Dietary Supplementation of Calcium Propionate and Calcium Butyrate Improves Eggshell Quality of Laying Hens in the Late Phase of Production

Effects of low dietary calcium and lipopolysaccharide challenges on production performance, eggshell quality, and bone metabolism of laying hens

Dietary calcium supply is essential for bone development and egg production in laying hens. This study investigated the effects of low dietary calcium and lipopolysaccharide (LPS) induced immune challenge in aged laying hens. A total of thirty-two Hy-Line Brown laying hens at 80 weeks old with an average laying rate of 62% were randomly divided into two groups and fed a normal calcium diet (3.57% Ca, NCA) or low calcium diet (2.08% Ca, LCA). At 88 weeks, the experiment was designed using a 2 × 2 factorial arrangement, and hens were intraperitoneally injected with saline (SAL) or LPS (0.5 mg/kg, 0.5 mg/kg, or 1.5 mg/kg body weight) once every 48 h intervals over 5 days. Production performance, egg quality, and bone physiology were evaluated. Results showed that LPS challenge decreased the hen-day egg production, egg mass, and eggshell traits (p < 0.05), but increased (p < 0.05) the calcium content of the tibia compared to SAL-injected hens. LCA diet decreased (p < 0.05) the hen-day egg production, and eggshell traits such as weight, percentage, strength, and thickness compared to the NCA diet. LCA diet increased the serum alkaline phosphatase (ALP) activity (p < 0.01) and tibial expression of ALP (p < 0.05) compared to NCA diet. LPS injection suppressed both the serum ALP activity (p < 0.05) and tibial expression of ALP (p < 0.001) compared to SAL injection. Furthermore, LPS injection increased (p < 0.05) the expression of both pro and anti-inflammatory cytokines in the spleen and tibia. The expression of cathepsin K ( Cts K ) and matrix metalloproteinase 9 ( MMP-9 ) were downregulated by LPS injection (p < 0.001). Broken and shell-less egg production and calcium content of eggshell, as well as tibial mRNA expression of osteocalcin ( Ocn ), tumor necrosis factor-alpha ( TNF-α ) and tartrate-resistant acid phosphatase ( TRAP ) were affected by the interaction (p < 0.05) of diet and injection. Therefore, this study demonstrated that to certain extents, low dietary calcium and LPS challenge dysregulated bone homeostasis and metabolism, with detrimental effects on the performance and eggshell quality of aged laying hens.

Photoperiod manipulation corrects the negative effect of low dietary crude protein levels during weeks 12 to 26 on bone quality and fertility of male Guinea fowl (Numida meleagris)

Improving the reproductive performance of guinea fowl (Numida meleagris) based on the management of environmental factors is important for developing meleagriculture. Thus, the present study was conducted to evaluate the effect of dietary crude protein levels and photoperiod during the 12th to 26th wk of age on growth performance, calcium and phosphorus mobilization, and fertility of local Pearl Gray male guinea fowl. In total, 120 twelve-week-old male guinea fowl were divided into 3 groups with 8 replicates each and 5 birds per replicate using a completely random design. The experimental groups included: a group fed a diet containing 15% crude protein and subjected to 16 h of light and 8 h of darkness (16LL), a group fed a diet containing 19% crude protein and subjected to 16 h of light and 8 h of darkness (16HL), and a group fed a diet containing 15% crude protein and subjected to 18 h of light and 6 h of darkness (18LL) during the 12th to 26th wk of age. The results showed that guinea fowl in the 16HL treatment had a significantly (P = 0.003) lower feed conversion ratio than those in the 16LL and 18LL groups. Calcium and phosphorus levels in the tibia and femur were significantly higher (P < 0.05) in guinea fowl of the 16HL and 18LL groups than in that of the 16LL group. Birds in the 16HL and 18LL treatments had significantly higher peripheral testosterone levels (P < 0.00001) than those in the 16LL treatment. The 16HL and 18LL treatments had significantly higher (P < 0.05) sperm volume, sperm concentration and motility, and fertility rate than the 16LL group. Therefore, a decrease in crude protein level from 19 to 15% in the diet of male guinea fowl between the 12th and 26th wk of age negatively affects the growth performance and fertility of these birds, but this is corrected by an increase in the photoperiod before sexual maturity.

