Effects of dietary threonine supplementation on productivity and expression of genes related to protein deposition and amino acid transportation in breeder hens of yellow-feathered chicken and their offspring

Abstract

This study investigated the effects of the dietary threonine (Thr) levels on the performance, offspring traits, embryo amino acid transportation, and protein deposition in breeder hens of yellow-feathered chickens. In total, 720 breeder hens of Lingnan yellow-feathered chickens were randomly assigned to 1 of 6 dietary treatments, with 6 replicates per treatment (20 birds per replicate). The breeder hens were fed either basal diet (Thr = 0.38%) or basal diet supplemented with 0.12, 0.24, 0.36, 0.48, or 0.60% Thr from 197 to 266 D. There was a positive response in terms of the laying rate after adding different levels of Thr to the diet, but no significant effects on the average daily gain, average daily egg weight, feed conversion ratio, average broken eggs, and unqualified egg rate (P > 0.05). However, the eggshell strength and eggshell percentage decreased in a linear manner as the dietary Thr concentration increased (P = 0.05). Dietary supplementation with Thr had significant effects on the expression of mucin 2 (MUC2) in the uterus and zonula occludens protein 1 (ZO-1) in the duodenum of breeders (P < 0.05). In chick embryos at embryonic age 18 D, significant upregulation of poultry target of rapamycin (pTOR) occurred in the liver and breast muscle, as well as threonine dehydrogenase (TDH) in the thigh, and aminopeptidase (ANPEP) (P < 0.05) in the duodenum and ileum due to dietary Thr supplementation, but there were no effects on MUC2 expression in the duodenum and ileum (P > 0.05). The livability of the progeny broilers tended to increase with the dietary Thr concentration (quadratic, P = 0.08). Thus, dietary supplementation with Thr had positive effects on the laying production by breeder hens and offspring performance, and it also regulated the expression levels of genes related to amino acid transportation and protein deposition. The optimal dietary Thr concentration that maximized the laying rate in yellow-feathered chicken breeders aged 197 to 266 D was 0.68% according to quadratic regression analysis.

Effects of amino acid levels during rearing on Cobb 500 slow-feathering broiler breeders: 2. Reproductive performance

“…On the other hand, shell strength and yolk color were affected linearly as AA increased in rearing diets and shell weight and elasticity in a quadratic way. Jiang et al (2019) reported a linear decrease in the eggshell percentage, thickness, and strength in broiler breeders supplemented with Thr ranging from 0.50 up to 0.98% of total dietary content in the laying phase from 28 to 38 wk of age. However, these levels were higher than those used in the experimental rearing diets and standard layer diets in our experiment.…”

Natural Products of Plants and Animal Origin Improve Albumen Quality of Chicken Eggs

“…This, in turn, promotes the metabolic rate in the magnum, increases the activity of the shell gland, and produces eggshells with enhanced integrity, reducing the loss of carbon dioxide and improving albumen quality. In another study, threonine improved albumen percentage in a dose-dependent manner via upregulation of genes related to AA transport and protein deposition (183). In another study, (34), suggested that supplementing diets that enhance upregulation of AA transporters would enhance albumen synthesis and quality.…”

“…Similarly, lysine supplementation enhanced albumen percentage (182). Also, dietary threonine supplemented in a dosedependent manner increased albumen weight and percentage (183). Improved albumen indices with AA supplementation may be due to increased nutrient concentration and protein levels in the diet (184), which enhance protein synthesis (185).…”

Effects of Dietary Arginine on Growth Performance, Digestion, Absorption Ability, Antioxidant Capability, Gene Expression of Intestinal Protein Synthesis, and Inflammation-Related Genes of Triploid Juvenile Oncorhynchus mykiss Fed a Low-Fishmeal Diet

“…The NF-κB signalling pathway plays a key role in inflammation and is involved in the regulation of anti-and proinflammatory cytokines [25]. Proinflammatory cytokines contribute to the host's prevention mechanism of bacterial colonization or invasion [26,27], and anti-inflammatory cytokines inhibit the overactivation of the immune response [28].…”