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Effect of xylanase on the performance of laying hens fed a low energy corn and soybean diet
Effect of xylanase on the performance of laying hens fed a low energy corn and soybean diet Ashley E. Bigge,∗,1 Sheila Purdum,∗ and Kathryn Hanford§ ∗
Animal Science Department, University of Nebraska-Lincoln, Lincoln, NE 68583, USA; and § Statistics Department, University of Nebraska-Lincoln, Lincoln, NE 68583, USA weeks 0, 10, 20, and 35 of the study. Egg production did not differ among treatment groups (phase 1: P = 0.47; phase 2: P = 0.54). In phase 1, EW and EM were significantly lower in the NC diet with enzyme B, compared to both the PC and NC diets (P = 0.019; P = 0.01). The PC diet yielded higher EW than all other treatments in phase 2 (P = 0.036), but no differences in EM were present (P = 0.12). Baseline BW was not different (P = 0.63), but hens fed the PC diet had higher BW in subsequent measurements (P ≤ 0.05). Hens fed the PC diet had lower FI than all other treatment groups in both phases (P = 0.0001), and had an improved FC than the 2 enzyme groups in phase 1 (P = 0.0001) and all other treatment groups in phase 2 (P = 0.0001). The enzymes did not improve the performance of the birds.
ABSTRACT This study was conducted to determine the effect of high- and low-activity xylanase in a corn and soybean diet on the performance of laying hens. There were 2 phases each with 4 treatment diets: positive control (PC), negative control (NC) with lower metabolizable energy (ME) and nutrient density, and 2 different xylanases supplemented to the NC diet. Phase 1 was 23–43 wk of age and phase 2 was 43–58 wk, for a total duration of 35 wk. The NC diet had a lower ME in phase 2 than phase 1. There were 72 cages with 3 Bovan White Leghorns each. Egg production (EP) was recorded daily, feed intake (FI) weekly, and average egg weights (EW) biweekly. Egg production and FI were calculated using biweekly periods, also used to determine egg mass (EM) and feed conversion (FC) with biweekly EW. BW was recorded and analyzed for
Key words: xylanase, NSP degrading enzyme, laying hen 2018 Poultry Science 0:1–5 http://dx.doi.org/10.3382/ps/pey200
INTRODUCTION
ergy from these sources efficiently (Choct 2006). Birds fed lower energy diets tend to have poorer feed conversion (FC) ratios since more feed is needed to provide energy needed for growth, maintenance, and/or production of eggs (O’Neill et al., 2012). With enzyme supplementation, producers may now be able to use feed ingredients that, on their own, would normally be poor in apparent metabolizable energy (ME). Xylanase is a common non-starch polysaccharidedegrading enzyme added to poultry diets that hydrolyzes bonds between sugars in xylan molecules, including arabinoxylans. The structure of the enzyme allows multiple sugars to be bound randomly due to an open cleft active site (Davies and Henrissat, 1995). Xylanase generally improves digestibility of amino acids of the indigestible fraction of an ingredient by about 16% when added to poultry diets. However, the effect can vary depending on the chosen ingredient (Cowieson and Bedford, 2009). The improvement of digestibility by xylanase activity may be due to its effect on lowering intestinal viscosity (Cowieson and Bedford, 2009). Xylanase may also enhance the fermentative capability of the ceca as the birds age (O’Neill et al., 2012). Mathlouthi et al. (2002) determined that the enzyme can improve egg production (EP), egg mass (EM), and FC
Scientific research into the effects of enzyme inclusion in poultry diets has been conducted for nearly a century, with one of the first studies being presented in the mid-1920s (Clickner and Follwell, 1926). Over time, enzymes have become increasingly popular as feed additives, with xylanases and glucanases being introduced as recently as the 1980s (Cowieson and Bedford, 2009). A substantial amount of nutritional research has been conducted in just the past few decades. Much of the motivation for this sudden increase in enzyme usage stems from the need to increase efficiency of feed ingredients to decrease costs, as well as increased ethanol production reducing availability of whole corn to be used for animal agriculture (O’Neill et al., 2012). Use of plant protein sources also creates a need for exogenous enzyme supplementation, as non-starch polysaccharides can decrease the bird’s ability to utilize protein and en C 2018 Poultry Science Association Inc. Received December 13, 2017. Accepted June 8, 2018. 1 Corresponding author: Animal Science Department, University of Nebraska-Lincoln, NE 68583, USA. E-mail: ashley.bigge@huskers. unl.edu
1 Downloaded from https://academic.oup.com/ps/advance-article-abstract/doi/10.3382/ps/pey200/5039610 by Nagoya University user on 23 June 2018
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BIGGE ET AL.
