Effects of dietary rapeseed meal on laying performance, egg quality, apparent metabolic energy, and nutrient digestibility in laying hens

Effects of fermented rapeseed meal on performance, intestinal morphology, the viscosity of intestinal content, phosphorus availability, and egg quality of laying hens

Fermented rapeseed meal has the potential to partial replace soybean meal in feed mixtures for poultry without a negative impact on the health condition and performance of birds. This is due to the fact that the fermentation process can reduce the amount of antinutritional factors, improve the use of nutrients and impart probiotic properties to rapeseed meal. Therefore, this study was undertaken to investigate the effect of fermented rapeseed meal on the performance, egg quality, intestinal morphometry, the viscosity of intestinal content and total phosphorus availability. A total of 108 Lohmann Brown laying hens at 26 wk of age were used in the 90-day study. All hens were randomly divided into 3 treatment groups, with 12 replicates (cages) each, as follows: control group received no rapeseed meal, the URSM group received 3% unfermented rapeseed meal and the FRSM group received 3% fermented rapeseed meal. In the case of performance, egg traits, sensory evaluation of eggs, the viscosity of intestinal content and the availability of total phosphorus, if the distribution was normal, a 1-way analysis of variance was performed. If the distribution was not normal, the Kruskal-Wallis test was performed. In the case of histomorphometric evaluation of the intestine, if the distribution was normal, the Student t test for independent samples was performed. If not, a Mann-Whitney U test was performed. The performed analyses showed that the supplementation of fermented rapeseed meal had no negative effect on the performance of birds and the quality of eggs. Fermented rapeseed meal was also associated with improved histomorphometric parameters of the small intestine compared to the group receiving unfermented rapeseed meal in the feed. Laying hens from FRSM group were characterized by significantly lower viscosity of intestinal content (P < 0.05) compared to URSM group. Phosphorus in FRSM group was significantly more available to the birds (P < 0.05) compared to URSM group. These results suggest that supplementation with fermented rapeseed meal may be beneficial, especially in times of unstable prices of soybean meal and problems with its availability.

Effect of fermented rapeseed meal on growth performance, nutrient digestibility, and intestinal health in growing pigs

To explore the effects of fermented rapeseed meal (FRSM) on growth performance and intestinal health, a total of 30 growing pigs were randomly allotted to three treatments consisting of corn-soybean meal diet (CSD), rapeseed meal diet (RSD), and fermented rapeseed meal diet (FRSD). Results showed that compared with RSD, FRSD feeding increased the average daily gain and final body weight in pigs (P < 0.01). Compared with RSD feeding, FRSD feeding elevated the apparent digestibility of crude protein, acid detergent fiber, and ether extract in pigs (P < 0.01). Moreover, the FRSD group exhibited greater apparent ileal digestibility of His, Thr, Lys, and Ser than the RSD group (P < 0.01). The digestible energy, metabolic energy, and nitrogen utilization were higher in the FRSD and CSD groups than in the RSD group (P < 0.01). As compared to the RSD, FRSD feeding decreased the serum concentration of leptin but significantly increased the concentrations of immunoglobulin (Ig) A, IgG, ghrelin, and enzyme activities of amylase, lipase, and trypsin in the pancreas (P < 0.05). Interestingly, the villus height, the ratio of villus height to crypt depth, and the activities of brush border enzymes (e.g., maltase and sucrase) in the small intestine were higher in the CSD and FRSD groups than in the RSD group (P < 0.05). As compared to the RSD, the FRSD feeding not only increased the expression level of the occludin in the small intestinal epithelium (P < 0.05) but also elevated the expression levels of claudin-1, MUC1, and PepT1 genes in the duodenum, and elevated the expression levels of SGLT1 and CAT1 genes in the jejunum (P < 0.05). Importantly, FRSD feeding significantly decreased the abundance of Escherichia coli, but increased the abundance of Lactobacillus and the content of butyrate in the cecum and colon (P < 0.05). These results indicated that compared with rapeseed meal, fermented rapeseed meal exhibited a positive effect on improving the growth performance and intestinal health in growing pigs, and the results may also help develop novel protein sources for animal nutrition and the feed industry.

