Improvement of eggshell quality by dietary N-carbamylglutamate supplementation in laying chickens

Abstract

Egg quality defects seriously reduce the quality grade and increase egg breakage in egg marketing activities. In this study, the effect of N-carbamylglutamate ( NCG ) on eggshell quality was investigated by evaluating calcium absorption and calcification in laying hens. A total of 30 newly hatched female Hy-Line chicks were randomly assigned to the control group (basal diet) and treatment group (basal diet supplemented with 1% NCG). At 25 wk, eggs from each group were obtained to assess egg quality parameters. Blood samples were collected for analysis of mineral, hormone, and amino acids levels at 16 h after laying egg. Uterine tissues were removed and fixed in 4% neutral paraformaldehyde solution or kept in liquid nitrogen for mineral determination, quantitative PCR, and Western blot. Results showed that the egg quality (eggshell thickness, strength and percentage, egg specific gravity, and eggshell effective thickness) was significantly increased while effective thickness of mastoid layer, width of mastoid gap, and mammillary knobs were significantly decreased by dietary NCG supplementation ( P < 0.05). The levels of minerals (Ca, P, Fe, Mg, Na, K) in eggshell, plasma, and uterus were remarkably elevated ( P < 0.05). Meanwhile, the concentrations of calcium metabolism–related hormones (17β-estradiol, parathyroid hormone, and calcitonin) were increased in the NCG group ( P < 0.05). Moreover, expression of calbindin 1, carbonic anhydrase 2, ovalbumin, ovotransferrin, ovocleidin-17, ovocleidin-116, and clusterin mRNAs, as well as calbindin 1 and ATP2A1 proteins in uterus, duodenum, and kidney, was all upregulated in hens fed with NCG ( P < 0.05). In addition, the number of blood vessels in the uterus, height of uterine mucosal folds, villus length in endometrium, and areas of uterine mucosal folds were significantly increased in the NCG group ( P < 0.05). In conclusion, dietary 1% NCG supplementation during 0 to 25 wk can improve eggshell quality through changes in endometrial morphology, expression of calcium metabolism–related genes, and secretion of related hormones to promote eggshell formation in the laying hens.

Integration of transcriptomic and metabolomic analysis of the mechanism of dietary N-carbamoylglutamate in promoting follicle development in yaks

“…It has been previously reported that NCG, an activator of carbamoyl phosphate synthase-1 and pyrroline-5 carboxylate synthase in the ornithine cycle, increases the synthesis of endogenous arginine ( 56 ) and promotes the process of ovarian tissue angiogenesis to provide adequate nutrients and oxygen, and favorable conditions for follicle growth and development ( 24 , 25 ). Dietary supplementation with NCG has also been reported to increase blood estradiol concentrations in yaks ( 25 ) and chickens ( 57 ). Supplementation of NCG also promoted cell proliferation and inhibited apoptosis of pig placental trophoblast cells ( 58 ), and stimulated cell proliferation of bovine granulosa cells ( 59 ), both of which can synthesize estrogen.…”

Naringin prevents follicular atresia by inhibiting oxidative stress in the aging chicken

“…Hens were sacrificed after anesthesia, and the ovaries were separated for collection of small white follicle ( SWFs ) (2–4 mm). Composition and nutrient levels of basal diet is the same as that in a published article ( Ma et al., 2020 ).…”

Egg Shell: An Essential Waste Product to Improve Dietary Calcium Uptake

“…Chemically speaking, an ES from a hen has 65.6 percent water, 11.8 % proteins, 11 % fat, and 11.7 % ash. Chemically, ES powder is made up of 21.2 % carbon, 0.93 % magnesium oxide, 76.9 % calcium oxide, 0.42 % porosity, 0.02 % iron oxide, and 0.11 percent sodium oxide [22][23][24][25] (Figure 1). ESs also contains 0.3 % phosphorus, which is found in little amounts but is particularly beneficial for regenerating hen bones.…”

“…This can boost the absorption of micro minerals, such as calcium, because calcium is converted to an ionic form in an acidic environment, making it more soluble and accessible. The shortchain fatty acids produced during the prebiotic fiber fermentation process, along with the acidic environment they create, cause the mucosal cells to swell, which increases the surface area of the intestine and enhances calcium absorption [18][19][20][21][22][23][24][25].…”

“…Researchers discovered that mice given food enriched with monounsaturated fatty acids had considerably higher levels of hepatic cytochrome P450 protein, intestinal calbindine D9k gene expression, and trabecular volume thickness than mice given an unaltered diet. Therefore, a diet high in monounsaturated fatty acids is advised since it has the best effects on bone health and slightly increases intestinal calcium absorption [22].…”