White Leghorn Hens Research Articles

PSVIII-12 Nutrient digestibility, production performance, and eggshell calcium and phosphorus levels of White Leghorn hens fed ahiflower press cake and micronized seed

Abstract Laying hens can benefit from dietary inclusions of oil seeds and their co-products such as ahiflower seeds and ahiflower press cake as sources of energy and nutrients. However, the type and inclusion level of the ahiflower product to achieve these beneficial effects is yet to be investigated. This study aims to determine the effect of ahiflower seed and press cake on production performance, nutrient digestibility, and eggshell calcium (Ca) and phosphorus (P) contents in laying hens. A total of 240 64-week-old Lohman LSL-Lite laying hens were randomly allotted to 1 of 8 treatments for 3 periods (4 weeks/period). The experiment was a completely randomized design with six replicate cages/treatment and 5 hens/cage. The treatments included a control diet (CD), or CD supplemented with 10% Flaxseed as a reference oilseed diet (FS), 1%, 5%, and 10% micronized ahiflower seed (AS), and 5%, 10%, and 15% ahiflower press cake (APC). Production performance was determined at the end of each period, while Ca and P concentrations in eggshell and nutrient digestibility were determined in the third period. Dietary treatment had no significant effect (P >0.05) on eggshell P and Ca levels, body weight (BW), feed conversion ratio (FCR), and hen-day production percentage (HDEP). Although feed intake (FI) was significantly reduced (P < 0.05) in 15% APC when compared to CD, it was not different from 5 and 10% APC inclusion levels. Furthermore, FI and HDEP increased (P < 0.05), while FCR and BW decreased (P <0.05) along the periods. Compared to CD (2129kcal/kg), nitrogen corrected apparent metabolizable energy (AMEn) increased (P < 0.05) in 10% FS (2754kcal/kg), 1% (2681kcal/kg), and 10% AS (2546kcal/kg) and 15% APC (2673kcal/kg). 10% APC (78.9) reduced (P <0.05) P digestibility compared to 10%FS (85.5) and 1%AS (78.9). Calcium digestibility was higher (P <0.05) in hens fed 10% FS (85.5) compared to 10%AS (63.0) and 5%,10% and 15%APC but similar to CD (83.4) and 1% (78.9) and 5%AS (65.3). In conclusion, dietary inclusion of up to 10% AS and 15% APC did not affect BW, FCR, and HDEP in older Lohman LSL-Lite laying hens. Also, AMEn and the digestibility of CP, Ca, and P were positively influenced by different inclusion levels of APC and AS.

Enhancing Laying Hens' Performance, Egg Quality, Shelf Life during Storage, and Blood Biochemistry with Spirulina platensis Supplementation.

Enhancing the sustainability of chicken farming involves improving health and productivity and product qualities. This study explores the influence of Spirulina platensis (SP) supplementation on the productivity, egg quality, shelf life during storage, and blood biochemistry of laying hens. A total of 192 thirty-nine-week-old White Leghorn hens were randomly divided into 4 dietary groups: a control group and 3 treatment groups receiving 2.5 g/kg, 5 g/kg, or 10 g/kg of SP, respectively. The study was conducted for six weeks with measuring feed intake, feed conversion ratio, egg production, egg quality, shelf life, and blood biochemistry. The results demonstrated significant enhancements in egg weight (p < 0.05) and egg mass (p < 0.05) in the treatment of SP groups. The SP treated hens showed significant improvements in yolk color (p < 0.05) and Haugh unit scores (p < 0.05). The SP supplementation showed a hepatoprotective effect, as indicated by significant reduction in Alanine aminotransferase (ALT) (p < 0.05) and alkaline phosphatase (ALP) (p < 0.05) levels; however, increases in total protein, albumin, and globulin levels were observed. Furthermore, the egg quality of stored eggs for 21 days linearly increased with increments in the SP levels. In conclusion, it can be speculated that adding SP at 2.5 g/kg and 5 g/kg can significantly improve the productivity of laying hens, eggs' quality, shelf life, and blood biochemistry, thereby contributing to a more sustainable and efficient chicken production.

