The Effects of Various Dietary Levels of Phytase and Available ...

Research Notes The Effects of Various Dietary Levels of Phytase and Available Phosphorus on Performance of Laying Hens S. D. Boling, M. W. Douglas, R. B. Shirley, C. M. Parsons,1 and K. W. Koelkebeck Department of Animal Sciences, University of Illinois, Urbana, Illinois 61801 experiment. By 28 wk of age, the 0.10% AP diet, with no supplemental phytase or P, resulted in significantly lower (P < 0.05) egg production and body weight compared with all other dietary treatments. Feed consumption, feed efficiency, and egg yield were subsequently depressed by 32 wk of age in hens fed the 0.10% AP diet. No other significant differences among treatments were observed for performance averaged over the entire 40-wk experimental period. The mean daily AP intake of hens fed the 0.15% AP, 0.45% AP, and 0.10% AP + phytase diets was 155, 474, and 103 mg, respectively. The results of this study indicate that phytase improves the utilization of P in corn-SBM diets for laying hens and that corn-SBM diets containing 0.10% AP + 100 units of phytase/kg diet or 0.15% AP supported egg production performance that was not significantly different (P > 0.05) from that of hens fed a corn-SBM diet containing 0.45% AP.

ABSTRACT Data previously obtained from our laboratory indicated that addition of 300 U of phytase/kg diet supported optimal long-term performance of laying hens (20 to 70 wk) fed a corn-soybean meal (SBM) diet containing 0.10% available phosphorus (AP). Our primary objective was to determine if a phytase level lower than 300 units/kg is adequate for a commercial strain of Single Comb White Leghorn laying hens (n = 504) fed a cornSBM diet containing no supplemental P (0.10% AP). Dietary treatments consisted of the corn-SBM basal diet (0.10% AP, 3.8% Ca, and 17% CP) supplemented with 0, 100, 200, 250, or 300 U of phytase/kg, 0.05% inorganic P (0.15% AP), and a positive control diet containing 0.45% AP. Each of the seven dietary treatments was fed to six replicate groups of 12 hens from 20 to 60 wk of age. No significant differences in performance were observed among treatments during the first 8 wk of the

(Key words: available phosphorus, phytase, laying hens) 2000 Poultry Science 79:535–538

supplemental P was included at 0, 0.30, 0.60, or 0.90%. It was concluded that 0.30% supplemental P or as little as 100 U phytase/kg resulted in optimal performance in their study. However, the diet used in the study by van der Klis et al. (1997) was apparently not very deficient in P, because the unsupplemented basal diet yielded an egg production level of 84% for the 16- to 68-wk experimental period. The objective of our current experiment was to determine if lower levels of phytase ( 0.05) negative effect on performance. The latter is particularly important when considering P excretion. Average analyzed total P values for the diets containing 0.10% AP + 100 U/kg phytase, 0.10% AP + 300 U/kg phytase, 0.15% AP, and 0.45% AP were 0.23, 0.26, 0.30, and 0.58% total P, respectively. Excreta P level measured from hens consuming 0.45% AP was 1.12%. When dietary P levels were reduced to 0.10% AP + 100 or 300 U/kg phytase, excreta P levels decreased to 0.65%.

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RESEARCH NOTE 1

TABLE 1. Influence of dietary available phosphorus level (AP) and phytase on hen-day egg production Age (wk) Dietary AP2

Phytase

(%) 0.10 0.10 0.10 0.10 0.10 0.15 0.45 Pooled SEM

(U/kg) 0 100 200 250 300 0 0

21

22

23

24

25

26

27

28

29

30

37a 41a 41a 49a 43a 42a 40a 4.6

64d 74abc 75ab 75ab 66cd 68bcd 77a 2.9

80c 87ab 87ab 90a 82bc 85abc 89a 2.1

88b 91ab 92ab 91ab 89b 89b 95a 2.0

85b 89ab 92a 92a 89ab 85b 92a 1.8

84c 87bc 94a 91abc 90abc 90abc 93ab 2.3

84b 87ab 93a 90ab 87ab 88ab 89ab 2.4

81b 88ab 93a 88a 88a 87ab 89a 2.8

(%) 72c 72c 85b 85ab 94a 92a 89ab 91a 85b 86ab 84b 78bc 94a 92a 2.8 2.8

31

32

33

34

35

40

50

60

72c 86ab 92a 90ab 87ab 84b 89ab 2.7

72d 89abc 94a 88bc 90ab 84c 93ab 2.0

63c 85b 93a 89ab 90ab 85b 94a 2.2

56c 85ab 90a 88ab 90a 83b 89ab 2.3

51b 87a 93a 88a 89a 85a 88a 3.0

49c 85ab 92a 88ab 83b 84ab 89ab 2.9

— 73a 77a 77a 77a 78a 80a 3.2

— 74ab 78a 74ab 70b 69b 78a 2.2

Within a column, values with no common superscript letters are significantly different (P < 0.05). Data are means of six replications of 12 hens. 2 The 0.10% AP with no phytase treatment was terminated at 40 wk of age. a–d 1

