Effect of PHYTASE 5000 (Granular) on the Performance and Nutrient Digestibility of Growing Finishing Pigs 1. Introduction Vegetal materials contain plenty of phytate phosphorus, the utilization rate of livestock and poultry to phosphorus in corn and soybean meal is 10% to 30%. Some studies show that phytase can not only improve the digestibility of phosphorus phytate for growing finishing pigs, but promote the absorption and utilization of calcium, protein, amino acid and minor elements. But the results varied much which was mainly due to the influence of the types of diets, trial animals, phytase activity and other factors. In order to ascertain the optimal dosage rate of phytase in swine diet, this experiment studied the effect of phytase at different dosgae levels on performance and nutrients digestibility of diet contained different DCP. 2. Materials and Methods 2.1 Trial animals and their grouping On hundred and twenty crossbreed growing pigs were distributed into 5 groups of 6 pigs per group. Four replicated pigs were assigned to receive one of 5 dietary treatments. The control: Normal DCP level Diet 1: 400U/kg phytase (80mg/kg) instead of 50% DCP Diet 2: 400U/kg phytase (80mg/kg) instead of 75% DCP Diet 3: 400U/kg phytase (80mg/kg) instead of 100% DCP Diet 4: 600U/kg phytase (120mg/kg) instead of 75% DCP 2.2 Phytase The phytase was Microtech 5000 Plus (granular) provided by Guangdong VTR Bio Tech Co., Ltd., the activity of which was 5000U/g. 2.3 Diet composition Diets were offered in pelleted form. The nutrient contents of different experimental diets were same except the phosphorus content. The composition showed as Table 1. Table 1. Ingredients and nutrient composition of experimental diets (%) Composition The control The control Diet 1 Diet 2 Diet 3 Maize 64.00 64.00 64.00 64.00 64.00 1
Soybean meal 21.70 21.70 21.70 21.70 21.70 Rape meal 3.00 3.00 3.00 3.00 3.00 Bran 8.00 8.00 8.00 8.00 8.00 Lysine 0.03 0.03 0.03 0.03 0.03 Salt 0.30 0.30 0.30 0.30 0.30 Premix 1.00 1.00 1.00 1.00 1.00 DCP 0.70 0.35 0.18 0.00 0.18 Stone meal 1.25 1.44 1.54 1.64 1.50 Phytase 0.00 0.008 0.008 0.008 0.012 Zeolite 0.00 0.17 0.25 0.32 0.24 Total 100.00 100.00 100.00 100.00 100.00 Calculated values: Crude protein 17.00 17.00 17.00 17.00 17.00 Digestable energy (kca/kg) 3.13 3.13 3.13 3.13 3.13 Ca 0.62 0.62 0.62 0.62 0.62 TP 0.52 0.52 0.44 0.41 0.44 2.4 Animals feeding management The animals were fed in the open piggeries, one replication (6 pigs) in one piggery. Water was provided by automatic watering trough, natural illumination. Routine immunity procedure was carried out. Fed twice per day (8:00 am, 4:00 pm). The detachment was executed at night, pre experiment for one week as adaptive period and then carried out the formal trial. 2.5 Trial parameters 2.5.1 Performance The feed consumptions for every replication were logged daily, and the pigs were weighted with empty stomach at the beginning and end of the experiment separately in order to work out the daily body weight gain and FCR for every replication. At the same time the health condition of the swine and death amount were logged on the basis of replication. 2.5.2 The digestive trial During the trial, we selected one boar from every replication with similar body weight to feed in single metabolic cages and then conducted a digestibility trial. There was a pretest for 5 days before collecting feces, and then serially collected feces for 72 hours using full feces collecting method. Feces kept at 18 promptly after collecting. The dry matter, phosphorus, calcium, crude ash, crude protein, amino acid and digestive energy were determined, and digestibility were calculated. 2
3. Results 3.1 Performance Effect of PHYTASE 5000 (Granular)on the performance of pigs showed in Table 2. As showed in Table 2, the effect of diet 1 gave the best result. Compared with the control, the daily body weight gain was improved by 15.6% (P>0.05), FCR was improved by 11.3% (P>0.05). The effect of diet 4 was also slightly better than the control. While the performance of diet 3 decreased to some degree. We knew from the gross profit brought by unit weight gain that diet 1 could bring the best economical efficiency to the farm, the next was diet 4. Table 2. Effect of PHYTASE 5000 (Granular) on daily weight gain Starting Average daily Gross profit / weight Treatments weight (kg) weight gain (g)* Feed intake (g) FCR gain ( /kg) # The control 35.25±4.71 649±65 ab 2239±207 3.46±0.23 100 Diet 1 34.17±5.72 750±49 a 2301±111 3.07±0.09 177 Diet 2 33.96±5.21 643±45 ab 2210±150 3.44±0.28 101 Diet 3 34.29±4.82 589±103 b 2036±270 3.48±0.27 90 Diet 4 35.76±7.44 654±88 ab 2136±210 3.30±0.49 126 *: P<0.05 #: Unit gain gross profit was calculated according to the market price in Oct. 2010. The price of Microtech 5000 Plus (Granular) was RMB100/kg and the price of live pigs was RMB6.8/kg. The data based on unit gain income minus feed cost, the control was assumed to be 100, without consideration of other cost. 3.2 Nutrient digestibility Table 3 indicated that the dry matter digestibility of diet 1 of was improved by 5.86% compared with the control, while little effect on the apparent digestibility of crude protein and energy. Phytase obviously improved the apparent digestibility of crude ash, calcium and phosphorus on pigs. Compared with the control, digestibility of crude ash, calcium and phosphorus in diet 1 was separately improved by 13.9% (P>0.05), 13.8% (P>0.05) and 20.1% (P>0.05). Phytase supplementation improved the phosphorus digestibility obviously. 3