Effects of oligosaccharides on performance, intestinal morphology, microbiota and immune reactions in laying hens challenged with dextran sodium sulfate

The aim of this study was to determine the effect of oligosaccharide extract from bamboo shoot (BOS) on the performance, intestinal morphology, microbiota and immune reaction of laying hens challenged with dextran sodium sulfate (DSS). Thirty-two White Leghorn hens (480 days old) were divided into 4 groups (8 hens each) with similar mean body weights: C (basal diet), D (basal diet + DSS), B (5 g/kg BOS diet), and BD (5 g/kg BOS diet + DSS). They were administered a single oral dose of 4 mL of distilled water/kg body weight with or without 0.45 g of DSS for 7 consecutive days from the 14th d to the 21st d of the experiment. The important findings were that (1) The egg yolk ratio was decreased by DSS treatment, but it was improved by BOS treatment, which also increased the egg shell ratio. (2) The diversity of intestinal microbiota and relative abundance of 4 bacteria genera were increased by BOS treatment. (3) Intestinal morphology was not affected by DSS and BOS, but the leukocytes accumulation in the liver was increased by DSS treatment and suppressed by BOS treatment. (4) Dietary BOS treatment influenced the mRNA expression of Th-1 and Treg cytokines in the liver and Th-17 cytokines in both intestine and liver of laying hens. These results suggest that BOS may enhance egg quality, Th-1 and Th-17 immune function without causing tissue damage under normal condition, and may suppress the excessive inflammatory responses during inflammation.

Body length as predictor for improving body weight of White Leghorn chicken breed

The association between live body weight and morphometric traits plays a major role in the daily management and improvement of poultry. The objective of the current study was to determine the association between morphometric features and live body weight, as well as to investigate the direct and indirect effects of morphometric traits on White Leghorn laying hens' live body weight. Live body weight (BW) and morphometric traits including shank circumference (SC), body length (BL), wing length (WL), shank length (SL), toe to back length (TBL), beak length (BKL), beak to comb length (BCL), height (CH) and chest girth (CG) were collected from one hundred (n = 100) White Leghorn laying hens aged 40 weeks. The correlation findings showed that BW was positively correlated to SL, WL, SC, BL, and CH (p &lt; 0.05). The Path analysis results reported that BL (0.45) had the highest direct effect on BW while WL (0.14) had the highest indirect effect on BW via BL. Correlation results propose that improvement of BL, SL, SC, CG and CH might increase the BW of White Leghorn hens. Path analysis results on the other hand, imply that BL and SC may be used as selection basis during breeding to improve BW in chickens. This study suggests that BW of White Leghorn is correlated with some morphometric traits that might be used during breeding. The findings also suggest that body length directly influence the live body weight of White Leghorn chicken breed. Keywords: Correlation matrix, Morphometric traits, Regression, Shank circumference, Wing length.

Comparative responses of Lohmann Select Leghorn-lite and Shaver Heritage White Leghorn hens when fed diets containing fine and coarse oat hulls

A standard commercial mash (control), or a mixture of control and fine (FOH) or coarse oat hulls (COH) at a ratio of 80:20 w/ w were fed to 57-week old Lohmann Select Leghorn-lite (LSL) and 44-week old Shavers Heritage White Leghorns (SHW) for 28 days. There was no ( P &gt; 0.05) strain and diet interaction or diet effects on egg production indices (EP) and feed intake (FI). However, LSL hens had similar ( P &gt; 0.05) FI but higher ( P &gt; 0.05) EP than SHW. There was no strain and diet interaction observed on apparent retention of gross energy (ARGE) and gizzard weight ( P &gt; 0.05). However, the control hens had higher ARGE, and lighter gizzards compared to oat hull-fed hens ( P &lt; 0.01). In addition, COH hens had higher ARGE and heavier gizzards compared to FOH hens. The SHW hens exhibited greater jejunal crypt depth ( P = 0.011) compared to LSL hens. An interaction ( P = 0.041) between strain and diets on ceca digesta short chain fatty acids (SCFA) was such that oat hulls reduced SCFA in LSL but not in SHW hens. In conclusion, despite differences in age, relative to predecessors the modern hen is adaptable to ingestion of structural material rich insoluble fiber without negative impact on egg production and feed intake.