Effects of 28 h ahemeral light cycle on production performance, egg quality, blood parameters, and uterine characteristics of hens during the late laying period

This study aimed to systematically determined the effect of 28 h ahemeral light cycle on production performance, egg quality, blood parameters, uterine morphological characteristics, and gene expression of hens during the late laying period. At 74 wk, 260 Hy-Line Brown layers were randomly divided into 2 groups of 130 birds each and in duplicates. Both a regular (16L:8D) and an ahemeral light cycle (16L:12D) were provided to the hens. The oviposition pattern in an ahemeral cycle shifted into darkness, with oviposition mostly occurring 3 to 5 h after light out. Production performance was unaffected by light cycle (P > 0.05). Nonetheless, compared to the normal group, the ahemeral group exhibited increased egg weight, eggshell weight, eggshell percentage, yolk percentage, eggshell thickness, and eggshell strength (P < 0.05). There were rhythmic changes in the uterine morphological structure in both cycles, however, the ahemeral group maintained a longer duration and had more uterine folds than the normal group. In the ahemeral cycle, the phases of the CLOCK and PER2 genes were phase-advanced for 3.96 h and 4.54 h compared to the normal cycle. The PHLPP1 gene, which controls clock resetting, exhibited a substantial oscillated rhythm in the ahemeral group (P < 0.05), while the expression of genes presenting biological rhythm, such as CRY2 and FBXL3, was rhythmically oscillated in normal cycle (P < 0.05). The ITPR2 gene, which regulates intracellular Ca2+ transport, displayed a significant oscillated rhythm in ahemeral alone (P < 0.05), while the CA2 gene, which presents biomineralization, rhythmically oscillated in both cycles (P < 0.05). The ahemeral cycle caused 2.5 h phase delays in the CA2 gene compared to the normal cycle. In conclusion, the 28 h ahemeral light cycle preserved the high condition of the uterine folds and changed the uterine rhythms of CLOCK, PER2, ITPR2, and CA2 gene expression to improve ion transport and uterine biomineralization.

Fermented calcium butyrate supplementation in post-peak laying hens improved ovarian function and tibia quality through the "gut-bone" axis

The compromised egg quality and leg abnormality during the end of the laying cycle (after 40 weeks) have been leading to poor animal welfare and substantial economic losses. Therefore, the effects of fermented calcium (Ca) butyrate, produced by fermentation by Clostridium butyricum, on production, eggshell quality, and tibial property of hens were explored. A total of 192 Hy-line brown laying hens at 50-week-old were assigned to a basal diet or the basal diet with 300 mg/kg of the fermented Ca butyrate from 50 to 58 weeks of age. Each treatment had 6 replicates with 16 hens each. The diet supplemented with 300 mg/kg fermented Ca butyrate notably increased egg weight, ovarian follicle number, and eggshell strength (P = 0.072) as compared to the basal diet, which were associated with cytokine secretion, toll-like receptor signaling pathways, and intestinal immunity based on the RNA-seq data from the granulosa. Dietary Ca butyrate inclusion decreased the expression of ileal tumor necrosis factor-alpha and serum pro-inflammatory cytokine concentration, as well as increased the content of serum immunoglobulin A when compared to the basal diet (both P < 0.05). The birds that received fermented Ca butyrate diets exhibited higher villus height (P < 0.05) and upregulated expression of tight junction proteins, whereas it did not alter the composition of cecal microbiota (P > 0.05). In addition, the diet with fermented Ca butyrate reduced the number of osteoclasts in the proximal tibia and the level of C-terminal cross-linked telopeptide of type I collagen, a bone resorption marker (P < 0.05), whereas it tended to increase the concentration of the procollagen type I N-terminal propeptide that reflects bone formation marker in serum. Moreover, the layers fed fermented Ca butyrate diets possessed higher (P < 0.05) bone area and trabecular number of the proximal tibia, yield load, and ultimate load than those that consumed basal diets. Collectively, dietary fermented Ca butyrate supplementation in post-peak layer diets improved the ovarian function and tibia quality, which might be related to enhancing intestinal integrity and consequently decreasing inflammation mediated bone resorption.

