The 2016 Feeding the Genes study, conducted by Dr John Morton, for ADHIS, investigated interactions between sire genetics and feeding systems on:
- milk solids production;
- and the cow’s chance of lasting in the herd.
The milk production results were clear. The study found that in all feeding systems, the daughters of high index (BPI, HWI or TWI) sires produce more milk
solids than daughters of low index sires.
In terms of survival, the daughters of high index (BPI, HWI and TWI) sires last longer than daughters of low index sires in all pasture-based feeding systems.
The scale of effects of sire index vary by index and feeding system:
The HWI has larger effects on longevity than BPI or TWI.
In low bail feeding systems the daughters of high BPI and HWI sires last longer than daughters of low index sires.
In moderate to high bail feeding, partial mixed ration (PMR) and hybrid feeding systems, the daughters of high index (BPI, HWI and TWI) sires last longer.
In total mixed ration (TMR) systems the daughters of high HWI sires last longer.
The findings support the take-home message that herd managers should select high index sires whose ABVs are aligned with the breeding objectives for their
herd, regardless of their feeding system.