Interference between Escherichia coli genotypes from the E. coli peritonitis syndrome given simultaneously to productive SPF White Leghorn hens by intratracheal inoculation

ABSTRACT The purpose of the present study was to examine if potentiation of mortality occurred after simultaneous administration of several Escherichia coli genotypes, each capable of inducing the E. coli peritonitis syndrome, in comparison with single genotype application. Five groups of productive specified pathogen free White Leghorn hens were housed in isolators. Groups 1–4 consisted of 32 hens each, group 5 of 10 hens. At 32 weeks of age all groups were inoculated intratracheally. Groups 1 and 2 were inoculated with a mix of four E. coli genotypes and groups 3 and 4 with a mix of four other genotypes. Groups 1 and 3 were given 1 median lethal dose (LD50) of each genotype per hen and groups 2 and 4 had a dose of 0.1 LD50 per genotype per hen; group 5 was mock inoculated. The experiment ended one week after inoculations. In Group 5, no mortality occurred and gross lesions were absent at post-mortem examination. Mortality in groups 1 and 3 was 84% and 81%, respectively; in groups 2 and 4 59% and 66%, respectively. Although mortality in groups 1 and 3 exceeded the expected 50%, this could not be due to potentiation as cluster analysis of reisolates showed that in individual hens only one genotype was found, indicating interference between E. coli genotypes. In groups all four or only two genotypes were recovered, showing that not all genotypes will induce colibacillosis in all experimental groups. Therefore, broad protection can be best assessed by challenging with various single genotypes. RESEARCH HIGHLIGHTS All four or only two E. coli genotypes were found in groups of hens given mixes of four genotypes. In contrast, only one genotype was found in individual hens. E. coli genotypes interfere with each other in hens after given as a mix. Interference is likely based on a random process. Broad protection can best be assessed by challenging with single genotypes.

Identification of 3 neutralizing linear epitopes on the VP8 outer capsid protein of group A equine rotavirus.

To identify protective equine rotavirus group A (ERVA) VP8 epitopes and demonstrate that immunizing hens with synthetic peptides based on these epitopes would yield high-titered, neutralizing egg yolk antibodies for potential application in foals. 26 rotavirus-positive, client-owned foals were included in the study. Five white leghorn hens were used for antibody production. Chicken antibodies were raised against 3 synthetic epitope peptides from the VP8 protein of the common ERVA P-type, P4[12] using CD40-targeted streptavidin-peptide complexes. Antipeptide serum- and egg yolk antibodies were subject to ELISA and in vitro virus neutralization assays to evaluate binding and neutralization activities. Lyophilized anti-VP8 egg yolk antibodies were orally administered (30 g; q 24 h for 5 days) to foals with rotaviral diarrhea. Physical examinations were performed daily. The duration of diarrhea and any adverse effects were recorded. CD40-targeted vaccination of hens generated high titers of anti-VP8 serum and egg yolk antibodies after just 3 immunizations. These antibodies prevented in vitro infection of ERVA with titers of 128 in the serum and 94.5 in the yolk. Oral administration (30 g; q 24 h for 5 days) of lyophilized hyperimmune egg yolk to foals with rotaviral diarrhea did not reveal any adverse effects of the treatment. This study demonstrated that antibodies raised against neutralizing epitopes of the ERVA VP8 protein could prevent ERVA infection in vitro. Based on these results and previous work in other animals, in vivo evaluation of the therapeutic efficacy of anti-VP8 egg yolk antibodies is warranted.

Egg production in nests and nesting behaviour: genetic correlations with egg quality and BW for laying hens on the floor.

