diets during phase 1, but a common diet in phase 2. The four experimental diets in phase 1 were formulated to have: 1. 5% fish meal, 2.5% plasma, and no torula yeast; 2. 5% fish meal, 4.75% torula yeast, and no plasma; 3. 2.5% plasma, 6% torula yeast, and no fish meal and 4. 10.75% torula yeast, no fish meal, and no plasma. Results indicated that inclusion of torula yeast in diets did not affect growth performance (Table 1), diarrhoea incidence, or
Table 1- Growth performance of pigs fed the experimental diets, experiment 1.
Item
Phase 1, d 1 to 14 Initial BW, kg ADG, kg ADFI, kg G:F
Final BW, kg
Phase 2, d 15 to 28 ADG, kg ADFI, kg G:F
Final BW, kg
Overall, d 1 to 28 ADG, kg ADFI, kg G:F
No torula No yeast
6.71
0.097 0.176 0.542 8.07
0.348 0.536 0.648 12.59
0.217 0.349 0.621
No plasma 6.73 fish meal 6.70
Torula yeast
6.70 SEM
0.097 0.118 0.119 0.01 0.156 0.178 0.176 0.01 0.656 0.654 0.689 0.06 8.09
8.35 8.36
0.353 0.345 0.361 0.02 0.530 0.543 0.552 0.03 0.663 0.639 0.655 0.02 12.67
12.83 13.06 P-value
0.27 0.638 0.192 0.440 0.274
0.32 0.341
0.916 0.916 0.766
0.56 0.752
0.220 0.227 0.236 0.01 0.336 0.354 0.357 0.02 0.654 0.642 0.663 0.02
Table 2- Growth performance of pigs fed the experimental diets, experiment 2.
Torula yeast inclusion (%)1 Item 0/0
d 1 to 14 Initial BW, kg ADG, kg ADFI, kg G:F
Final BW, kg
d 15 to 28 ADG, kg ADFI, kg
d 1 to 28 ADG, kg ADFI, kg G:F
1Phase 1/Phase 2 18 ▶ WEANING | JUNE 2020 6.11
0.115 0.186 0.618 7.72
0.419 0.639a
G:F 0.657c Final BW, kg
13.59 0.267
0.410a 0.631
10/8 6.11 18/14 6.11 26/20 6.12 SEM
0.104 0.095 0.099 0.01 0.181 0.180 0.171 0.02 0.574 0.527 0.578 0.04 7.57
7.44
0.580ab 0.728a 13.36
7.51
0.547b 0.718ab 13.01
0.359b
0.415 0.423 0.395 0.03 0.622a 0.670bc 13.31
0.380ab P-value
0.24 0.434 0.326 0.541 0.346
0.40 0.342 0.671
0.04 0.034 0.02
0.026 0.69 0.264
0.257 0.259 0.246 0.02 0.398a
0.646 0.680 0.648 0.03 0.151
0.03 0.020 0.556
0.709 0.804 0.294
blood indicators for nutrient utilisation and inflammatory re- sponses in weanling pigs. In addition to digestible amino acids and P, torula yeast con- tains β-glucans and glycoproteins, which may have support- ed growth of pigs in diets without fish meal and plasma pro- tein, and it was concluded that at least 10.75% torula yeast may be included in diets for weanling pigs as replacement for fish meal and plasma protein. However, results of this experi- ment did not determine if greater inclusion rates may be used. Therefore, a follow-up experiment was conducted to test the hypothesis that inclusion of torula yeast above 10.75% in diets fed to pigs improves growth performance. A 2-phase feeding programme was used with d 1 to 14 as phase 1, and d 15 to 28 as phase 2. Phase 1 diets contained 0, 10, 18, or 26% torula yeast, whereas phase 2 diets contained 0, 8, 14, or 20% torula yeast. Torula yeast was included in diets at the expense of animal proteins and soybean meal. Results indicated that torula yeast can be included in phase 1 diets up to 26% without affecting growth performance (Table 2) or diarrhoea incidence of pigs. No differences were observed for final body weight (BW), average daily gain (ADG), or gain to feed ratio (G:F) among pigs fed the four experimental diets. During phase 2, a reduction in average daily feed intake (ADFI) was observed in pigs fed diets containing 20% torula yeast, but an improvement in G:F of pigs was observed if diets contained at least 14% torula yeast. It therefore appears that pigs digest and utilise nutrients more efficiently from diets containing torula yeast and it is possible that torula yeast exerts a positive effect on digestive function and nutrient digestibility of pigs, but data from this experiment were not sufficient to confirm this hypothesis. There were also positive changes in blood concentrations of albumin, total protein, and tumour necrosis factor-α of pigs fed diets containing torula yeast indicating that torula yeast may improve nutrient utilisation and inflammatory responses of weanling pigs. Globulin accounts for approximately 38% of the total plasma protein, and β-glucans from torula yeast may have increased globulin production resulting in a subsequent improvement in the immune function of pigs.
Positive effect of torula yeast Torula yeast contains highly digestible amino acids and can replace fish meal and plasma protein in diets for weanling pigs without affecting growth performance. However, feed efficiency of pigs may be increased if 14% torula yeast is in- cluded at the expense of animal proteins and soybean meal. This improvement in G:F of pigs is likely a result of an en- hanced digestive function and nutrient digestibility, which is supported by the positive effect of torula yeast on blood indi- cators for nutrient utilisation and inflammatory responses. However, additional research is needed to fully understand the mechanism for the improved G:F.
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40
