Determination of optimal protein level in exotic fattener pig’s diet bases on balancing some amino acids

tatistics Department USA, version 4.0. 9 2.3.5.3. Parameters measured in mass production trial Accumulative gain (kg/animal), FCR, economic efficiency, results were calculated similar to study 1. 2.3.6. Statistical analysis Statistic analysis was undertaken by statistic software STATGRAPH of Statistics Department USA, version 4.0. and MS Exel 2003. Data obtained from the results of experiments 1 and 2, Candidate have used combinatorial methods to rank as A, B, C, D to determine the percentage of dietary crude protein and amino acid levels difference to growth, feed efficiency, yield, meat quality and the environment. CHAPTER 3: RESULTS AND DISCUSSION 3.1. Effect of dietary protein and some essential animo acids level on commercial exotic pig production 3.1.1. Effect of dietary protein and some essential animo acids level on grow performance 3.1.1.1. Accummulative gain The commercial hybrid lines have a rapid growth potential, especially during growing period. The optimal protein level in the diets bases on balancing essential amino acids would adequate requirement of animal which on one hand, improves production efficiency from relying on the saving of protein source and on the other hand reduces surplus of N excretion in to environment. Results of observation on growth capacity of pig is illustrated in Table 3.1. We analysed the data in 3 directions as follows: Table 3.1. Accummulative growth of experimental pigs through periods(kg) (n=33) Catego ries 1a (18-16/ 11-9) 1b (18-16/ 10-8) 1c (18-16/ 9-7) 2a (17-15/ 11-9) 2b (17-15/ 10-8) 2c (17-15/ 9-7) 3a (16-14/ 11-9) 3b (16-14/ 10-8) 3c (16-14/ 9-7) Ex initiation 18.15 0.49 18.10 0.51 18.22 0.47 18.22 0.47 18.21 0.51 18.22 0.46 18.20 0.45 18.21 0.51 18.21 0.41 15 days 28.37 0.75 27.95 0.72 27.68 0.65 28.23 0.71 27.86 0.64 27.30 0.59 27.88 0.63 27.53 0.56 26.53 0.55 30 days 39.04 0.89 38.25 0.76 37.53 0.73 38.62 0.88 37.86 0.71 36.68 0.71 37.87 0.71 37.12 0.65 35.09 0.56 45 days 50.85 a 0.81 49.65 abc 1.05 48.46 bc 0.86 50.09 ab 0.61 48.87 abc 0.85 46.98 c 0.83 48.94 abc 0.82 47.71 c 0.83 44.63 d 0.70 Comparis on % 100 97.64 95.30 100 97.56 93.79 100 97.49 91.19 60 days 63.22 0.95 61.93 0.97 60.23 1.03 62.65 0.98 61.11 1.02 58.81 1.00 60.11 0.98 58.50 0.95 53.60 1.12 75 days 76.47 0.96 74.88 0.98 72.98 1.23 75.43 1.16 73.65 1.00 70.67 0.99 71.98 0.99 69.70 1.01 64.02 1.09 90 days 90.33 a 0.96 88.10 ab 1.00 86.12 b 1.02 88.76 ab 0.98 86.45 ab 1.01 82.95 c 1.02 85.06 b 1.01 81.87 c 1.12 75.86 d 1.25 Compar.% 100 97.53 95.34 100 97.40 93.45 100 96.25 89.18 Overall comp.(%) 100 97.53 95.34 98.26 95.71 91.83 94.17 90.63 83.98 a, b,c,d Identical subdescription letters in the same row is not significantly different (P > 0,05) 10 a. Effect of different dietary protein level bases on balancing the same essential amino acids in the diet on grow performance of commercial hybrids. Results in Table 3.1. have shown that, when decreased dietary protein level in the diet from 18 - 17 - 16% but remained high level of first 4 essential amino acids (equivalant to 11 gam lysine/1 kg feed, at unit 1a, 2a and 3a), then BW of pig tends to decrease. BW at 45 days of experiment is in experimental units order were 50.85 – 50.09 and 48.94 kg/pig, with a rate of decrease was 1.48% (unit 2a) andà 3.76% (unit 3a) compared to that of unit 1a; however, this different was not statistical significant (P>0,05). Decreased of BW of pig at finishing stage of fattening period (after 90 days) between units 2a and 3a in comparison to that of unit 1a was 1.74 - 5.83% respectively. This different was not significant when decreased 1% protein level, however, this different was significant (P<0,05) when decreased this level by 2 %. Thus, dietary protein level in the diet for commercial exotic hybrid could be reduced by 1% with balancing of essential amino acids which show no negative effect on grow performance of pig. There are also several research studies supported our results, Nguyễn Nghi et al. (1995). Regression equation was used in order to evaluate the correlation between those factors (dietary protein and amino acids in diet) on grow performance. The correlation coefficient of these factors for lysine at the level of 11g/kg feed during growing period was 0.16; at 10g/kg was 0.18; at 9 g/kg was 0.33. Similarly, that of the finishing stage of fattening period was 0.35; 0.38 and 0.53 for each lysine level was 9, 8 and 7 g/kg feed respectively. This results have proved our hypothesis that dietary protein level in the diet for commercial hybrid pig can be reduced but it’s necessary to balance the amino acids in the diet. Base on these results, it could be concluded that dietary protein level in the diet for commercial exotic hybrid could be 18-16% or 17-15% provided that the first 4 essential amino acids were balanced by lysine levels, which were 11- 9 and 10-8 gam/kg feed. This balanced diet showed no effect on grow performance of experimental pigs. b. Effect of amino acids reduction bases on retaining of dietary protein level in the diet. The trials were conducted with several diets with high level of dietary protein level (18 - 16%); average dietary protein level (17-15%) and low dietary protein level (16- 14%) (During growing period and fattening period) with decreased of essential amino acids level (The decreased equivalent to lysine level reduction from 11, 10 and 9 g/kg feed during growing period and that reduction from 9, 8 and 7 g/kg feed during fattening period). For the diets with similar high dietary protein level, when decreased essential amino acids (Experimental unit 1a, 1b and 1c), it showed tendency of BW decreased (50.85 - 49.65 - 48.46 kg/pig during 45 days of experiment; 90.33 - 88.10 - 86.12 kg/pig during 90 days of experiment in those experimental units 1a, 1b and 1c). in other words, the BW decreased by 2.36 - 4.70% during growing period and by 2.47 - 4.66% during fattening period. However, this decreased was not significant different when decreased amino acids based on lysine from 11 - 10 gam/kg feed (P>0.05); The significant difference in reduction of BW was seen when continue to decreased this level to a lower level (calculated base on lysine was 9 g/kg feed) (P<0.05). 