Animals with a negative NFI value consume less feed than expected based on their growth rate and body weight maintained.
A significant amount of new feed intake data in now analysed in the Angus BREEDPLAN analysis.
This is a direct result of the feed intake data being collected in the Angus Sire Benchmarking Project (ASBP), with direct feed intake data now available on 2,348 steers, representing 189 sires in Cohorts 1, 2, 3, 4 and 5 of the ASBP.
The feed intake data is collected at UNE’s Tullimba feedlot, Kingstown, NSW through the GrowSafe system
Feed intake and serial weight data are used to calculate net feed intake (NFI) values for each steer measured.
NFI is a measure of residual feed intake after adjustment for differences in average body weight maintained and growth rate through the test period.
Animals with a negative NFI value consume less feed than expected based on their growth rate and body weight maintained. While animals with positive NFI value consume more feed than expected for their growth performance and average body weight.
Whilst most steers had a net feed intake value close to zero (i.e. actual feed intake close to expectation) some steers consumed up to 4kg/day more than expected for their growth rate and body weight maintained, whilst other steers consumed up to 4kg/day more than expected.
Importantly, the NFI data collected through the ASBP is analysed in Angus BREEDPLAN to produce the Net Feed Intake – Feedlot Finishing EBV (NFI-F EBV).
This EBV is an estimate of genetic differences between animals in feed intake at a standard weight and rate of weight gain when animals are in a feedlot finishing phase. NFI-F EBVs are expressed as kilograms (kg) of feed intake per day. Lower, or more negative, NFI-F EBVs are more favourable.
For example, a bull with a NFI-F EBV of –0.6 kg/day would be expected to produce progeny that consume less feed per day than the progeny from a bull that has a NFI-F EBV of +0.8 kg/day (when the progeny are of similar weight, are growing at a similar rate, and are in a feedlot finishing phase).