Effects of Non-Starch Polysaccharide Complex Enzymes on Meat Quality in Broilers
Cheng Zhi-bin1, LIAO Qi-shun2, ZHANG Hong-bin3, wei Yu3, SU Zi-feng4*, LIU Shao-gui4
1.Animal Science and Technology College of Yunnan Agricultural University, Kunming 650201, China; 2. Yunnan Agricultural Vocational Technical College, Kunming 650031, China; 3. Yunnan Xi Ernan Feed Co., Ltd, Kunming 650224, China; 4. Department of Agriculture and Biological Science of Dali University, Dali 671003, China; 5. Yunnan Breeder Farm, Kunming 650212, China
Abstract [Objective] The study aimed to research the effect of several commercial NSP complex enzymes products on broiler meat quality, and provide scientific basis for feed enterprise and breeding farmers choosing NSP complex enzymes. [Method] Two hundred ROSS broilers at age of 21 days were designed to five treatment groups, including the positive and negative control treatments, and Group 1 to 3 with feed additive of the commercial non-starch polysaccharide complex enzymes each on base of the negative group diet. At 56 days of age, broilers were killed and meat quality was analyzed. [Result] The thigh meat color CIELAB a value for the negative control broilers was lower (P < 0.05) than those of the positive control and Group 1. The drip loss of breast meat for Group 1 was the lowest, and the drip loss of thigh meat for the negative control was the highest among all treatments. The shear force for the negative control and Group 3 were higher than those of other three groups. There were no differences (P > 0.05) on the contents of chemical components, crude moisture, crude protein, crude fat, crude ash, and inosine acid for breast and thigh meat among all treatments. [Conclusion] NSP complex enzymes with complete enzyme categories and high enzyme activity can improve meat quality in broilers.
Key words Non-starch polysaccharide complex enzymes; Broiler; Meat quality
The aim of modern animal husbandry is efficiently transforming low-nutritional food crops and its by-products as livestock feed into high-nutritional and safe livestock food with high quality for human consumption[1]. Therefore, good meat quality is an important productive performance and economic benefits indicator of modern livestock and poultry breeding[1-2]. Because of the growing shortage and price rising of conventional feed grain and raw materials in both domestic and abroad currently[3], in order to make full advantage of wheat bran, wheat middling and miscellaneous meal, feed and breeding enterprises often use single or complex NSP enzymes preparation during the actual production of broilers feed. This will not only low the feed cost efficiently, but also be one of the effective technical ways of solving “human fighting for food against livestock” problem and easing breeding environment pollution[4-6]. Many researches have proved that single and complex NSP enzymes preparation have positive effect on broilers’ growth performance[6-9]. However, regarding NSP enzymes preparation, especially complex ones’ effect on broiler meat quality as an important productive performance indicator, there are few reports in current domestic. Therefore, the experiment mainly compares and researches the effect of several commercial NSP complex enzymes preparation on broiler meat quality, and provides scientific basis for feed enterprise and breeding farmers choosing NSP complex enzymes.
1. Materials and Methods
1.1 NSP Complex enzymes products For the NSP complex enzymes products existing in current market, the enzyme category and activity are diversified. Normally, the recommended adding dosage is divided into “Low, Medium, High” in order to meet different customer’s actual needs. The experiments follow actual production situation and choose 3 treatments, group 1 to 3 with NSP complex enzyme additive doses 0.15, 0.5, 1 kg/T(Complete Ration) respectively. In order to illustrate the experimental results fully, the single NSP enzyme’s activity of the 3 selected enzymes products is tested in realtime, Enzyme product #1 (Reference: AKT-S), Enzyme product#2 (Reference: 8411B), Enzyme product #3 (Reference: SSF) , please refer to Table 1.