11 For the diets with similar average dietary protein level, when decreased essential amino acids level (ex units 2a, 2b and 2c), it showed a tendency of decreased of BW in experimental pigs (50.09 - 48.87 - 46.98 kg/pig during 45 days of experiment; 88.76 - 86.45 - 82.95 kg/pig during 90 days of experiment in those experimental units 2a, 2b and 2c). The magnitude of BW decreased in comparison to that of pig fed with high dietary level diet was higher which was 2.44 - 6.21% during growing period and 2.60 - 6.55% during fattening period. Similar to that of high dietary protein level, the statistical analysis didn’t show the significance when decreased amino acids level base on lysine from 11 - 10 gam/kg feed (P>0.05); The significant difference in reduction of BW was seen when continue to decreased this level to a lower level (calculated base on lysine was 9 g/kg feed) (P<0.05). For the low dietary protein level, when decreased essential amino acids level (ex unit 3a, 3b and 3c), it showed the same trend of BW decreased and this decreased was seen more clearer than those of higher dietary protein levels (48.94 - 47.71 - 44.63 kg/pig during 45 days of experiment: 85.06 - 81.87 - 75.86 kg/pig during 90 days of experiment in those experimental units 3a, 3b and 3c). in other words, this decreased was 2.51 - 8.81% during growing period and 3.75 - 10.82% during fattening period. Similar to that of those in higher level of dietary protein fed pig, there was no significant different when decreased amino acids level base on lysine from 11 - 10 gam/kg feed (P>0.05); The significant difference in reduction of BW was seen when continue to decreased this level to a lower level (calculated base on lysine was 9 g/kg feed) (P<0.05). Thus, similar to decreased dietary protein level in the diet but with balanced essential amino acids, the decreased of essential amino acids level with protein level constant also had an effect on grow performance of pig. This effect was more significant than the decreased of dietary protein level but amino acids level kept similar. This results revealed the important role of essential amino acids in diet for commercial exotic hybrid pig. Research results from Vũ Thị Lan Phương et al. (2001) when studied effect of optimal lysine and energy ratio for growing and fattening Yorkshire revealed that with the different lysine level, it showed significant effect on growth rate of experimental pigs (8 - 16 weeks). Other results from Nguyễn Ngọc Hùng et al. (2000), British Animals and Meat Council (cited by Nguyễn Thị Thoa (2001), Guzik et al. (2005a)... also showed the similar effect of amino acids in diet on grow performance of pigs. We also used regression equation to estimate the correlation between amino acids levels in diets and animal’s growth. The correlation coefficient of this equation were 0.19; 0.28 and 0.37 during growing period and were 0.22; 0.31 and 0.50 during fattening period, It can be interpreted that the growth rate of pig is depended on amino acids level in the diet. When dietary protein level is decreased, this dependence is higher which illustrated by higher correlation coefficient. From that finding, it can be concluded that amino acids level in the diet base on lysine levels were 11- 9 gam or 10 - 8 g/kg feed for commercial hybrid pigs, any level lower than above recommendation would negatively affect animal performance. 12 Results of grow performance of experimental pigs are illustrated in Figures 3.1, 3.2 and 3.3. c. Effect of simultaneous decrease of dietary protein and essential amino acids levels in the diets on pig performance. Effect of simultaneous decrease dietary protein and essential amino acids levels in the diets on animal performance have seen in exp. units 1a, 2b and 3c (With protein and lysine levels were 18% - 11 gam/kg feed; 17% - 10gam/kg and 16% - 9 gam/kg feed, respectively). Pig BW in these exp. Units at the end of growing period were 50.85 - 48.87 - 44.63 kg/pig; The difference in comparison to unit 1a of units 2b and 3c were 3.89% - 12.24%, respectively. That at the end of experiment period were 90.33 - 86.45 - 75.86 kg/pig; the difference were 4.29% and 16.02% respectively. Statistical analysis showed no significant different on grow rate seen in 1a and 1b exp units when simultaneously decreased dietary and essential amino acids levels in the diets (P>0.05), however, there was significant different in grow rate of 1a and 1b when compare to that of 3c unit (P<0.05). The correlation equation on simultaneous decrease dietary and essential amino acids levels in the diets during growing period is Y13 = - 4.736 + 3.109 X13 ; R= 0.50, that of fattening period is Y14 = - 24.337 + 7.237 X14; R = 0.65. 