Dietary protein levels during 12 to 26 wk improve the growth performance, bone quality, and testosterone in Pearl Gray male guinea fowl (Numida meleagris)

Guinea fowl (Numida meleagris), although native to Africa and despite its many potentials, does not represent the dominant species on the continent because of its seasonal reproductive nature and high keets mortality. This study was conducted to assess the effect of crude protein levels on growth performance, bone characteristics and reproductive activity of Pearl Gray male breeder guinea fowl from 12 to 26 wk of age. A total of 120 twelve-wk-old guinea fowls were randomly allotted to 3 dietary treatments with 8 replicates each and 5 birds per replicate using a completely randomized design. The dietary treatments comprised low level (LL), normal level (NL), and high level (HL) with diets respectively containing 15, 17, and 19% crude protein (CP). The results showed that guinea fowl in the HL treatment had a significantly lower feed conversion ratio (P = 0.008) than those in the other treatments. The birds fed the HL diet had significantly higher concentrations of testosterone (P < 0.05) than in the other treatments. High levels of calcium and phosphorus were observed in the femur of the HL group relative to the LL group. The birds in the LL treatment had a significantly higher (P = 0.007) femur robusticity index than those in the HL treatment. In conclusion, feeding 19% crude protein to Pearl Gray male guinea fowl from 12 to 26 wk of age improves growth performance, the density and strength of the femur and tibia and the reproductive tract. The CP level for the best performance of male guinea fowl from 12 to 26 wk of age is 19%.

Analysis of growth performance and carcass and meat quality of different crossbreeds of Cherry Valley duck

Duck breeding and production are facing great opportunities in China, as the market for small-sized high-quality duck is rapidly expanding. Therefore, breeding the most suitable genetic stock has become an important goal.This study assessed body and carcass weight, slaughter rate and meat quality of offspring of three cross combinations; Cherry Valley duck (CV♂) × Small-sized Pekin duck (PK♀), CV♂×Taiwan white duck (TW♀), CV♂×Putian white duck (PT♀) and the corresponding pure lines at 56 d of age. These 420 ducks were raised in seven separate groups (10 pens/group, 3♂+3♀/pen).Body and carcass weights were significantly lower in the three cross combinations than CV ducks (P=0.042 and P=0.012). Abdominal fat and sebum weight were lowest in CV♂×PK♀, whereas the breast and the leg muscle weights were significantly higher in CV♂×PK♀ compared to CV♂×TW♀ and CV♂×PT♀ (P=0.018 and P=0.023). No difference was observed in the visceral tissues among the three cross combinations or compared to CV ducks.The performance indicators suggested that CV♂×PK♀, CV♂×TW♀ and CV♂×PT♀ cross combinations are best suited for segmented duck meat, featured duck meat and whole-duck processing, respectively.

Low Ca diet leads to increased Ca retention by changing the gut flora and ileal pH value in laying hens