The effect of fermented rapeseed meal on production performance, egg quality, and hatchability in broiler breeders after peak production

1. This experiment was conducted to evaluate the effects of replacing soybean meal (SBM) with different levels of rapeseed meal (RSM) or fermented rapeseed meal (FRSM) on performance, egg quality and hatchability in broiler breeders.2. RSM was fermented with Bacillus subtilis and Aspergillus niger for 25 d. A total of 140 Ross 308 broiler breeder hens (52 weeks old; 20 per treatment, four hens per cage replicate) were assigned to seven dietary treatments in a completely randomised design involving a control (maize-SBM diet) and a 2 × 3 factorial arrangement, consisting of two types of meal (RSM and FRSM) and three replacement levels (33%, 66% or 100%) for SBM, with one cockerel housed within each cage replicate for 12 weeks.3. Fermentation increased the population of lactic acid bacteria and crude protein and decreased pH, dry matter, crude fibre and anti-nutrients in FRSM meal compared to RSM (P < 0.05).4. Body weight gain and egg weight were not affected by RSM or FRSM. Feeding FRSM compared to RSM increased egg production and egg mass (P < 0.05). FRSM or RSM at the level of 100% significantly decreased egg production and egg mass compared to the control group (P < 0.05). Neither types of meal nor levels of replacing significantly affected egg quality variables except eggshell strength. Yolk colour in all experimental treatments was significantly higher than the control group (P < 0.05). By increasing the level of RSM or FRSM in the diet, hatching rate and chicken weight decreased (P < 0.05).5. Microbial fermentation improved the nutritional value of RSM which could be used to replace SBM with RSM or FRSM at levels lesser than 66% as a suitable protein alternative for broiler breeders.

Partial Replacement of Soybean Meal with Canola Meal or Corn DDGS in Low-Protein Diets Supplemented with Crystalline Amino Acids-Effect on Growth Performance, Whole-Body Composition, and Litter Characteristics

A 42-day study was conducted to explore the application of supplemental amino acids (AA) in low-protein diets with soybean meal (SBM), canola meal (CM) or corn distillers dried grain with solubles (cDDGS) as the main protein feedstuffs. The responses of interest were growth performance, carcass yield, whole-body composition, litter ammonia and litter N. On d 0, a total of 540 Cobb 500 (off-sex) male broilers were allocated to 36 floor pens. All the birds received one starter diet that met nutrient requirements during the first 10d. Thereafter, six experimental diets were provided in grower and finisher phases. The diets included a positive control (PC): a corn−SBM diet with adequate protein. The protein level of the negative control (NC) was decreased by 45 g/kg relative to the PC. The next two diets had the same protein levels as the NC but with cDDGS added at 50 or 125 g/kg. The last two diets had the same CP as the NC but with CM added at 50 or 100 g/kg. All the low-protein diets had the same level of standardized ileal digestible indispensable AA according to Cobb 500 recommended level. Gly and Ser were added as sources of non-specific N. The dietary protein reduction in corn−SBM diets at both phases decreased (p < 0.05) weight gain and increased (p < 0.05) feed conversion ratio (FCR). Increasing levels of cDDGS or CM, at a constant CP level, linearly decreased (p < 0.05) the weight gain and feed intake, whereas increasing CM level linearly increased (p < 0.05) FCR in the grower and finisher phases. The eviscerated and carcass yields decreased, whereas the fat yield increased (p < 0.05) with reduced protein in corn−SBM diet. Increasing levels of cDDGS and CM at a constant CP level quadratically decreased (p < 0.05) the eviscerated weight, whereas the fat weight linearly decreased (p < 0.05) with increasing levels of cDDGS and CM. The birds receiving the PC diet had a lower (p < 0.05) lean muscle (%) and a higher fat (%) compared to birds receiving the NC diet at d 21. However, on d42, birds receiving the PC diet had decreased (p < 0.05) bone mineral density, bone mineral content and lean weight compared to those receiving the NC diet. The litter ammonia increased (p < 0.05) with the increasing levels of protein in the SBM diets. In conclusion, 50 g/kg inclusion levels of CM and cDDGS at the same low-protein levels as SBM produced a similar growth response to the NC, whereas higher levels were detrimental. Hence under the conditions of the current experiment, complete replacement of SBM with DDGS or CM in low-protein diets was not feasible.