In laying hen production, cage-free housing is growing rapidly to provide living conditions that meet hens' needs. Unlike cages, this housing requires nests for automatic collection of eggs, as eggs laid outside nests must be collected by hand. Selecting hens for nest-related traits, such as egg production in nests and nesting behaviour, could help meet the requirements of cage-free housing. However, genetic correlations between these traits and major traits of breeding programmes, such as egg quality or BW, are poorly known. In addition, the genetic determinism of major traits has rarely been studied under cage-free conditions. The objective of the present study was to estimate the heritability of egg quality and BW measured on the floor and their genetic correlations with nest-related traits. Egg production in nests was based on the laying rate in nests, laying rhythm (clutch number and mean oviposition time), and nest acceptance. Nesting behaviour was based on nest preference (mean distance between nests used for laying) and mean laying duration (time spent in the nest for laying). Nest-related traits were recorded from 24 to 64weeks of age. BW and egg quality were measured at 50 and 55weeks of age, respectively. Nest-related traits and identification of the eggs laid by each hen (for individual measurements of egg quality) were obtained using individual electronic nests used by hens raised in groups and on the floor. The phenotypes of 1455 Rhode Island Red and 1538 White Leghorn hens were analysed. Heritability coefficients and genetic correlations were estimated using a multi-trait animal model for each line. Heritability estimates for egg quality and BW were moderate to high for both lines (0.17-0.74). Overall, weak genetic correlations were estimated between nest-related traits and egg quality or BW for both lines. However, strong and antagonistic genetic correlations were estimated between eggshell strength and laying rate in the nests (-0.46 to -0.42) or laying rhythm (+0.46 to +0.68) for both lines. Several moderate-to-strong genetic correlations were found for White Leghorn between nest-related traits and egg weight, eggshell shape, albumen height, and BW. This study shows that nest-related traits can be used to select hens better adapted to cage-free housing without degrading overall egg quality and BW. It also shows that some traits, like the eggshell strength, must be carefully monitored if these new traits are included in breeding goals. These results must now be confirmed for other populations and larger datasets.

Passive immunization with anti-FimA egg yolk antibodies (IgYs) mitigate Acinetobacter baumannii pneumonia in mice

Acinetobacter baumannii is a formidable pathogen, characterized by high mortality rates and pan-drug-resistant strains. Current commercial antibiotics lack efficacy against drug-resistant variants, necessitating the search for alternative treatments. This study investigates the potential of egg yolk immunoglobulin (IgY) as a cost-effective biomolecule for passive protection against A. baumannii pneumonia. FimA (ABAYE2132), a key virulence factor involved in biofilm development and lung cell adherence, emerges as a promising antigen for triggering protective IgY production. Recombinant FimA was expressed, purified, and used for intramuscular immunization of laying White Leghorn hens. IgY antibodies were subsequently extracted from egg yolks, with their reactivity assessed through indirect ELISA. Neutropenic mice received intranasal administration of IgYs one hour prior to the challenge with a clinical A. baumannii isolate (10 ×LD50). The specific anti-FimA IgYs detected recombinant FimA and provided 100% protection against bacterial infection, while non-specific IgYs prolonged survival for up to 72 h. In contrast, control mice succumbed to infection within 24 h. Analysis of bacterial loads in lungs and spleens after 16 h reveals the following order: control > non-specific IgY > anti-FimA IgY. These findings highlight FimA as a suitable antigen for the development of protective IgYs against A. baumannii.

Egg-yolk antibodies raised to VacJ passively immunize mice against Acinetobacter baumannii pneumonia in a neutropenic murine model

There is no effective antibiotic against emerging highly resistant Acinetobacter baumannii strains, and there is a need for alternative treatment options. Egg-yolk antibodies (IgYs) are the avian equivalent of mammalian IgG that could confer passive protection against various infections. VacJ is a virulence factor of the pathogen in the lungs. In addition, previous studies have shown that immunization of mice with this antigen resulted in decreased bacterial burden in the lung. Hence, it could be a suitable antigen to achieve protective IgYs. In the current study, the recombinant VacJ was expressed, purified, and administered to laying White Leghorn hens followed by IgY extraction from egg yolks. Indirect ELISA showed maximum IgY titers against VacJ raised two weeks following the last immunization. The immunoprotective effects of IgYs were investigated in neutropenic mice. The mice received intranasal IgYs one hour before the nasal instillation of the 10 ×LD50 with a clinical isolate of A. baumannii. A significant reduction in bacterial population loaded in the lungs and spleen was noted. A 100% survival was recorded in the group receiving anti-VacJ antibodies. The results indicate that VacJ is a good immunogen for the production of anti-A. baumannii IgY.