Table 1. Diet Composition. Phase 1 Ingredient (%)
Phase 2
Positive control
Negative control
Positive control
Negative control
56.90 19.10
55.48 19.70 10.00 2.57 10.24 1.16 0.36 0.13 0.19 0.03 0.20
57.18 17.90 2.15 10.00 0.50 10.22 1.18 0.38 0.14 0.17 0.03 0.20
2,866 16.45 5.25 2.02 4.30 0.54 2.79 0.898 0.79 0.422 0.66 0.553
2,712 15.93 3.24 2.72 4.30 0.54 1.68 0.859 0.771 0.396 0.63 0.53
Corn Soybean Meal Soy Hulls DDGS Vegetable Oil Limestone Dical Phosphate Salt Lysine Methionine Threonine Premix1
10.00 2.20 9.64 1.28 0.40 0.14 0.18 0.03 0.20
58.50 18.30 0.50 10.00 0.50 9.98 1.29 0.40 0.15 0.18 0.02 0.20
Calculated nutrient composition Nutrient Metabolizable Energy (kcal/kg) Crude Protein (%) Crude Fat (%) Crude Fiber (%) Calcium (%) Available Phosphorus (%) Linoleic Acid (%) Digestible Arginine (%) Digestible Lysine (%) Digestible Methionine (%) Digestible Total Sulfur Amino Acids (%) Digestible Threonine (%)
2,866 16.53 4.92 2.03 4.10 0.46 2.60 0.89 0.79 0.419 0.66 0.553
2,756 16.33 3.28 2.20 4.23 0.46 1.70 0.874 0.78 0.41 0.65 0.535
1
Poultrymate Pinnacle Premix (Nutra Blend LLC, Neosho, MO). DDGS, distiller’s grains and solubles
in layers fed low energy wheat and wheat–barley-based diets. Mirzae et al. (2012) also reported increased EP and EM, improved FC ratio, and decreased digesta viscosity due to xylanase supplementation in diets containing wheat. Studies of laying hens fed diets containing corn distiller’s grains with solubles have shown that enzyme addition does not affect performance, and may decrease nitrogen and phosphorus content in the manure (Deniz et al., 2013). The purpose of this experiment was to test whether addition of exogenous xylanase enzymes to a low ME corn/soybean diet results in equivalent performance compared to layer hens fed a normal ME corn/soybean diet. It was hypothesized that the xylanase would improve the performance of the hens on the low ME diet enough to perform on par with the hens fed a normal ME diet.
MATERIALS AND METHODS Birds and Housing Research protocol and use of live animals met the guidelines approved by the University of Nebraska IACUC. This study used 72 cages, containing three 23-wk-old Bovan White (ISA North America, Ontario, Canada) leghorn hens each, which were assigned 1 of 4 dietary treatments using a complete randomized block design. Each block was comprised of 12 cages contained in a Chore-Time cage system that had 2 sides with
3 rows of wire cages separated vertically by manure belts (CTB, Inc 2016). This resulted in 3 replicates per block, and 18 replicates total for each treatment. There was 688.17 cm2 of floor space per hen in each cage with removable feeder troughs. The hens were allowed maximum access to 110 g of feed per hen per day. The hens also had ad libitum water accessible via pressurized nipple drinkers. The housing unit was in a windowless, climate controlled room maintained at 72◦ F (22◦ C) with a 16-h light:8-h dark photoperiod.
Diets The treatments tested in this study consisted of a positive control (PC) diet, a negative control (NC) diet with lower ME and amino acid density, and 2 diets with xylanases, labeled enzyme A and enzyme B supplemented using the NC as the basal diet. There were 18 replicates for each treatment within the 72 cages used for this study. All diets were corn/soybean meal mash with 10% dried distiller’s grains and solubles. The lower ME in the NC was achieved by diluting the diet with soy hulls and decreasing fat content. The formulated values for diet composition and key digestible amino acids can be viewed in Table 1, and overall analyzed amino acid composition for the phase 1 diets in Table 2. Amino acid content was not analyzed for phase 2. Diets were formulated according to commercial standards. Feed samples were collected in each of 2 phases. Phase 1 was 23–43 wk of age and
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XYLANASE IN LAYING HENS
Statistical Analysis
Table 2. Amino acid analysis of diets (phase 1). Amino acid (%)
Positive control
Negative control
16.80 0.68 1.02 0.25 0.58 0.66 0.70 1.37 0.66 0.99 0.96 1.27 0.19
16.40 0.68 1.03 0.27 0.49 0.66 0.74 1.45 0.59 0.80 0.99 1.24 0.23
Protein Threonine Alanine Cystine Methionine Valine Isoleucine Leucine Tyrosine Phenylalanine Lysine Arginine Tryptophan
3
Data were analyzed using the GLIMMIX procedure in SAS 9.4 (SAS Institute Inc., Cary, NC, 2015) The experimental unit was the cage and significance was observed at P < 0.05. All of the response variables were analyzed using a repeated measures model including random block effect and fixed effects of time, treatment and their interaction. Various error covariance structures were evaluated for each response variable to determine the one that fit the best. BW response in specific weeks was analyzed using a model with a random block effect and fixed treatment effect.
Analysis by Midwest Laboratories, Omaha, NE
RESULTS AND DISCUSSION
Table 3. Enzyme activity. Xylanase Enzyme A (low-activity xylanase) Dosage (kg/tonne) Activity (U/kg) Enzyme B (high-activity xylanase) Dosage (kg/tonne) Activity (U/kg)
Phase 1
Phase 2
0.2 68
0.2 102
0.375 432
0.375 669
Analysis by Kerry Global Technology and Innovation Centre, Kildare, Ireland via Kerry’s internal SAM method.
phase 2 was 43–58 wk. The ME of the NC and diets 3 and 4 was decreased further during phase 2. Enzyme A was added at 0.2 kg/tonne, and enzyme B was added at 0.375 kg/tonne and feed was mixed at the University of Nebraska-Lincoln’s feed mill (Ithaca, NE) prior to the start of each phase of the study. Both xylanases were provided by Kerry Ingredients (Kerry Inc 2016). Each respective enzyme was added at the same level in phase 1 and phase 2. Feed sample analysis showed enzyme B had a higher xylanase activity (analysis by Kerry Global Technology and Innovation Centre, Kildare, Ireland) than enzyme A, and the activity of both enzymes increased in the phase 2 diets (Table 3). These values were reported to be as expected for animal feed samples.
Measurements Egg production was recorded daily. Feed intake (FI) was determined weekly and calculated by subtracting the amount of feed remaining from the feed given then divided by the number of hens in each cage. Egg weights (EW) were measured biweekly using a sample of 2 eggs per cage. A baseline average BW per cage was determined at the beginning of the study, and subsequent BWs were measured at 10, 20, and 35 wk. Percent EP was calculated by dividing the number of eggs collected by the number of hen day eggs expected, EM by multiplying average EW by EP per cage, and FC ratio by dividing FI by EM. All calculated data used biweekly periods, and statistical analysis also used biweekly data. There were 2 mortalities and calculations were adjusted accordingly.