3.1.1.2. Absolute body weight gain (BW) Results of absolute BW gains are showed in Table 3.4 and illustrated in figure 3.4. Table 3.4. Absolute body weight gain (gr/animal/day) Exp units Growing period Compare. (%) Fattening period So sánh (%) Overall Compare. (%) 1a 726.67 a ±31.54 100 877.33 a ±28.83 100 802.00 a ±38.73 100 1b 701.11 abc ±30.69 96.48 854.44ab±18.62 97.39 777.78ab±37.86 96.98 1c 672.00 bc ±29.31 92.48 836.89b±27.16 95.39 754.45a±40.97 94.07 2a 708.22 ab ±29.16 97.46 859.33ab±15.26 97.95 783.78a±36.86 97.73 2b 681.33 abc ±27.21 93.76 835.11 ab ±10.78 95.19 758.22 a ±36.79 94.54 2c 639.11 c ±24.47 87.95 799.33c±9.68 91.11 719.22a±37.71 89.68 3a 683.11 abc ±28.08 94.01 802.67b±18.34 91.49 742.89a±39.62 92.63 3b 655.55 c ±25.75 90.21 759.11c±6.80 86.53 707.33a±35.19 88.20 3c 587.11 d ±24.88 80.79 640.56 d ±39.42 73.01 640.56 b ±39.42 79.87 a, b,c,d Identical subdescription letters in the same row is not significantly different (P > 0,05) In general, the trend of absolute BW gain of exp. Pig was similar to accumulative BW gain. Pigs fed with high dietary protein level diets or average protein level diets at lysine level 11 - 9 g and 10 - 8 g/kg feed had higher BW gain. Growers fed with 18 - 16% dietary protein level diets and with 11- 9 g lysine /kg feed still gained up to 802.00 g/pig/day (unit 1a). Come in second was growers fed with diets contain 17 - 15% protein and 11 - 9 g lysine/kg feed, reached 783.78 g/pig/day (unit 2a); Come in third was growers fed with diets contain 18 - 16% protein and 10 - 8 g lysine/kg feed, reached 777.78 g/pig/day (unit 1b); come in fourth was growers fed with diets contain 17 - 15% protein and 10 - 8 g lysine/kg feed, reached 758.22 g/pig/day (2b). The supplement of CP needs to take into account the amount of supplement and the balance of amino acids which should meet pig requirement. The other authors have discovered that the supplementation of first limit and second limit 13 amino acids (lysine, threonine) brought the best results. Our results are supported by findings from Nguyễn Nghi et al. (1995); Van de ligt et al. (2002); Hoàng Nghĩa Duyệt et al. (2002); Phùng Thăng Long et al. (2004). Conclusion: With respect to grow performance of commercial exotic hybrid, the following diet formulas could be utilized effectively without interference on pig performance (Ranked in accordance to final BW at the end of experimental period): (1) Diet contains 18 - 16% protein and lysine base amino acids of 11 - 9g/kg feed; (2) Diet contains 17-15% protein and lysine base amino acids of 11 - 9 g/kg feed; (3) Diet contains 18-16 % protein and lysine base amino acids of 10 - 8g/kg feed; (4) Diet contains 17-15% protein and lysine base amino acids of 10 - 8g/kg feed; 3.1.2. Effect of dietary protein and amino acids level on feed utilization efficiency 3.1.2.1. Feed intake Results in Table 3.5 showed that, at both priod of rearing (growing and fattening periods), the daily feed intake of the fatteners decreased with the decrease of dietary protein and lysine based essential amino acids level (g/kg feed). Fatteners fed with diets contain the same dietary protein level of 18-16%; feed intake decreased at 1.906 - 1.891 - 1.883 kg (0.79 - 1.21%) when decrease essential amino acids level. The similarity also observed in fatteners feed diets with 17-15% protein, feed intake decreased by 1.31 - 2.57% (1.904 - 1.879 - 1.855 kg/pig/day) when amino acids level decreased. For those fed with diets with 16 - 14% protein, the decreased in feed intake was more obvious when amino acids level decreased, this decrease by 1.64 - 3.23% (1.890 - 1.859 - 1.829 kg/pig/day). 3.1.2.2. Feed conversion ratio (FCR) Results in Table 3.6 and Figure 3.5 showed that, the FCR was increased when dietary protein and amino acids levels in the diets decreased. When dietary protein level was decreased but amino acids level remained constant then FCR increased by 2.26 - 7.02% for the lysine level 11-9 g/kg feed); increased by 1.95 - 7.94% for the lysine level 10 - 8 g/kg feed and increased by 1.74 - 14.26% for the lysine level 9 - 7 g/kg feed. Statistical analysis showed no significant different when reduced lysine level at 1g/kg feed, but dietary protein level remained (P>0.05); however, the difference in FCR was significant when decrease 2 g lysine/kg feed (P<0.05). When protein and amino acids levels in the diets decreased simultaneously (from 18/16% - 17/15% - 16/14% for protein and from 11- 9; 10 - 8 và 9 - 7 gam/kg feed for lysine), the FCR increased compare to that of both above scenarios (2.350 - 2.452 - 2.820 in 1a, 2b and 3c). The increased of this FCR was very high(compare to that of 1a was 4.34% and 20.0%). Thus, in all three cases, the decrease of dietary protein level but not for the amino acids level has increase FCR value, however this increased was lesser than that of the scenario when both protein and amino acids level decreased simultaneously. For exotic commercial pigs, when feed intake decreased, then BW gain also decreased alongs with the increased of FCR. Our finding results are supported by Nguyễn Nghi et al. (1995);Van de ligt et al. (2002); Phùng Thăng Long et al. (2004); Phan Văn Hùng và Đặng Vũ Bình (2008) when reported on 3 exotic hybrids. 14 Table 3.6. Feed conversion ratio Exp. units categories 1a 1b 1c 2a 2b 2c 3a 3b 3c FCR of grower phase 1.783 1.822 1.858 1.831 1.868 1.935 1.882 1.925 2.065 comparison (%) 100 102.19 104.21 100 102.02 105.68 100 102.28 109.72 FCR of fattener phase 2.867 2.931 3.007 2.922 2.976 3.093 3.108 3.243 3.523 comparison (%) 100 102.23 104.88 100 101.85 105.85 100 104.34 113.35 Overall FCR 2.350 a 2.405 a 2.468 b 2.403 a 2.452 b 2.551 c 2.515 c 2.596 c 2.820 d Comparison (%) 100 102.34 105.02 100 102.04 106.16 100 103.22 112.13 Compare to 1a (%) 100 102.34 105.02 102.26 104.34 108.55 107.02 110.46 120.00 a, b,c,d Identical subdescription letters in the same row is not significantly different (P > 0,05) In order to have more precise assessement on effect of dietary protein and amino acids levels in the diet on FCR, the regression equation was used to determine the correlation between these factors. The results were shown in Table 3.7 and 3.8. Table 3.7 showed that the correlation between the decrease of dietary protein level and FCR during grower phase was negative correlation (-) which were - 0.65; - 0.65 and -0.88 for lysine levels 11 gam, 10 gam và 9 gam/ kg feed, respectively. During fattener phase this correlation coefficients were - 0.86; - 0.88 và - 0.92 for lysine levels 9; 8 và 7 gam/kg feed respectively. The negative correlation between these factors can be interpreted that decrease of protein level in the diet led to increase in FCR. The correlation coefficient of these factors also increased with the decrease of lysine level in the diets, it can be inferred from the results that when decrease dietary protein level with supplementation of essential amino acids to meet the requirement then the FCR would not significantly affected. 