Table 3. Effect of phytase on nutrient digestibility of pig Treatments Dry matter Crude protein Digestable energy Crude ash Calcium Phosphorus The control 63.64±2.58 86.92±1.78 87.41±1.77 54.97±8.09 63.55±8.17 50.60±4.78 Diet 1 67.37±3.35 86.50±1.35 88.16±1.36 62.59±5.39 72.30±0.53 60.77±5.54 Diet 2 60.21±6.55 84.84±2.80 86.40±2.13 52.88±14.67 61.83±15.19 55.20±11.93 Diet 3 61.59±1.60 86.70±1.08 87.60±0.65 56.66±5.80 66.85±6.49 58.25±5.44 Diet 4 65.51±9.61 87.50±3.61 88.81±2.72 61.38±15.00 70.27±11.00 66.83±9.77 Table 4 indicated that effect of phytase on apparent digestibility of amino acid of pigs. Phytase had no effect on apparent digestibility of amino acid. Table 4. Effect of phytase on apparent digestibility of amino acid of pigs The control Diet 1 Diet 2 Diet 3 Diet 4 Lysite 87.39±1.87 86.25±0.95 83.69±2.35 86.70±1.48 86.75±4.06 Methionine 88.38±1.87 86.45±1.24 84.50±2.50 85.95±1.75 85.53±4.82 Arginine 87.38±1.88 85.87±1.08 84.06±2.30 86.54±1.32 84.73±5.14 Histidine 89.28±1.36 87.53±1.30 85.94±2.16 87.53±1.09 85.91±4.69 Leucine 82.38±3.50 79.42±1.95 76.18±3.46 79.50±2.27 78.65±6.25 Isoleucine 76.00±3.63 72.91±2.78 68.03±5.21 72.93±2.61 72.71±8.30 Threonine 77.55±3.46 75.12±2.20 70.60±4.21 74.77±1.80 74.34±7.88 Phenylalanine 81.44±2.83 78.59±1.82 75.78±3.83 79.16±1.95 78.94±6.03 Valine 80.96±3.12 79.00±1.89 76.20±3.65 78.77±2.32 79.33±5.78 Cystine 92.71±1.06 92.72±0.51 91.35±1.70 92.21±0.62 92.41±1.96 Total essential amino acid 84.35±2.42 82.39±1.51 79.63±3.11 82.41±1.60 81.93±5.47 Aspartic acid 77.07±3.41 a 74.29±1.89 ab 68.55±4.63 b 74.02±2.69 ab 73.12±8.11ab Sernine 84.63±2.47 83.13±1.84 79.43±2.75 82.96±1.54 81.49±6.06 Glutamic acid* 85.72±2.74 a 84.64±1.31 ab 80.57±2.58 b 83.16±1.96 ab 82.26±5.30 ab Proline* 83.29±3.15 a 81.20±1.52 ab 77.49±3.03 b 79.80±2.02 ab 79.75±5.84 ab Glycin 69.75±4.76 66.77±3.05 61.10±5.47 64.28±3.79 66.50±9.16 Alanine 71.55±5.24 69.35±2.75 64.79±5.47 68.84±3.57 69.22±8.59 Tyrosine 86.13±1.98 84.08±1.93 81.20±2.95 83.65±1.69 83.42±5.04 Total nonessential amino acid 79.73±3.36 77.64±1.91 73.31±3.79 76.67±2.38 76.53±6.83 Total amino acid 82.04±2.89 80.01±1.71 76.47±3.44 79.54±1.99 79.24±6.15 4
4. Discussion A great deal of studies showed that addition of phytase into diet for monogastric animal could obviously improve the performance of animals. The main reason was that the untilization of phytate phosphorus had been improved. The result of this trial was consistent with the studies. In this trial, the performance improvement of growing pig mainly attributed to two factors, namely increase of feed intake or improvement of nutrient utilization. If phosphorus content was lower, feed intake of pig would be reduced. For instance, feed intake of pigs in diet 2 and diet 3 was reduced while. As diet 4 was higher, its effect on nutrient digestibility improvement was more obviouse than its negative influence on feed intake of pig, consequently, the average daily weight gain and FCR was improved better. Lei (1993) reported that when the dosage of phytase in the piglet diet increased to 1200U/kg, the most utilization of phytate phosphorus was attained, and then could replace for all supplementation of inorganic phosphorusus. Although the animal of this trial were growing pigs, its utilization of phytate phosphorus was higher than piglets. In Diet 2 and diet 3 the enzyme activity may still be not high enough, which led the performance was lower than the that of the control. Under the condition of the trial, addition of phytase could improve the digestibility of total phosphorous by 9% 24%. This was consistent with the result of this trial. In this trial, adding phytase improved the utilization of calcium. This was because the phytate molecules can chelate with bivalent and trivalent cations and form insolvable inorganic salts under neutral condition. While adding phytase can make phosphorus, calcium and other mineral to dissociate, and then can be utilized by animal. The appearance utilization of crude ash was also improved after the utilization of element of phosphorus and calcium was improved. 5. Conclusion 5.1 The improvement effect of diet 1 was the best on performance for growing finishing pigs. The average daily weight gain was increased by 15.6% and FCR was improved by 11.3%. The second was diet 4. 5.2 Phytase instead of DCP had little effect on digestibility of crude protein, energy and amino acid of pigs. 5.3 All phytase groups obviously improved digestibility of phosphorus. Diet 1 improved the digestibility of dry matter by 5.86, while improved digestibility of crude ash, calcium and phosphorus by 13.9%, 13.8% and 20.1% respectively. 5