There was no significant interaction between treatment and time for all parameters. The effect of time was significant for all parameters excluding FC in both phases and EM in phase 2. The results for EP, EW, and EM are found in Table 4. There were no differences in overall EP (P = 0.48). Egg production was not affected by the lower ME diets during both phases 1 and 2 (P ≥ 0.05). The lack of differences in EP could be due to the young age of the birds as they were early into their first egg laying cycle. No differences in EP between the NC and the 2 negative diets with enzymes may also be due to insufficient enzyme activity. There was an overall treatment effect for EW and EM (P = 0.017; P = 0.027). The hens fed the PC and NC diets in phase 1 had higher EW than the NC with enzyme B (P = 0.019), and a similar result was seen for phase 1 EM (P = 0.01). In phase 2, EW was significantly higher for hens fed the PC diet (P = 0.036), but no differences were seen for EM (P = 0.12). Egg mass is a function of EP and EW, and with the exception of PC EW, neither exhibited a treatment response in phase 2. The results for BW, FI, and FC are in Table 5. BW and FI were most responsive to treatments. No differences existed in BW across treatment groups at the beginning of the study (P = 0.63). While all hens were slightly underweight compared to the breed management guidelines of 1550 g at 23 wk of age (HendrixISA LLC, 2015), the hens fed the PC gained significantly more weight during the trial (P < 0.05), and were closer to the standard. Hens on the PC diet consumed significantly less feed overall and during both phases (P = 0.0001). These data indicate that the higher energy in the PC diet resulted in less feed being consumed. There was a significant treatment effect on FC overall and during both phases (P ≤ 0.0001). Hens fed the PC diet had the most efficient FC in phase 2 with an FI:EM ratio of 1.944. As mentioned earlier, the hens fed the PC laid heavier eggs in phase 1 compared to the hens fed the NC diet with enzyme B, and in phase 2 the PC hens produced heavier eggs than all other treatment groups. During phase 2, the hens fed the PC laid heavier eggs than all other treatments (P = 0.036).
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Table 4. Effect of treatment on egg percent production, egg weight (EW), and egg mass (EM). Egg production (%) Treatment Positive Control Negative Control Neg. Ctl + Enzyme A Neg. Ctl + Enzyme B SEM1 P Values Treatment Time Trt∗ time
Phase 1
Phase 2
Overall
92.1 91.9 91.5 91.0 0.547
89.4 90.0 89.2 88.5 0.735
90.3 91.3 90.5 90.1 0.482
0.47 0.006 NS
0.54 ≤0.0001 NS
0.48 ≤0.0001 NS
EW (g), EM (g/d) Phase 1 Treatment Positive Control Negative Control Neg. Ctl + Enzyme A Neg. Ctl + Enzyme B SEM1 P Values Treatment Time Trt∗ time ∗ 1
Phase 2
Overall
EW 58.0a 58.4a 57.6a,b 57.0b 0.326
EM 53.97a 54.10a 53.22a,b 52.33b 0.417
EW 60.98a 59.65b 59.66b 59.70b 0.392
EM 54.74 54.21 53.48 53.27 0.481
EW 59.15a 58.86a,b 58.33b,c 57.96c 0.279
EM 54.07a 53.96a 53.21a,b 52.52b 0.401
0.019 ≤0.0001 NS
0.01 ≤0.0001 NS
0.036 0.016 NS
0.12 0.36 NS
0.017 ≤0.0001 NS
0.027 ≤0.0001 NS
Means within a column with differing superscripts are significantly different (P ≤ 0.05). Standard error of the mean.
Table 5. Effect of treatment on bodyweight, feed intake, and feed conversion. Average bodyweight (g) Baseline Treatment Positive Control Negative Control Neg. Ctl +Enzyme A Neg. Ctl +Enzyme B SEM1 P Values Treatment Time Trt∗ time
Phase 1
Overall 1589 1540 1541 1553 15.781
Week 0 1510 1486 1487 1511 18.082
Week 10 1603a 1533b 1542b 1550b 15.901
Week 20 1628a 1562b 1567b 1564b 15.980
Week 35 1639a 1572b 1570b 1574b 18.690
0.63
0.01
0.01
0.03
Feed intake (g/bird/d), feed conversion (g feed:g egg) Phase 1 Treatment Positive Control Negative Control Neg. Ctl +Enzyme A Neg. Ctl +Enzyme B SEM1 P Values Treatment Time Trt∗ time
Phase 2
0.1 ≤0.0001 NS
Phase 2
Overall
FI 104.8a 106.8b,c 106.2b 107.6c 0.407
FC 1.962a 1.986a,b 2.011b 2.070c 0.166
FI 104.8a 107.7b 107.8b 108.9b 0.6312
FC 1.944a 2.010b 2.035b 2.061b 0.0179
FI 104.6a 106.9b 106.7b 107.9b 0.480
FC 1.954a 1.997b 2.021b 2.067c 0.0114
0.0001 ≤0.0001 NS
0.0001 0.13 NS
0.0001 ≤0.0001 NS
0.0001 0.33 NS
0.0001 ≤0.0001 NS
0.0001 0.82 NS
∗
Means within a column with differing superscripts are significantly different (P ≤ 0.05). Standard error of the mean. FC, feed conversion; FI, feed intake
1
Consuming more, yet laying smaller eggs causes the FC ratio to increase, showing that hens are less efficient at converting feed into a product (eggs). Feed conversion can also affect body weight since the hens will need to consume more feed not only to produce eggs, but also to grow and eventually maintain body weight. The differences seen in the study were caused by the decrease in ME and amino acid density in the NC diet. There was no interaction between time and treatment
for the parameters measured in this study. The enzyme supplementation to the NC diet did not support bodyweight or EW equivalent to hens fed the PC diet. As expected, the enzyme activity increased numerically in the lower ME diet due to the higher NSP content from the soy hulls. However, the activity was still quite low compared to similar studies. Xylanase has been shown to have some success in broiler studies, notably when supplemented to
