for Control
% protein: 3.46 for Elite, 3.36 for Control
kg milk solids: 234 for for Elite, 234 for Control
Weight (kg): 482 for Elite, 503 for Control
Body condition score: 2.85 for Elite, 2.73 for Control