Osteoporosis is a common degenerative metabolic bone disease in caged laying hens. Intensive egg production mobilizing large amounts of Ca from bone for eggshell formation, consequently leading to Ca deficiency, has been recognized as a critical factor causing osteoporosis in commercial laying hens. The aim of this study was to examine the effect of Ca deficiency on the function of the gut microbiota-bone axis and related egg production traits and bone health in laying hens. Twenty-four 48-week-old laying hens were fed a control diet (Control, 3.72%) or a low Ca diet (LC, 2.04%) for 60 d (n = 12). Compared to the Control hens, the LC hens had higher levels of alkaline phosphatase and tartrate resistant acid phosphatase (P < 0.05) with lower bone strength, eggshell thickness, and eggshell strength (P < 0.05). In addition, the LC hens had higher plasma estradiol concentrations, while having lower concentrations of interleukin-1 (IL-1) and IL-6. The LC hens also had a lower pH value in the ileum with an increased Ca retention. The principal co-ordinates analysis showed significantly separate cecal microbiota populations between the Control and LC hens. The Prevotellaceae_UCG-001, Subdoligranulum, Peptococcus, and Eubacterium_hallii_group (P < 0.05) were higher, while the CHKC1001 and Sutterella (P < 0.05) were lower at the genus level in the LC hens. In addition, Prevotellaceae_UCG-001, Subdoligranulum and Eubacterium_hallii_group had a negative correlation, while Sutterella was positively correlated with ileal pH values. The transcriptome analysis revealed that the low Ca diet caused 20 and 31 genes to be significantly up- and down-regulated, respectively. The gene expressions of cystic fibrosis transmembrane conductance regulator, solute carrier family 26 member 3 of the anion exchangers, and mitogen-activated protein kinase 12 of pro-inflammatory factors were lower in the LC birds, which was correlated with the lower ileal pH values. These results suggest that the hens with low Ca diet-induced osteoporosis have an increased intestinal Ca retention with a decreased ileal pH value, correlated with the changes in Prevotellaceae_UCG-001, Subdoligranulum, and Eubacterium_hallii_group of beneficial genera. The results provide insights for further understanding and preventing osteoporosis in laying hens.

Clostridium butyricum Can Promote Bone Development by Regulating Lymphocyte Function in Layer Pullets

Bone health problems are a serious threat to laying hens; microbiome-based therapies, which are harmless and inexpensive, may be an effective solution for bone health problems. Here, we examined the impacts of supplementation with Clostridium butyricum (CB) on bone and immune homeostasis in pullets. The results of in vivo experiments showed that feeding the pullets CB was beneficial to the development of the tibia and upregulated the levels of the bone formation marker alkaline phosphatase and the marker gene runt-related transcription factor 2 (RUNX2). For the immune system, CB treatment significantly upregulated IL-10 expression and significantly increased the proportion of T regulatory (Treg) cells in the spleen and peripheral blood lymphocytes. In the in vitro test, adding CB culture supernatant or butyrate to the osteoblast culture system showed no significant effects on osteoblast bone formation, while adding lymphocyte culture supernatant significantly promoted bone formation. In addition, culture supernatants supplemented with treated lymphocytes (pretreated with CB culture supernatants) stimulated higher levels of bone formation. In sum, the addition of CB improved bone health by modulating cytokine expression and the ratio of Treg cells in the immune systems of layer pullets. Additionally, in vitro CB could promote the bone formation of laying hen osteoblasts through the mediation of lymphocytes.

Dietary supplementation with Clostridium butyricum and its ferment substance improves the egg quality and ovarian function in laying hens from 50 to 58 weeks of age

The current study was conducted to explore the effects of dietary Clostridium butyricum (C. butyricum) and fermented calcium (Ca) butyrate produced by C. butyricum on the performance and egg quality of post-peak laying. A total of 384 50-week-old hens were fed a basal diet, the basal diet with 300 mg/kg of fermented Ca butyrate or 1 × 109  CFU/kg C. butyricum for 8 weeks. Hens received a C. butyricum exhibited higher yolk properties, albumen height, and Haugh unit. A diet with fermented Ca butyrate or C. butyricum increased the egg mass and the pre-grade yellow follicle number. RNA-sequencing (RNA-seq) data showed that these observations were associated with cytokine-cytokine receptor interaction and intestinal immune status. Accordingly, when compared with the basal diet group, Ca butyrate and C. butyricum addition decreased serum pro-inflammatory cytokine levels and increased the concentration of immunoglobulin A, along with improved intestinal barrier. In addition, dietary C. butyricum inclusion induced a higher abundance of Ruminococcaceae and Lachnospiraceae at the family level. In summary, dietary fermented Ca butyrate or C. butyricum supplementation improved egg quality and ovarian function, which might be related to the enhanced intestinal barrier and immunity in post-peak laying hens.