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non-corn/soy diets. Olukosi et al. (2007) conducted a study of a xylanase, amylase, and protease complex that was dosed to provide 650 U/kg of feed of xylanase, 1650 U/kg of feed of amylase, and 4000 U/kg of feed of phytase in a corn/soybean diet. The enzyme complex increased nutrient retention in young broilers (<3 wk of age), but the researchers attributed much of this to phytase instead of the xylanase in the XAP complex (Olukosi et al., 2007). Another study with broilers used a much higher dosage of xylanase which resulted in 5500 U/kg of feed of xylanase in a wheat-based diet which yielded a significant decrease in FC ratio, and an increase in apparent ME when compared to the control diet (Guo et al., 2014). In laying hen studies, xylanase has had mixed success. Bobeck et al. (2014) conducted a study using xylanase in a corn–soybean meal-dried distiller’s grain diet in first cycle Hy-Line W36 laying hens. The researchers tested 3 energy levels with or without enzyme supplementation. Enzyme activity ranged from <100 to 1550 U/kg depending on diet. Egg production increased with xylanase supplementation, while FI was unaffected. Rather, it was the low-energy diets that caused a significant increase in intake. Egg mass also increased, but the researchers noted it was likely due to the increase in production, not enzyme supplementation (Bobeck et al., 2014). Another study by HahnDidde and Purdum (2014) examined the effect of a xylanase/amylase/protease complex in laying hen diets containing dried distiller’s grains and solubles. This complex was calculated to provide 225 U/g of xylanase, 300 U/g of amylase, and 3000 U/g of phytase. No negative effects were observed for the enzyme supplemented diets, though the specific effect of xylanase was not discussed (Hahn-Didde and Purdum, 2014). The highest xylanase activity in this study was 669 U/kg of feed by enzyme B during phase 2. The use of different xylanases and analytical methodologies may account for the variation in enzyme activities across different studies. The results indicate that this activity level was still not high enough to improve the NC diet to permit the hens to perform at the same level as those fed the PC. As mentioned earlier, the young age of the hens in this study meant that they were highly productive, which may be why no differences were seen for EP despite the effects on bodyweight and FI. Repeating this study using older laying hens may help to
elucidate the effects of xylanase inclusion in low-energy diets.
REFERENCES Bobeck, E. A., N. A. Nachtrieb, A. B. Batal, and M. E. Persia. 2014. Effects of xylanase supplementation of corn-soybean meal-dried distiller’s grain diets on performance, metabolizable energy, and body composition when fed to first-cycle laying hens. J. Appl. Poult. Res. 23:174–180. Choct, M. 2006. Enzymes for the feed industry: past, present and future. Worlds Poult. Sci. J. 62:5–16. Clickner, F. H., and E. H. Follwell. 1926. Application of ”protozyme” (Aspergillus orizae) to poultry feeding. Poult. Sci. 5:241–247. Cowieson, A. J., and M. R. Bedford. 2009. The effect of phytase and carbohydrase on ileal amino acid digestibility in monogastric diets: complimentary mode of action? Worlds Poult. Sci. J. 65:609–624. R Accessed CTB, Inc. 2016. Cage Systems for Layers. Chore-Time. Nov. 2016. http://www.choretime.com/Cage-Systems-for-Layers. Davies, G., and B. Henrissat. 1995. Structures and mechanisms of glycosyl hydrolases. Structure 3:853–859. Deniz, G., H. Gencoglu, S. S. Gezen, I. I. Turkmen, A. Orman, and C. Kara. 2013. Effects of feeding corn distiller’s dried grains with solubles with and without enzyme cocktail supplementation to laying hens on performance, egg quality, selected manure parameters, and feed cost. Livestock Sci. 152:174–181. Guo, S., D. Liu, X. Zhao, C. Li, and Y. Guo. 2014. Xylanase supplementation of a wheat-based diet improved nutrient digestion and mRNA expression of intestinal nutrient transporters in broiler chickens infected with Clostridium perfringens. Poult. Sci. 93:94– 103. Hahn-Didde, D.,, and S. E. Purdum. 2014. The effects of an enzyme complex in moderate and low nutrient-dense diets with dried distillers grains with solubles in laying hens. J. Appl. Poult. Res. 23:23–33. Hendrix-ISA LLC. 2015. Bovans White Commercial Management Guide. Accessed Nov. 2016. http://www.hendrix-isa.com/ en/products/bovans-white/. Kerry Inc. 2016. Global Locations. Kerry. Accessed Nov. 2016. https://www.kerry.com/contact-us/global-locations Mathlouthi, N., M. Larbier, M. A. Mohamed, and M. Lessire. 2002. Performance of laying hens fed wheat, wheat-barley or wheatbarley-wheat bran based diets supplemented with xylanase. Can. J. Anim. Sci. 82: 193–199. Mirzae, S., M. Zaghari, S. Aminzadeh, M. Shivazad, and G. G. Mateos. 2012. Effects of wheat inclusion and xylanase supplementation of the diet on productive performance, nutrient retention, and endogenous intestinal enzyme activity of laying hens. Poult. Sci. 91:413–425. Olukosi, O. A., A. J. Cowieson, and O. Adeola. 2007. Age-related influence of a cocktail of xylanase, amylase, and protease or phytase individually or in combination in broilers. Poult. Sci. 86:77– 86. O’Neill, H. V. M., G. Mathis, B. S. Lumpkins, and M. R. Bedford. 2012. The effect of reduced calorie diets, with and without fat, and the use of xylanase on performance characteristics of broilers between 0 and 42 days. Poult. Sci. 91:1356–1360.