Table 1. The analyzed enzyme activities of the commercial NSP complex enzyme products U/g
|
NSP enzyme 1
|
NSP enzyme 2
|
NSP enzyme 3
|
Xylanase
|
2645
|
1198
|
3109
|
Glucanase
|
102
|
154
|
88
|
Cellulase
|
13855
|
21205
|
17455
|
Pectinglycosidase
|
5037
|
——
|
3437
|
Mannanase
|
532
|
——
|
——
|
“——” no data.
1.2 Experimental Animals Two hundred 21-days ROSS broilers were divided into 5 treatment groups in this experiment, including the positive and negative control group, and treatment group 1-3 with additive of NSP complex enzyme product 1-3 respectively on the basis of negative control group’s ration. For the experimental treatment groups and enzyme’s dose, please refer to Table 2. The positive and negative control groups have the same nutritional levels for the ration, but with different feed materials. Compared with the positive control, the negative one chose a certain portion of non-conventional feed materials (See Table 3). Each treatment group has half male and half female, total 40 broilers. The experiments were carried out in the test chicken farm of Yunnan Agricultural University. Testing period is from broilers aged at 28 days to 56 days.
Table 2 Experimental treatment groups, NSP enzyme recommended dose, and the calculated NSP enzyme activities
|
|
Positive control
|
Negative control
|
Negative+NSP enzyme 1
|
Negative+NSP enzyme 2
|
Negative+NSP enzyme 3
|
NSP enzyme recommended dose//kg/T
|
|
——
|
——
|
1.00
|
0.50
|
0.15
|
Calculated NSP enzyme activities in diets//U/T
|
Xylanase
|
——
|
——
|
2.64×106
|
0.60×106
|
0.47×106
|
Glucanase
|
——
|
——
|
1.02×105
|
0.77×105
|
0.13×105
|
Cellulase
|
——
|
——
|
1.38×107
|
1.06×107
|
0.26×107
|
Pectinglycosidase
|
——
|
——
|
5.04×106
|
——
|
0.51×106
|
Mannanase
|
——
|
——
|
5.32×105
|
——
|
——
|
1.3 Experimental Ration The basic ration of broilers with age 4-6 weeks and 7-8 weeks was made up, with reference to the Ministry of Agriculture’s standards《Feeding Standards of Chicken (2004) 》and the actual breeding situation of Yunnan province. During each feeding phase, the positive control ration was designed as conventional formula style “corn–soybean meal” while negative control used a certain portion of non-conventional feed materials on the basis of “corn– soybean meal”ration, like wheat bran, wheat middling and DDGS, which represent a proportion of 9% for broilers with age 4-6 weeks and 15% for aged at 7-8 weeks. The ration of treatment group 1-3 was added commercial products 1-3 of NSP complex enzyme respectively (See Table 2). All the ration for experiments was made into pellet feed under the low temperature of 65℃.
Table 3. Composition of the fed diets and nutrient levels
|
|
4-6 weeks
|
7-8 weeks
|
Positive control
|
Negative control
|
Positive control
|
Negative control
|
Ingredient //kg/T
|
|
649.5
|
570.0
|
698.0
|
568.0
|
Soybean meal
|
194.0
|
170.8
|
150.4
|
106.8
|
Expanded soybean
|
60.0
|
60.0
|
60.0
|
65.0
|
Fish meal
|
10.0
|
10.0
|
——
|
——
|
Wheat bran
|
——
|
30.0
|
——
|
50.0
|
Wheat middling and red dog
|
——
|
30.0
|
——
|
50.0
|
Corn gluten meal
|
35.0
|
35.0
|
40.0
|
40.0
|
DDGS
|
——
|
30.0
|
——
|
50.0
|
Choline chloride
|
1.0
|
1.0
|
1.0
|
1.0
|
Limestone
|
13.0
|
14.0
|
12.0
|
13.5
|
Dicalcium phosphate
|
13.3
|
12.0
|
13.0
|
10.5
|
Lys-HCl
|
1.0
|
1.4
|
1.2
|
2.0
|
Soybean oil
|
11.0
|
23.6
|
12.2
|
31.0
|
Salt
|
2.2
|
2.2
|
2.2
|
2.2
|
Premix
|
10.0
|
10.0
|
10.0
