Advanced Practical Strategies to Enhance Table Egg Production

Management factors associated with the survival and market weight of broiler chickens among small-scale farmers in the Dodoma City of Tanzania

Broiler chickens have the genetic potential for significant weight gain over a very short period of time. As a result, they account for over 92 % of the world's poultry meat production in different parts of the world. Yet, to fully realise their growth potential, effective management practices are crucial, encompassing aspects like nutritious feeds, disease control, optimal temperature, and adequate housing. The purpose of the study was to determine the management practices associated with the survival and market weight of broiler chickens in small-scale production. Small-scale poultry production plays a significant role in poverty reduction and household nutrition in developing countries. One hundred and forty small-scale broiler farmers were visited for interviews in the Dodoma City. Employing a structured questionnaire, data on management practices was gathered, while past production records determined market weight and survival rates. Most chickens weighed 1.8-2.3 kg at the end of the production cycle, with a mean live weight of 2.0 kg. Heat provision to chick housing in the early growth stages increased both survival and market weight. Conversely, chicken vaccination and the farmer's experiences were correlated with an increased survival rate. Furthermore, higher feed quantities offered to growers and finishers were linked to greater market weight. It was concluded that enhancing knowledge among small-scale farmers through training and extension services has the potential to increase broiler productivity.

Stress-Related Gene Expression in Liver Tissues from Laying Hens Housed in Conventional Cage and Cage-Free Systems in the Tropics

Global egg production is mainly based on cage systems, which have been associated with negative effects on the welfare of birds. Stress factors in restrictive production systems can lead to changes in gene transcription and protein synthesis, ultimately impacting the quality of poultry products. The liver serves various metabolic functions, such as glycogen storage, and plays a crucial role in animals' adaptation to environmental changes. Consequently, both internal and external conditions can influence liver functions. The aim of this study was to evaluate the gene expression of AGP, CRP, NOX4, SOD1, CAT, GPX1, SREBF1, and FXR in the liver of laying hens under two different production systems. Liver tissues from Hy-Line Brown hens housed in conventional cage and cage-free egg production systems at 60 and 80 weeks of production were used. mRNA transcript levels were determined by qPCR using the relative quantification method and ACTB as the reference gene. AGP, SOD1, and SREBF1 gene expressions were significantly higher in the conventional cage group at the 60 weeks of production. Furthermore, the mRNA levels of transcripts related to oxidative stress and lipid metabolism were higher in the group of laying hens housed in conventional cages compared to those in cage-free systems. These results suggest differential gene expression of genes related to oxidative stress in liver tissues from hens housed in conventional cages compared to cage-free systems. The conditions of the egg production system can impact the gene expression of oxidative stress and lipid synthesis genes, potentially leading to changes in the metabolism and performance of hens, including egg quality.

Soybean oil addition to wheat bran-based diet improves laying hens' performance

Background and Aim

Wheat bran (WB) is used extensively in animal feed. Despite its nutritional value, its use is limited because of its high-fiber content. We evaluated the effect of soybean oil on laying hen performance with maize meal partly replaced by WB.

Materials and Methods

Thirty-six ISA Brown laying hens, 40 weeks old, were used in a completely randomized design in which laying hens were distributed in individual cages, with three replications of four birds and assigned to three treatments: T1 (basal diet), T2 (60% basal diet + 20% maize meal + 20% WB), and T3 (60% basal diet + 20% maize meal + 17.5% WB + 2.5% soybean oil).

Results

Compared with the control group (T1), replacing 20% of yellow maize with WB (T2) did not affect average live weight, egg laying rate, soft-shelled egg production, egg mass, feed conversion per dozen eggs, or laying hen viability (p > 0.05). When 20% of the maize meal was replaced with WB, feed intake and feed conversion per egg mass increased (p < 0.05). Furthermore, adding 2.5% soybean oil to feed containing WB improved laying hen performance by significantly reducing feed conversion per egg mass (p < 0.05).

Conclusion

Adding 2.5% soybean oil to diets containing WB instead of 17.5% yellow maize improved the feed conversion per egg mass performance of laying hens.

Influence of non-ventilating intervals during early incubation stage on egg hatching process

Background and Aim

The exchange of oxygen and carbon dioxide (CO2) in the incubator plays a key role in embryonic development and hatching. This study aimed to study the effect of non-ventilated (NV) intervals during the early stage of embryonic development on the hatching process.

Materials and Methods

Hatching eggs (n = 7200) were equally divided into four treatment groups and incubated in four incubators. The first group was incubated in normal ventilated condition (V) during the setting phase of incubation. Ventilation holes of the three remaining incubators were closed for the first 3, 6, and 9 days and termed as NV groups (NV1, NV2, and NV3, respectively). A gradual increase in CO2 was allowed for NV groups, followed by opening the incubator holes to permit ventilation throughout the rest of the incubation periods.

