Poultry
xClose

Loading ...
Swine
xClose

Loading ...
Dairy & Ruminant
xClose

Loading ...
Aquaculture
xClose

Loading ...
Feed
xClose

Loading ...
Animal Health
xClose

Loading ...
Functional Additives
Monday, April 11, 2016 11:36:29 AM
Print this articleForward this article

 

Supplementation of phytase on diet improves the apparent ileal digestibility of amino acids and P in growing piglets

 

Jie Pan et al.

   

 

Abstract

 

The present study evaluated the effect of dietary phytase supplementation on the performance, apparent ileal digestibility (AID) of amino acids (AA) and P of growing piglets. A total of 32 growing piglets with a mean body weight (18.36±1.39 kg) were divided into 4 groups randomly: positive control group (A) is basal diet without phytase; negative control group (B) is similar to A except that available P was reduced by 0.18%, and two experiment groups C and D with 500 and 1000 U/kg phytase (5000 U/g), respectively, in B group diet. All piglets were fed for 30 days and then killed for sample collection. Consequently, no significant difference was observed on average daily gain (ADG) and ratio of feed to gain (F/G) in all groups, but ADG was 3.5% higher in D group compared with positive control group. Supplementing of phytase increased the AID of methionine, threonine, isoleucine, histidine and lysine (P<0.05). For D group, the AID of P was increased 24% (P<0.001) and the amount of P excreted was decreased by 17.9% (P<0.05) compared with A group. Dietary supplementation of phytase improved P digestion and utilization in growing piglets under the condition of the present study.

 

Introduction
 

In corn-soybean meal-based diet of swine husbandry, about 60 to 90% of P commonly occurs as phytate P, which is one of the main antinutritional factors for swine growth  1 . Since the structure characters of phytate and chelating with other dietary nutrients, phytate P cannot be used directly in swine intestine  2-4 . Phytase is a phosphatase enzyme, produced by microbes survived in the gut of ruminant animals, which catalyzes the hydrolysis of phytic acid and releases the bound nutrients for utilization  6-8 . The phytase in diet and piglet organism are not sufficient for gastric efficiency of phosphorus utilization  9, 10 . Therefore, dietary supplementation of phytase in pig industry is an effective approach for improving the digestibility of P and other nutrients  11 .

 

Even though phytase has been found in animals, plants, fungi and bacteria  12-14 , it is mostly collected from transgenic microbes and produced from genetically modified yeast on a large commercial scale recently  15, 16 . Some studies were made for the supplementation of phytase to diets for pigs, but conclusions lack of consistency  17, 18 . Some studies showed improvements on the apparent ileal digestibility (AID) of crude protein (CP) and amino acids (AA), but others have no effect on both characters  19 . This phenomenon may due to the diet composition inconsistency and the swine basic mechanism response.

 

Our study was designed to evaluate the effects of commercial phytase which produced by KDN Biotech Company on theperformance, feed utilization and AID of growing piglets.

 

Materials and Methods
 
Materials: Phytase (5000 U/g) was obtained from Weifang KDN Biotech Co., Ltd. Growing piglets were supplied by the pig farm of Shandong Liuhe Group Co., Ltd. 
 
Animal, diets and measures: The protocols for the animal experiments of this study were approved by the Animal Care and Use Committee of the Institute of Subtropical Agriculture, the Chinese Academy of Sciences  20 . Four experiments, each lasting for 30 days, were conducted with a total of 32 growing pigs (60 days old). Pigs were Landrace-Yorkshire-Duroc crossbreds with a mean body weight (BW) 18.36+1.39 kg. There were 32 piglest that were blocked and divided into four groups (n = 8) randomly. Positive control group (A) was fed with basal diet requirement for pig  25 . Negative control group (B) was fed with basal diet except that available P was reduced by 0.18%. The other two experiment groups C and D were with 500 and 1000 U/kg phytase (5000 U/g) added, respectively, in B group diet. The gross composition and mineral composition of the basal diets are shown in Table 1.

