Egg Production

The poultry red mite, D. gallinae has been involved in the transmission of many pathogenic agents, responsible for serious diseases both in animals and humans. Nowadays, few effective methods are available to control the ectoparasite in poultry farms. Consequently, this is an emerging problem which must be taken into account to maintain good health in commercial egg production. This paper addresses the vector capacity of the ectoparasite with special emphasis on salmonellae, pathogenic agents responsible for many of the ...

Two different Calanus finmarchicus (Gunnerus) cohorts originating from 60°N (Bergen) and 69°N (Tromsø) were investigated in equal environmental conditions to study their different physiological responses to the same environment. A two-plus-two-bag mesocosm study was carried out between March and July 1998, in Håkøybotn, Tromsø, in order to determine development and mortality rates of the two parallel cohorts of C. finmarchicus. For practical reasons, the cohort from Bergen was incubated 10 days earlier than the Tromsø cohort. Consequently, they were exposed to elevated food conditions as compared to the Tromsø cohort. A high initial mortality among the Bergen cohort could clearly be ascribed, by genetic discrimination, to "contamination" with C. helgolandicus. After this initial mass mortality, the mortality was constantly 0.03–0.04 day−1. In cohorts starting from naupliar stage I, there was no significant difference in development or growth, the median development time (NI–CIV) differing by only 7 days (~6%). The difference in development time can be explained to a large extent (~4 days) by temperature differences. This is substantiated with model simulations using a physiological model developed for C. finmarchicus. There was a time lag in incubation between the two cohorts, resulting in elevated temperature during incubation of the Tromsø cohort. A fraction of both cohorts differentiated sexually at stage CV, with males differentiating before females. Females from both cohorts produced eggs, but specific egg production differed significantly (P>0.001, t-test). This was supported by elevated RNA:DNA ratio in females from the Bergen cohort. Both cohorts demonstrated quite similar development and physiological growth rates and, consequently, are considered to belong to the same genetic population inhabiting the Norwegian Shelf. The study demonstrates that C. finmarchicus is capable of adaptation to changes in environment and, thereby, demonstrates a significant physiological plasticity.

Spatial and seasonal egg production rates (Er) and egg hatching success in the copepods Calanus finmarchicus and Calanus helgolandicus were measured in the North Sea from March to September. Food availability was monitored by chlorophyll and protist concentrations and three size fractions of seston fatty acids. Seasonal and spatial distribution and production differed between the species. Calanus finmarchicus was found only offshore of the 50-m isobath, with decreasing Er (37–28 eggs female−1 day−1) from March to July. Calanus helgolandicus had two abundance peaks, in spring and autumn, with a low in May during which time the highest Er were observed (38 eggs female−1 day−1). At other times, Er in C. helgolandicus remained lower than in C. finmarchicus (∼20 eggs female−1 day−1). Normalized Er (En) in both C. finmarchicus and C. helgolandicus were positively related to ciliate biomass while only negative relationships were found for all other variables measured. Hatching success in b...

Current methods of intensive breeding of the red-legged partridge (Alectoris rufa) are based on "in- dustrial" laying practices, including removal and artificial incubation of eggs. These procedures can alter the repro- ductive behavior and physiology of the birds and, there- fore, may not be suitable for use in breeding programs designed to increase wild populations. This study aimed to determine

This study was conducted to investigate the effects of dietary dried baker’s yeast on laying performance, egg traits and some blood parameters of quails. In the experiment a total of 342 Japanese quails (Coturnix coturnix japonica) aged ten weeks were equally divided into six groups of 57 (three replicates of 19 quails each). Six levels (0, 4, 8, 12, 16 and 20%) of dried baker’s yeast were included in isonitrogenous and isocaloric diets. The experimental period lasted 14 weeks. At the end of the experiment, there were no significant differences among the groups in body weight, feed intake, protein intake, egg production, feed efficiency, egg yolk index and egg haugh unit. Blood serum levels of total protein, triglyceride and cholesterol were not affected by dietary dried baker’s yeast. Diets containing 4 and 8% of dried baker’s yeast increased the egg weight significantly (p < 0.01). The inclusion of dried baker’s yeast at the level of 20% to the diets reduced egg shell thickness and egg albumen height. It is concluded that dried baker’s yeast can be used up to 16% in the diets of laying quails without adverse effects on the measured parameters.

Rhode Island Red (RIR) and Fayoumi chickens were evaluated on-station in a college farm and on-farm in village farms, whereas local chickens were only tested under on-farm condition. Traits recorded are egg production and egg quality, body weight and feed efficiency at 4, 8 and 12 months of age. Significant age effect was found for most traits except for shell thickness, albumen height and egg length. Also, significant breed by management system interactions were found for all traits measured in both systems. Fayoumi chickens were higher in egg production in both management systems. Moreover, they were higher than RIR in feed efficiency. RIR were higher in most egg quality traits and had higher weight gain. Local chickens performed below the two exotic breeds in most of the traits, but had higher weight gain than Fayoumi. Chickens kept on-farm had poorer performance than those kept on-station in all traits except for yolk colour.

