Average Egg Weight Research Articles

Effect of Adding Lecithin to Diets on Productive Performance of Laying Hens

This study was conducted in the poultry farm of the Department of Animal Production / College of the Agriculture / University of Anbar, during the period from 20/7/2021 to 15/10/2021, with the aim of studying the effect of adding lecithin to the diet on the productive performance of laying hens. 60 layer hens of the Lohmann Brown breed, aged 43 weeks were used in this experiment. The layer hens were distributed randomly into five treatments with four replicates per treatment (3 hens/repeat). Birds fed balanced diets contain 5 levels of lecithin as below: T1 (control groups ), T2, T3, T4 and T5 adding 0.25, 0.50, 0.75 and 1.0% of lecithin respectively to the basic diet. The results showed the superiority of the additional treatments in the productive traits during most of the production periods, As all the additional treatments during the most stages of production. All additive treatments showed superiority significantly during the third productive period, When calculating the general average, treatments T2 and T5 were significantly superior to the control treatment in the percentage of egg production (Hen Day Production%). Also, T5 showed superiority in the average egg weight during the second and third periods, and in the general average.T5 and T4 showed an increase in the egg mass-produced during the second period and three periods and with the general average. The results showed that there were significant differences between the different treatments in the rates of feed consumption during all stages of production. Also, the additive treatmentT5 showed the best feed conversion ratio during the second and third production periods and in the general average.

Dietary Chitosan Supplementation Improved Egg Production and Antioxidative Function in Laying Breeders.

Simple SummaryChitosan is a natural, non-toxic and biodegradable compound, which has antibacterial, antioxidant and anti-tumor properties. Several studies have shown that chitosan also improve the antioxidant capacity of poultry. Recent research showed that chitosan decreased oxidative damage by activating the nuclear factor erythroid-2 related factor 2 pathway, then elevated the meat quality of broilers. Egg breeders are susceptible to oxidative stress during peak egg production, which increase their susceptibility to diseases and lead performance decline. In addition, previous reports on the effect of chitosan on poultry production performance were inconsistent. Based on above reports, this study explored whether chitosan could promote the production performance, and antioxidant defense of laying hens by affecting the nuclear factor erythroid-2 related factor 2 pathway. The results showed that addition chitosan to layer hen diet could increase egg production and feed conversion ratio, and the effect was better at the level of 250~500 mg/kg; as well as, chitosan promoted the antioxidant status in serum, liver and duodenum tissues and the effect was better at the level of 500 mg/kg. Chitosan was likely to increase antioxidant enzyme activities by enhancing the expression of nuclear factor erythroid-2 related factor 2, thereby improving the antioxidant capacity of laying breeders.This study was conducted to explore the dietary effect of chitosan on the production performance, and antioxidative enzyme activities and corresponding gene expression in the liver and duodenum of laying breeders. A total of 450 laying breeders (92.44% ± 0.030% of hen-day egg production) were randomly assigned to five dietary treatments fed 8 weeks: maize-soybean meal as the basal control diet and the basal diet containing 250, 500, 1000 and 2000 mg/kg of chitosan, respectively. Each treatment was randomly divided into 6 equal replicates, with 15 laying breeders in each replicate. The results showed that dietary chitosan could increase hen-day egg production and feed conversion ratio, especially at the level of 250~500 mg/kg; however, chitosan had no prominent effect on feed intake and average egg weight. Dietary chitosan could dose-dependently promote the antioxidant status in serum, liver and duodenum of layer breeders. It has a better promotion effect at the level of 500 mg/kg; however, the effect was weakened at the level of 2000 mg/kg. Chitosan was likely to enhance the gene expression and activities of Nrf2-mediated phase II detoxification enzyme by up-regulating the expression of Nrf2, thereby improving the antioxidant capacity of laying breeder hens.