Comparison of Ahiflower oil containing stearidonic acid to a high-alpha-linolenic acid flaxseed oil at two dietary levels on omega-3 enrichment of egg yolk and tissues in laying hens.

Enrichment of egg yolks with very long chain omega-3 fatty acids (VLCn-3 FA) is of interest because of their beneficial effects on human health. The ability of Ahiflower® oil (AHI; Buglossoides arvensis), which is naturally rich in stearidonic acid (SDA), and a high-alpha-linolenic acid (ALA) flaxseed (FLAX) oil to enrich eggs and tissues of laying hens with VLCn-3 FA was investigated. Forty 54-week-old Hy-Line W-36 White Leghorn hens were fed a diet that contained soybean oil (control; CON) or AHI or FLAX oils at 7.5 or 22.5 g/kg of the diet in substitution for the soybean oil for 28 days. Dietary treatments had no effects on egg number or components or follicle development. Total VLCn-3 FA contents of egg yolk, liver, breast, thigh, and adipose tissue were greater in the n-3 treatments compared to CON, with the greatest increase observed at the higher oil level, especially for AHI oil which had the greater VLCn-3 enrichment than FLAX in yolk (p < 0.001). Efficiency of VLCn-3 enrichment of egg yolks was decreased with n-3 oils and by increasing oil level with lowest efficiency at 22.5 g/kg FLAX. In conclusion, both SDA-rich (AHI) and ALA-rich (FLAX) oils increased VLCn-3 FA deposition into egg yolks and hens' tissues, but dietary AHI oil promoted a greater enrichment than comparative amounts of FLAX oil, especially in liver and egg yolks.

Effects of the rearing environment complexity on laying hens’ spatial cognition: A holeboard test approach

The rearing environment of layer chicks can differ greatly in degree of complexity. With the industry moving towards cage-free housing systems, greater demands are placed on the birds’ cognitive abilities in order for them to find resources such as food, water and nest-boxes. Because early environmental complexity can influence cognition, we aimed at increasing our knowledge of how two different rearing environments affect the cognitive abilities of the hens. We habituated 64 hens to a spatial holeboard test, half of which were reared in cages and the other half in an aviary. Out of these 64 hens, 14 cage- and 14 aviary-reared White Leghorn hens were tested twice a day every workday in a holeboard test from 32 to 40 weeks of age. The test consisted of 4 consecutive phases, namely the uncued, cued, over-training and reversal phases, during which the hens had to find baits in a subset of cups in an arena. All cups were identical, so hens had to rely on spatial cues to find the baits which were always hidden in the same cups. During the cued phase, cues were added to the baited cups to give additional information to the hens. During the reversal phase, baits were hidden in a new subset of cups to study cognitive flexibility. The results show the birds were able to successfully complete the task. Aviary-reared hens had a higher reference memory score than cage-reared hens in the first block of the cued phase (F1,26 = 4.21, p < 0.05). Cage-reared hens also had a significantly higher latency to find the first bait than the aviary-reared hens for the uncued, cued and over-training phases (F1,26 = 5.26, p < 0.03; F1,26 = 6.32, p < 0.02; F1,26 = 6.29, p < 0.02). The same was observed for the transition between them (uncued-cued: F1,26 = 6.19, p < 0.02; cued-over-training: F1,26 = 5.87, p < 0.03). No significant treatment effects were found for the reversal phase. In conclusion, cage-reared hens were slower to find the first bait than aviary-reared hens and seemed to be more sensitive to changes in the environment, as shown by the differences during the transition between phases. Aviary-reared hens might therefore be better at adjusting to complex laying environments.