3.1.2.3. Energy / BW gain In addition to FCR parameter, we calso calculated energy and weight gain ratio. The results were showed in Table 3.9. Conclusion: When consider energy/weight gain ratio, the following diets showed the positive results(Ranked from the lowest to the highest) (1) Diet with 18 - 16% protein and lysine based 11 - 9g/kg feed (2.35 kg and 7,370 Kcal ME/kg BW gain) (2) Diet with 17-15% protein and lysine based 11 - 9 g/kg feed (2.403kg and 7,536.36 Kcal ME/kg BW gain) (3) Diet with 18-16 % protein and lysine based 10 - 8 g/kg feed (2.405 kg and 7,541.93 Kcal ME/ kg BW gain) (4) Diet with 17-15% protein and lysine based 10 - 8 g/kg feed (2.452 kg and 7,689.55 Kcal ME/ kg) . 3.1.2.4. Protein/BW gain 15 Results of protein and amino acids for each kg BW gain were showed in Table 3.10. Table 3.10 showed that: Protein for each kg weight gain was differed compare to that of FCR and energy for gain. The decrease of protein level, protein for each kg gain decreased for lysine based amino acids lysine 11 - 9 và 10 - 8 g/kg feed respectively; however, this phenomenon was not true when amino acids level decreased to 9 - 7g/kg feed. Therefore, protein for each kg gain depended on dietary protein and amino acids levels in the diet. The higher dietary protein level in the diet, the higher protein used for each kg gain. The lower amino acids level in the diet, the higher protein used for each kg gain, this even goes higher protein used for each kg gain if protein level is low. This can be concluded that, for commercial exotic hybrid, those produce higher percentage of lean meat, that require adequate provision of amino acids. If they are fed with high dietary protein level diet, there would be a surplus amount of unutilized nitrogen. In contrast, if they are fed with lower dietary protein level diet, there would be shortage of amino acids to meet the requirement, which lead to depressed in grow and increase in FCR. 3.1.2.5. Lysine / kg BW gain Lysine utilization for each kg gain is a detail for protein used for each kg gain since protein requirement in animal is specifically that requirement for amino acids. Our results were showed in Table 3.11. Table 3.11 showed that lysine for each kg gain was higher with decrease of protein level but amino acids level remained and that spend was lower when decrease amino acids level but protein level remained constant. The was no significance different in spending lysine for each kg when simultaneously decreased both protein and amino acids levels in the diet. This results showed that lysine spent for each kg gain was differed compare to that in protein used for each kg gain. The lower protein level, the lesser spent for each kg gain, however when lower this level to a certain low level, then this phenomenon was in vice versa. The decreased of amino acids level in the diet, the increased in protein spent for each kg gain. Whereas lysine spent increased with the decreased of protein level and this decreased when amino acids level in the diet dereased. This occurrence need to pay more attention from scientists when take into account the cost of production and subsequent, the price of the products. 3.1.2.6. Feed cost for each kg BW gain Feed cost/kg gain is the economic assessment tool to evaluate economic efficiency of animal production. Results of this finding were shown in Table 3.12 and were illustrated in Figure 3.6. The results showed that the decreased of dietary protein level but amino acids level constant, the increased feed cost for each kg gain. The decreased of amino acids level but protein leven constant, the decreased in feed cost for each kg gain at the first decreased, however, this increased when continue to decrease amino acids level. When simultaneously decreased protein and amino acids levels in the diet, feed cost for each kg gain was not increased when the change at 1% different, this increased when the changes were higher. 16 Table 3.12. Feed cost per 1 kg of BW gain Categories 1a (18-6/ 11-9) 1b (18-16/ 10-8) 1c (18-16/ 9-7) 2a (17-15/ 11-9) 2b (17-15/ 10-8) 2c (17-15/ 9-7) 3a (16-14/ 11-9) 3b (16-14/ 10-8) 3c (16-14/ 9-7) 1. Grower phase Feed cost/kg gain (đ) 8227.04 8105.45 8242.98 8552.73 8347.15 8463.07 8998.00 8738.96 9055.89 2. fattener phase Feed cost/kg gain (đ) 12,120.7 11,576.6 11,822.4 12,482.2 12,020.7 12,190.6 13,520.9 13,267.8 14,076.3 3. Overall Feed cost/kg gain (đ) 10,264.4 a 9,929.7 a 10,143.7 a 10,613.8 b 10,283.1 a 10,446.2 b 11,334.1 c 11,061.5 c 11,656.1 c Compare of similar Pr (%) 100 96.74 98.82 100 96.89 98.42 100 97.60 102.84 Overall comparison(%) 100 96.74 98.82 103.40 100.18 101.77 110.42 107.77 113.56 a, b,c,d Identical subdescription letters in the same row is not significantly different (P > 0,05) When protein level decreased, feed cost for each kg BW gain increased from 10,264.41đ - 10,613.77đ - 11,333.12đ (increased by 3.4 - 10.42% in comparison of 2a and 3a with 1a exp. units). Similarly, this cost increased from 9.929,66đ - 10.283,12đ - 11,061.53đ (increased by 3.55 - 11.39% in comparison of 2b and 3b with 1b exp. units); The increased from 10,143.67 - 10,446.23 - 11,656.09 đ (by 2.98 - 14.91% in comparison of 2c and 3c with 1c unit). There was no significant difference of the first pairs comparison (P>0.05), however, of the other pairs comparison, the difference was significant (P<0.05). The correlation between feed cost for each kg BW gain and dietary protein and amino acids levels in the diets also showed the same trend. It can be inferred that the changes of amino acids levels in the diets have significant effect on grow performance, FCR as well as economic efficieny