Feeding Canola Meal to Beef Cattle
Due to the higher protein solubility of CM compared to SBM it is speculated that less protein will be available in the small intestine. Although, this may reduce ADG of young fast growing calves (Fiems et al. 1985 {1193}), performance results using CM as a protein supplement for calf starter and grower diets have been positive.
The digestibility of a calf starter containing 20%
RSM fed to sheep reduced (P < 0.05) organic matter (OM), CP,
CF and N-free extract digestibility compared to the starter containing
SBM. However, when the starter (15% CP) was fed to male calves
(49 kg) at a rate of 0, 10 or 20% RSM with high (12.90 g/kg) or
low (1.06 g/kg) GL, ADG were not different and averaged 0.80,
0.76 and 0.77 kg, respectively (Fiems et al. 1985 {1193}). Total
intakes were 267.5, 255.1, and 259.8 kg for SBM, 10% RSM (low
GL) and 20% RSM (low GL), respectively and were not different.
The substitution of SBM by RSM (12.90 g kg-1 GL) decreased
total starter intake (259.3 vs. 276.4 kg; P < 0.05) at 20%
inclusion in comparison to SBM indicating a significant effect
due to the GL content (Fiems et al. 1985 {1193}). The reduction
in starter intake was compensated by an increase in hay, resulting
in similar DM and energy intakes. This effect diminished over
time. When 20% RSM was fed, the rate of intake decreased (83.7%
for low GL and 76.6% for high GL in comparison to SBM), but not
at 10% RSM. Since neither GL nor the level of RSM affected ADG,
it was recommended that 20% of RSM (high or low GL) could be incorporated
in calf starters (Fiems et al. 1985 {1193}). In another study,
45d-old Holstein calves were fed CM, cottonseed meal (CSM) and
SBM as protein supplements in a starter ration containing 16%
CP (table 3). The ADG for the preweaning period was 0.61 kg and
for the postweaning period was 0.89 kg. There were no differences
between ADG of calves fed the different protein supplements for
either period or over the 16-wk trial. There were no treatment
effects on starter or milk consumption or plasma thryroxine concentration
(Claypool et al. 1985 {1181}). A study by Stedman and Hill (1987
{1139}) using 3-4 month old calves and lambs fed four varieties
of RSM (Brassica napus (Britain), CM (Canada), Loras and
Tower(Canada)) and SBM measured FI at 30, 60 minutes and 24 hrs.
Large differences in voluntary intake were demonstrated during
short periods after feeding, but only very small differences over
a 24-h period. Intakes of calves after 60 min of feeding were
higher for calves supplemented with SBM compared to RSM (138.7
mmol/g GL) but were not different than calves fed the low GL varieties,
Loras and Tower. Over a 24 hr period there were no differences
in calf FI between any varieties. Treatment of high GL RSM with
ammonia, steam + ammonia, steam and calcium hydroxide significantly
reduced the GL content of RSM. However, only steam alone significantly
increased calf FI at 60 min (Stedman and Hill 1987 {1139}).
| Table 3. Performance of 45 d old Holstein calves fed diets based on CM, CSM or SBMz | |||
|---|---|---|---|
| Canola meal | CSM | SBM | |
| Ingredients (% as fed) | |||
| Grain supplement | 80.5 | 84.5 | 87.8 |
| CM | 19.5 | - | - |
| CSM | - | 15.5 | - |
| SBM | - | - | 12.2 |
| Nutrients | |||
| CP (%) | 16.0 | 16.0 | 16.0 |
| TDN (%) | 70.0 | 70.0 | 70.0 |
| Performance | |||
| 7 wks preweaning gain kg/day | 0.58 | 0.62 | 0.62 |
| 8 wks postweaning gain kg/d | 0.89 | 0.87 | 0.91 |
| 16 wk gain, kg/d | 0.75 | 0.76 | 0.77 |
zClaypool et al. 1985 {1181}.
Canola meal was less digestible compared to SBM protein in 75 d-old Holstein male calves (68 kg). Canola meal (18% CP DM) had reduced apparent ileal and total tract digestibility of CP and all AA (except methionine) (Khorasani et al. 1990 {1010}; Khorasani et al. 1989 {1050}). Both SBM and CM diets supplied similar quantities of AA to the small intestine. However AA digestibility (except methionine) was greater in SBM than in CM fed calves. The total tract DM and CP digestibility (% of intake) of the canola based diet was 75.5 and 66.1% vs. 81.8 and 73.7% for the SBM based diet. The lower DM digestion observed in the large intestine in the CM fed calves was attributed to the high-fiber hull fraction of CM that is largely indigestible (Khorasani et al. 1990 {1010}; Khorasani et al. 1989 {1050}). The volume of pancreatic juice secreted and concentrations of protein, chymotrypsin and trypsin in pancreatic the juice were similar for both diets (Khorasani et al. 1990 {1010}; Khorasani et al. 1989 {1050}).
Products developed from CM have been well received by young calves. An evaporated whey-canola (EWC) meal feedstuff was fed to 35 d old Holstein calves in combination with either a grain-based starter ration or chopped hay. Bloat was a problem when the EWC was fed with a grain-based starter ration, but not with chopped hay. It was concluded from this study that EWC could be fed in combination with chopped hay at up to 90% of the total DM intake of young calves without causing acidosis or digestive upsets (Fisher and Buckley 1985 {1185}; Fisher 1983 {1242}).
Calf starter and grower diets containing CM are well accepted and performance of calves is equivalent to calves fed a SBM diet. Canola meal is less digestible than SBM, but not to the point it hinders performance. Methionine one of the limiting AA in young growing cattle, is more available from CM than SBM. Canola meal can be used as the sole protein supplement for calves with positive results.