Comparison of electrocardiogram parameters during two methods of euthanasia in white leghorn hens

This study's objective was to evaluate if electrocardiogram (ECG) parameters differ depending on euthanasia method, and if welfare implications result. Sixteen mature laying hens previously outfitted with subcutaneous wireless telemetry and housed in conventional cages or aviaries were used. Manual cervical dislocation (CD) and 30% CO2 displacement were chosen. Continuous ECG data collection began 5 min prior to the procedure to establish a baseline, then continued during and following euthanasia until complete cessation of cardiac activity. Insensibility and euthanasia were determined by an experienced handler to be loss of posture and the end of neuromuscular convulsions with no noticeable breathing. The attending veterinarian monitored and confirmed successful euthanasia via auscultation of the heart. Veterinary confirmation occurred within 5 min for all hens, thus a 5-min sampling period was used. Samples of ten successive QRS complexes per hen per minute were used to calculate average QRS complex amplitude and heart rate. Data were analyzed using the Glimmix Procedure in SAS 9.4, and reported as deviations from baseline. Housing was not a significant factor (p > 0.05). Heart rate showed a significant effect for method (p = 0.0232), time (p < 0.0001), and method*time interaction (p = 0.0001). Compared to baseline, heart rate for CD was 238 bpm higher at minute 1 (p < 0.0001) and 106 bpm higher at minute 2 (p = 0.0027) compared to CO2. While there was no significant effect of method on QRS amplitude (p = 0.6220), there was a time effect (p = 0.0266). Cervical dislocation as a method of euthanasia may induce a greater stress response in laying hens compared to CO2 displacement.

Dietary inclusion of flaxseed oil, fish oil and their combinations on production performance and egg quality traits in White Leghorn hens

A total of 120, 28-week-old White Leghorn hens were randomly selected to study the effect of dietary inclusion of flaxseed oil (FSO) , fish oil (FO) and their combinations on production performance and egg quality traits in White Leghorn hens and the birds were divided into six treatments that had four replicates of five birds each. The experimental groups were fed with control diet and diet containing 5.0 per cent FSO, 5.0 per cent FO, 2.5 per cent FSO + 2.5 per cent FO, 3.5 per cent FSO + 1.5 per cent FO and 1.5 per cent FSO +3.5 per cent FO. The experiment was conducted from 29 to 40 weeks of age comprising three, 28-day periods. The obtained data on statistical analysis, did not reveal any significant difference in body weight, egg production, feed intake, feed conversion ratio, egg weight and egg quality traits of White Leghorn hens among all the treatment groups at all the periods of age.

Effects of domestication on responses of chickens and red junglefowl to conspecific calls: A pilot study.

Beyond physical and zootechnical characteristics, the process of animal domestication has also altered how domesticated individuals, compared to their wild counterparts, perceive, process, and interact with their environment. Little is known, however, on whether and how domestication altered the perception of conspecific calls on both domesticated and wild breeds. In the present work, we compared the vigilance behavior of domestic and captive-born wild fowl following the playback of chicken alarm calls and contentment calls (control). The playback tests were performed on four different breeds/lines. We first compared the behavioral reaction of domesticated White Leghorn (WL, a breed selected for egg production) and Red Junglefowl (RJF) hens (ancestor of domestic chickens). We also compared the behavior of Red Junglefowl hens selected for high or low fear of humans (RJF HF and RJF LF, respectively), a proxy to investigate early effects of domestication. Contrary to our expectations, no breed/line reacted accordingly to the calls, as the increase in vigilance behavior after the playback calls was similar for both alarm and contentment calls. Although no call discrimination differences were found, breeds did differ on how they reacted/habituated to the calls. Overall, WL were more vigilant than RJF, and birds from the RJF LF line decreased their vigilance over testing days, while this was not the case for the RJF HF line. These results suggest that birds under commercial-like conditions are unable to discriminate between alarm and contentment calls. Interestingly, domestication and selection for low fear of humans may have altered how birds react to vocal stimuli. It is important to consider that farmed animals may interpret and be affected by the vocalizations of their conspecifics in unexpected ways, which warrants further investigation.