Acute effects of cypermethrin, a pesticide used to treat ectoparasite infestations of salmon, were assessed using the calanoid copepod Acartia tonsa. A. tonsa has been widely used for hazard assessment of chemicals in the marine environment using acute toxicity tests, but only with randomly selected adults, assuming a sex ratio of 1:1. The present study assesses the environmental hazard of cypermethrin by exposing nauplii and adult males and females, separately. Our results showed that the naupliar stages were 28 times more sensitive to cypermethrin than adults after 96 h of exposure, with LC50s of 0.005 μg L−1 and 0.142 μg L−1, respectively. Significant differences in sensitivity between sexes were only found during the first 24 h of exposure, with males being approximately twice as sensitive as females. The results of age-related variation in sensitivity are supported by studies with other species of copepods and toxicants, where the increased capacity of the adults for detoxification, the allometric differences in weight and size, and the molting process are given as explanations. Variation in sensitivity between sexes is discussed in terms of faster depuration rates in females through egg production and implications of feeding rate changes after 24 h of exposure. Our results suggested that standard toxicity test methods using A. tonsa are unsatisfactory because the most sensitive life stage is not included and sex-related differences in tolerance are not taken into account. We also found that cypermethrin caused significant mortality in Acartia at exposures concentrations from one to three orders of magnitudes lower than the recommended field treatment concentration for copepodic infestations.

Background and Aim: Duck eggs have high cholesterol levels; inulin addition combined with probiotic is known in several studies to lower cholesterol, while maintaining egg production capacity and blood hematology. This study aimed to investigate the effect of the addition of synbiotic preparations on egg production, egg quality, and hematology of Pengging ducks.

Materials and Methods: A total of 200 female Pengging ducks aged 75 weeks (late production phase) and weighing 1467±90.87 g were maintained in litter cages, each measuring 1×1 ducks. The treatment included the addition of synbiotics between the inulin of gembili tuber (Dioscorea esculenta L. and Lactobacillus plantarum Ina CC B76) as follows: T0=control feed ("farmer feed"), T1=control feed+synbiotics 1 mL/100 g, T2=control feed+synbiotics 1.5 mL/g, and T3=control feed+synbiotics 2 mL/100 g in the feed. A completely randomized design was used in this study. The production performance, physical and chemical qualities of eggs, and hematological parameters of Pengging ducks were evaluated.

Results: The addition of synbiotics had no significant impact on the production performance, physical and chemical qualities of eggs, and hematological parameters (p>0.05), except for the egg yolk cholesterol content. The cholesterol content decreased significantly (p<0.05) with T2 and T3 treatments, but they had no significant effect (p>0.05). A significant decrease (p<0.01) in cholesterol levels was observed when the synbiotic dose was given at 1.5 ml/100 g feed (T2). However, there was no further decrease in cholesterol level when the synbiotic dose was increased to 2 ml/100g fed (T3).

Conclusion: The addition of synbiotics preparations at 1.5 mL/100 g reduced the cholesterol content but did not improve egg production, egg physical quality, and hematology of Pengging ducks.

A total of 2001 un-sexed day-old chicks of each Desi, Fayoumi and Rhode Island Red (RIR) breeds were obtained from hatchery of Poultry Research Institute, Rawalpindi. The birds were maintained on deep litter system for a period of 72 weeks. In floor pens, each breed was reared separately in a single pen until seven weeks of age when 2001 birds were randomly distributed between pens, with 21 to 24 birds of the same breed per pen (2.00 to 2.50 ft2/bird). The results revealed that the average day-old weight was highest in RIR, intermediate in Desi and lowest in Fayoumi. The RIR breed consumed more feed and gained maximum (p&lt;0.05) weight than those of Desi and Fayoumi breeds at all ages of growing phase. The feed conversion was poor (p&lt;0.05) in Desi and better in RIR breed. Desi and Fayoumi chicks had lowest (p&lt;0.05) mortality than RIR breed. The breast and thigh meat composition was found non-significant (p&gt;0.05) amongst three breeds. The age of sexual maturity was lowest i...

Rhode Island Red (RIR) and Fayoumi chickens were evaluated on-station in a college farm and on-farm in village farms, whereas local chickens were only tested under on-farm condition. Traits recorded are egg production and egg quality, body weight and feed efficiency at 4, 8 and 12 months of age. Significant age effect was found for most traits except for shell thickness, albumen height and egg length. Also, significant breed by management system interactions were found for all traits measured in both systems. Fayoumi chickens were higher in egg production in both management systems. Moreover, they were higher than RIR in feed efficiency. RIR were higher in most egg quality traits and had higher weight gain. Local chickens performed below the two exotic breeds in most of the traits, but had higher weight gain than Fayoumi. Chickens kept on-farm had poorer performance than those kept on-station in all traits except for yolk colour.