Growth, Egg Production, and Phenotypic Characteristics of the Commercial Hybrid Egg-type Philippine Mallard Duck (IP Kayumanggi) under Intensive Management System

Five separate studies were conducted to determine the growth and egg production performance of Itik Pinas (IP) Kayumanggi, a new commercial hybrid egg-type mallard duck in the Philippines under an intensive management system. Results showed that the IP Kayumanggi produced by crossing male IP Khaki and female IP Itim as parents showed significant sexual dimorphism in down feather patterns. The male and female ducklings have 98% black and 99% brown down feathers upon hatch, respectively. In addition, the female ducklings have significantly higher body weight from Weeks 0–4, whereas males were heavier from Weeks 10–18. Cumulative feed consumption was 10.72 kg from brooding (Weeks 1–4) to growing (Weeks 5–16). Daily feed consumption per bird was 124 g during the pre-laying (Weeks 17–18) and laying (Weeks 19–50) periods. Phenotypic characterization revealed that males have predominantly dusky black plumage, green bill, and brown shank, whereas females have mallard-type brown plumage, black bill, and orange shank. The males have significantly higher values for all the body measurements. The average age at first lay was 18 wk, and it reached 80% egg production at 26 wk of age. Average egg weight was 67 g. The average fertility, hatchability, and hatch of fertile were 89, 55, and 62%, respectively. This study provided baseline information on the productive and reproductive performance of IP Kayumanggi.

Flaxseed and sunflower oil affect egg production and quality in hens exposed to stress

This experiment was performed to investigate the effect of flaxseed oil and sunflower oil supplementation on the production performance, egg quality, and egg sensory characteristics in laying hens under density stress. A totaly of 144 Atak-S hens were used. The animals were assigned into 2 groups as stressed and unstressed. These were allocated into three subgroups as those who were fed with basal diet, diets containing 2% sunflower oil, and 2% flaxseed oil. Density stress was applied to those in the stress group by providing an area of 357 cm2 per hen. Egg production performance, average egg weight and egg mass, eggshell weight, eggshell thickness, eggshell strength, Haugh unit, albumen height, yolk color and sensory carateristics of the eggs were measured. Flaxseed oil reduced egg production and egg mass in those who are unstressed. On the contrary, it increased egg production and egg mass in the stressed groups. Sunflower oil was found to increase the average egg weight and egg mass in all groups. It was observed that when sunflower oil was added to the diets of the stressed chickens, the yolk color index decreased. In addition, it was determined that the eggs of the nostressed hens taste better than the stressed chickens. It was determined that flaxseed oil added to the diets increased the sensory quality of the eggs in both stressed and non-stressed groups. Therefore, incorporation of flaxseed and sunflower oil into the diets of layer hens can be recommended.

Evaluation of Production Peak of Laying Hens Strain Lohman Brown in CV. Lawu Farm Malang

Background: The productivity of laying hens is a key measurement in the laying hens business. One of the targets for laying hens is to achieve peak production. The optimal peak production period is necessary to attain the maximum profit. Purpose: To determine the productivity of laying hens strain Lohman Brown aged 25-49 weeks at CV. Lawu Farm Malang Regency as an evaluation of the peak production period. Case Analysis: The descriptive method with the case study technique was used. Primary data were obtained from observations by participating in direct livestock activities, interviews, and documentation, and secondary data were obtained from literature studies. The variables observed in this study were Hen Day Production, Feed Conversion Ratio, egg weight, and mortality. Results: Observation of laying hens productivity in CV. Lawu Farm showed that 71.42% of Hen Day Production value of the full cages had met the target with HDP of more than 92%, while 28.58% did not reach the peak production target by only getting HDP less than 90%. The FCR value was 2.4 – 2.15, the average egg weight wais 63.03 grams/egg, and the mortality was ≤3%. Conclusion: The productivity of laying hens of the Lohman Brown strain aged 24-59 weeks at CV. Lawu Farm has met production standards in terms of HDP, FCR, egg weight, and mortality.