Comparative effect of stocking density and flock size on performance and egg quality of laying hens in conventional and furnished California cages

Two experiments were carried out with an objective to test the comparative performance of laying hens reared in conventional California cages vs furnished California cages with regards to production performance, egg quality parameters and immune status. Experiments were conducted at Poultry Research and Training Centre, Department of Poultry Science, Nagpur Veterinary College during 2019-21. Commercial White Leghorn (BV300) hens (n =72) in each experiment were assigned into two treatments with six replicates in conventional and furnished California cages, and reared for a 20 week period. The furnished cages (FC) are provided with perches, nesting area and scratch pad to meet the natural behaviour of the birds. There were two different treatments viz. 548 cm2/b×6 birds and 645cm2/b×6 birds to see the effect of different stocking density in cages. The performance of the laying hens reared in furnished cages were recorded and compared with findings of birds reared in conventional California cages (CC). The results showed that body weight, weight gain, hen day egg production percentages, feed : egg ratio, egg weight and proportion of broken eggs and dirty eggs were not significantly affected by cage types. However, Haugh unit and albumen height of the eggs from furnished cages hens were significantly higher than those from the conventional California cage hens. While H/L ratio and corticosterone values were significantly lowest in furnished cage system birds. It can be concluded from study that the layer birds can be reared in stress free condition in furnished cage system.

A comparative study on the effects of hemp seed oil versus four different UFA-rich seed oils’ dietary supplementation on egg production performance, egg quality, and yolk fatty acids in laying hens

This study compared the effects of hemp seed oil versus four different UFA-rich seed oils in the diet of laying hens on egg production, egg quality, and fatty acid profile of the yolk. Soybean oil (SBO), sunflower oil (SFO), corn oil (CO), canola oil (CAO), and hemp seed oil (HSO) were included in the hens' diets in equal proportions. A total of one hundred and twenty White Leghorn hens were allocated into five groups with 8 replicates, each with 3 hens. The trial lasted 84days and data were collected on egg production, quality, and fatty acid profile of the yolk. The results showed that none of the incorporated seed oils affected egg production parameters and eggshell quality. However, hemp seed oil altered yolk colour values similarly to canola oil by increasing the L* value of the yolk whilst decreasing the a* value (P < 0.05). Hemp oil increased the PUFA content in the yolk, similar to soybean, corn, and sunflower oil, but unlike the latter, it also enriched the n-3 fatty acids in the yolk (P < 0.05). In conclusion, hemp seed oil can be safely used in the diet of chickens without negative effects on egg production and egg quality like other seed oils. Furthermore, hemp seed oil can improve the desirable fatty acid content in the yolk and has the potential to produce n-3-enriched eggs.

Identification of crucial genes and metabolites regulating the eggshell brownness in chicken

BackgroundProtoporphyrin IX (Pp IX) is the primary pigment for brown eggshells. However, the regulatory mechanisms directing Pp IX synthesis, transport, and genetic regulation during eggshell calcification in chickens remain obscure. In this study, we investigated the mechanism of brown eggshell formation at different times following oviposition, using White Leghorn hens (WS group), Rhode Island Red light brown eggshell line hens (LBS group) and Rhode Island Red dark brown eggshell line hens (DBS group).ResultsAt 4, 16 and 22 h following oviposition, Pp IX concentrations in LBS and DBS groups were significantly higher in shell glands than in liver (P < 0.05). Pp IX concentrations in shell glands of LBS and DBS groups at 16 and 22 h following oviposition were significantly higher than WS group (P < 0.05). In comparative transcriptome analysis, δ-aminolevulinate synthase 1 (ALAS1), solute carrier family 25 member 38 (SLC25A38), ATP binding cassette subfamily G member 2 (ABCG2) and feline leukemia virus subgroup C cellular receptor 1 (FLVCR1), which were associated with Pp IX synthesis, were identified as differentially expressed genes (DEGs). RT-qPCR results showed that the expression level of ALAS1 in shell glands was significantly higher in DBS group than in WS group at 16 and 22 h following oviposition (P < 0.05). In addition, four single nucleotide polymorphisms (SNPs) in ALAS1 gene that were significantly associated with eggshell brownness were identified. By identifying the differential metabolites in LBS and DBS groups, we found 11-hydroxy-E4-neuroprostane in shell glands and 15-dehydro-prostaglandin E1(1-) and prostaglandin G2 2-glyceryl ester in uterine fluid were related to eggshell pigment secretion.ConclusionsIn this study, the regulatory mechanisms of eggshell brownness were studied comprehensively by different eggshell color and time following oviposition. Results show that Pp IX is synthesized de novo and stored in shell gland, and ALAS1 is a key gene regulating Pp IX synthesis in the shell gland. We found three transporters in Pp IX pathway and three metabolites in shell glands and uterine fluid that may influence eggshell browning.