The Quality of Eggs Derived from Japanese Quail Fed with the Fermented and Non-Fermented Rapeseed Meal

The most popular protein source in poultry feed mixtures is soybean. However, cheaper and more available alternative protein sources are being sought, and feed manufacturers more and more often turn their attention to the post-extraction meals of local oil plants, e.g., rapeseed. Therefore, the effect of fermented and non-fermented post-extraction rapeseed meal used as a feed additive for Japanese quails was investigated on the eggs’ quality. The study was performed on 280 females of Japanese quails fed with a mixture without rapeseed meal, with non-fermented post-extraction rapeseed meal (5%, 10% and 15%) and with fermented one (5%, 10% and 15%). During the experiment, eggs were collected from each group four times (every 4 weeks) and evaluated for their quality characteristics. The addition of 10% fermented rapeseed meal had the most beneficial effect on such eggs quality traits as egg weight, specific gravity, yolk index and color and albumen pH. However, in the majority of examined parameters, no significant differences were found between birds fed with soybean meal and those fed with fermented and non-fermented rapeseed meal (morphological elements proportions, yolk weight, albumen height and Haugh’s units, eggshell quality). This supports the thesis that the use of rapeseed meals instead of soybean meals may allow obtaining the proper quality of animal raw materials at a lower cost and with the use of local feed resources.

Rapeseed meal as a feed component in monogastric animal nutrition – a review

Rapeseed is an important oil crop worldwide, with an annual production of more than 70 million tons. Rapeseed meal (RSM) is a by-product of rapeseed oil production and is second after soybean meal (SBM) in the world production of protein meal. Rapeseed meal derived from black-seeded winter oilseed rape (Brassica napus L.) usually contains between 35 and 40% of crude protein (CP), which is considered to be one of the more valuable plant proteins. It has a good balance of essential amino acids and a very high protein efficiency ratio (PER=3.29). However, full utilisation of this protein is difficult due to presence of the non-protein components of the seed which are associated with it. These are called antinutritional factors and they limit the utilisation of RSM in monogastric animal nutrition. The main antinutritional factors in RSM are dietary fibre, glucosinolates, phytic acid, and phenolic compounds (sinapine, tannins). For many years, research has been conducted in many centers around the world to improve the nutritional value of RSM, which will consequently increase its use in feeding monogastric animals. The attempts that have been undertaken include breeding strategy, optimisation, modernisation and better control of the oil extraction process, as well as technological treatments of seeds and meal. This review provides information on how RSM has evolved in recent years, as well as on its nutritive value, particularly protein, fibre and glucosinolate content. Techniques which have been used to improve the nutritional value of rapeseed products are also discussed. However, the used methods do not allow for full replacement soybean meal by RSM in monogastric animal nutrition.

Effects of rapeseed meal on laying performance and egg quality in laying ducks

This study was conducted to investigate the effect of different varieties of rapeseed meal (RSM) with different concentrations of glucosinolates (Gls) and erucic acid (EA) on performance and egg quality of laying ducks. A total of 576 twenty eight-wk-old laying ducks were randomly allocated to 4 treatments. Each treatment had 8 replicates of 18 laying ducks raised in 6 adjacent cages with 3 laying ducks per cage. The control diet was corn soybean meal based without RSM. Three varieties of RSM varying in Gls concentrations were supplemented to the base diet at 10% by substituting soybean meal to formulate the three RSM diets. The experiment lasted 12 wk. Diets with 10% RSM decreased average egg weight (P < 0.01) and feed intake (P = 0.07) compared with the control diet, but there was no significant difference in laying performance among the 3 RSM diets. RSM increased color value (P < 0.05) and crude protein (CP) content (P < 0.05) of yolk compared with the control diet, but had no significant effects on the other egg quality indexes including eggshell strength, albumen height, Haugh unit, and the composition ratio of eggshell, albumen and yolk. RSM decreased total monounsaturated fatty acids (MUFA) (P < 0.01) and increased total polyunsaturated fatty acids (PUFA) (P < 0.01) of yolk, but total saturated fatty acids (SFA) proportions and UFA/SFA ratio of egg yolk were not significantly affected by RSM. RSM increased deposition of trimethylamine (TMA) and 5-vinyl-1,3-oxazolidine-2-thione (5-VOT) in yolk (P < 0.01); moreover, the high Gls RSM increased deposition of TMA (P < 0.01) and 5-VOT in yolk (P < 0.01) compared with the RSM varieties low in Gls. These results suggested that dietary inclusion of 10% RSM decreased egg weight of laying ducks, and affected yolk quality especially yolk color, fatty acid profile, CP, TMA, and 5-VOT content of yolk. Moreover, RSM with higher Gls concentration resulted in higher deposition of TMA and 5-VOT in egg yolk.

