Effect of dietary serine supplementation on performance, egg quality, serum indices, and ileal mucosal immunity in laying hens fed a low crude protein diet

Abstract

This study was designed to evaluate the effect of dietary Ser on performance, egg quality, serum indices, and ileal mucosal immunity in laying hens fed low crude protein ( LCP ), essential amino acids ( EAA ) balanced diets. A total of 480 Hy-Line Brown layers at 24 wk of age were randomly assigned into 5 dietary treatments with 8 replicates of 12 birds each. Treatments included a control diet (16.49% CP), and 4 LCP, EAA balanced diets (14.05% CP) supplemented with 0, 0.114%, 0.306%, 0.498% L-Ser, respectively. Dietary Ser supplementation linearly increased hen-day egg production ( HDEP ; P < 0.05) and decreased feed-to-egg ratio ( P < 0.05) among LCP groups from wk 6 to 10, and the optimal HDEP of layers occurred at Ser level of 0.498%. At the end of wk 10, birds in the control had higher albumen height and thick white proportion than those fed the LCP diet without Ser addition ( P < 0.05), and presented a lower yolk color score than all LCP groups ( P < 0.05). Among LCP groups, serum total protein and globulin contents were significantly increased by dietary Ser addition at the levels of 0.306% and 0.498% ( P < 0.05), and had a linear response to the supplemental Ser levels ( P < 0.05). Furthermore, dietary 0.498% Ser supplementation significantly increased serum immunoglobulin G and immunoglobulin M contents ( P < 0.05) and up-regulated the expression of mucin 2, secretory immunoglobulin A, and relevant glycosyltransferases of O-glycosylation in ileal mucosa ( P < 0.05). The increased expression of proinflammatory cytokines IFN-γ and IL-1β induced by LCP diets ( P < 0.05) was reversed following 0.498% Ser addition ( P < 0.05). Collectively, dietary CP reduction by 2.44% could maintain the productive performance of layers when it was fortified with certain EAA, though poor albumen quality, and ileal inflammation were occurred. The addition of Ser to LCP diets improved performance probably through enhancing humoral and ileal mucosal immunity and attenuating the ileal inflammation of layers.

Effects of a low‐protein diet supplemented with essential amino acids on egg production performance and environmental gas emissions from layer‐manure composting in laying hens in the later laying period

“…The conventional layer diet contained sufficient essential amino acids and nonessential amino acids; however, it is possible that a low‐protein diet does not supply enough nitrogen for the synthesis of nonessential amino acids (Macelline et al, 2021). Additionally, Zhou et al (2021) reported that LPS supplemented with serine recovered the egg‐laying rate depending on the serine concentration. In the present study, the reduction of dietary CP of the low‐protein diet was relatively small (two percentage points), possibly resulting in sufficient dietary nitrogen for the synthesis of nonessential amino acids, and we designed the composition of the experimental diets based on the Japanese Feeding Standard for Poultry and ensured that they contained adequate amounts of essential amino acids and Gly + Ser (NARO, 2011).…”

Lipoamide Alleviates Oxidized Fish Oil-Induced Host Inflammatory Response and Oxidative Damage in the Oviduct of Laying Hens

“…A study found that as a coenzyme of mitochondria, LA can alleviate the loss of mitochondrial function due to aging and reduce the oxidative stress and inflammatory response of the ovary and oviduct ( 43 ), thus improving the reproductive pathway. Zhou et al ( 44 ) found that the addition of antioxidants improved performance probably through enhancing the immunity and attenuating inflammation of laying hens. Here in this study, it was found that OFO induced an increase in serum inflammatory factors, and the dietary addition of LAM significantly increased immunoglobulin (IgA, IgG, and IgM) levels and reduced the inflammatory factors (TNF-α, IL-1β, IL-6, and IFN-γ).…”

Enhancing egg production and quality by the supplementation of probiotic strains (Clostridium and Brevibacillus) via improved amino acid digestibility, intestinal health, immune response, and antioxidant activity

“…Upon breakage of each egg, the albumen and the yolk were separated with the aid of an egg separator, and the weight of each was recorded. To measure the thick and thin albumen fractions, the weighed albumen was placed in a 60-mesh sieve at a time bound of 30 s, the thick portion of the albumen was glued to the sieve while the thin portion passed through the sieve as filtrate, and the corresponding weight of each fraction was recorded ( Zhou et al, 2021 ). The eggshells were cleaned to remove any albumen fragments and then naturally dried for 48 h, and the weight was obtained.…”