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Animal Science Department, University of Nebraska-Lincoln, Lincoln, NE 68583, USA; and § Statistics Department, University of Nebraska-Lincoln, Lincoln, NE 68583, USA weeks 0, 10, 20, and 35 of the study. Egg production did not differ among treatment groups (phase 1: P = 0.47; phase 2: P = 0.54). In phase 1, EW and EM were significantly lower in the NC diet with enzyme B, compared to both the PC and NC diets (P = 0.019; P = 0.01). The PC diet yielded higher EW than all other treatments in phase 2 (P = 0.036), but no differences in EM were present (P = 0.12). Baseline BW was not different (P = 0.63), but hens fed the PC diet had higher BW in subsequent measurements (P ≤ 0.05). Hens fed the PC diet had lower FI than all other treatment groups in both phases (P = 0.0001), and had an improved FC than the 2 enzyme groups in phase 1 (P = 0.0001) and all other treatment groups in phase 2 (P = 0.0001). The enzymes did not improve the performance of the birds.
ABSTRACT This study was conducted to determine the effect of high- and low-activity xylanase in a corn and soybean diet on the performance of laying hens. There were 2 phases each with 4 treatment diets: positive control (PC), negative control (NC) with lower metabolizable energy (ME) and nutrient density, and 2 different xylanases supplemented to the NC diet. Phase 1 was 23–43 wk of age and phase 2 was 43–58 wk, for a total duration of 35 wk. The NC diet had a lower ME in phase 2 than phase 1. There were 72 cages with 3 Bovan White Leghorns each. Egg production (EP) was recorded daily, feed intake (FI) weekly, and average egg weights (EW) biweekly. Egg production and FI were calculated using biweekly periods, also used to determine egg mass (EM) and feed conversion (FC) with biweekly EW. BW was recorded and analyzed for
Key words: xylanase, NSP degrading enzyme, laying hen 2018 Poultry Science 0:1–5 http://dx.doi.org/10.3382/ps/pey200
INTRODUCTION
ergy from these sources efficiently (Choct 2006). Birds fed lower energy diets tend to have poorer feed conversion (FC) ratios since more feed is needed to provide energy needed for growth, maintenance, and/or production of eggs (O’Neill et al., 2012). With enzyme supplementation, producers may now be able to use feed ingredients that, on their own, would normally be poor in apparent metabolizable energy (ME). Xylanase is a common non-starch polysaccharidedegrading enzyme added to poultry diets that hydrolyzes bonds between sugars in xylan molecules, including arabinoxylans. The structure of the enzyme allows multiple sugars to be bound randomly due to an open cleft active site (Davies and Henrissat, 1995). Xylanase generally improves digestibility of amino acids of the indigestible fraction of an ingredient by about 16% when added to poultry diets. However, the effect can vary depending on the chosen ingredient (Cowieson and Bedford, 2009). The improvement of digestibility by xylanase activity may be due to its effect on lowering intestinal viscosity (Cowieson and Bedford, 2009). Xylanase may also enhance the fermentative capability of the ceca as the birds age (O’Neill et al., 2012). Mathlouthi et al. (2002) determined that the enzyme can improve egg production (EP), egg mass (EM), and FC
Scientific research into the effects of enzyme inclusion in poultry diets has been conducted for nearly a century, with one of the first studies being presented in the mid-1920s (Clickner and Follwell, 1926). Over time, enzymes have become increasingly popular as feed additives, with xylanases and glucanases being introduced as recently as the 1980s (Cowieson and Bedford, 2009). A substantial amount of nutritional research has been conducted in just the past few decades. Much of the motivation for this sudden increase in enzyme usage stems from the need to increase efficiency of feed ingredients to decrease costs, as well as increased ethanol production reducing availability of whole corn to be used for animal agriculture (O’Neill et al., 2012). Use of plant protein sources also creates a need for exogenous enzyme supplementation, as non-starch polysaccharides can decrease the bird’s ability to utilize protein and en C 2018 Poultry Science Association Inc. Received December 13, 2017. Accepted June 8, 2018. 1 Corresponding author: Animal Science Department, University of Nebraska-Lincoln, NE 68583, USA. E-mail: ashley.bigge@huskers. unl.edu
1 Downloaded from https://academic.oup.com/ps/advance-article-abstract/doi/10.3382/ps/pey200/5039610 by Nagoya University user on 23 June 2018
2
BIGGE ET AL.
Table 1. Diet Composition. Phase 1 Ingredient (%)
Phase 2
Positive control
Negative control
Positive control
Negative control
56.90 19.10
55.48 19.70 10.00 2.57 10.24 1.16 0.36 0.13 0.19 0.03 0.20
57.18 17.90 2.15 10.00 0.50 10.22 1.18 0.38 0.14 0.17 0.03 0.20
2,866 16.45 5.25 2.02 4.30 0.54 2.79 0.898 0.79 0.422 0.66 0.553
2,712 15.93 3.24 2.72 4.30 0.54 1.68 0.859 0.771 0.396 0.63 0.53
Corn Soybean Meal Soy Hulls DDGS Vegetable Oil Limestone Dical Phosphate Salt Lysine Methionine Threonine Premix1
10.00 2.20 9.64 1.28 0.40 0.14 0.18 0.03 0.20
58.50 18.30 0.50 10.00 0.50 9.98 1.29 0.40 0.15 0.18 0.02 0.20
Calculated nutrient composition Nutrient Metabolizable Energy (kcal/kg) Crude Protein (%) Crude Fat (%) Crude Fiber (%) Calcium (%) Available Phosphorus (%) Linoleic Acid (%) Digestible Arginine (%) Digestible Lysine (%) Digestible Methionine (%) Digestible Total Sulfur Amino Acids (%) Digestible Threonine (%)
2,866 16.53 4.92 2.03 4.10 0.46 2.60 0.89 0.79 0.419 0.66 0.553
2,756 16.33 3.28 2.20 4.23 0.46 1.70 0.874 0.78 0.41 0.65 0.535
1
Poultrymate Pinnacle Premix (Nutra Blend LLC, Neosho, MO). DDGS, distiller’s grains and solubles
in layers fed low energy wheat and wheat–barley-based diets. Mirzae et al. (2012) also reported increased EP and EM, improved FC ratio, and decreased digesta viscosity due to xylanase supplementation in diets containing wheat. Studies of laying hens fed diets containing corn distiller’s grains with solubles have shown that enzyme addition does not affect performance, and may decrease nitrogen and phosphorus content in the manure (Deniz et al., 2013). The purpose of this experiment was to test whether addition of exogenous xylanase enzymes to a low ME corn/soybean diet results in equivalent performance compared to layer hens fed a normal ME corn/soybean diet. It was hypothesized that the xylanase would improve the performance of the hens on the low ME diet enough to perform on par with the hens fed a normal ME diet.