Feeding laying hens docosa hexaenoic acid-rich microalgae oil at 40 g/kg diet causes hypotriglyceridemia, depresses egg production, and attenuates expression of key genes affecting hepatic triglyceride synthesis and secretion, but is rescued by dietary co-supplementation of high-oleic sunflower oil

The primary goal of this study was to investigate the effect of feeding White Leghorn hens graded levels of a docosahexaenoic acid (DHA)-rich microalgae oil (MAO) on productive performance and enrichment of eggs with very long-chain (VLC) omega-3 (n-3) polyunsaturated fatty acids (PUFA). Forty-nine-week-old hens (8 per diet) were fed the following diets for 28 d: 1) A corn-soybean meal-based diet with no supplemental oil (CON); 2) CON+10 g/kg MAO; 3) CON+20 g/kg MAO; 4) CON+30 g/kg MAO; 5) CON+40 g/kg MAO; 6) CON+40 g/kg MAO+20 g/kg high-oleic sunflower oil (HOSO); and 7) CON+40 g/kg MAO+40 g/kg HOSO. Diets 6 and 7 were included because we previously reported that co-feeding high-oleic acid oils with n-3 PUFA-containing oils attenuated egg yolk n-3 PUFA contents vs. feeding hens the n-3 oils alone. All data were collected on an individual hen basis. Egg VLC n-3 PUFA enrichment plateaued, in terms of statistical significance, at the 30 g/kg MAO level (266 mg/yolk). Hens fed 40 g/kg MAO had greatly attenuated measures of hen performance, marked liver enlargement, an altered ovarian follicle hierarchy, greatly lowered circulating triglyceride levels, and depressed hepatic expression of key genes involved in triglyceride synthesis and secretion. As compared to hens fed 40 g/kg MAO alone, feeding hens 40 g/kg MAO co-supplemented with HOSO (Diets 6 and 7) restored egg production, ovarian morphology, and all other measures of hen productive performance to CON levels, elevated plasma triglyceride levels, prevented liver enlargement, and increased the hepatic expression of key genes involved in triglyceride synthesis and secretion. In conclusion, MAO can greatly enrich hens' eggs with VLC n-3 PUFA, but its recommended dietary inclusion should not exceed 20 g/kg. This would allow for near-maximal yolk VLC n-3 PUFA enrichment without impairing hen productive performance, altering the ovarian follicle hierarchy or, based on the work of others, presumably imparting off-flavors in the egg.

Pharmacokinetics and Egg Residues of Oral Meloxicam in Bantam Cochin Chickens.

Backyard poultry are commonly treated in veterinary hospitals; however, there is limited information regarding appropriate dosing of medications and withdrawal times for eggs. Six healthy adult bantam Cochin hens were given a single oral dose of meloxicam (1 mg/kg). Meloxicam plasma concentrations and egg residues were analyzed by high-performance liquid chromatography. Noncompartmental analysis was used to calculate pharmacokinetic parameters. The apparent terminal half-life, maximum concentration, and time to maximum concentration were 5.94 ± 0.92 hours, 7.03 ± 2.68 µg/mL, and 2.83 ± 1.33 hours, respectively. Meloxicam was detected in egg whites for 4.8 ± 1.5 days and egg yolks for 9.8 ± 2.4 days. Results were compared with previous studies in white leghorn and Columbian Wyandotte hens. Bantam Cochin hens demonstrated a significantly longer mean apparent terminal half-life, greater area under the curve, smaller elimination rate constant, and longer egg residue times compared with white leghorn hens. However, the pharmacokinetic results from the bantam Cochin hens did not significantly differ from those reported for the Columbian Wyandotte hens. Until pharmacodynamic studies can be performed, dosing of oral meloxicam in bantam Cochins should follow recommendations for Columbian Wyandotte hens to reduce the likelihood of adverse effects. These results better inform appropriate dosing of meloxicam in domestic hens, as well as recommended withdrawal times for egg consumption.