Abstract
This experiment was carried out to evaluate biological availability of Ca and P in 4 different sources of tricalcium phosphate in young chicks. One hundred and twenty five-day-old male Single Comb White Leghorn chicks (10 treatments$\times$3replication$\times$4chicks) were used in trial 1 and 2, respectively, for 12 days of feeding period. Trial I was to evaluate the availability of phosphorus in the supplements, Standard purified diets were prepared to supply 0.07, 0.14 and 0.21％P using a mixture (1 : 1) of NaH$_2$PO$_4$ and KH$_2$PO$_4$ as the reference Phosphorus sources. Bone breaking strength of the tibia determeined by an Instron instrument appeared inadequate to be used as a criterion due to very high variations of the measurement within a treatment. Thus, tibia bone ash content was utilized as a criterion to evaluate th biological avilability of phosphorus in the supplements. The levels of the biological availability of the four different sources of dicalcium phoshate were 77.1, 91.0, 96.4 and 95.5％, respectively, and those of the three tricalcium phosphate sources were 94.1, 95.0 and 99.5％ , respectively. Trial 2 was to determeine the levels of Ca biologically available in the supplements. Standard purified diets were made to supply 0.2, 0.3 and 0.4％ Ca using CaCo$_3$ as the reference calcium source. When bone ash content was utilized as a criterion for the availability, the levels of calcium biologically available to the chicks were 78.3, 234.1, 87.6 and 244.5％, respectively, for the 4 different sources of dicalcium phosphate and 99.5, 84.0 and 101.5％ , respectively, for the 3 different sources of tricalcium phosphate. The observation that two calcium sources appeared to be utilized with an unusual efficiency can hardly be explained at this moment. When they were revaluated on the basis of body weight gain, the availabilities of the four sources of dicalcium phosphate were 89.2, 58.2, 104.1 and 103.1％ and of the three tricalcium phosphate were 112.6, 106.0 and 96.3％ , respectively.
본 실험은 사료첨가제로 사용되는 인산칼슘제에 들어있는 Ca과 P의 생물학적 이용성을 측정 비교하고자 실시하였다. 5일령의 수평아리를 사용하여 12 일간의 실험기간 후에 경골의 회분함량율 기준으로 하여 표준계선에 의한 least square방식으로 측정한 이용성의 결과는 다음과 같다. 1. P의 이용성은 DiCa-P첨가제가 각각 77.1, 91.0, 96.4 그리고 95.5％를 나타냈고 TriCa-P첨가제는 각각 94.1, 95.0 및 99.5％를 나타냈다. 2. Ca의 이용성은 DiCa-P 첨가제에서 각각 78.3, 234.1, 87.6 그리고 244.5％였고 TriCa-P첨가제는 각각 99.5, 84.0 및 101.5 ％였다. 3. 전반적으로 TriCa-P첨가제가 DiCa-P첨가제보다 이용성이 약간 높게 나타났다. 4. 국산과 외국산 인산칼슘제의 이용성의 차이는 없었다.