Productive and economic evaluation of supplementation of Holstein-Brahman crossbred growing cows fed with sugar cane (Saccharum officinarum) in confinement conditions

To evaluate growth and economic benefit of 26 female cattle with 236.8 +/- 9.74 kilograms (kg) of body weight (BW) fed with sugar cane (SC) were assigned both yearling (n= 15; 166.8 +/- 12.6 kg BW) and heifers (n= 11; 306.7 +/- 14.8 kg BW) to two commercial supplements (S; 2 kg.animal(-1).d(-1)) for 70 days (d): S1 (percentages of crude protein and starch of 15.5 and 37.0) and S2 (15.8 and 29.1%). The animals were housed individually. Weekly BW and SC intake (SCI) were determined and average daily gain (ADG) was calculated. Body weight, ADG and SCI were analyzed with ANOVA under a completely randomized design corresponding to a 2 x 2 factorial arrangement (two supplements and two age groups) with repeated measures. The economic evaluation was performed by partial budget and gross margin (GM). Body weight showed Supplement x Time interaction (P= 0.02) with higher BW in S1 from d 7, and despite experiencing weight loss on 28 and 56 days, finished with BW greater than S2 (281.9 vs 271.1 kg) due to its higher ADG (0.56 vs 0.38 kg/d). Fresh matter and dry matter SCI were equals between treatments with averages of 19.25 and 4.67 kg.animal(-1).d(-1), respectively. The economic evaluation showed that it is not possible to replace S1 by S2, even if the latter was more affordable, a situation due to the lower animal performance and negative rate of return on costs (-100 % on average). For both supplements, GM per feeding is negative at a sale price of females for breeding showing economic infeasibility, situation surpassed if the sale price is of crossbred dairy females