of commercial pig production. The results also showed that, the decrease of dietary crude protein would save protein in the diet (Table 3.10), however, if this level decreased up to 2% CP/ kg feed (units 3a, lô 3b, 3c), then feed cost increased, thus it’s necessary to balance lysine, methionine and tryptophan according to animal’s requirement by synthesis animo acids, whereas the price of these amino acids are quite expensive. This is a limiting factor of actual production, it requires the improvement of synthesis amino acids production technology in order to archieve high economic efficiency of pig production using reduction of dietary protein level diets. More over, when dietary protein level decreased, although the first 4 essential amino acids are balanced, but there will be the gap of other essential amino acids which negatively affect animal performance, and increase FCR. 3.1.3. Meat yield and meat quality 3.1.3.1. Meat yield assessment In order to evaluate meat yield, pigs were dissected at 45 days (finishing of grower phase) and 90 days of trials (Finishing of fattener phase), results were shown in Table 3.15; Figure 3.7 and Table 3.16; Figure 3.8. 17 Table 3.15. Carcass quality at the end of grower phase (49-50kg) (n=3) ( X mX  ) Categ Exp. units Live weight (kg) Carcass (%) Lean meat (%) Back fat thickness (cm) Sirloin cross section (cm 2 ) 1a (18/11) 50.00± 0.29 68.10± 0.22 62.19 a ± 0.26 1.02± 0.03 31.00±1.16 1b(18/10) 50.67± 0.88 67.14± 0.62 62.31 a ± 0.09 1.02± 0.01 30.33± 0.88 1c(18/9) 49.57± 0.99 67.64± 0.38 61.14 ab ± 0.89 1.04±0.03 27.50±1.26 2a(17/11) 49.17± 0.44 66.32±0.92 62.15 a ±0.58 1.02±0.06 33.33±0.67 2b(17/10) 49.83± 0.93 67.72± 0.15 61.98 a ± 0.47 1.03±0.06 26.67± 2.40 2c(17/9) 49.23± 1.01 66.85± 0.62 61.31 ab ± 1.42 1.05± 0.02 26.67± 2.40 3a(16/11) 49.00± 0.5 67.84± 0.37 60.49 ab ± 0.66 1.02± 0.01 31.00± 0.58 3b(16/10) 49.23± 1.01 67.71± 0.39 59.65 b ± 0.24 1.03± 0.01 26.33±1.33 3c(16/9) 49.67±1.33 66.82± 0.69 58.89 b ± 0.41 1.04± 0.02 26±1.53 a, b,c,d Identical subdescription letters in the same colum is not significantly different (P > 0,05) Results of meat yield evaluation showed that there was no significant difference of carcass quality during grower and fattener phases when dietary protein and amino acids levels in the diet decreased. Carcass percentage at grower phase was 66.82 – 68.10%; that of the fattener phase was 74.03 – 74.83%. Table 3.16. Carcass quality of fattener at the end of fattening period (87-90kg) (n=3) ( X mX  ) and (See annex 3 ) Categ. Exp unit Live weight (kg) Carcass (%) Lean meat (%) Back fat thickness (cm) Sirloin cross section (cm 2 ) 1a (16/9) 89.67± 0.67 74.30± 0.58 58.16 a ± 0.18 2.03± 0.23 61.73± 4.80 1b (16/8) 88.50± 0.29 74.30± 0.40 58.12 a ± 0.35 2.11± 0.08 61.67± 2.17 1c (16/7) 88.00±0.57 74.03±0.12 57.62 a ±0.11 2.97±0.58 61.70±0.57 2a (15/9) 89.33± 0.88 74.27±0.23 58.14 a ±0.26 2.27±0.28 60.87±3.92 2b (15/8) 87.67± 0.88 74.13±0.14 57.87 a ±0.07 2.30±0.06 60.97±2.31 2c (15/7) 86.67± 2.31 74.07±0.32 57.47 ab ±0.43 2.22±0.04 57.53±4.97 3a (14/9) 89.00± 0.57 74.83±2.77 57.93 ab ±2.18 2.22± 0.06 60.56± 2.57 3b (14/8) 87.00±1.15 74.73±1.52 56.96 ab ±1.30 2.25±0.11 60.07±2.08 3c (14/7) 87.00±0.58 74.07±0.17 56.44 b ±0.21 2.37±0.09 57.30±4.21 a, b,c,d Identical subdescription letters in the same colum is not significantly different (P > 0.05) 18 Alongs with the decreased of lean meat percentage, fat in meat increased. This can be inferred that amino acids level in the diet has significant effect on lean meat percentage, especially this effect is more significant at lower level of amino acids and protein diet. Our finding is also supported by reports of Nguyen Thien et al. (2005), Nguyen Văn Thang and Đang Vu Binh (2006), Phan Văn Hung and Đang Vu Binh (2008), Vu Đinh Ton et al. (2008). 3.1.3.2. Chemical composition of pork To evaluate the influence of protein level with balanced of essential amino acids to chemical composition of meat, we analyzed the chemical composition of lean meat collected from hum and shoulders, results are presented in Table 3:17 to 3:18. Table 3.17. Chemical composition of pork in grower phase (% in fresh pork, n=3) ( X mX  )(see annex 3.12) exp DM CP C. lipid Ash Hams Shoulder Hams Shoulder Hams Shoulder Hams Shoulder 1a 23.49 23.52 20.86 18.97 1.12 3.25 1.19 1.04 1b 23.25 23.39 21.22 19.02 1.20 3.32 0.99 1.01 1c 23.37 23.49 21.13 19.21 1.14 3.14 1.03 1.09 2a 23.45 23.25 21.04 18.72 0.93 2.89 1.17 1.12 2b 23.21 23.87 21.15 18.54 1.07 3.42 1.11 1.06 2c 23.51 23.68 20.98 18.94 1.12 3.38 1.15 1.19 3a 23.49 23.99 21.47 20.01 0.89 2.47 1.17 1.14 3b 23.34 23.78 21.06 18.56 0.95 3.75 1.12 1.18 3c 23.27 23.83 21.00 18.86 1.03 3.68 1.13 1.21 Results analyzed the chemical composition of pig meat products of growth period (Table 3.18) showed no difference in the composition of dry matter, protein, fat and ash of lean hips and shoulders of pigs fed diets with protein and the proportion of different amino acids. This suggests that the reduction ratio of dietary protein that retains some of the essential amino acids did not significantly affect the chemical composition of lean meat. Bảng 3.18. Chemical composition of pork in fattener phase (% in fresh pork, n=3) ( X mX  )(see annex 3.12) exp DM CP C. lipid Ash Hams Shoulder Hams Shoulder Hams Shoulder Hams Shoulder 1a 26.37 26.27 22.45 21.91 2.51 3.06 1.24 1.07 1b 26.25 26.04 22.05 21.61 2.55 3.15 1.20 1.15 1c 26.08 25.89 21.69 21.35 2.59 3.27 1.25 1.10 2a 26.12 25.15 21.74 20.77 2.87 3.09 1.17 1.13 2b 26.49 25.31 22.49 20.84 2.81 3.22 1.12 1.08 2c 25.95 26.65 21.79 20.88 2.92 4.01 1.20 1.18 19 3a 26.28 26.95 22.01 22.00 2.96 3.66 1.21 1.12 3b 26.57 26.69 21.85 21.35 2.35 3.82 1.14 1.13 3c 26.06 25.88 21.50 20.77 3.03 3.91 1.12 1.15 For fattening period (Table 18.3), percentage of lean protein buttocks reached from 21.69 to 22.49% in lean shoulder is 20.77 to 22.0%. Lipid ratio was 2.51 to 2.96% of lean meat as a 3.06 to 4.01%. We have not seen any research published about how the chemical composition of pork when fed the lower protein diet supplemented with essential amino acids. Therefore, the results of our study is a scientific literature for references used in scientific research and training. 