Effect of varying ratios of dietary calcium and phosphorus on performance, phytate P and mineral retention in Japanese quail (Coturnix cotnurnix Japonica).

The effect of different ratios of dietary calcium (Ca) to total phosphorus (tP) on the performances and retention of minerals and phytate phosphorus (pP) by quails were studied using 600 unsexed broiler quails from 1 to 21 days of age. Treatments consist of five corn and soybean meal (CSM) based diets with variable ratios of Ca:tP (1.96, 1.81, 1.66, 1.53 and 1.39) with four replicate of 30 birds each. Diets contained 3g chromium oxide (Cr2O3)/kg as marker. All ratios of Ca and P had no significant effect on feed consumption of birds. There were pronounced differences (P < 0.05) in body weight gain of chicks among treatments at second and third week of age. Improved (P < 0.05) feed conversion ratio was observed at 3 wk of age. Higher ratios of Ca:tP (1.96 and 1.81) increased (P < 0.05) the retention of P compared to other treatments while ratio of 1.96 decreased (P < 0.05) the retention of Ca and phytate. In conclusion, Ca:tP ratio of 1.81 showed positive effect on most of parameters measured in this study

Studies on zinc deficiency: changes in trace elements and enzyme activities in tissues of zinc-deficient rats

Summary. Zinc content of testes, bones, esophagus, kidneys, and muscles was decreased, whereas iron content was increased in the testes of zincdeficient rats compared to restrictedly fed control rats. Histochemical enzyme determinations revealed reduced activities of certain enzymes in the testes, bones, esophagus, and kidneys. In the testes, lactic dehydrogenase (LDH), malic dehydrogenase (MDH), alcohol dehydrogenase (ADH), and NADH diaphorase; in the bones, LDH, MDH, ADH, and alkaline phosphatase; in the esophagus, MDH, ADH, and NADH diaphorase; and in the kidneys, MDH and alkaline phosphatase were decreased in zinc-deficient rats compared to restrictedly fed controls. Succinic dehydrogenase (SDH) revealed no significant changes under the conditions of our experiments in various groups of rats that were investigated. In a &quot;repleted&quot; group of rats, content of zinc in testes and bones increased significantly, compared to the deficient group. The iron content of the testes decreased after repletion with zinc. In the testes, bones, esophagus, and kidneys, the activities of various enzymes increased after repletion with zinc

The decreased molar ratio of phytate:zinc improved zinc nutriture in South Koreans for the past 30 years (1969-1998)

For the assessment of representative and longitudinal Zn nutriture in South Koreans, Zn, phytate and Ca intakes were determined using four consecutive years of food consumption data taken from Korean National Nutrition Survey Report (KNNSR) every 10 years during 1969-1998. The nutrient intake data are presented for large city and rural areas. Zn intake of South Koreans in both large city and rural areas was low during 1969-1988 having values between 4.5-5.6 mg/d, after then increased to 7.4 (91% Estimated Average Requirements for Koreans, EAR = 8.1 mg/d) and 6.7 mg/d (74% EAR) in 1998 in large city and rural areas, respectively. In 1968, Zn intake was unexpectedly higher in rural areas due to higher grain consumption, but since then until 1988 Zn intake was decreased and increased back in 1998. Food sources for Zn have shifted from plants to a variety of animal products. Phytate intake of South Koreans during 1969-1978 was high mainly due to the consumption of grains and soy products which are major phytate sources, but decreased in 1998. The molar ratios of phytate:Zn and millimmolar ratio of phytate×Ca:Zn were decreased due to the decreased phytate intake in South Koreans, which implies higher zinc bioavailability. The study results suggest that Zn nutriture has improved by increased dietary Zn intakes and the decreased molar ratio of phytate:Zn in South Koreans in both large city and rural areas