Results

Obtained results demonstrated that CO2 concentration gradually increased up to 0.19% for the NV1 group, 0.41% for the NV2 group, and 0.90% for the NV3 group, while CO2 concentration remained at 0.08% during the first 9 days of incubation in the V group. Albumen pH was lowered for all NV groups. The highest hatchability percentage was recorded for NV3 followed by NV2 and NV1 groups. All NV groups represented earlier and narrower spread of hatch and higher hatched chick weight. Embryos and hatched chicks in the NV groups had higher hormonal levels of thyroxin and corticosterone.

Conclusion

All non-ventilation periods had positive effects on narrowing the spread of hatch, increasing hatched chick weight and hatchability percentage compared to the normal V condition. Furthermore, the non-ventilation throughout the first 9 days of incubation yielded the best hatching results.

Influence of dietary chitosan-oligosaccharides supplementation on productive and reproductive performance of laying hens

This experiment aimed to ascertain whether adding chitosan-oligosaccharides (COS) to the diet will affect Mandarah laying hens’ productivity and reproductive efficiency. At the age of 34 weeks, 120 laying hens and 12 cocks of the Mandarah chicken strain were separated into four groups, each consisting of 30 hens and three cocks. The 1st group served as a control group, receiving only a basic diet. The 2nd, 3rd, and 4th experimental groups received 0.1, 0.2, and 0.5 g/kg of chitosan-oligosaccharides as an addition to the base diet, respectively. According to the findings of this study, the majority of the analyzed attributes differed significantly between treatment groups. Comparing the COS-treated birds to the control birds, the COS-treated birds significantly increased egg production, improved feed conversion, haugh unit score, shell thickness, fertility, hatchability, ovary weight, and the number of yellow ovarian follicles as well as blood estradiol-17β (E2) and testosterone concentrations. Furthermore, compared to the other treated groups, introducing COS at a level 0.1 g/kg diet resulted in the best laying rate, egg mass, and feed conversion. The highest percentage of fertility, hatchability of hatching eggs, ovary weight, number of yellow ovarian follicles, and serum E2 concentration was also found in birds fed COS at a dose of 0.2 g/kg feed. In addition, compared to the control diet, COS treatment at 0.1, 0.2, and 0.5 g/kg enhanced relative economic efficiency by 464.43, 457.41, and 352.75%, respectively. It is concluded that chitosan improves economic efficiency, reproductive performance, productivity in laying hens, and overall health when used at a 0.1 g/kg diet.

The use of purple carrot powder in the diet of laying quails improved some egg quality characteristics, including antioxidant capacity

The goal of the current experiment was to investigate the effect of dietary concentrations of purple carrot powder (PCP) on performance, egg production, egg quality, and the antioxidant capacity of the yolk in laying quails. A total of one hundred and fifty 22-week-old Japanese laying quails were allotted to 5 dietary treatments each with 6 replicates of 5 quails. Quails were allocated to five dietary treatments (0, 0.1, 0.2, 0.3, and 0.4%) with PCP addition at an increasing level from 0 to 4000 mg/kg diet respectively, which were fed ad-libitum throughout the duration of the experiment. No differences were detected between dietary treatments for any of the performance parameters or egg production. Eggshell weight and eggshell thickness (P < 0.05) were linearly affected by PCP dietary, reaching maximum levels at 0.4% of PCP supplementation, while the percentage of damaged egg and egg-breaking strength remained similar for all experimental groups (P < 0.05). Quails receiving PCP diets showed a yellowness (b*) (P < 0.05) egg yolk color than those fed the control diet, without affecting the rest of the color parameters and egg internal quality. Increasing PCP levels in diets reduced linearly yolk TBARS (P < 0.01) and increased linearly DPPH (P < 0.01). The addition of PCP, a safe and readily available agricultural by-product, as a component of the diet of laying quail was effective without adversely affecting quail production. Moreover, the inclusion of PCP in the diet might benefit laying quails' eggs by improving some quality traits and enhancing the yolk's antioxidant capacity, which could improve their shelf-life and acceptability.