Productive Performance, Egg Quality and Yolk Lipid Oxidation in Laying Hens Fed Diets including Grape Pomace or Grape Extract.

Simple SummaryPhenolic compounds from grape products are known to possess antioxidant activity. Furthermore, grape polyphenols (anthocyanins) could be valorised as natural pigments. However, the dietary use of grape products in laying hen husbandry and its effect on egg quality traits and yolk lipid oxidation have been scarcely studied. In the present research work, egg yolk colour and Haugh units were increased with the intake of grape pomace and extract. Moreover, dietary inclusion of grape pomace at 60 g/kg increased the proportion of polyunsaturated fatty acids in the yolk and improved the yolk lipid oxidative stability during the storage of eggs, whereas no effect was obtained with grape extract. Regarding hen performance, both grape products reduced feed intake, feed conversion ratio and average egg weight, but they did not affect daily egg production and mass. Feeding grape pomace, at 60 g/kg, and grape extract, either at 0.5 or 1.0 g/kg, decreased protein digestibility. In conclusion, the addition of grape products in the diet of laying hens improved the egg quality but reduced feed intake and egg weight. Dietary grape pomace showed higher antioxidant potential in egg yolk than grape extract.An experiment was conducted to assess in laying hens the effect of including grape pomace (GP, at 30 or 60 g/kg) or grape extract (GE, at 0.5 or 1.0 g/kg) on egg production, feed conversion ratio, protein and polyphenol digestibility, egg weight, egg quality, yolk fatty acid profile and oxidative stability of yolk lipids. No differences were detected among diets for egg production (83.8%, on average) or egg mass (56.8 g/d, on average). However, the average egg weight was lower (p = 0.004) for dietary treatments GP 30, GP 60 and GE 0.5 (67.5 g, on average) than for control hens (68.5 g). Accordingly, in hens fed the GP diets the proportion of XL eggs was lower (p = 0.008) than in control hens, while the proportion of M eggs was higher (p < 0.001) in hens fed the diets GP 30, GP 60 and GE 0.5 than in the control group. The dietary inclusion of both GP and GE decreased daily feed intake (120.9 vs. 125.3 g/d, p < 0.001) and the feed conversion ratio (2.09 vs. 2.18, p = 0.01). Feeding GP at 60 g/kg or GE reduced excreta protein digestibility (54.7 vs. 62.8%, p < 0.001), whereas all GP and GE diets showed higher excreta polyphenol digestibility than the control treatment (57.2 vs. 41.0%, p < 0.001). While yolk colour score was increased with all grape diets (8.12 vs. 7.34, p < 0.001), the dietary inclusion of GP, either at 30 or 60 g/kg, and that of GE at 1.0 g/kg increased the Haugh units of the albumen (80.8 vs. 76.4 Haugh units, p = 0.001). Shell thickness remained unaffected by dietary treatments (365.2 μm, on average). When included in the diet at 60 g/kg, GP reduced the proportion of saturated fatty acids in the yolk (31.6 vs. 32.9%, p = 0.001) and that of monounsaturated fatty acids (39.5 vs. 41.4%, p < 0.001), while it increased the percentage of polyunsaturated fatty acids (28.9 vs. 25.7%, p < 0.001). In fresh eggs, no significant differences were found for the malondialdehyde (MDA) concentration (0.146 mg/kg, on average). In stored eggs, the MDA amount was lower in the eggs of the laying hens fed GP at 60 g/kg than in the eggs of the control hens (1.14 vs. 1.64 mg/kg, p = 0.025). In conclusion, the inclusion of grape pomace, either at 30 or 60 g/kg, and grape extract at 1.0 g/kg in the diet of laying hens improved some egg quality traits, but feeding grape pomace resulted in a lower average weight of eggs. Nevertheless, feeding laying hens with diets containing grape pomace resulted in a higher antioxidant potential in egg yolk than dietary inclusion of grape extract.

Use of Manihot esculenta leaves on physiological and production parameters of Sasso breeder hens.