3.1.4. General summary of experiments on the effect of the protein and amino acids levels The percentage of dietary protein 18-16% and 17-15% with balanced of essential amino acid levels (by lysine is 11-9 and 10-8 g / kg feed) had similar effect on grow performance, feed intake and and feed cost / kg BW gain. However, these protein diets have lower levels (17-15%), protein / kg gain lower than that of high protein levels (18- 16%). No differences were seen in dissection results. However, the proportion of dietary protein and amino acid levels lower, the percentage of lean meat is declining markedly at the lowest protein and amino acids (16-14% protein and 9-7 g lysine / kg diet) while the rate increased fatty meats. No differences in chemical composition of pork when fed diets with protein and the proportion of different amino acids. Besides the results of research on the impact of the level of protein and amino acids in the diet on the growth, feed efficiency and meat yield and quality. In the farm industry, environmental pollution problems in the pig is now mostly due to the use of inappropriate diet and balanced nutrition leads to excretion of substances that the body can not use. Therefore, to assess the specific impact of dietary protein and amino acid levels to different environments, from which to draw the dietary proportion of protein and amino acid levels on the rational aspects of life growth, meat quality, economic efficiency and environmental impact, we conducted a second experiment 3.2. Results of study the relationship between the proportion of different protein with balanced of some essential amino acids in feed mixtures for elimination of nitrogen, sulfur in the urine and faeces Experiments conducted on gilt at growth stages. Results of monitoring of nitrogen, sulfur ingested and excreted in urine and faeces are presented in Table 3.19 and Figure 3.9; 3.10. Research results showed that nitrogen, sulfur emissions in the feces and urine were reduced under way to reduce the rate of protein and amino acid levels. For pigs fed diets with different protein ratio while maintaining the same level of four essential amino acids is the first release of nitrogen in dung and urine decreased substantially. At the amino acid lysine is 11g/kg by food, the amount of nitrogen excreted in feces (g / head / day) by way of reducing the rate of protein, decreased from 9,12 - 8.21 to 7.47 (corresponding lots 1a, 2a and 3a, a decline from 9.97 to 18.09% when compared lot 2a, 3a with 1a). Similarly, at the amino acid lysine is 10g/kg by food, the amount of nitrogen excreted in feces (g / head / day) 20 decreased from 8,31 - 6.90 to 5.92 (with lots of 1b, 2b and 3b, a decline from 16.67 to 28.76% when compared lot 2b, 3b with 1b) at the amino acid lysine by a 9 g / kg feed from 6,66 - 5.92 to 5.95 (with lots of 1c, 2c and 3c, the decrease 11.11 - 10.66% when compared lot 2c, 3c to 1c) the difference in the amount of nitrogen discharged in the middle of the diets is statistically significant (P <0.05) except at 9 g / kg feed. Table 3.19. Results of monitoring of nitrogen and sulfur emissions in the feces and urine of experimental pigs (n = 3) Categories 1a 1b 1c 2a 2b 2c 3a 3b 3c N intake (g/day) 53.72 ± 1.01 50.48 ± 1.27 45.38 ± 0.78 51.45 ± 0.91 45.87 ±0.94 39.62 ± 0.70 48.43 ± 1.83 39.80 ± 0.86 39.12 ± 0.79 S intake (g/day) 4.65 ± 0.36 4.16 ± 0.39 3.58 ± 0.08 4.63 ± 0.19 4.13 ± 0.53 3.48 ± 0.20 4.60 ± 0.43 4.12 ± 0.06 3.43 ± 0.06 Faecal Nexcretion (g/pig/day) 9.12 a ±0.82 8.31 ab ± 0.73 6.66 d ± 1.13 8.21 bc ± 0.52 6.90 c ± 0.47 5.92 e ± 1.66 7.47 bc ± 0.26 6.18 cd ± 1.45 5.95 e ± 0.45 Comparison (%) 100 91.12 73.03 100 83.97 72.12 100 82.81 79.69 Urinal N excretion (g/pig/day) 23.83 a ± 0.72 22.19 ab ± 3.54 19.08 d ± 3.02 22.48 b ± 1.42 18.80 c ± 3.52 15.74 de ± 0.42 20.41 cd ± 2.13 16.57 d ± 1.99 16.28 e ± 1.13 Comparison (%) 100 93.09 80.07 100 83.63 70.02 100 81.20 79.78 N accumulation in the body (g/pig/day) 20.77 a 19.98 b 19.64 b 20.76 a 20.17 a 17.96 c 20.55 a 17.05 c 16.89 c %N accumulation than N intake 38.66 39.58 43.28 40.35 43.97 45.33 42.43 42.84 43.18 Faecal Sexcretion (g/pig/day) 1.23 a ± 0.05 1.09 a ± 0.09 0.90 b ± 0.03 1.20 a ± 0.07 1.06 b ± 0.17 0.89 bc ± 0.10 1.19 a ± 0.07 1.04 b ± 0.08 0.92 c ± 0.07 Comparison (%) 100 88.89 73.44 100 88.86 74.37 100 87.64 77.53 Urinal Nexcretion (g/pig/day) 3.05 a ± 0.11 2.67 ab ± 0.50 2.30 c ± 0.26 3.04 a ± 0.19 2.70 b ± 0.31 2.25 c ± 0.26 3.00 ab ± 0.26 2.70 b ± 0.49 2.17 c ± 0.29 Comparison (%) 100 87.75 75.60 100 88.83 73.82 100 90.10 72.53 S accumulation in the body (g/pig/day) 0.37 b 0.40 a 0.38 b 0.39 ab 0.37 b 0.34 c 0.41 a 0.38 b 0.34 c % Cumulative S / S intake 7.96 9.85 10.61 8.42 8.96 9.77 8.91 9.22 9.91 a, b,c Identical subdescription letters in the same row is not significantly different (P > 0,05) For the same dietary protein level but have different levels of amino acids, nitrogen excreted in urine (g / head / day) also significantly reduced. The rate is 18% protein, nitrogen emissions are 23,83 - 22.19 to 19.08 g / head / day (with lots 1a, 1b and 1c; decrease from 6.91 to 19.33% Lot 1b and 1c when compared with 1a). Similarly, the percentage of protein is 17% 22,48 - 18.80 to 15.74 g / head / day (with lots of 2a, 2b and 2c and the decrease from 16.37 to 29.98% when compared Lot 2b with 2a and 2c) from 20,41 - 16.57 to 16.28 g / head / day (with lots 3a, 3b and 3c; decrease from 18.80 to 20.22% when compared with plots 3b and 3c 3a). The difference in the amount of nitrogen excreted in the urine of these blocks is statistically significant (P <0.05). Results calculated