Excreta from hens consuming 0.15% AP was analyzed to contain 0.64% AP. Therefore, approximately a 50% reduction in excreta P was obtained by feeding a cornSBM diet containing as little as 100 U/kg phytase or only 0.05% supplemental inorganic P compared with feeding 0.45% AP. Simons et al. (1990) observed a 20 to 30% reduction in excreta P when broilers were fed low-P (0.45% total P) corn-SBM-sorghum-sunflower seed meal diets supplemented with phytase. A reduction in excreta P is of great importance when considering environmental aspects of the poultry industry. Our results for egg production performance are in agreement with those of van der Klis et al. (1997) who also observed that addition of 100 U phytase/kg was adequate in a P-unsupplemented corn-SBM–based diet during a 50-wk laying cycle. However, a point of contrast between the current study and van der Klis et al. (1997) is the difference of severity in response of the hens fed the diet containing no supplemental P or phytase. As previously stated, hens in the current experiment fed the unsupplemented corn-SBM diet (0.10% AP) were removed from the experimental diet at 40 wk of age when egg production had declined to only 49%. Average egg production from 20 to 40 wk of age for hens fed 0.10% AP in the current study was only 66%. Conversely, van der Klis et al. (1997) observed an average egg production of 84% when hens were fed an unsupplemented corn-

SBM–based diet from 18 to 68 wk of age. The hens in that 50-wk study did not reach the low production levels observed within 8 wk in the current study. A probable explanation for this difference between studies is that the corn-SBM diet fed in our study was more deficient in AP than the corn-SBM based diet fed by van der Klis et al. (1997). In the latter study, they fed two batches of a cornSBM-based diet, which contained from 6.1 to 10.6% corn gluten feed and 2% sunflower seed meal. Inclusion of the latter ingredients may have increased the AP content. Indeed, the second batch of diet fed by van der Klis et al. (1997) was analyzed to contain 0.13% AP, which may not be low enough to induce a severe P deficiency based on the results of our current study, in which 0.15% AP with no phytase supplementation (a value not much different from 0.13% AP) was adequate for performance of laying hens. The hens in the current study were clearly more P deficient than the hens in the van der Klis et al. (1997) study. Therefore, it is particularly notable that the marked AP deficiency in our study was totally alleviated by as little as 100 U/kg phytase supplementation. The latter results indicate that the phytase utilized herein was efficacious. Our results provide additional evidence that phytase improved P utilization in corn-SBM diets for laying hens, as other studies have indicated (Gordon and Roland, 1997; van der Klis et al., 1997; Carlos and Edwards; 1998; Um

TABLE 2. Effect of available phosphorus (AP) level and phytase on performance of laying hens from 20 to 60 wk of age1 Dietary AP

Phytase

(%) 0.10 0.10 0.10 0.10 0.15 0.45 Pooled SEM

(U/kg) 100 200 250 300 0 0

AP intake

Egg production

Egg size

Daily egg mass

Feed efficiency

Specific gravity

Body weight

(mg/hen/d) 104 106 103 104 155 474 —

(%) 80 85 82 81 79 85 2.9

(g) 61 60 60 60 61 59 .8

(g/hen/d) 49 51 49 49 48 51 1.7

(g/g) 0.47 0.48 0.49 0.47 0.47 0.48 0.014

(g/cm3) 1.081 1.082 1.082 1.081 1.081 1.081 1.9 × 10–3

(g) 1473 1476 1471 1489 1485 1503 19.0

1 Data are means of six replications of 12 hens. There were no significant differences (P > 0.05) among treatments for any of the measured production parameters.

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BOLING ET AL.

and Paik, 1999). Furthermore, the current study demonstrated that a corn-SBM diet containing 0.10% AP and as little as 100 U phytase/kg (104 mg AP/hen per d) could be fed for as long as 40 wk with no significant deleterious effects on performance. Moreover, a diet containing only 0.15% AP (155 mg AP/hen per d) could also be fed without a significant negative effect on performance and confirms the results from our previous study (Boling et al., 2000).

ACKNOWLEDGMENTS The authors wish to express their thanks to Purina Mills, Inc., St. Louis, MO 63166, and to BASF Corp., Mount Olive, NJ 07828-1234, for financial support of this project.

REFERENCES Boling, S. D., M. W. Douglas, M. L. Johnson, X. Wang, C. M. Parsons, K. W. Koelkebeck, and R. A. Zimmerman, 2000. The effects of dietary available phosphorus levels and phytase

on performance of young and older laying hens. Poultry Sci. 78:79:224–230. Carlos, A. B., and H. M. Edwards, Jr., 1998. The effects of 1,25dihydroxycholecalciferol and phytase on the natural phytate phosphorus utilization by laying hens. Poultry Sci. 77:850– 858. Gordon, R. W., and D. A. Roland, 1997. Performance of commercial laying hens fed various phosphorus levels, with and without supplemental phytase. Poultry Sci. 76:1172–1177. National Research Council, 1994. Nutrient Requirements of Poultry. 9th rev. ed. National Academy Press, Washington, DC. SAS Institute, 1990. SAS威 Users Guide: Statistics. Version 6, Fourth Edition. SAS Institute Inc., Cary, NC. Simons, P.C.M., H.A.V. Versteegh, A. W. Jongbloed, P. A. Kemme, P. Slump, K. D. Bos, M.G.E. Wolters, R. F. Beudeker, and G. J. Vershoor, 1990. Improvement of phosphorus availability by microbial phytase in broilers and pigs. Br. J. Nutr. 64:525–540. Um, J. S., and I. K. Paik, 1999. Effects of microbial phytase supplementation on egg production, eggshell quality, and mineral retention of laying hens fed different levels of phosphorus. Poultry Sci. 78:75–79. van der Klis, J. D., H.A.J. Versteegh, P.C.M. Simons, and A. K. Kies, 1997. The efficacy of phytase in corn-soybean mealbased diets for laying hens. Poultry Sci. 76:1535–1542.