Influence of Brassica spp. rapeseed and canola meal, and supplementation of bioactive compound (AITC) on growth performance, intestinal-permeability, oocyst shedding, lesion score, histomorphology, and gene expression of broilers challenged with E. maxima

This study was performed to investigate the effect of feeding Brassica spp. including full-fat rapeseed, canola meal, and allyl isothiocyanate (AITC) to broiler chicken challenged with E. maxima. A total of 576 one-day old male broiler chicks were completely randomized to 8 treatments with 6 replicated cages and 12 birds per cage. The treatment diets consisted of nonchallenge control (NC, corn-SBM based diet), challenge control (CC), 10% rapeseed (10RS), 30% rapeseed (30RS), 20% canola (20CLM), 40% canola (40CLM), 500 ppm AITC (500AITC), and 1,000 ppm AITC (1000AITC). At d 14, all birds were challenged, except NC group, with a subclinical dose of E. maxima. Intestinal permeability was conducted on 5 d post-infection (dpi) and for oocyst shedding 5 to 6 dpi feces were pooled and collected. On 6 dpi, growth performance, lesion score, histomorphology, and gene expression were measured. The growth performance result showed that 10RS and 30RS groups had lower BW, BWG, FI, and higher FCR (P < 0.0001). During the challenge and overall periods, NC group had highest BW, BWG, and FI, and lowest FCR. The inclusion of canola meal showed lower performance during prechallenge period but was able to catch up BWG during challenge period. The AITC levels showed similar growth performance to CC group. Intestinal permeability for 20CLM, 40CLM, 500AITC and 1000AITC was similar to NC group, whereas CC, 10RS, and 30RS had higher permeability compared to NC (P < 0.0001). Oocyst shedding was significantly lower for 40CLM and NC, whereas all other treatments had higher oocyst shedding (P < 0.0001). All the challenged treatment groups had higher lesion score and microscore than NC (P < 0.0001). Histomorphology data showed that jejunum villus height (VH) for 1000AITC was similar to NC group, whereas CC group had the lowest VH (P = 0.01). The 30RS group had lower VH: crypt depth (CD) ratio in the jejunum and ileum. The gene expression at 6 dpi for claudin1, occludin, IL2, IL6, GLUT5, EAAT, BoAT, and LAT1 was significantly changed among the treatments. The results suggest that 30RS retards growth performance and deteriorate gut health during coccidiosis and should not be fed to chicken during the starter phase. Canola meal showed decline in growth prechallenge but maintained growth and intestinal health during the challenge period at 40% inclusion. AITC at 1,000 ppm showed similar growth as control group, but with improved gut health during the challenge period. Canola meal could be a good alternative to SBM especially during coccidiosis, whereas AITC needs to be tested vigorously in animal feeding regime.

Performance and Egg Quality of Laying Hens Fed Diets Containing Raw, Hydrobarothermally-Treated and Fermented Rapeseed Cake

The present study was conducted to investigate how raw rapeseed cake (RRC), hydrobarothermally-treated rapeseed cake (HRC) and fermented rapeseed cake (FRC) fed to laying hens over a period of 12 weeks affected their performance, and the quality, fatty acid (FA) profile and oxidative stability of eggs. A total of 304 Hy-Line Brown laying hens at 36 weeks of age were distributed in a completely randomized design to four treatment groups with 38 replicates per treatment and two hens per replicate. The birds had ad libitum access to feed and water throughout the study. During the experiment, the birds were fed isonitrogenous and isocaloric diets in mash form, with various protein sources. In the control group (C), soybean meal (SBM) was the main source of dietary protein, whereas the experimental groups were fed diets containing 20% of RRC, HRC or FRC. Hydrobarothermal treatment and fermentation decreased the glucosinolate (GLS) content of RC, and fermentation reduced the concentration of phytate phosphorus (PP). In comparison with the RRC group, layers from the HRC and FRC groups were characterized by higher laying performance, comparable with that in group C. Irrespective of its physical form, RC added to layer diets adversely affected eggshell quality in all experimental groups, whereas albumen quality was highest in the FRC group. In comparison with group C, diets containing RRC, HRC and HRC led to a significant decrease in the content of saturated fatty acids (SFAs), an increase in the proportion of n-3 and n-6 polyunsaturated fatty acids (PUFAs) in the total FA pool in egg yolks, and a decrease in the n-6/n-3 PUFA ratio. The inclusion of RRC, HRC and FRC in layer diets decreased the activity of superoxide dismutase (SOD) in egg yolks, relative to group C. Group FCR eggs were characterized by the highest activity of catalase (CAT) and the lowest lipid peroxides LOOH concentration, compared with the remaining groups. The addition of RC to layer diets did not compromise the sensory quality of eggs, and eggs produced in group FRC received the highest overall score. It can be concluded that the inclusion of 20% RRC, HRC and FRC in layer diets does not compromise the sensory quality of eggs and has a beneficial influence on the FA profile and antioxidant potential of egg yolks. The use of FRC is recommended because it contributes to the highest laying performance, superior albumen quality and the highest sensory quality of eggs, relative to RRC and HRC.