 

Table 1. The ingredients of basal diets for growing pigs
  Ingredients   (%)
  Corn (%)   68.54
  Soybean meal (%)   22.92
  Fish meal (%)   2.00
  Canola oil (%)   2.51
  Salt (%)   0.40
  Limestone (%)   1.14
  Monocalcium phosphate (%)   0.85
  Premix feed (%)   1.00
  Other (%)   0.64
The feed premix provided the following per kg of diet: Fe (ferrous sulfate), 80 mg; Zn (zinc carbonate), 50 mg; Mn (manganese sulfate), 20 mg; Cu (copper sulfate), 25 mg; I (potassium iodate), 0.58 mg; Co (cobalt sulfate), 0.5 mg; and Se (sodium selenite), 0.5 mg, Vitamin A, 10395 IU; Vitamin D3, 1974 IU; Vitamin E, 23.63 IU; Vitamin K3, 1.63 mg; Thiamine, 1.58 mg; Riboflavin, 4.73 mg; Pyridoxine, 2.00 mg; Vitamin B12, 0.0098 mg; Niacin, 15.75 mg; Pantothenic acid, 6.51 mg; Folic acid, 0.65 mg; Biotin, 0.47 mg. 
 

Sample collection and biochemical analysis: Individial BW of pig was measured at the beginning and end of experiment for calculation of average daily gain (ADG)  21 . The pen feed disappearance were determined weekly, in order to calculate average daily feed intake (ADFI) and ratio of feed to gain (F/G). At the final week of experiment, one pig was selected at random from each block, fed in the metabolic cage. Feces were collected using total feces collection method and frozen at -28°C for analysis 22. AID of AA and P analyses were measured according to procedures outlined by Fang et al.  23 and Jones and Gilligan  24 . P excretion was determined based on the method of Omogbenigun et al. 26 .

 

Statistical analysis: Data were subjected to one-way analysis of variance (ANOVA) and means were separated by Duncan's multiple range test using SPSS 13.0.

 

Results

 

Evaluation of phytase supplementation on the performance of growing pigs: In our study, no significant difference was observed on average daily gain (ADG) and ratio of feed to gain (F/G) in all groups, but F/G was 2.84% and 2.2% lower in C and D group compared with positive control group, respectively (Table 2).

 

Apparent ileal digestibilities of amino acids: Table 3 shows the apparent ileal digestibilities (AID) of amino acids (AA) in different supplementation of phytase in low P basal diet. It is obvious that supplementing of phytase increased AID of methionine, threonine, isoleucine, histidine and lysine (P<0.05). For C group, the AID of methionine was 10.83%, 11.29% higher compared with A and B groups, respectively (P<0.01); as to the AID of threonine, phytase supplementation in D group also increased the value by 11.23% and 13.34% compared to A and B control groups, respectively

 

(P<0.01). Meanwhile, the AID of isoleucine, histidine and lysine in D group was increased by 5.72%, 4.27% and 6.08% severally compared with A group (P<0.05). The AID of other amino acids was not changed significantly, but some had the tendency of improvement.

 

Evaluation of phytase supplementation on the AID of P and Pexcretion of growing pigs: The evaluation of phytase on the AIPof P and P excretion are presented in Table 4. For C group, theAID of P was increased 24% (P<0.001) compared with A group. As to the amount of P excretion, it was decreased in D group by 17.9% (P<0.05) compared with A group.

 

Discussion

 

In our study, we investigated the effect of dietary supplementation of phytase on the performance and the AID of amino acids and P in growing pigs. Both 500 and 1000 U/kg phytase supplementation can decrease the F/G of growing pigs, but the ADG has no significant difference among 4 groups. Previous studies have demonstrated that the supplementation of phytase will improve the performance. Adding phytase in diet increased the ADG and improved the phosphorus utilization  27, 28 . Lower P concentration in diet will inhibit the appetite of animals  22 . Phytase improved the utilization of phytate P in feedstuffs and other nutrients, which were binding to phytate in digest process and therefore improved the digestibility of proteins, AA, fat and crude fibre  29, 30 . The AID of P was significantly increased in current experiment, especially in 500 U/kg phytase supplementation group  31 . P excretion in 1000 U/kg showed an obvious decrease compared with two control groups  32 . Other studies also revealed potential environmental benefits through a 30 to 40% reduction in P excretion 33 . For P excretion, it depends on levels of phytase in the diet; in weanling pigs, P digestibility was increased from 30 to 190% 31 .

