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Hen breed and age are key factors influencing egg quality. In this study, 250 eggs were categorised into five groups: Lohmann Pink‐shell (LMP, 50 ± 2 weeks), Dongxiang Green‐shell (DXG, 50 ± 2 weeks), Dongxiang Pink‐shell (DXP, 50 ± 2 weeks), first‐laid Dongxiang Green‐shell (DXGF, 23 ± 1 week), and first‐laid Dongxiang Pink‐shell (DXPF, 23 ± 1 week). We compared egg quality traits, biochemical parameters, chemical composition, and amino acid profiles across these groups. Average egg weights were 59.89 g (LMP), 52.11 g (DXG), 59.45 g (DXP), 42.01 g (DXGF), and 42.56 g (DXPF). Yolk colour scores were higher in DXGF (13.72) than in LMP, DXG, and DXP (12.93, 12.72, and 12.81, respectively; p < 0.05). Egg yolk high‐density lipoprotein (HDL) levels were lower in LMP, DXG, and DXP (0.0316, 0.0390, and 0.0334 mmol/g, respectively) than in DXGF and DXPF (0.0411 and 0.0424 mmol/g; p < 0.05). Yolk crude fat was higher in DXG, DXP, DXGF, and DXPF (50.00%, 49.29%, 49.54%, and 49.93%, respectively) than in LMP (47.70%; p < 0.05). The EAA/TAA ratios in yolk ranged from 54.53 to 55.33, while those in albumen ranged from 53.38 to 53.71. Overall, this study demonstrates that hen breed and age significantly affect egg quality, biochemical traits, and amino acid composition. These findings may guide consumer egg selection and support the conservation and efficient utilization of chicken genetic resources. Hen breed and age – Lohmann Pink‐shell (LMP), Dongxiang Green‐shell (DXG), Dongxiang Pink‐shell (DXP), first‐laid Dongxiang Green‐shell (DXGF), and first‐laid Dongxiang Pink‐shell (DXPF) – significantly influence egg quality, biochemical traits, and amino acid composition, with yolk EAA/TAA ratios of 54.53–55.33 and albumen ratios of 53.38–53.71.

Studies on the prevalence of feather pecking in different commercial laying hen systems and its welfare and economic impacts are reviewed in the following paper. Current methods for controlling feather pecking include beak-trimming and alterations to light regimes, but these methods have significant disadvantages from the perspective of bird welfare. A substantial body of research has now identified risk factors for feather pecking during both the rearing and laying periods. It is argued that these findings can be translated into optimised management practices that can prevent and control feather pecking whilst simultaneously conferring welfare benefits. The genetic basis of feather pecking is considered, and studies that suggest group selection techniques could produce birds with a reduced tendency to feather peck in commercial flocks are highlighted.

Background The energy/protein imbalance in a low-protein diet induces lipid metabolism disorders in late-phase laying hens. Reducing energy levels in the low-protein diet to adjust the energy-to-protein ratio may improve fat deposition, but this also decreases the laying performance of hens. This study investigated the mechanism by which different energy levels in the low-protein diet influences liver lipid metabolism in late-phase laying hens through the enterohepatic axis to guide feed optimization and nutrition strategies. A total of 288 laying hens were randomly allocated to the normal-energy and normal-protein diet group (positive control: CK) or 1 of 3 groups: low-energy and low-protein diet (LL), normal-energy and low-protein diet (NL), and high-energy and low-protein diet (HL) groups. The energy-to-protein ratios of the CK, LL, NL, and HL diets were 0.67, 0.74, 0.77, and 0.80, respectively. Results Compared with the CK group, egg quality deteriorated with increasing energy intake in late-phase laying hens fed low-protein diet. Hens fed LL, NL, and HL diets had significantly higher triglyceride, total cholesterol, acetyl-CoA carboxylase, and fatty acid synthase levels, but significantly lower hepatic lipase levels compared with the CK group. Liver transcriptome sequencing revealed that genes involved in fatty acid beta-oxidation ( ACOX1 , HADHA , EHHADH , and ACAA1 ) were downregulated, whereas genes related to fatty acid synthesis ( SCD , FASN , and ACACA ) were upregulated in LL group compared with the CK group. Comparison of the cecal microbiome showed that in hens fed an LL diet, Lactobacillus and Desulfovibrio were enriched, whereas riboflavin metabolism was suppressed. Cecal metabolites that were most significantly affected by the LL diet included several vitamins, such as riboflavin (vitamin B 2 ), pantethine (vitamin B 5 derivative), pyridoxine (vitamin B 6 ), and 4-pyridoxic acid. Conclusion A lipid metabolism disorder due to deficiencies of vitamin B 2 and pantethine originating from the metabolism of the cecal microbiome may be the underlying reason for fat accumulation in the liver of late-phase laying hens fed an LL diet. Based on the present study, we propose that targeting vitamin B 2 and pantethine (vitamin B 5 derivative) might be an effective strategy for improving lipid metabolism in late-phase laying hens fed a low-protein diet.

