The effect of zinc, iron, calcium, and copper from organic sources in pheasant diet on the performance, hatching, minerals, and fatty acid composition of eggs

Abstract

The paper presents findings about how the substitution of calcium, iron, zinc, and copper salts with glycine chelates affects specific reproductive parameters of pheasants, the hatching potential and nutritional components of pheasant eggs, and the fatty acid profiles and cholesterol content in pheasant yolk. 4 groups were created for the experiment: the control, in which the birds received a feed containing standard calcium, iron, zinc, and copper salts, and 3 experimental groups in which chelates were used to replace 25, 50, and 75% of the mineral salts. The group with the 75% chelate share was not supplemented with the salts, and cholecalciferol was replaced with calcitriol. The groups included pheasant females (7 birds) and 1 male, respectively, and were maintained in outdoor aviaries. The birds were administered granulated feed mixes ad libitum, with free access to water. Their feed intake was recorded each day. The birds were weighed at the beginning and end of the egg-laying period. The eggs were collected throughout the egg-laying period, and the eggs gathered at the culmination of the egg-laying period were used for hatching. The eggs were morphometrically analyzed and the hatching process and subsequent hatchling survival rates were investigated. Nutritional components in the eggs were determined, and the fatty acid profiles and cholesterol content were assayed in the yolk. The results showed the use of Ca, Fe, Zn, and Cu chelates in place of salts in the pheasant brood hen diet had contributed to enhancing the egg-laying performance, with a concurrent fall in the size and weight of the eggs. The highest egg-laying performance, with the lowest egg weight, was observed in the group that consumed the highest (75%) share of mineral chelates and received calcitriol supplementation. This corresponded with the highest incubation yield and hatchling survival. The thickest shells and highest crude ash percentages were identified in the eggs of the pheasant group that received a 50% by 50% proportion of salts and glycine chelates. In comparison with the control birds that received the mineral salts, the yolk of the pheasants that consumed the feed with the 75% share of calcitriol and Ca, Fe, Zn, and Cu chelates had a higher percentage of n-6 and n-3 polyunsaturated fatty acids (PUFAs), with a far more advantageous n-6/n-3 proportion. No differences related to the source and levels of Ca, Fe, Zn, and Cu in the feed were observed in the cholesterol content of the pheasant yolk.