 

Apparent ileal AA digestibility was affected by the amount of phytase supplementation in diet. In this study, adding of phytase increased the AID of AA significantly. The AID of threonine, isoleucine, histidine and lysine were higher in 1000 U/kg group than in control groups. AID of methionine was higher in 500 U/kg supplementation. Zhang et al.  6 showed that 500 U/kg phytase supplementation was not enough for enhancing AID of AA  32 . Furthermore, 1200 U/kg phytase supplementation significantly increased the AID of crude protein and some AAs, such as lys, try and thr  33 . However, some reports pointed out that phytase supplementation does not consistently improve the AID of AA, some AA response factors would have a possible effect on AID of AA in phytase supplemented pigs  34 . Therefore, it can be seen that the efficiency of phytase on swine AID of AA depends on the activity of phytase and types of AA  35, 36 .

 

In conclusion, the results of this study clearly showed that dietary phytase supplementation significantly increased the AID of P and AA, as well as decreased the P excretion. These findings provide more important evidence for the phytase application in swine industry and how to use it more efficiency.

 

Table 2. Evaluation of phytase on growing pig performance.
Parameters Group A   Group B   Group C   Group D
Initial Weight (kg) 18.52±0.7   19.31±0.6   18.17±0.93   18.21±0.64
Final Weight (kg) 39.71±1.04   40.41±1.06   40.06±.095   40.15±1.23
Daily Gain (g)   710.21±0.38   704.29±0.12   729.83±0.29  7 31.17±0.83
Daily Feed Intake (g/pig) 2293.98±31.42   2260.77±18.34   2138.42±32.69   2310.50±23.65
Feed/Gain Ratio   3.23±0.07   3.21±0.08   2.93±0.06   3.16±0.10
Values are expressed as mean ± SEM and represent data obtained from 8 pigs in each group
         
Table 3. Evaluation of phytase on AID of amino acids of growing pigs.
Amino Acids   Group A   Group B   Group C   Group D
Essential AA         
Arginine   89.61±0.35   90.27±0.29   91.34±0.16   91.19±0.35
Histidine  88.30±1.22b   86.63±1.67c   89.84±0.89ab   92.07±1.41a
Methionine   70.05±0.73c   69.76±1.28c   77.64±1.57a   75.29±0.43ab
Isoleucine   75.54±0.49bc   74.82±0.58c   76.56±0.29b   79.86±0.57a
Leucine   80.37±0.54   80.25±1.31   81.17±1.52   80.49±0.46
Lysine   74.52±1.70b   73.69±1.24c   75.19±0.24a   75.26±1.73a
Phenylalanine   84.02±0.62   82.71±1.56   83.38±0.74   84.13±0.71
Threonine   71.82±1.52b   70.48±0.84b   74.31±0.42c   79.88±0.33a
Valine   78.20±1.67   79.18±0.76   77.24±0.60   79.32±0.77
Nonessential AA         
Alanine   79.81±1.41   77.38±0.29   76.43±0.37   79.59±0.31
Aspartic acid   79.65±0.47   79.37±1.09   77.43±0.36   80.49±0.27
Glutamic acid   89.72±1.10   90.25±0.72   86.15±1.23   90.34±0.88
Glycine   75.79±0.22   78.81±0.63   76.15±0.92   79.17±1.30
Serine   86.28±1.70   85.69±0.37   82.94±0.95   85.02±0.21
Tyrosine   86.17±1.49  84.07±0.84   82.31±0.94   83.46±0.59
Values are expressed as mean ± SEM and represent data obtained from 8 pigs in each group.
# Different superscript means significant difference (P<0.05).
         
Table 4. Evaluation of phytase on AID of P and P excretion of growing pigs.
Parameters   Group A   Group B   Group C   Group D
AID of P   39.15±0.47c   30.13±0.82d   48.55±1.25a   43.81±1.29b
P Excretion (g/kg)   3.23±0.31a   3.13±0.46ab   2.89±0.45cd   2.74±0.28d
Values are expressed as mean ± SEM and represent data obtained from 8 pigs in each group.
# Different superscript means significant difference (P<0.05).

 

 

For more of the article, please click here

 

Article made possible through the contribution of Jie Pan et al.

Share this article on FacebookShare this article on TwitterPrint this articleForward this article
Previous
My eFeedLink last read