Background The increasing trend of ban on the use of antibiotic growth promoters (AGPs) across the globe in the poultry industry has led to a growing need for alternatives to AGPs. Prebiotic, probiotic and their combination as a synbiotic have been considered as potential alternatives. This study aimed to investigate the effects of a prebiotic (isomaltooligosaccharide, IMO), a probiotic (PrimaLac®), and their combination (synbiotic) on hen performance, biochemical and haematological responses, and relative organ weights from 20 to 52 weeks of age. Results Supplementation of 1% IMO (PRE), 0.1% PrimaLac® (PRO) and 1% IMO + 0.1% PrimaLac® (SYN) improved ( P  < 0.05) feed intake and egg production at 20–36 weeks of age; body weight gain, feed conversion ratio and egg mass at 20–36 and 20–52 weeks of age; and egg weight at 20–36, 37–52 and 20–52 weeks of age. Compared to control-fed hens at 20–36 weeks of age, PRO- and SYN-fed hens produced less ( P  < 0.05) small size eggs while SYN-fed hens produced more large size eggs. From 37 to 52 weeks of age, PRE-, PRO- or SYN-fed hens produced less ( P  < 0.05) medium size eggs, and more large and extra-large size eggs. PRE, PRO or SYN supplementation decreased ( P  < 0.05) the serum total cholesterol at 36 weeks of age, and serum low-density lipoprotein (LDL) cholesterol, alanine aminotransferase (ALT) and alkaline phosphatase (ALP) at 36 and 52 weeks of age. At 36 and 52 weeks of age, supplementation of PRE, PRO or SYN increased ( P  < 0.05) lymphocyte percentage and decreased ( P  < 0.05) heterophil percentage, leading to a lower heterophil to lymphocyte (H/L) ratio. No significant differences were observed in the relative weights of the heart, liver, ovary, pancreas and spleen of all dietary treatment groups. Conclusions Supplementation of PRE, PRO or SYN improved performance, serum total cholesterol, LDL cholesterol, ALT, ALP and H/L ratio of hens from 20 to 52 weeks of age. These results demonstrated the use of PRE, PRO and SYN as alternative feed additives to AGPs for improving the health and productivity of hens, while PRO is the best for commercial layer production to yield maximum profit.

This study analyzed the productive performance, egg quality and physiological and behavioral parameters of laying hens at different housing densities in a cage-free system, following animal welfare guidelines and improvements in animal housing in intensive systems. 252 Novogen Brown laying hens, 52 weeks old and with an average weight of 1,740 ± 0.11 kg, were used over 63 days, divided into three periods of 21 days. The study adopted a completely randomized experimental design, with four treatments and seven replications. The housing densities tested were: 6 birds box-1 (0.406 m2 bird-1), 8 birds box-1 (0.305 m2 bird-1), 10 birds box-1 (0.244 m2 bird-1) and 12 birds box-1 (0.203 m2 bird-1 bird). The data were analyzed for normality of residuals, homogeneity of variance and independence of errors, using linear and quadratic regression models for each variable. In cage-free poultry production systems, housing densities of 6 to 8 birds per box can be used without affecting performance, egg quality, physiological or behavioral parameters of the hens.

The number and size of free-range laying hen (Gallus gallus domesticus) production systems are increasing within Australia in response to consumer demand for perceived improvement in hen welfare. However, variation in outdoor stocking density has generated consumer dissatisfaction leading to the development of a national information standard on free-range egg labelling by the Australian Consumer Affairs Ministers. The current Australian Model Code of Practice for Domestic Poultry states a guideline of 1500 hens/ha, but no maximum density is set. Radio-frequency identification (RFID) tracking technology was used to measure daily range usage by individual ISA Brown hens housed in six small flocks (150 hens/flock – 50% of hens tagged), each with access to one of three outdoor stocking density treatments (two replicates per treatment: 2000, 10 000, 20 000 hens/ha), from 22 to 26, 27 to 31 and 32 to 36 weeks of age. There was some variation in range usage across the sampling periods and by weeks 32 to 36 individual hens from the lowest stocking density on average used the range for longer each day (P<0.001), with fewer visits and longer maximum durations per visit (P<0.001). Individual hens within all stocking densities varied in the percentage of days they accessed the range with 2% of tagged hens in each treatment never venturing outdoors and a large proportion that accessed the range daily (2000 hens/ha: 80.5%; 10 000 hens/ha: 66.5%; 20 000 hens/ha: 71.4%). On average, 38% to 48% of hens were seen on the range simultaneously and used all available areas of all ranges. These results of experimental-sized flocks have implications for determining optimal outdoor stocking densities for commercial free-range laying hens but further research would be needed to determine the effects of increased range usage on hen welfare.