the correlation between the amount of nitrogen excreted in faeces and urine at the rate of protein in the diet are presented in Table 21 3.20. Correlation between the percentage of dietary protein with nitrogen excreted in faeces and urine is high, reaching from 0.70 to 0.92 (in distribution) and from 0.61 to 0.93 (in urine) demonstrate the relationship between two quantities is quite tight. This means the amount of nitrogen excreted in faeces and urine depends largely on the proportion of protein in the diet. This correlation bears (+) shows the rate of the higher protein in the diet, the more nitrogen emissions. The value of this coefficient is increased by reducing the amino acid lysine from 11 to 10 g / kg diet and then decreased when further down the food 9g/kg. This shows the amount of nitrogen excreted in urine and faeces is lower than in the diets and the rate of protein and amino acid levels low, while lower down, nitrogen emissions will be reduced. Similarly in sulfur emissions in the urine. At the amino acid lysine by 11 g / kg feed, as 3,05 - 3.04 to 3.0 g / head / day (with lots of 1a, 2a and 3a; decrease from 0.32 to 1.64% when compared lot 2a, 3a with 1a) at 10g/kg food are 2.67 - 2.70 to 2.70 (with lots of 1b, 2b and 3b) and at a food 9g/kg 2.30 - 2.25 to 2.17 (with lots of 1c, 2c and 3c). Results calculated the correlation between the amount of sulfur emitted by feces and urine and the percentage of protein in the diet showed that the value of the correlation is not high (from -0.03 to 0.20 for volume sulfur emissions in the stool; from - 0.04 to 0.43 for sulfur emissions in the urine, Table 3.22). This shows that sulfur emissions in the stool or urine less dependent on the rate of protein in the diet. But the correlation coefficient between the amount of sulfur emitted by feces and urine and amino acids in the dietary value of the correlation coefficient is very high (from 0.63 to 0.81 for sulfur emissions in distribution and from 0.81 to 0.84 for sulfur emissions in the urine; Table 3.23). This shows that sulfur emissions in the feces and urine depends on the level of dietary amino acids Thus, reducing protein in the diet and reduce the excretion of amino acids, the nitrogen, sulfur in the feces and urine were reduced, especially in the diet simultaneously reduce the rate of protein and amino acids reduces . This shows that the reduced rate of crude protein, just save the feed protein simultaneously reduces nitrogen and sulfur elements reduce environmental pollution. However, if you drop too low to reduce environmental pollution caused significant but lack the amino acids and affects the growth and economic efficiency of pigs. 3.3. General summary of the results of experiments determining the optimal protein and amino acids level Results of the impact of the protein level and different amino acids to the growth, feed efficiency, yield and meat quality and environmental impact are presented in Table 3.24. Table 3.24. Results graded influence of different protein and of amino acids levels on the growth, feed efficiency, productivity and environmental efficiency Lô Protein/ amino acids growth FCR Protein/gain Feed cost/gain Environmental effect Overall 1a 18-16/ 11-9 A A B A D B 1b 18-16/ 10-8 A A B A C B 1c 18-16/ 9-7 B B C A B B 2a 17-15/11-9 A A A B B A 2b 17-15/ 10-8 A B A A B A 22 2c 17-15/ 9-7 C C B B A C 3a 16-14/ 11-9 B C A C B C 3b 16-14/ 10-8 C C A C A C 3c 16-14/ 9-7 D D D D A D Note: in order from A-D, the same letter description diets have similar effect (P>0,05) the A graded diets are the best. In general, the proportion of dietary protein and amino acid levels after a positive impact on growth, feed efficiency and meat yield and quality and reduce environmental pollution are: Diets Grower phase Fettener phase protein (%) Lysine based amino acids (g/kg TA) Protein (%) Lysine based amino acids (g/kg TA) 2a 17.0 11.0 15.0 9.0 2b 17.0 10.0 15.0 8.0 The percentage of dietary protein and amino acids outside logical effects as analyzed above, there are important implications in the use of protein feed. At present rates of protein in feed pigs are very large fluctuations. The discount is mainly due to the advancement of biotechnology in the production of synthetic amino acids, are important factors leading to use them to produce and process food for pigs and poultry. We can use amino acids instead of soybeans to reduce total dietary protein. In the formula of our experiments, in experiment a (1a-2a-3a) (the lysine is 11gam/kg food) rose 0.10% lysine in the diet will save 3% soybean . In experiment b (1b-2b- 3b), and c (1c-2c-3c) are similar, while increasing 0.1% lysine would save 2.87% - 2.96% soybean . So, when you use a ton L-lysine HCl can be substituted for 30 tons of soybeans. Combined with the use of amino acids such as DL-methionine and L- threonine, we will save an extra soybean meal and fish meal. 3.4. Mass production trial Results of the above-mentioned studies were applied in mass production of exotic pigs: Diet formula 1(unit 2a): Each kg feed contains 3200 Kcal ME, 170 g protein, 11 g lysine, 10 g calcium and 8 gram photpho in the growing period and 3100 Kcal ME, 150 g protein, 9 grams of lysine, 8 g calcium and 6 gamphotpho in fattening period Diet formula 2 (unit 2b): Each kg feed contains 3200 Kcal ME, 170 g protein, 10 g lysine, 10 g calcium and 8 grams of phosphorus in the growing period and 3100 Kcal ME, 150 g protein, 8 grams of lysine, 6 grams of phosphorus in phase fattening. Observation results of cumulative growth of pigs showed in Table 3.25 and the absolute growth was in Table 3.26. Table 3.25. Cumulative growth of experimental pigs (kg/animal) ( X mX  ) Categories DietT 1 (17-15%/11- 8 g) Diet 2 (17-15%/10- 8 g) Control (19- 17%/11–8 g) Number of animal (pig) 100 100 100 Initiate BW (kg/pig) 18.79 ± 0.40 18.82 ± 0.39 18.79 ± 0.40 BW after 30 days 39.59 ± 0.44 39.69 ± 0.46 