|
10.0
|
Total
|
1000.0
|
1000.0
|
1000.0
|
1000.0
|
Calculated nutrient levels //%
|
ME (Kcal/kg)
|
3000
|
3000
|
3050
|
3050
|
CP
|
19.00
|
19.00
|
17.00
|
17.00
|
Ca
|
0.90
|
0.90
|
0.90
|
0.90
|
TP
|
0.65
|
0.65
|
0.65
|
0.65
|
Lys
|
1.00
|
1.00
|
0.87
|
0.87
|
Met
|
0.30
|
0.30
|
0.30
|
0.30
|
The premix provided per kilogram of diet: VA 8500 IU; VD3 800 IU; VE 25 IU; VK 1.2 mg; VB1 2.0 mg; VB2 5.0 mg; VB6 2.0 mg; Folic acid 0.8 mg; Nicotinic acid 25 mg; D-Pantothenic acid 13.2 mg; Biotin 0.15 mg; Se 0.30 mg; I 0.35 mg; Cu 8 mg; Mn 100 mg; Fe 80 mg; Zn 75 mg. The diets of Group 3 to 5 were added with the commercial NSP complex enzyme products.
1.4 Feeding Management Natural light was supplemented with artificial light. Broilers can look for food and water freely. Conventional management and routine immunity were adopted. Special person took charge of feeding experiments in order to guarantee broilers’ health.
1.5 Measuring Index Choose 20 broilers (half male and half female) randomly from each treatment group when broilers grow to 56 days. Take the samples of breast and thigh muscle, remove the fat in surface layer and fascia, and then measure the below meat quality index.
1.5.1 Physical Characteristic analysis. Measure the main meat quality physical characteristic index, like PH value, color, drip loss, shear force of breast and thigh muscle meat 24 hours later after butchering. The specific methods have referred to the reports from Cheng Zhi-bin and others. PH value was tested by waterproof portable Acidity meter # HANNA-HI9025 (HANNA Instrument, Italy). CIELAB L (Lightness), a(Red value), b (Bellow value) and meat color value[11] were tested by brand Meinengda Color Difference Meter # CR-400 (Minolta-CR400, KONICA MINOLTA SENSING INC, Osaka, Japan). Shear force was tested by Tenderness meter # C-LM.
1.5.2 Measuring of Chemical Ingredients. Take 3 samples of 1-2 g fresh breast and thigh muscle meat right after butchering and measure crude moisture GB/T 5009.3-2003)and crude protein(GB/T 5009.5-2003). Then Air-dry the rest samples and measure the crude fat (GB/T 5009.6-2003 and crude ash(GB/T 5009.4-2003)[10]. Inosine acid content was tested by high-effective Liquid Chromatography. Samples’ pretreatment and chromatographic conditions have referred to the reports from Huang Tao and others[12].
1.6 Statistical analysis SAS software did multiple comparison among all the treatment groups. T-test was adopted for each measurement value’s comparison of breast and thigh muscle, Significance P< 0.05.
2. Results
2.1 NSP complex enzyme’s effect on physical properties of broiler meat From Table 4 we can see that thigh muscle meat color A value (P<0.05) is less than the one of positive control and treatment group 1. Among all the treatment groups, the breast muscle meat of group 1 has the lowest drip lost (P<0.05) while the thigh muscle meat of negative control have the highest drip lost (P<0.05). The thigh muscle meat’s shear force of negative control and group 3 are much bigger than the rest 3 groups. Moreover, the comparison of breast and thigh muscle meat quality shows that for all the treatment groups, broiler meat color L value, a value and shear force of thigh muscle are dramatically bigger than the ones of breast muscle (P<0.05). Breast muscle meat’s drip loss of positive and negative control, group 3 is higher than thigh muscle meat’s.
