본 시험은 microbial phytase을 첨가하여 산란계에 급여시 산란율, 계란 품질, 인 이용율 및 영양소 소화율에 미치는 영향을 조사하기 위하여 수행하였다. 32주령 Hy-Line Brown 갈색계 120수를 공시하여, 4주간 사양시험을 실시하였다. 시험 설계는 CON(control), LP(low phosphorus diet), NP(low phosphorus diet + 0.03% normal microbial phytase) 및 CP(low phosphorus diet + 0.03% coated microbial phytase)로 4개 처리를 하여 처리당 5반복, 반복당 6수씩 완전 임의 배치하였다. 전체 기간 동안 산란율은 CON과 CP 처리구가 LP 처리구보다 높게 나타났다(P<0.05). 난각 강도와 난각 두께는 LP 처리구에 비해 CON, CP 및 NP 처리구가 높게 나타났다(P<0.05). 난황색과 haugh unit에서는 CON, CP 및 NP 처리구가 LP 처리구보다 높게 나타났다(P<0.05). 혈액내 칼슘과 인 농도는 CP 처리구가 LP 처리구에 비해 높게 나타났다(P<0.05). 건물 소화율과 질소 소화율에서는 CP 처리구가 CON, LP 및 NP 처리구에 비하여 유의적으로 증가하였다(P<0.05). 회분소화율은 CON, CP 및 NP 처리구가 LP 처리구에 비해 증가하였다(P<0.05). 칼슘 소화율과 인 소화율에서는 CP와 NP 처리구가 CON과 LP 처리구에 비해 높게 나타났다(P<0.05). 칼슘 흡수량은 CON, CP 및 NP 처리구가 LP 처리구보다 유의적으로 높게 나타났다(P<0.05). 인 흡수량은 CP와 NP 처리구가 CON과 LP 처리구와 비교하여 유의적으로 높게 나타내었다(P<0.05). 질소와 칼슘 배출량은 CON, NP 및 CP 처리구가 LP 처리구에 비해 유의적으로 낮게 나타냈다(P<0.05). 인 배출량은 LP, NP 및 CP 처리구가 CON 처리구에 비해 유의적으로 낮게 나타내었다(P<0.05). 결론적으로, 산란계에 있어 코팅된 microbial phytase의 첨가는 산란율, 계란 품질, 혈액 내 칼슘과 무기태 인, 영양소 소화율과 칼슘 및 인 흡수량을 증진시키며, 질소와 칼슘 배출량을 감소시키는 것으로 나타났다.
The study was conducted to evaluate the effects of dietary microbial phytase on egg productivity, egg quality, phosphorus utilization and nutrient digestibility in laying hens. The animals used in the experiment were a total of 120 Hy-Line Brown laying hens (32 weeks old). Dietary treatments included 1) CON (basal diet), 2) LP (low phosphorus diet) 3) NP (low phosphorus diet + 0.03% normal microbial phytase) and 4) CP (low phosphorus diet + 0.03% coated microbial phytase). Six laying hens were allotted to a block (pen) with five replicated. Through the whole period of experiment, egg production was significantly increased in CON and CP treatments compared to LP treatment (P<0.05). CON, CP and NP treatments significantly increased their egg shell breaking strength and egg shell thickness compared to LP treatment (P<0.05). CON, CP and NP treatments resulted higher yolk color and Haugh unit than LP treatment (P<0.05). Calcium and inorganic phosphorus contents in blood were higher in CP treatment compared to LP treatment (P<0.05). Dry matter digestibility and nitrogen digestibility were greater in CP treatment than CON, LP and NP treatments (P<0.05). Crude ash was increased in CON, CP and NP treatments compared to LP treatment (P<0.05). Calcium digestibility and phosphorus digestibility were significantly improved in CP and NP treatments than CON and LP treatments (P<0.05). Calcium retention of CON, CP and NP treatments were higher than LP treatment (P<0.05). Phosphorus retention was increased in CP and NP treatments compared to CON and LP treatments (P<0.05). LP treatment significantly increased their nitrogen, calcium excretion compared to CON, CP and NP treatments (P<0.05). Phosphorus excretion was decreased in LP, CP and NP treatments compared to CON treatment (P<0.05). In conclusion, CP treatment improved egg production, egg quality, inorganic calcium and phosphorus in blood, calcium and phosphorus retention and nutrient digestibility and decreased nitrogen and calcium excretion in laying hens.