BackgroundThe world population is increasing, leading to competition between humans and animals for the use of farm produce. The use of non‐conventional resources in poultry feed is increasingly being explored. Cassava (Manihot esculenta) have been studied in layers and broilers feed. However, there is very little information on the impact of the leaves on breeder hens.ObjectivesThis study was conducted to determine the effect of M. esculenta leaf meal (MELM) on breeder hen performance, hatching egg quality and blood parameters.MethodsA total of 180 hens and 24 cocks Sasso breeders at 32 weeks of age were used and equally assigned into two dietary treatments having six replicates of 15 hens and two cocks each. The dietary treatments were basal diet supplemented with 0% MELM and basal diet supplemented with the MELM group (5% MELM). Data were collected on feed intake, egg production, feed conversion ratio as well as egg quality indices during the experiment. The blood samples were collected from 18 birds per treatment (three3 per replication) for the determination of total protein, uric acid, triglycerides and total cholesterol at 45th week of age.ResultsThe results showed that there was no significant difference on the feed intake of the birds across the treatments. Average egg weight and egg production were higher with a lower (p < 0.05) feed conversion rate in the MELM group hens. Total protein, uric acids, total cholesterol and triglyceride level increased significantly (p < 0.05) in hens fed 5 % of MELM. The proportions of yolk, egg shell and Haugh unit showed no significant difference between the treatments, while the proportion of albumen and yolk colour increased significantly (p < 0.05) in the MELM group hens.ConclusionsIt was concluded that 5% MELM can be used as feed ingredients in formulating breeder hen diets to improve productive performance.

Research Note: Effects of Bacillus coagulans X26 on the production performance, intestinal structure, short-chain fatty acids and flora composition of laying hens during the peak laying period

This study investigated the effects of Bacillus coagulans X26 on the production performance, egg quality, intestinal structure, intestinal short-chain fatty acids, and microbial diversity of laying hens during the peak laying period and explored the possibility of using B. coagulans X26 as an alternative to antibiotics. The results showed that adding 1.0 × 106 CFU/g B. coagulans X26 to the basal diet had the best effect: the average laying rate increased by 4.20% (P < 0.05), the survival rate increased by 7.15% (P < 0.05), the feed intake decreased by 3.06% (P < 0.05), the ratio of feed to egg decreased by 7.42% (P < 0.05), the rate of soft-broken eggshell decreased by 73.04% (P < 0.05), the average egg weight increased by 2.94% (P < 0.05), and the content of egg white protein increased by 5.77% (P < 0.05). The production performance and egg quality of laying hens reached the same level as that of hens fed a diet supplemented with chlortetracycline hydrochloride in this study, and there were significant advantages in the average laying rate and feed-egg ratio (P < 0.05). Both chlortetracycline hydrochloride and B. coagulans X26 altered the flora composition and the SCFA content of the intestinal contents; however, B. coagulans X26 also significantly increased the villus height of the ileum and the ratio of villus height to crypt depth (P < 0.05).

REPRODUCTIVE, SERUM BIOCHEMICAL AND HORMONAL TRAITS OF LOCAL QUAIL IN RESPONSE TO DIETARY SUPPLEMENTATION OF GREEN TEA POWDER

This study was conducted on 90 local quail females in six different treatments in order to know the effect of adding green tea powder to the quail diet on the productive, reproductive, biochemical and hormonal characteristics of quail females. The results showed a significant superiority of the birds of the group fed on 1% of green tea powder in hot and cold carcass weight, average egg weight, albumin weight, yolk height and color, and the lowest feed consumption, while the control-treated birds in the number of eggs produced, HDP, ALT, Alkaline and Bilirubin exceeded the other treatments birds. Concerning the lipid profile, blood urea ratio, and AST, the highest significant figures were recorded in the treatment of birds fed a ration to which 3% lipids were added. In contrast, the lowest values ​​for total cholesterol, Tri, VLDL, and blood nitrogen were recorded for birds of the treatment fed at 2% of green tea powder. The results showed that there were significant differences between the six treatment birds in the level of blood hormones, as the highest level of (estrogen), (Ghrelin, leptin, FSH), (T4) and (Growth and LH) were recorded for the control birds, 3% lipid and 1% dried green tea and 2% green tea with 3% lipid, respectively. We conclude from the above that birds fed a supplemented diet of 1% green tea powder were superior in most productive and reproductive traits, especially carcass weight, dressed %, egg weight and internal egg characteristics, compared to other treated birds.