Table 4. Effects of NSP complex enzymes on physical properties of broiler meat quality
Physical properties
|
Positive
|
Negative
|
Treatment 1
|
Treatment 2
|
Treatment 3
|
pH value
|
Breast
|
5.72±0.11
|
5.80±0.13
|
5.76±0.13
|
5.71±0.10
|
5.75±0.12
|
Thigh
|
5.75±0.12
|
5.73±0.10
|
5.71±0.11
|
5.78±0.14
|
5.69±0.09
|
Meat color L value
|
Breast
|
52.46±1.83 B
|
51.68±1.71 B
|
52.57±1.94 B
|
51.38±1.90 B
|
51.62±1.75B
|
Thigh
|
54.75±1.90 A
|
54.17±1.84 A
|
55.60±1.81 A
|
54.81±1.75 A
|
53.96±1.81A
|
Meat color a value
|
Breast
|
5.58±0.20 B
|
5.41±0.19 B
|
5.70±0.24 B
|
5.61±0.21 B
|
5.52±0.22 B
|
Thigh
|
7.05±0.23a A
|
6.70±0.24 b A
|
7.18±0.28a A
|
6.92±0.25abA
|
6.84±0.24ab A
|
Meat color b value
|
Breast
|
13.27±0.71
|
13.54±0.80 B
|
13.16±0.87 B
|
13.32±0.74 B
|
13.21±0.82 B
|
Thigh
|
13.92±0.75
|
14.88±0.84 A
|
15.03±0.81 A
|
14.96±0.72 A
|
14.75±0.90 A
|
Drip loss //%
|
Breast
|
2.63±0.20a A
|
2.85±0.25 a A
|
2.41±0.21 b
|
2.58±0.24 ab
|
2.76±0.24a A
|
Thigh
|
2.39±0.18b B
|
2.60±0.22 a B
|
2.30±0.19 b
|
2.37±0.20 b
|
2.35±0.21b B
|
Shear force //N
|
Breast
|
15.61±1.95 B
|
17.56±2.01 B
|
15.17±1.88 B
|
15.52±1.76 B
|
17.43±2.06 B
|
Thigh
|
18.95±2.12 b A
|
21.41±2.16 a A
|
19.04±2.07 b A
|
19.16±1.90 b A
|
21.07±2.25 a A
|
ab Least square means without a common superscript letter differ (P< 0.05) within a row;AB Least square means without a common superscript letter differ (P< 0.05) within a list.
2.2 NSP complex enzyme’s effect on chemical ingredient of broiler meat The difference of nutritional chemical ingredients index, crude moisture, crude protein, crude fat and crude ash among all the treatment groups is little (P>0.05). The crude protein content of breast muscle meat among all treatment groups is much higher than thigh muscle meat’s (P<0.05) while crude fat content of breast muscle meat is much lower than thigh muscle meat’s. There is no significant difference of inosine acid content for all treatment groups’ broilers.