Genetic parameters for production, quality, and colors from eggs in Brazilian lineages of chickens

Genetic parameters were estimated for egg production, egg quality, and eggshell colors in eight lineages of Brazilian laying hens. Age at first egg (AFE), total egg production up to the 45th week (PROD), egg weight (EW), albumen height (AH), yolk color (YC), the Haugh units (HU), eggshell strength (ESS), eggshell thickness (EST), yolk weight (YW), eggshell weight (ESW), and eggshell color (L*, a*, and b*) were measured in 2030 eggs obtained from 645 laying hens. Variance components were estimated from a mixed animal model, which included the fixed effects of contemporary groups, cage location, and hen line, and the additive genetic, permanent environmental, and residual as random effects. In general, heritabilities were low to moderate (h² = 0.11 to 0.48). Genetic correlations among eggshell quality traits were moderate to high (0.36 and 0.69). High genetic correlations were obtained between the eggshell color traits [r_g = -0.90 (L* and a*); r_g = -0.64 (L* and b*); and r_g = 0.65 (a* and b*)]. Results suggest that EW is strongly correlated with ESW, but the genetic correlations between EW and ESS and between EW and EST were low. Genetic correlations between L* and eggshell quality traits were low to moderate, suggesting that L* has little or no relation with external egg quality. However, genetic correlations between a* and b* values and eggshell quality traits were high. The genetic correlations between eggshell color and eggshell quality traits were low, suggesting that the eggshell color does not influence external egg quality. Genetic correlations between PROD and egg quality traits were negative and varied between -0.42 and -0.05. This antagonistic relationship emphasizes the importance of adopting breeding schemes that allow the simultaneous genetic progress of these traits by considering their genetic correlation and economic relevance, such as the selection index.

Impact of Cannabis Seed Incorporation in Layer Diet on Productive Performance and Egg Quality Traits

The production of nonindustrial cannabis is highly developed in the Moroccan Rif region; however, local farmers consider hemp seeds which are rich in omega 3 and tocopherols, only as by-products of cannabis cultivation with low market value. The local ecotype is considered to be a plant with a cannabinoid content of more than 0.4%. So, the objective of this research is to investigate how the incorporation of this local hemp seed affects productive performance and egg quality traits. The experiment is conducted to evaluate the effects of hemp seed (HS) incorporation on hen laying performance and physical egg quality at three levels: 10% (HS-10% group), 20% (HS-20% group), and 30% (HS-30% group). Ninety-six Lohmann Brown classic laying hens were randomly assigned to a control group and three feed treatments. The sampling was taken after the 28-week rearing period (peak egg laying). Throughout the experiment, low-rate HS inclusion (HS-10%) showed no significant differences in egg-laying performance (p > 0.05). However, the high incorporation rates of HS (20% and 30%) negatively affected the egg-laying performance (84-94% and 80-86%, respectively). The albumen quality was also improved by the HS inclusion, where the highest values of the Haugh unit were recorded, ranging between 68.69 and 73.91 for the HS-30% groups. The results also show that HS inclusion and duration influence significantly the yolk color (p < 0.001). The yellow intensity decreases with HS incorporation and aging, from a dark yellow (b ^∗  = 38.63 for the control group) to a very pale yellow (b ^∗  = 26.29 for HS 30% group). Based on these findings, we can conclude that the incorporation of nonindustrial Moroccan cannabis seeds (ecotype Beldiya) at low rate in the diet of laying hens does not alter the laying performance or the quality of the egg; therefore, they could be used in poultry feeding as an alternative constituent to partially replace high-cost imported ingredients, such as corn and soybeans.

The genetic impact of heat stress on the egg production of Thai native chickens (Pradu Hang dum)

Sustainable poultry production in adverse weather conditions is a widely debated issue, which has led to research into the development of breeds of poultry that are genetically resistant to heat. This study aimed to investigate the effects of heat stress on the genetics of monthly egg production and examine the threshold point of heat stress for preventing thermal stress and its effects on chicken productivity. The data of 5,965 monthly egg production records of 629 Thai native Pradu Hang dum chickens were used for analysis in combination with the temperature-humidity index (THI) calculated by meteorological data near the testing station. The average THI throughout the year was 76.6, and the highest was 82. The THI data were subsequently used to find the threshold point of heat stress. The THI equation used in this study was chosen by its highest correlation (-0.306) between THI values and monthly egg production. At a THI of 74, the lowest -2 logL was found and was considered the threshold point of heat stress. This means that monthly egg production would start decreasing when the THI was 74. Heritability was 0.15±0.03, and genetic and permanent environmental correlations were -0.29 and -0.48, respectively. The threshold point was used to estimate the estimated breeding values (EBVs) of the monthly egg production and heat stress individually, and EBVs were calculated into the selection index. The selection index values when the animal was selected for the replacement herd for all chickens (top 50%, 30%, 20%, and 10%) were 0.14, 0.90, 1.27, 1.53, and 1.91, respectively, and the genetic progress was 0.55, 0.60, 0.68, 0.75, and 0.77, respectively. This shows that the selection index values are lower if there are many selected animals. The recommendation for animal genetic selection is that the top 10% is appropriately because it seems to be most preferred. Therefore, using a selection index for high egg production and heat tolerance in Thai native chickens is possible to achieve genetic assessment in a large population.