Effect of cold fog disinfection on Escherichia coli affecting commercial egg layer flocks

On a field level among poultry flocks a study was conducted to estimate the efficacy of the most common disinfectants against E. coli (APEC isolates) was determined. The selected disinfectants were; Formalin, Phenol, QAC, Halamid, Virkon" S and Micro Sept M against E. coli isolates of commercial egg- layer flocks in Egyptian farms. The recovered results showed that: (1) the incidence of E. coli in the observed commercial egg-layer flocks; the isolation of E. coli (APEC of rfbO157 gene ) from 4 commercial egg-layer flocks (26.7 %) out of 15 flocks, the mortalities rates at the end of 78 weeks of age was 20% and also, the current egg-production, average egg weight, hen housed day, hen housed egg and percent peak of egg-production were: 69.2%,58.3 gm, 70%,326,78% and 69%,respectivel. (2) Formalin, Micro Sept M and Virkon'S treatment demonstrated a significant reduction in E. coli populations especially by cold fogging method.

Field trial to monitor the efficacy of some commercial poultry disinfection on Salmonella typhymurium through cold fogging

The recovered results showed that: the incidence of Salmonella typhymurium in the observed commercial egg-layer flocks; the isolation of Salmonella typhymurium from 5 flocks (33.7 %) out of 15 flocks, the mortalities rates at the end of 78 weeks of age was 16 % and also, the current egg-production, average egg weight, hen housed day, hen housed egg and percent peak of egg-production were: 68 %,59.2 gm, 68.4%, 318, 78% and 70%, respectively. The efficacy of the most common disinfectants against Salmonella typhymurium was determined. The selected disinfectants were; Formalin, Phenol, QAC, Halamid, Virkon'S and Micro Sept M against Salmonella typhymurium isolates of the studied commercial egg- layers in Egypt (hfq gene of Salmonella typhimurium). It was observed that, S. typhimurium affected significantly only by Micro Sept M and Virkon'S, at low rate of application; the Log 10 of populations after15 mint exposure were 4.2, 4.4, respectively the recovered results showed also, that: Formalin, Phenol, Micro Sept M and Virkon'S treatment demonstrated a significant reduction in Salmonella typhymurium populations at high rate of application. It is evident from the results using formalin, phenols and QAC at concentration of 4% ,5% and 33.3 % by fogging other than spraying had increased action on the tested pathogens S. typhimurium after 15 min contact time (35.7%,42.8 % and 76.8%, respectively).

Influence of dietary phosphorus concentrations on the performance of rearing pigeons (Columba livia), and bone properties of squabs