Invited Review: Glucosinolates Might Result in Low Methane Emissions From Ruminants Fed Brassica Forages

Methane is formed from the microbial degradation of feeds in the digestive tract in ruminants. Methane emissions from ruminants not only result in a loss of feed energy but also contribute to global warming. Previous studies showed that brassica forages, such as forage rape, lead to less methane emitted per unit of dry matter intake than grass-based forages. Differences in rumen pH are proposed to partly explain these low emissions. Rumen microbial community differences are also observed, but the causes of these are unknown, although altered digesta flow has been proposed. This paper proposes a new mechanism underlying the lower methane emissions from sheep fed brassica forages. It is reported that feeding brassica forages to sheep can increase the concentration of free triiodothyronine (FT3) in serum, while the intramuscular injection of FT3 into sheep can reduce the mean retention time of digesta in the rumen. The short retention time of digesta is associated with low methane production. Glucosinolates (GSLs) are chemical components widely present in plants of the genus Brassica. After ruminants consume brassica forages, GSLs are broken down in the rumen. We hypothesize that GSLs or their breakdown products are absorbed into the blood and then may stimulate the secretion of thyroid hormone FT3 in ruminants, and the altered thyroid hormone concentration may change rumen physiology. As a consequence, the mean retention time of digesta in the rumen would be altered, resulting in a decrease in methane emissions. This hypothesis on mitigation mechanism is based on the manipulation of animal physiological parameters, which, if proven, will then support the expansion of this research area.

Evaluation of feeding value of combination of alternate protein sources in White Leghorn layers

1. A study was conducted to evaluate the effects of including graded levels of an alternate protein mixture (APM) containing cottonseed meal, distillery dried grain with solubles and mustard seed meal in a fixed ratio as a substitute for soybean meal in layer diets (hens aged 27 to 46 weeks). The trial studied the possibility of higher inclusion levels of APM with increased dietary concentrations of crude protein (CP) or critical amino acids (CAA). 2. Maize-soybean meal diet was used as the control diet. In experiment 1, APM was included at 0, 120, 160 and 200 g/kg diet (145 g/kg CP). In experiment 2, the control and three test diets (200 g/kg APM) with three levels of CP (145, 155 and 165 g/kg) were used. In experiment 3, a control and four test diets (200 g/kg APM) with four concentrations of CAA (100%, 105%, 110% and 115% relative to the control) were used. In all experiments, each diet was fed ad libitum to nine replicates of 88 birds each, housed in colony cages. 3. In experiment 1, egg production (EP) and feed intake (FI) were not affected by feeding up to 160 g/kg APM, but, at 200 g/kg, EP was significantly reduced. Feed conversion ratio (FCR) for the hens fed the highest level of APM was similar to the control. Egg weight (EW) and egg mass (EM) in the 160 and 200 g/kg AMS groups were lower than the control group. 4. Increase in dietary CP from 145 to 155 g/kg improved EP and reduced FCR to levels similar to the control group. EM in hens fed 165 g/kg APM was similar to the control in experiment 2. 5. Increasing concentrations of CAA progressively improved EP and reduced FCR in experiment 3. The EP at CAA 110% and FCR at CAA 105% were similar to the control group. 6. Based on the results, it was concluded that the APM can be included up to 160 g/kg diet without affecting layer performance, as long as the diet supplied the recommended levels of protein and amino acids. By increasing either protein from 145 to 155 g/kg or CAA concentrations by 10%, the dietary levels of the APM could be increased to 200 g/kg without affecting the layer performance.