Table 5. Effects of NSP complex enzymes on chemical components of broiler meat quality
Chemical components
|
Positive
|
Negative
|
Treatment 1
|
Treatment 2
|
Treatment 3
|
Crude moisture //%
|
|
73.70±2.43
|
73.81±2.75
|
73.73±2.46
|
73.69±2.62
|
73.78±2.27
|
Thigh
|
72.26±2.61
|
72.54±2.37
|
72.18±2.23
|
72.25±2.36
|
72.43±2.40
|
Crude protein //%
|
Breast
|
23.49±1.40A
|
23.38±1.32A
|
23.32±1.35A
|
23.47±1.29A
|
23.40±1.34A
|
Thigh
|
19.57±1.25B
|
19.73±1.30B
|
19.46±1.23B
|
19.78±1.21B
|
19.66±1.27B
|
Crude fat//%
|
Breast
|
1.37±0.13B
|
1.34±0.14B
|
1.45±0.16B
|
1.38±0.15B
|
1.32±0.13B
|
Thigh
|
6.69±0.62A
|
6.24±0.67A
|
6.88±0.71A
|
6.53±0.73A
|
6.47±0.68A
|
Crude ash //%
|
Breast
|
1.08±0.05
|
1.10±0.05
|
1.12±0.06
|
1.09±0.06
|
1.11±0.06
|
Thigh
|
1.11±0.06
|
1.14±0.06
|
1.09±0.05
|
1.11±0.06
|
1.08±0.05
|
IMP //mg/g
|
Breast
|
2.72±0.49
|
2.64±0.45
|
2.95±0.47
|
2.83±0.46
|
2.74±0.45
|
Thigh
|
3.07±0.52
|
2.76±0.47
|
3.12±0.53
|
2.94±0.50
|
2.85±0.51
|
AB Least square means without a common superscript letter differ (P< 0.05) within a list.
3. Discussion
Based on practical production of broiler feeding, the paper studied, under the condition of ration with additive of a certain proportion non-conventional feed materials, the effect of adding NSP complex enzyme on meat quality in broilers. Therefore, below several points were under serious consideration when designing the experiments. 1All experimental groups have the same basic ration’s nutritional levels. 2Both positive and negative control groups were designed. Under the condition of cheap feed material in the market, positive control group’s ration used the conventional formula style“corn – soybean meal”while negative control chose a certain portion of non-conventional feed materials on the basis of “corn – soybean meal”ration under the condition of high overall price for current feed material in the market. With the design of positive and negative control, it is easy to observe the meat quality of group 1-3 which used additive of 3 kinds of NSP complex enzymes on the basis of negative control’s ration, and if it is similar to positive control, and there are any improvements compared with negative control. 3Non-conventional feed materials used wheat bran, wheat middling and DDGS as this three often used materials have comparatively high contents of Xylan, Dextran, Cellulose and other anti-nutrition factors[6-9].
Numerous studies show that single NSP enzymes mainly include Xylanase, Dextranase, Cellulase, Pectinase, mannanase [13-16]. Xylanase mainly works on the main carbon chain, only focuses on degrading β - (1-4) glycosidic bond[13] which is connected by Xylose. Dextranase only works on β - (1-3) glycosidic bond[14] which is inside of Dextran chain. Cellulase is divided into two kinds, endonuclease and exonuclease, which degrades Cellulose into cellobiose and cellodextrin[15]. Mannanase degrades β - (1-4) glycosidic bond[9] which is connected by Mannose. Pectic enzyme is more complicated. Generally, it has 3 types, Peetinestersase, Pectinase and Protopeetinase. Pactinase mainly degrades galacturonic acid[16] connected by α-1,4 glycosidic bond in Pactins. Table 2 and Table 3 show that on the whole, NSP enzyme in the ration of group 2 is lack of Pectic enzyme and Mannanase. Group 3 is lack of Mannanase while NSP complex enzyme in group 1 has all the enzymes, and the activity of single NSP enzyme, whose additive content in the testing ration is calculated theoretically, is higher than those of group 1 and 2 (See Table 3). The above results indicate that the enzyme category and activity of commercial NSP complex enzyme products existing in current market. With the increasingly diversified unconventional feed raw materials used by feed and breeding enterprises, as well as the increase of the proportion, it is recognized commonly that adding NSP complex enzyme in livestock and poultry’s ration can improve the growth performance of broilers[6-9], but there is still few reports of its effect on meat quality in broilers in domestic. Thus, the paper mainly studies NSP complex enzyme’s effect on meat quality in broilers.