The objective of this study was to investigate the effects of dietary P levels on the performance of rearing pigeons, and bone characteristics of squabs from 7 to 21 d of age. A total of 192 pairs of adult Silver King pigeons (40 wk of age) were used. The pigeons were randomly allocated to one of 4 treatment groups, each consisting of eight replicates of 6 pigeon pairs per replicate. Dietary treatments included the basal diet (containing 0.3% of P), the basal diet supplemented with 0.2, 0.4, or 0.8% inorganic P. And the dietary Ca content was kept at 1.40% across all treatments. The experimental diets were fed to parent pigeons as corn-soybean complete pellet feed, and squabs fed with crop milk secreted by parent pigeons. Pigeons in the group of 0.4% supplemental non-phytate phosphorus (NPP) had shorter (P = 0.045) oviposition interval than those in the control group and group of 0.8% NPP. When the diet was supplemented with 0.8% of NPP, the least average egg weight was observed (P = 0.006). Female breeding birds had much higher (P < 0.01) Ca, P, and ALP in serum than male ones. At 7-d of age, dietary P supplementation influenced P and Ca content in tibia ash of squabs (P < 0.05). The tibia ash Ca content in the group of 0.2% NPP was the highest among the treatments (P = 0.007). At d 21 of age, both the birds in the group of 0.4 and 0.8% NPP had higher tibia breaking strength (P < 0.01) and tibia ash contents (P < 0.001) compared to the ones in the control group. In conclusion, the P deficiency in the diet of parent pigeons could cause poor bone mineralization of squabs, especially impaired the bone-breaking strength and bone ash content. The 0.8% of NPP supplementation in the diet has a positive influence on mineralization of squabs although production depression was observed. Both P and Ca metabolism of female breeding birds were more active than male ones at earlier time points of rearing period. The desirable supplemental NPP level in diet for breeding pigeon was 0.4% according to the performance data in the present trial. The recommended Ca: P ratio for pigeons, which was different from the optimum value for broilers, needs to be studied in the future.

Review of chicken productive and reproductive performance and its challenges in Ethiopia

This review gathered information about the reproduction and production performance of indigenous, exotic chickens and hybrids in Ethiopia. The indigenous chicken egg production performance under the backyard system within the ranges of 30–80 eggs per hen annually, with an average egg weight of 38–45 g, laying 10–15.7 eggs per month. Indigenous chicken eggs had a hatchability rate of 78.6–85.8%, however more than 40% of chicks died before reaching sexual maturity. At hatch, local chickens weigh 27.1–28.8 g, whereas at maturity they weigh 1300–1600 and 987–1300 g, respectively, and indigenous male and female chickens reach sexual maturity within 23.48–26 and 20–28 weeks, respectively. Each exotic chicken produces 135–185 eggs per year in the village with a 43–52.5 g weight, but it may rise to 250 eggs with a 60 g weight in the marketable sector. Exotic chickens were low in hatchability, 39.3–76.1%. While their cross laid 33 eggs in 3.1 clutches in 31.6–38 days and their eggs weighed 40–49 g with 67.9–85.8% hatchability. Cross-breed chickens and exotics produce a weight of 27–40.1 and 35.2–38.8 g respectively.

Evaluation of Mewari, a native chicken breed vis-à-vis Pratapdhan, an improved chicken variety under an intensive system of rearing

Mewari is an indigenous chicken breed and Pratapdhan is a dual purpose chicken variety developed using Mewari, coloured broiler and Rhode Island Red. Pratapdhan birds were well accepted by the farmers of Rajasthan and adjoining areas. The study was undertaken for comparative evaluation of Mewari and Pratapdhan chicken under intensive system. The data were analyzed using factorial design with genotype, sex and generation (2 × 2 × 3) as main effects. The body weights differed significantly at all ages with significant higher weights in Pratapdhan as compared to Mewari chicken. Sex had significant effect on body weights at all ages except at 2nd week. Males had significantly higher body weights across the genotypes and generations. The interaction effects were significant between the genotypes, sex and generations, except at 2nd week of age. The body weights showed an increasing trend over the generations with few exceptions. ASM and egg weights significantly varied between the genotypes and across the generations with significant interaction effects. The average annual egg production and egg weight (72 weeks) in Mewari and Pratapdhan chicken were 92.02±0.52 and 158.25±1.20 and 46.85±0.22 and 55.74±0.28, respectively. The fertility per cent was 80.39±1.45 and 83.28±0.64 in Mewari and Pratapdhan, respectively. The results suggest that Pratapdhan could be one of the potential improved germplasm for backyard poultry production.