Inulin improves the egg production performance and affects the cecum microbiota of laying hens

Egg production performance, egg quality, nutrient digestibility, and microbial composition as affected by dietary inulin supplementation were evaluated in laying hens. A total of 300 laying hens were divided into 5 groups and fed diets containing inulin at levels of 0 (control), 5, 10, 15 and 20 g/kg, respectively. The results showed that the 15 g/kg inulin supplementation level improved average egg weight by 2.54%, egg mass by 5.76%, and laying rate by 3.09%, and decreased the feed conversion ratio by 3.61% compared to those of the control during feeding weeks 1 to 8. Dietary inulin supplementation improved eggshell thickness, nutrient digestibility and cecum Bacteroidales_S24-7_ group abundance in the laying hens. In conclusion, dietary inulin supplementation, particularly at the level of 15 g/kg, improved the egg production performance and eggshell thickness of laying hens, mainly due to increased nutrient digestibility and selective modulations of the cecum microbial communities.

The effects of varieties and levels of rapeseed expeller cake on egg production performance, egg quality, nutrient digestibility, and duodenum morphology in laying hens

The objective of this study was to evaluate the effects of rapeseed expeller cake (REC) derived from Brassica napus rapeseed with different concentrations of glucosinolate (Gls) and erucic acid (EA) on the egg-production performance, egg quality, apparent nutrient digestibility, and intestinal morphology in laying hens. At 33 wk of age, a total of 1,080 laying hens were randomly divided into 9 treatment groups in a completely randomized design involving a control treatment without REC (a corn-soybean diet) and a 2 × 4 factorial arrangement with 2 concentrations of REC (at 7 and 14%) from 4varieties of rapeseed varying in Gls and EA concentrations [DY6 REC: 22.67 μmol/g (Gls, relative to rapeseed meal), 0.7% (EA, relative to total fatty acids); MB1 REC: 43.23 μmol/g, 3.5%; DY5 REC: 74.66 μmol/g, 16.20%; XH3 REC: 132.83 μmol/g, 44.60%]. The trial lasted for 8 wk. Compared with the control group, REC addition decreased the ADFI, egg production, egg weight, and egg mass of laying hens during wk1 to wk4, wk5 to wk8, and wk1 to wk8 (P < 0.05), and REC did not affect FCR, mortality during wk1 to wk4, wk5 to wk8, and wk1 to wk8 (P > 0.05). The XH3 REC group had a trend to lower egg weight when compared with the DY6 REC group during wk1 to wk8 (P = 0.07).REC decreased AME and DM digestibility at wk8 (P < 0.01), and REC addition in diet did not affect apparent nitrogen digestibility (P = 0.6). REC decreased villi height (P < 0.01) and increased crypt depth (P < 0.01). The XH3 REC group had a lower crude fat digestibility than the DY6 REC group, and the crude fat digestibility of the DY5 and MB1 REC groups was lower than the XH3 REC group (P < 0.01). The DY6 REC group had a higher villi height than the DY5, MB1, and XH3 REC groups (P < 0.01). The XH3 REC group had a higher crypt depth than the DY6, DY5, and MB1 REC groups (P < 0.01). The DY6 REC group had a higher value of the ratio of villi height to crypt depth than the DY5 and MB1 REC groups, and the DY5 and MB1 REC groups had a higher value of the ratio of villi height to crypt depth than the XH3 REC group (P < 0.01).REC decreased albumen height and Haugh unit during wk1 to wk8 (P < 0.01 and P = 0.004), and increased yolk color during wk1 to wk8 (P < 0.01).The XH3, MB1, and DY5 REC groups had a lower albumen height than the DY6 REC group during wk1 to wk8 (P < 0.01), and the XH3 and DY5 REC groups had a lower Haugh unit than the DY6 REC group during wk1 to wk8 (P < 0.01). The DY6 REC group had the highest value of yolk color than other three varieties of REC (DY5, MB1, XH3) at wk6 and wk8 (P < 0.01 and P < 0.01). It can be concluded that the exposure of laying hens to REC with higher Gls and EA (DY5, MB1, XH3) led to a lower egg weight, nutrient digestibility, intestinal absorptive area, and egg internal quality than those with lower Gls and EA (DY6).