Meat color is the most import factor effecting consumers buying livestock and poultry meat products, as customer will get the first impress of meat products’ freshness and hygienic status while observing the color[17]. Generally, consumers won’t buy meat products with bad color. Therefore, from consumers’ point of view, meat with bad color will not be sold normally, the other index of meat quality become meaningless as well[17]. Broiler meat belongs to White meat and is in dull red. We can’t give sensory evaluation for broiler meat just as what we do for pork, beef and mutton. So, the experiments used Chromascope Minolta-CR400 to determine meat color CIELAB L(Lightness), a(Red value), b (Bellow value) [10-11]. A value high means meat color is bright[10]. Table 4 indicates that thigh muscle meat color A value of negative control is much lower(P< 0.05)than the one of positive control, this means unconventional feed raw materials have negative effect on broiler meat color. Thigh muscle meat color a value of group 1, who had NSP complex enzyme on the basis of negative control, increased significantly, and had little difference from positive control. This result shows that NSP complex enzyme can improve broiler meat color. Furthermore, thigh muscle meat color L and a value of five groups are all higher than those of breast muscle meat. This objectively verified that “broiler thigh meat has deeper red color than breast muscle meat”. It may because thigh muscle meat has more exercise and richer myoglobin.
Drip loss is not only an important physical character index for meat quality, but also an important economic indicator evaluating meat productivity during production[19]. High drip loss value means fresh meat has high rate of water lose, meat output decreases. Table 4 indicates that negative control thigh muscle meat had the highest drip loss while group 1 breast muscle meat had the lowest value. This point shows on one hand, unconventional feed materials decrease broilers productivity, on the other hand, adding NSP complex enzyme products, especially the one with complete enzymes and high activity, could have positive effect on decreasing the drip loss, improving fresh meat quality in broilers as well as increasing output. Shear force is an objective index for evaluating meat tenderness[20]. Although breast muscle meat shear force of all 5 groups had no big difference, the thigh muscle meat shear force of group 1 and 2 were much lower than negative group’s, but similar to positive control. This means NSP complex enzymes can improve meat tenderness in big broilers.
The proximate analysis of chemistry composition of meat and meat products includes 4 indexes, crude moisture, crude protein, crude fat and crude ash. General labs can do the test as the measuring methods are simple. So it is an import method to evaluate meat and meat products’ nutritional value[10]. Table 5 indicate that for breast muscle and thigh muscle meat’s crude moisture, crude protein, crude fat and crude ash, there is no much difference among all 5 groups. This means NSP complex enzymes could not change big broilers’ nutritional value.
Adenosine triphosphate (ATP) can be hydrolyzed into adenosine diphosphate (ADP) and adenosine monophosphate(AMP). AMP can generate inosine acid (IMP) under the function of adenylic deaminase. IMP is an important substance generating flavor. High IMP content in broiler meat means good flavor[12]. IMP content of breast and thigh muscle meat in ROSS broilers for this experiment is 2~3 mg/g, it is close to the one determined by the previous and there is no difference among each groups (See Table 5). This means NSP complex enzyme can’t improve meat flavor in big broilers within the short breeding period.
4. Conclusions
The experiment results indicate NSP complex enzyme improved the meat color, tenderness and decreased the drip loss in big broilers. It had a certain improvement for broiler meat quality. The key to this effect is adding NSP complex enzyme with complete enzyme and the high activity. It is suggested that feed and breeding enterprises who have the ability to add NSP complex enzyme products should measure its enzyme categories and activity before using.
Acknowledgments
This work was funded by the State Ministry of Science and Technology’s scientific and technical personnel serving enterprises action project (2009GJF30046), Key project of Science and Technology of Yunnan Province (2008LA006), Science and Technology Bureau Project of Kunming City (08G100112) and Yunnan Innovation-oriented Enterprises Trial Projects’ Imbursement.
About the author
CHENG Zhi-bin (1977- ), male, doctor, vice-professor, engages in researches on animal nutrition and livestock product science.
*Corresponding author: Su Zi-feng (1975 - ), male, master, engages in researches of animal nutrition.