ЭКСТРАКТ ТОПИНАМБУРА В КОРМЛЕНИИ КУР-НЕСУШЕК

Jerusalem artichoke is a source of a complex of biologically active compounds, such as inulin, vita- mins B1, B2, B7, PP, C and organic acids. The use in feeding of laying hens of Helianthus tuberosus L. extract at a dose of 1,1 g/t feed contributed to an increase in their egg production by 7.2%, the average egg weight by 4.4%, safety by 4.0%, and a decrease in feed conversion by 10 eggs by 23.5 % and per 1 kg of egg mass by 24.2%. At the same time, the index of efficiency in the production of eggs of laying hens was 12.8% higher compared to the control.

Using protein concentrate in livestock and poultry diets for sustainable agriculture

The paper presents the main results of the experiment on the use of high-protein concentrate “Gorlinka” in the diets of dairy cows and laying hens on their productive qualities. It was found that in terms of the main indicators of nutritional value (protein, fat, nitrogen-free extractives, ash elements), as well as in terms of amino acid composition and mineral substances, the studied concentrate surpasses the traditionally used in feeding farm animals and birds, oil cake and meal from sunflower seeds. The results of studies have shown that the groups of animals that received protein concentrate with the diet were in the lead. The use of protein concentrate “Gorlinka” in the feeding of dairy cows and laying hens increased the average daily milk yields of cows by 5.47-7.12%. There were also positive changes in the mass fraction of protein in milk by 0.03-0.04%, in dry matter by 0.04-0.09%, in the number of eggs laid by laying hens by 216-822 pieces, in the average egg weight by 0.77-1.66 g. Thus, the use of protein concentrate “Gorlinka” in feeding dairy cows and laying hens had a positive effect on the quality of the products (milk and edible eggs), while economic indicators improved.

Vitality and productivity of laying hens under different light flickering frequency of led lamps

The vast majority of modern LED lighting systems for poultry use pulse-width modulation to control illumination in the poultry house. This work studied the vitality and productivity of laying hens under different frequencies of light flickering of LED lamps. The 113-day-old hens of the SP-789 cross were used to form 4 groups of 144 heads each. All groups of chickens were kept in the cage batteries up to 320 days of age, 8 hens per a cage. The light mode was 1L:4D:4L:2D:3L:10D (L-light, D-darkness), the luminance was 10 lx. The lamps in the control group No.1 had no light flickering, while in the experimental groups Nos. 2, 3, and 4 the lamps had light flickering frequencies of 120, 488, and 977 Hz, respectively. The study results showed that in groups Nos. 1, 2, 3, and 4, the livestock livability was 97.2%, 91.7%, 95.8%, and 95.8%; the egg production per the initial hen was 151.7, 144.4, 151.1, and 150.6 pcs., the average egg weight was 59.3, 59.5, 59.0, and 58.8 g; the yield of egg weight per the initial hen was 9.013, 8.635, 8.940, and 8.895 kg; the feed consumption was 1.43, 1.46, 1.39, and 1.40 kg for 10 eggs and 2.40, 2.43, 2.35, and 2.37 kg for 1 kg of egg weight. It was concluded that it is advisable to use LED lamps with light flickering frequency not less than 488 Hz for laying hens.

The effect of space allowance in the cage and floor systems on feather condition and egg production