MATERIALS AND METHODS Birds and Housing Research protocol and use of live animals met the guidelines approved by the University of Nebraska IACUC. This study used 72 cages, containing three 23-wk-old Bovan White (ISA North America, Ontario, Canada) leghorn hens each, which were assigned 1 of 4 dietary treatments using a complete randomized block design. Each block was comprised of 12 cages contained in a Chore-Time cage system that had 2 sides with
3 rows of wire cages separated vertically by manure belts (CTB, Inc 2016). This resulted in 3 replicates per block, and 18 replicates total for each treatment. There was 688.17 cm2 of floor space per hen in each cage with removable feeder troughs. The hens were allowed maximum access to 110 g of feed per hen per day. The hens also had ad libitum water accessible via pressurized nipple drinkers. The housing unit was in a windowless, climate controlled room maintained at 72◦ F (22◦ C) with a 16-h light:8-h dark photoperiod.
Diets The treatments tested in this study consisted of a positive control (PC) diet, a negative control (NC) diet with lower ME and amino acid density, and 2 diets with xylanases, labeled enzyme A and enzyme B supplemented using the NC as the basal diet. There were 18 replicates for each treatment within the 72 cages used for this study. All diets were corn/soybean meal mash with 10% dried distiller’s grains and solubles. The lower ME in the NC was achieved by diluting the diet with soy hulls and decreasing fat content. The formulated values for diet composition and key digestible amino acids can be viewed in Table 1, and overall analyzed amino acid composition for the phase 1 diets in Table 2. Amino acid content was not analyzed for phase 2. Diets were formulated according to commercial standards. Feed samples were collected in each of 2 phases. Phase 1 was 23–43 wk of age and
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XYLANASE IN LAYING HENS
Statistical Analysis
Table 2. Amino acid analysis of diets (phase 1). Amino acid (%)
Positive control
Negative control
16.80 0.68 1.02 0.25 0.58 0.66 0.70 1.37 0.66 0.99 0.96 1.27 0.19
16.40 0.68 1.03 0.27 0.49 0.66 0.74 1.45 0.59 0.80 0.99 1.24 0.23
Protein Threonine Alanine Cystine Methionine Valine Isoleucine Leucine Tyrosine Phenylalanine Lysine Arginine Tryptophan
3
Data were analyzed using the GLIMMIX procedure in SAS 9.4 (SAS Institute Inc., Cary, NC, 2015) The experimental unit was the cage and significance was observed at P < 0.05. All of the response variables were analyzed using a repeated measures model including random block effect and fixed effects of time, treatment and their interaction. Various error covariance structures were evaluated for each response variable to determine the one that fit the best. BW response in specific weeks was analyzed using a model with a random block effect and fixed treatment effect.
Analysis by Midwest Laboratories, Omaha, NE
RESULTS AND DISCUSSION
Table 3. Enzyme activity. Xylanase Enzyme A (low-activity xylanase) Dosage (kg/tonne) Activity (U/kg) Enzyme B (high-activity xylanase) Dosage (kg/tonne) Activity (U/kg)
Phase 1
Phase 2
0.2 68
0.2 102
0.375 432
0.375 669
Analysis by Kerry Global Technology and Innovation Centre, Kildare, Ireland via Kerry’s internal SAM method.
phase 2 was 43–58 wk. The ME of the NC and diets 3 and 4 was decreased further during phase 2. Enzyme A was added at 0.2 kg/tonne, and enzyme B was added at 0.375 kg/tonne and feed was mixed at the University of Nebraska-Lincoln’s feed mill (Ithaca, NE) prior to the start of each phase of the study. Both xylanases were provided by Kerry Ingredients (Kerry Inc 2016). Each respective enzyme was added at the same level in phase 1 and phase 2. Feed sample analysis showed enzyme B had a higher xylanase activity (analysis by Kerry Global Technology and Innovation Centre, Kildare, Ireland) than enzyme A, and the activity of both enzymes increased in the phase 2 diets (Table 3). These values were reported to be as expected for animal feed samples.
Measurements Egg production was recorded daily. Feed intake (FI) was determined weekly and calculated by subtracting the amount of feed remaining from the feed given then divided by the number of hens in each cage. Egg weights (EW) were measured biweekly using a sample of 2 eggs per cage. A baseline average BW per cage was determined at the beginning of the study, and subsequent BWs were measured at 10, 20, and 35 wk. Percent EP was calculated by dividing the number of eggs collected by the number of hen day eggs expected, EM by multiplying average EW by EP per cage, and FC ratio by dividing FI by EM. All calculated data used biweekly periods, and statistical analysis also used biweekly data. There were 2 mortalities and calculations were adjusted accordingly.
