Effects of barley and triticale silage based diets and residual feed intake on performance, profitability, and predicted CO2e emission of backgrounding steers

Background Feed costs are the largest expense in commercial beef production. Increasing cattle (Bos taurus) feed efficiency should reduce feed costs and increase beef profitability. This study used data from two years of a backgrounding trial conducted in Lacombe, Alberta, Canada. The evaluation looked at economic and predicted CH4 emission impacts of diet quality and cattle efficiency type in backgrounding systems. The hypothesis was that diet quality from use of barley (Hordeum vulgare c.v. Canmore) or triticale (x Triticosecale c.v. Bunker) silage-based diets and cattle efficiency type would interact to affect profitability and CH4 emissions. Results The experimental design was a four (cattle efficiency type; defined by residual feed intake (RFI)) by two (barley or triticale silage-based rations) factorial treatment with two replicates (pen of eight steers)/treatment/year over two years. Year was a random blocking factor. Cattle weight, intake, and diet composition data were combined with market prices to assess profitability. Methane emissions data were predicted from observed performance using a nutrient requirement model. Effects of diet and cattle efficiency type on profitability and CO2e emissions were assessed using statistical and stochastic risk simulation. By supporting greater gain and feed efficiency, the barley silage diet provided higher net revenue (NR) and lower CO2e emission (P < 0.01 for both). The NR was affected by observed pen average RFI. Risk simulation showed preference for efficient steers and use of barley silage-based diets. Conclusions The profitability of beef backgrounding was affected by cattle efficiency type and diet quality with higher quality diets also lowering CO2e emission and little evidence of interaction between cattle efficiency type and diet quality. The difference in certainty equivalent (~$30/steer) of efficient steers on barley silage and inefficient steers on barley silage or efficient or inefficient steers on triticale silage supports a beef backgrounding producer focus on diet quality and cattle efficiency type. However, inefficient steers on barley silage still generated higher certainty equivalent per steer than efficient or inefficient steers on triticale silage. This study did not address potential agronomic differences, including yield, which could provide nuance to forage choice.