The egg production sector is in a transitional period with regard to the permitted housing systems, i.e. rearing in conventional cages under certain conditions to the complete ban of any form of cage system. The changes were caused by concern for the layer wellfare but with the expected effects on productivity as well. The aim of the research was to determine the effects of the floor space allowance in cage and non-cage housing systems on the feather score and egg production of laying hens of three ages, from the aspect of the regulated minimum and optimal space in the cage system (C) and the space provided in the extensive rearing system with hens in smaller groups in the facility (extensive indoor -EI). In order to determine the feather score, the body weight of the laying hens and the weight of the eggs, three groups of laying hens were formed: C4 (564 cm2 per hen, cage system), C3 (751 cm2 per hen, cage system) and EI ( 3000 cm2 per hen, extensive indoor). The feather score and body weight of laying hens were determined in three ages of hens (30, 40, 50 weeks), by individual assessment and measurement of all hens in the experiment. The hen-day egg production and egg weight were determined in the same weeks of laying age. In addition to the expected decrease in feather score with the age of hens, results indicated a significant interaction between age and space allowance per hen. Observed by individual body parts, as well as based on the overall feather score, the space allowance per hen exhibited a full, cumulative effect at 50 weeks of age. Based on the space allowance, it was possible to rank the overall feather score, with the laying hens with the most space having the best feather score. The effect of the space allowance on the body weight of the laying hens was manifested through the space available on the feeder, which resulted in the lowest (p&lt;0.01) body weight values recorded in laying hens of the C4 group. Egg production was not significantly influenced by the space allowance per hen (p=0.069), but a connection between egg production and the housing system can be concluded. The average egg weight, in addition to the known effect of layer age, was the lowest (p&lt;0.01) in the group with the least space allowance per hen.

Applied Research Note: “Parameter estimates for egg production and egg weight of individually penned female ostriches maintained for artificial insemination purposes”

Ostrich females producing eggs in the absence of males was a major breakthrough for the development of an artificial insemination ( AI ) protocol. This study evaluated monthly egg production ( EP ) and average egg weight ( EW ) for 71 individually penned female ostriches from 2009 to 2020 and estimated the genetic parameters for these traits. EP was highly variable compared to EW (coefficients of variation: 124.9 vs. 10.27%, respectively). EP continued throughout the year with maxima from July to December and minima in February and May. The two-trait heritability ( h 2 ) for EP was low at 0.13, while EW had a higher h 2 of 0.40. EP and EW were not genetically correlated. The genetic improvement of EP and EW for females used for AI is feasible. Further studies should target incubation and hatching traits after AI.

Genetics and breeding of a black-bone and blue eggshell chicken line. 2. Laying patterns and egg production in two consecutive generations

The BG line was originated from the cross between 2 Chinese indigenous breeds, Dongxiang blue eggshell, and Jiangshan black-bone, and has been bred to combine dark heavy black-bone body and high production of blue-shell eggs, into single dual-purpose line. Full-pedigree hens from 2 generations, G4 (n = 441) and G5 (n = 464), were reared in the same single-cage laying facility in 2019–2020 and 2020–2021, respectively. Starting from the first egg of each hen, its daily egg production was recorded until 300 days-of-age. Up to 7 "no-egg" days were considered normal laying breaks between clutches, whereas laying cessation of 8 or more days was considered Pause, and the laying pattern of each hen was assigned either with Pause or No-Pause. The other traits included PsDays: number of Pause days; AFE: age at first egg; EN300: eggs laid until 300 d; %L300: total laying rate (EN300/[300-AFE]); %Lnet: net laying rate (EN300/[300-AFE-PsDays]); ClLng: average clutch length; EW200 and EW300: average egg weight around 200 d and 300 d. Estimates of heritability (h2) of each trait, and phenotypic and genetic correlation between traits, were calculated in each generation using the animal model. Heritability estimates were calculated also by regressing the means of full-sib G5 hens on their G4 parents' means. Mean overall laying rate of all G4 hens was low (%L300 = 57%) because 53% of them had Pause in their laying pattern. In G5, incidence of Pause was higher (75%) due to a 3-wk cold stress, with mean %L300 = 54%. However, significant estimates of heritability and genetic correlations suggest that selection for low PsDays will reduce the incidence of Pause in BG hens and elevate the line's mean laying rate towards %L300 = 70%, as the No-Pause hens in G5. PsDays-free laying rate (%Lnet) was found to be highly correlated with the significantly heritable (h2≈0.4) clutch length (ClLng). Selection index combining the genetically independent low PsDays and high ClLng is expected to maximize egg production improvement in the BG line, and in similar populations derived from indigenous breeds.