There was no significant interaction between treatment and time for all parameters. The effect of time was significant for all parameters excluding FC in both phases and EM in phase 2. The results for EP, EW, and EM are found in Table 4. There were no differences in overall EP (P = 0.48). Egg production was not affected by the lower ME diets during both phases 1 and 2 (P ≥ 0.05). The lack of differences in EP could be due to the young age of the birds as they were early into their first egg laying cycle. No differences in EP between the NC and the 2 negative diets with enzymes may also be due to insufficient enzyme activity. There was an overall treatment effect for EW and EM (P = 0.017; P = 0.027). The hens fed the PC and NC diets in phase 1 had higher EW than the NC with enzyme B (P = 0.019), and a similar result was seen for phase 1 EM (P = 0.01). In phase 2, EW was significantly higher for hens fed the PC diet (P = 0.036), but no differences were seen for EM (P = 0.12). Egg mass is a function of EP and EW, and with the exception of PC EW, neither exhibited a treatment response in phase 2. The results for BW, FI, and FC are in Table 5. BW and FI were most responsive to treatments. No differences existed in BW across treatment groups at the beginning of the study (P = 0.63). While all hens were slightly underweight compared to the breed management guidelines of 1550 g at 23 wk of age (HendrixISA LLC, 2015), the hens fed the PC gained significantly more weight during the trial (P < 0.05), and were closer to the standard. Hens on the PC diet consumed significantly less feed overall and during both phases (P = 0.0001). These data indicate that the higher energy in the PC diet resulted in less feed being consumed. There was a significant treatment effect on FC overall and during both phases (P ≤ 0.0001). Hens fed the PC diet had the most efficient FC in phase 2 with an FI:EM ratio of 1.944. As mentioned earlier, the hens fed the PC laid heavier eggs in phase 1 compared to the hens fed the NC diet with enzyme B, and in phase 2 the PC hens produced heavier eggs than all other treatment groups. During phase 2, the hens fed the PC laid heavier eggs than all other treatments (P = 0.036).
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BIGGE ET AL.
Table 4. Effect of treatment on egg percent production, egg weight (EW), and egg mass (EM). Egg production (%) Treatment Positive Control Negative Control Neg. Ctl + Enzyme A Neg. Ctl + Enzyme B SEM1 P Values Treatment Time Trt∗ time
Phase 1
Phase 2
Overall
92.1 91.9 91.5 91.0 0.547
89.4 90.0 89.2 88.5 0.735
90.3 91.3 90.5 90.1 0.482
0.47 0.006 NS
0.54 ≤0.0001 NS
0.48 ≤0.0001 NS
EW (g), EM (g/d) Phase 1 Treatment Positive Control Negative Control Neg. Ctl + Enzyme A Neg. Ctl + Enzyme B SEM1 P Values Treatment Time Trt∗ time ∗ 1
Phase 2
Overall
EW 58.0a 58.4a 57.6a,b 57.0b 0.326
EM 53.97a 54.10a 53.22a,b 52.33b 0.417
EW 60.98a 59.65b 59.66b 59.70b 0.392
EM 54.74 54.21 53.48 53.27 0.481
EW 59.15a 58.86a,b 58.33b,c 57.96c 0.279
EM 54.07a 53.96a 53.21a,b 52.52b 0.401
0.019 ≤0.0001 NS
0.01 ≤0.0001 NS
0.036 0.016 NS
0.12 0.36 NS
0.017 ≤0.0001 NS
0.027 ≤0.0001 NS
Means within a column with differing superscripts are significantly different (P ≤ 0.05). Standard error of the mean.
Table 5. Effect of treatment on bodyweight, feed intake, and feed conversion. Average bodyweight (g) Baseline Treatment Positive Control Negative Control Neg. Ctl +Enzyme A Neg. Ctl +Enzyme B SEM1 P Values Treatment Time Trt∗ time
Phase 1
Overall 1589 1540 1541 1553 15.781
Week 0 1510 1486 1487 1511 18.082
Week 10 1603a 1533b 1542b 1550b 15.901
Week 20 1628a 1562b 1567b 1564b 15.980
Week 35 1639a 1572b 1570b 1574b 18.690
0.63
0.01
0.01
0.03
Feed intake (g/bird/d), feed conversion (g feed:g egg) Phase 1 Treatment Positive Control Negative Control Neg. Ctl +Enzyme A Neg. Ctl +Enzyme B SEM1 P Values Treatment Time Trt∗ time
Phase 2
0.1 ≤0.0001 NS
Phase 2
Overall
FI 104.8a 106.8b,c 106.2b 107.6c 0.407
FC 1.962a 1.986a,b 2.011b 2.070c 0.166
FI 104.8a 107.7b 107.8b 108.9b 0.6312
FC 1.944a 2.010b 2.035b 2.061b 0.0179
FI 104.6a 106.9b 106.7b 107.9b 0.480
FC 1.954a 1.997b 2.021b 2.067c 0.0114
0.0001 ≤0.0001 NS
0.0001 0.13 NS
0.0001 ≤0.0001 NS
0.0001 0.33 NS
0.0001 ≤0.0001 NS
0.0001 0.82 NS
∗
Means within a column with differing superscripts are significantly different (P ≤ 0.05). Standard error of the mean. FC, feed conversion; FI, feed intake
1
Consuming more, yet laying smaller eggs causes the FC ratio to increase, showing that hens are less efficient at converting feed into a product (eggs). Feed conversion can also affect body weight since the hens will need to consume more feed not only to produce eggs, but also to grow and eventually maintain body weight. The differences seen in the study were caused by the decrease in ME and amino acid density in the NC diet. There was no interaction between time and treatment
for the parameters measured in this study. The enzyme supplementation to the NC diet did not support bodyweight or EW equivalent to hens fed the PC diet. As expected, the enzyme activity increased numerically in the lower ME diet due to the higher NSP content from the soy hulls. However, the activity was still quite low compared to similar studies. Xylanase has been shown to have some success in broiler studies, notably when supplemented to
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XYLANASE IN LAYING HENS
