1. Determination of optimal dietary calcium levels under different sources of zinc in Jing tint 6 layer chicks from 15 to 42 d of age.
- Author
-
Gong C, Shi H, Liu S, Gao X, Zhang S, Liu H, Liu X, Li R, and Wan D
- Subjects
- Animals, Female, Dose-Response Relationship, Drug, Random Allocation, Chickens growth & development, Chickens physiology, Animal Feed analysis, Diet veterinary, Zinc administration & dosage, Zinc metabolism, Animal Nutritional Physiological Phenomena drug effects, Calcium, Dietary metabolism, Calcium, Dietary administration & dosage, Calcium, Dietary analysis, Dietary Supplements analysis
- Abstract
An experiment was conducted to investigate the optimal dietary calcium (Ca) levels in Jing Tint 6 layer chicks fed different sources of zinc (Zn). The diets were formulated using 2 different Zn sources: organic Zn (80 mg/kg Zn as HMZn) and inorganic Zn (80 mg/kg Zn as sulfate). For each Zn source, 5 diets were formulated to contain Ca levels of 0.80, 0.90, 1.03, 1.10, and 1.20%. Results showed that dietary Ca levels had a significant effect on body weight gain (BWG) and feed conversion ratio (FCR) (P < 0.05). In addition, BWG was significantly enhanced by the organic Zn diets (P < 0.05). Dietary Ca levels significantly affected tibia length (P < 0.05) and serum Ca and P contents (P < 0.05) but did not affect serum total protein (TP), albumin (ALB), or alkaline phosphatase (ALP) levels (P > 0.05). The apparent total tract retention coefficients (ATTRC) of Ca showed a quadratic trend (P < 0.05) with increasing Ca levels. Furthermore, organic Zn diets reduced excreta Ca output and enhanced the ATTRC of Ca in birds on d 42 compared with inorganic Zn diets. The optimal dietary Ca levels were estimated as 0.93, 0.94, and 0.96% for birds fed organic diets and 1.07, 0.99 and 0.94% for birds fed inorganic diets using nonlinear models based on the criteria of BWG, tibial length, and serum P, respectively. In general, organic Zn supplementation improved growth performance and reduced the calcium requirements of birds on d 42., Competing Interests: DISCLOSURES The authors declare that there is no conflict of interest., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)
- Published
- 2024
- Full Text
- View/download PDF