39.62 ± 0.39 BW after 60 days 62.33 ± 0.47 61.96 ± 0.47 62.16 ± 0.51 BW after 90 days 88.24 a ± 0.53 86.91 a ± 0.53 88.39 a ± 0.53 So sánh (%) 99.83 98.32 100 23 a, b,c,d Identical subdescription letters in the same row is not significantly different (P > 0,05) Results on the growth of experimental pigs showed no significant differences P> 0.05. For detail analysis, we also assess the economic efficiency which showed in Table 3.27. Table 3.27 shows FCR of experimental period was 2.64 (CT1), 2.68 (CT2) and 2.55 (control), or increased by 3.53 to 5.10%, compared to animals fed with CP’s feed. However, because out formulated diets have the optimal protein and amino acid levels, thus, cost of feed production is lower, saved from 10.68% - 12.44% feed cost / kg BW gain. Thus, applying the three formulas to produce feed mixtures for pigs has contributed to a remarkable cost savings for livestock production. Bảng 3.27. Feed utilization efficiency and feed cost for each BW gain of diet formulas for mass production of exotic hybrids Categories Unit Diet 1 Diet 2 Control diet 1.Total gain kg 6945 6809 6960 2.Total feed intake kg 18,333.74 18,247.05 17,747.24 3. FCR - 2.64 2.68 2.55 Comparison % 103.53 105.10 100.00 4. Cost per 1 kg feed in grower phase vnd 8,757.27 8,520.00 11,900.00 5. Cost per 1 kg feed in fattener phase đồng 8,168.88 7,859.73 8,500 6. Total feed intake in grower phase kg 6,372.00 6,255.00 6,291.00 7. Total feed intake in fattener phase kg 11,961.70 11,992.00 11,456.20 8. Total feed cost đồng 153,515,375.8 147,546,859.4 172,240,897.5 9. Feed cost/kg gain đồng 22,105.72 21,670.66 24,748.32 Comparison % 89.32 87.56 100 In addition, observed on the rate of growth, development and productivity of commercial pig farming, the examination on the content of some gases such as NH3, H2S is very important because these gases are toxic to environment and affect animal health. Results are shown in Table 3.28. Bảng 3.28. Gas emission in the barn (mg/m3) ( X mX  ) Diets Status of measurement NH3 (n = 3) H2S (n = 3) Diet 1 Before cleaning 0.28 a ± 0.006 0.045 a ± 0.003 After cleaning 0.22 b ± 0.009 0.038 b ± 0.001 Diet 2 Before cleaning 0.27 a ± 0.012 0.04 a ± 0.001 After cleaning 0.21 b ± 0.009 0.036 ab ± 0.002 Control Before cleaning 0.34 a ± 0.027 0.061 c ± 0.002 After cleaning 0.31 a ± 0.012 0.051 d ± 0.002 a, b,c,d Identical subdescription letters in the same row is not significantly different (P > 0,05) Note: TCVN 5938-2005 describes the clean air as: NH3 < 0,2 mg/m 3 ; H2S: < 0,042 mg/m 3 . Results of measuring the concentration of H2S and NH3 gases in the barn showed that the experimental diet formulations showed measurable levels of emissions below the control unit. NH3 and H2S concentrations compared with TCVN 24 closed to satisfactory, that of the control unit were still 1.70 times higher than the permitted standard (for NH3), 1.45 times (for H2S). This suggests that the decline in the rate of protein to balance the amino acids has contributed significantly to reduce air pollution in the barn. CONCLUSION AND RECOMMENDATION Conclusion: For 4 exotic breeds hybrid, an optimal protein level in the diet is 17-15%, with two levels of the amino acid base on lysine are 11- 9 and 10-8 g / kg feed for growing and fattening periods. Pigs fed these diets showed high efficiency on growth, feed utilization, yield, meat quality and pollution levels. Specifically: a) The lower dietary protein level diets (17 - 15% and 16 - 14%) with balanced a number of essential amino acids did not affect the growth of crossbred pigs (P> 0.05) at lysine levels of 11 and 10 g/kg feed respectively, but have significant effect at lysine levels of 9 g/kg feed (P <0.05). b) Feed intake and feed cost / kg BW gain tend to increase (from 2.26 to 20.0% for feed intake and 0.18 to 13.56% with feed cost for each kg gain) when used the lower dietary protein level diets. However, these differences are not statistically significant (P>0.05) when some essential amino acids base on lysine are balanced at 10 and 11 g / kg feed. c) Yield and chemical composition of pork did not differ when fed diets with lower protein percentage (17-15%) with balanced essential amino acids. However, when the level of protein in the diet continued to decrease (16-14%) with the amino acid base on lysine as low as (9-7 g / kg feed), the percentage of lean meat decreased (declined by 3.30% in the growing period and 2.95% in fattening period; P <0.05). d) Diet with low dietary protein and amino acids level had a positive impact in reducing the concentration of N and S in feces and urine (decrease from 31.68 to 33.95% of N and from 26.23 to 28.85 % of S in the urine; P<0.05), significantly contributing to reduce environmental pollution. e) Pigs foreign hybrid varieties grow 4 servings use reasonable rate is 17-15% protein, with two levels of the amino acid lysine by a 11-9 and 10-8 g / kg feed corresponds to the period the growth and fattening period, achieved good breeding results. Pigs grow quickly, similar to food is used in livestock units (951S, 952S company's shares, rates of protein 19% - 17%) and reduced feed cost / kg increase in weight by 10.68 to 12.44%, while significantly reducing emission levels of NH3 and H2S in the cages. Persisting problems: Within scope of our study, we were able to balance the 3 first essential amino acids only (lysine, threonine and methionine). Recommendations: Applications of 2a experimental unit’s diet (17% protein, 11 g lysine / kg feed in the growing period and 15% protein, 9 g lysine / kg feed in fattening priod) and 2b experimental unit’s diet (17% protein, 10 g lysine / kg feed in the growing period and 15% protein, 8 g lysine / kg feed in fattening period) for commercial exotic hybrid 25 production in Thai Nguyen and other localities to develop sustainable animal husbandry practice, improve economic efficiency and contribute to protect the environment.