non-corn/soy diets. Olukosi et al. (2007) conducted a study of a xylanase, amylase, and protease complex that was dosed to provide 650 U/kg of feed of xylanase, 1650 U/kg of feed of amylase, and 4000 U/kg of feed of phytase in a corn/soybean diet. The enzyme complex increased nutrient retention in young broilers (<3 wk of age), but the researchers attributed much of this to phytase instead of the xylanase in the XAP complex (Olukosi et al., 2007). Another study with broilers used a much higher dosage of xylanase which resulted in 5500 U/kg of feed of xylanase in a wheat-based diet which yielded a significant decrease in FC ratio, and an increase in apparent ME when compared to the control diet (Guo et al., 2014). In laying hen studies, xylanase has had mixed success. Bobeck et al. (2014) conducted a study using xylanase in a corn–soybean meal-dried distiller’s grain diet in first cycle Hy-Line W36 laying hens. The researchers tested 3 energy levels with or without enzyme supplementation. Enzyme activity ranged from <100 to 1550 U/kg depending on diet. Egg production increased with xylanase supplementation, while FI was unaffected. Rather, it was the low-energy diets that caused a significant increase in intake. Egg mass also increased, but the researchers noted it was likely due to the increase in production, not enzyme supplementation (Bobeck et al., 2014). Another study by HahnDidde and Purdum (2014) examined the effect of a xylanase/amylase/protease complex in laying hen diets containing dried distiller’s grains and solubles. This complex was calculated to provide 225 U/g of xylanase, 300 U/g of amylase, and 3000 U/g of phytase. No negative effects were observed for the enzyme supplemented diets, though the specific effect of xylanase was not discussed (Hahn-Didde and Purdum, 2014). The highest xylanase activity in this study was 669 U/kg of feed by enzyme B during phase 2. The use of different xylanases and analytical methodologies may account for the variation in enzyme activities across different studies. The results indicate that this activity level was still not high enough to improve the NC diet to permit the hens to perform at the same level as those fed the PC. As mentioned earlier, the young age of the hens in this study meant that they were highly productive, which may be why no differences were seen for EP despite the effects on bodyweight and FI. Repeating this study using older laying hens may help to
elucidate the effects of xylanase inclusion in low-energy diets.
REFERENCES Bobeck, E. A., N. A. Nachtrieb, A. B. Batal, and M. E. Persia. 2014. Effects of xylanase supplementation of corn-soybean meal-dried distiller’s grain diets on performance, metabolizable energy, and body composition when fed to first-cycle laying hens. J. Appl. Poult. Res. 23:174–180. Choct, M. 2006. Enzymes for the feed industry: past, present and future. Worlds Poult. Sci. J. 62:5–16. Clickner, F. H., and E. H. Follwell. 1926. Application of ”protozyme” (Aspergillus orizae) to poultry feeding. Poult. Sci. 5:241–247. Cowieson, A. J., and M. R. Bedford. 2009. The effect of phytase and carbohydrase on ileal amino acid digestibility in monogastric diets: complimentary mode of action? Worlds Poult. Sci. J. 65:609–624. R Accessed CTB, Inc. 2016. Cage Systems for Layers. Chore-Time. Nov. 2016. http://www.choretime.com/Cage-Systems-for-Layers. Davies, G., and B. Henrissat. 1995. Structures and mechanisms of glycosyl hydrolases. Structure 3:853–859. Deniz, G., H. Gencoglu, S. S. Gezen, I. I. Turkmen, A. Orman, and C. Kara. 2013. Effects of feeding corn distiller’s dried grains with solubles with and without enzyme cocktail supplementation to laying hens on performance, egg quality, selected manure parameters, and feed cost. Livestock Sci. 152:174–181. Guo, S., D. Liu, X. Zhao, C. Li, and Y. Guo. 2014. Xylanase supplementation of a wheat-based diet improved nutrient digestion and mRNA expression of intestinal nutrient transporters in broiler chickens infected with Clostridium perfringens. Poult. Sci. 93:94– 103. Hahn-Didde, D.,, and S. E. Purdum. 2014. The effects of an enzyme complex in moderate and low nutrient-dense diets with dried distillers grains with solubles in laying hens. J. Appl. Poult. Res. 23:23–33. Hendrix-ISA LLC. 2015. Bovans White Commercial Management Guide. Accessed Nov. 2016. http://www.hendrix-isa.com/ en/products/bovans-white/. Kerry Inc. 2016. Global Locations. Kerry. Accessed Nov. 2016. https://www.kerry.com/contact-us/global-locations Mathlouthi, N., M. Larbier, M. A. Mohamed, and M. Lessire. 2002. Performance of laying hens fed wheat, wheat-barley or wheatbarley-wheat bran based diets supplemented with xylanase. Can. J. Anim. Sci. 82: 193–199. Mirzae, S., M. Zaghari, S. Aminzadeh, M. Shivazad, and G. G. Mateos. 2012. Effects of wheat inclusion and xylanase supplementation of the diet on productive performance, nutrient retention, and endogenous intestinal enzyme activity of laying hens. Poult. Sci. 91:413–425. Olukosi, O. A., A. J. Cowieson, and O. Adeola. 2007. Age-related influence of a cocktail of xylanase, amylase, and protease or phytase individually or in combination in broilers. Poult. Sci. 86:77– 86. O’Neill, H. V. M., G. Mathis, B. S. Lumpkins, and M. R. Bedford. 2012. The effect of reduced calorie diets, with and without fat, and the use of xylanase on performance characteristics of broilers between 0 and 42 days. Poult. Sci. 91:1356–1360.
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