Objective: The study aimed to evaluate the effect of purple corn cob powder (PCCP) at different percentages on performance, egg quality, egg weight loss, fatty acid profile, total solids, bromatological analysis, and lipoperoxidation in eggs from laying hens. Materials and Methods: One hundred twenty-eight Hy-Line Brown hens (29–35 weeks old) were divided into four treatments (0%, 0.2%, 0.4%, and 0.6% PCCP), with eight replicates and four hens per replicate. Results: Treatments with 0.4% and 0.6% PCCP significantly increased (p < 0.05) feed conversion ratio, laying percentage, and egg mass weight. Similar improvements were observed for yolk weight and Haugh units. There were no differences (p > 0.05) in shell weight, albumen weight, shell thickness, and yolk color. Treatments with 0.4% and 0.6% PCCP increased (p < 0.05) unsaturated fatty acids and decreased saturated fatty acids and thiobarbituric acid reactive substance levels. Eggs stored for 28 days showed lower weight loss (p < 0.05) in treatments with 0.2% and 0.4% PCCP. Conclusion: PCCP inclusion in laying hens’ diets can enhance productive indices, egg quality (both external and internal), increased unsaturated fatty acids, and help preserve egg properties during storage in the egg yolk.

This study aimed to evaluate the effectiveness of different LED lamp colors (red and white) on the productive performance and egg quality of light laying hens. A total of 144 birds of the commercial strain Hy-Line® W-36 aged 44 weeks were distributed in a completely randomized design with two treatments (red and white LEDs) and 12 replicates, totaling 24 experimental plots with six birds each. Treatment means were compared by the F Test (5% probability) on the statistical software SISVAR. This study found that laying hens under red LED lamps showed a trend of greater egg production bird-1 day-1 (%) (p = 0.084), average egg weight (g) (p = 0.0826), egg mass (p < 0.05), and shell thickness (mm) and height (mm) (p < 0.01), whereas birds under white LED light showed better yolk color (p < 0.05). It is concluded that red LED illumination increases egg production and quality in light laying hens.

On organic and free-range poultry farms, a free-range is provided for animal welfare reasons. However, farmers report sightings of birds of prey and sometimes foxes or other predators within the free-range areas. In addition to seeing actual attacks, they also find chicken carcasses in the free-range, the deaths of which they attribute to predators. In addition, and in contrast to indoor poultry farmers, organic/free-range farmers report hundreds of chickens missing, per flock, when comparing the slaughterhouse arrival numbers with farm mortality records. The farmers assume these missing animals are hens that vanished from the free-range area and that predation is the major cause for their disappearance. If so, predation may impact farm yields. This study investigated whether birds of prey kill chickens on organic/free-range egg production farms and the impact, in terms of numbers of chickens and yield losses. This study was to provide qualitative and quantitative information in support of chicken mortality caused by birds of prey. Data were collected through field observations on organic/free-range farms (n = 11) and an online survey among organic/free-range farmers. Seventy-nine field observations on 11 farms resulted in 141 sightings of birds of prey, mostly common buzzards (Buteo buteo) and northern goshawks (Accipiter gentilis). Forty-four dead hens were found, 36 of them were very likely killed by either birds of prey or foxes. Sixteen attacks on hens by goshawk or buzzard were seen. There were no reasons to assume the attacked hens were in a poor condition prior to the attack. From responses to the online survey (n = 27 farms experiencing predation), it was estimated that on average 3.7% of hens of organic/free-range flocks were killed by predators, while total mortality was 12.2%. After calculating missed yield per killed hen, it was roughly estimated that per flock, predation caused yield losses of EUR 5700 on an average organic farm (size 12,700 hens) and EUR 6700 on an average free-range farm (size 25,000 hens).

The effects of chitooligosaccharide (COS) supplementation in laying hen diets on egg production, egg quality, blood biochemistry, antioxidant capacity and immunity during the late laying period were investigated in this 10-week trial. A total of 3000 Fengda No.1 laying hens, 52 weeks of age, were randomly allocated to three treatment groups, each of which included five replicates of 200 hens. Treatments consisted of the basal diet only or the basal diet supplemented with COS at 75 or 125 mg/kg. Hens fed with both COS supplemented diets had improved hen-day egg production, egg mass and feed conversion ratio than control birds. The higher level of COS supplementation exerted positive effects on eggshell strength and eggshell thickness, but significantly decreased yolk colour. Addition of 125 mg/kg COS was also found to significantly increase serum albumin content and significantly decrease serum cholesterol level. Dietary supplementation with COS significantly decreased serum triglyceride level compared with birds fed the control diet. Moreover, COS significantly increased total antioxidative capacity and significantly decreased malondialdehyde level in serum, but had no significance on the activities of antioxidant enzymes. The only change in blood immune response compounds observed in this study was a significantly increased concentration of C3 when laying hens were fed COS supplemented diets. In conclusion, COS could improve laying performance and egg quality in hens during the late laying period. Inclusion of COS in the diet might be beneficial to hens' health by lowering serum lipids, enhancing antioxidant activity and slightly enhancing immune ability. HIGHLIGHTS COS improved laying performance and egg quality in hens during the late laying period. Inclusion of COS in the diet might be beneficial to hens' health by lowering serum lipids, enhancing the antioxidant activity and slightly enhancing immune ability. The optimum concentration of COS is 75 mg/kg in the basal diet in order to achieve an increased egg production, egg quality and health condition.