scholarly journals Factors affecting Oithona nana and Oithona similis along a salinity gradient

2021 ◽  
Vol 22 (3) ◽  
pp. 552
Author(s):  
NEILA ANNABI-TRABELSI ◽  
RAYDA KOBBI-REBAI ◽  
YOUSEF AL-ENEZI ◽  
MOHAMMAD ALI ◽  
M.N.V SUBRAHMANYAM ◽  
...  
Keyword(s):  
Egg Production ◽  
Salinity Gradient ◽  
Temporal Variations ◽  
Solar Saltern ◽  
Factors Affecting ◽  
Oithona Similis ◽  
Cephalothorax Length ◽  
Vital Component ◽  
Egg Production Rate ◽  
Egg Diameter

Spatial and temporal variations of reproduction variables of the two cyclopoid copepods Oithona nana Giesbrecht, 1893 and Oithona similis Claus, 1866 were evaluated monthly from September 2007 to August 2008 in four ponds at different salinities in the solar saltern of Sfax, Tunisia, under hypersaline conditions. Along the salinity gradient the abundance of O. nana and O. similis declined from 14,900 ± 15,200 ind. m-3 (A1) to 6,800 ± 7,200 (C31) and from 13,800 ± 17,100 ind. m-3 (A1) to 3,700 ± 5,800 (C31), respectively. The findings showed that the abundance of these Oithona species, particularly the ovigerous females, was positively correlated with the abundance of Diatomeae, and negatively correlated with salinity. The egg production rate (EPR), the egg diameter, the clutch size, as well as the cephalothorax length of mature females, were all negatively correlated with salinity and positively correlated with the abundance of Diatomeae. Along the existing salinity gradient, the EPR decreased from 4.7 ± 0.39 (A1) to 3.2 ± 0.13 (C31) eggs female-1 day-1 and from 5.19 ± 0.46 (A1) to 3.66 ± 0.05 (C31) eggs female-1 day-1 for O. nana and O. similis, respectively, and this could mainly be attributed to the hypersaline conditions. The positive relationship between the abundance of Diatomeae with all traits shows, that these may be a vital component of the diet for the investigated species. The reduction of body size of Oithona along the salinity gradient demonstrates that such a character could mainly be due to a network of causes, related with the confinement and not only to salinity.

scholarly journals Factors affecting egg production and layer bird mortality in private poultry farms in the subhumid zone of Nigeria

2003 ◽  
Vol 74 (3) ◽  
pp. 239-242
Author(s):  
Aduli Enoch Othniel MALAU-ADULI ◽  
Gideon Shaibu BAWA ◽  
Kayode JOEL
Keyword(s):  
Egg Production ◽  
Factors Affecting ◽  
Poultry Farms ◽  
Bird Mortality

scholarly journals Factors Affecting Feed Efficiency for Egg Production in Selected Strains of Caged Layers

1959 ◽  
Vol 38 (4) ◽  
pp. 757-766 ◽  
Author(s):  
Marshall M. Miller ◽  
J.H. Quisenberry
Keyword(s):  
Feed Efficiency ◽  
Egg Production ◽  
Factors Affecting

The impact of dietary protein:carbohydrate balance on lifespan and reproduction in Protaetia brevitarsis (Coleoptera: Scarabaeidae: Cetoniinae)

2021 ◽  
pp. 1-8
Author(s):  
S.-H. Kim ◽  
H. Park ◽  
W. Kim ◽  
J.-H. Song ◽  
S.J. Roh ◽  
...  
Keyword(s):  
Reproductive Performance ◽  
Egg Production ◽  
Detailed Knowledge ◽  
Reproductive Senescence ◽  
Egg Hatchability ◽  
Edible Insect ◽  
Age Related ◽  
Medicinal Value ◽  
Egg Production Rate ◽  
The Impact

The establishment of efficient and sustainable production of industrially important insects necessitates the detailed knowledge of the optimal mixture of macronutrients required for maximising their performance and fitness. The white spotted flower chafer, Protaetia brevitarsis (Coleoptera: Scarabaeidae: Cetoniinae), is one of the most important edible insects in East Asia with high nutritional and medicinal value. Here, we report how the ratio of protein to digestible carbohydrate (P:C) in the diet influenced lifespan and reproductive performance in the adults of P. brevitarsis. Throughout their lifespan, beetles were fed ad libitum one of five diets with differing P:C ratio (0:1, 3:7, 1:1, 7:3, 1:0). Both lifespan and the number of eggs produced over the lifetime were maximised at the P:C ratio of 3:7 and declined as the ratio deviated away from this optimal P:C composition. Beetles fed a diet containing only protein (P:C 1:0) not only had the shortest lifespan but also exhibited substantially reduced lifetime egg production compared to those fed the other diets. However, the effects of dietary P:C ratio on daily egg production rate and egg hatchability were marginal. The number of eggs produced at each age stage peaked at the age of week 2 and then gradually declined with increasing age, showing the sign of reproductive senescence. Age-specific egg production was higher in beetles confined to three intermediate P:C ratios (3:7, 1:1, 7:3) than those confined to two extreme P:C ratios (0:1, 1:0) throughout their lifespan. The speed of age-related decrease in reproductive performance was the slowest at P:C 3:7. Our data have implications for optimising the production of this edible insect with emerging economic importance.

New method of poultry selection

2021 ◽  
pp. 61-66
Author(s):  
E. Rehleckaya ◽  
A. Dymkov ◽  
L. Lazarets ◽  
A. Maltsev
Keyword(s):  
Egg Production ◽  
Initial Period ◽  
Large Diameter ◽  
Small Diameter ◽  
Live Weight ◽  
Individual Variability ◽  
Egg Laying ◽  
New Method ◽  
Egg Diameter ◽  
Correlation Rate

Purpose: Install the influence of the «small diameter of the egg» on the living mass and the reproductive qualities of chickens of meat crosses and the quail of meat breeds.Materials and methods. The selection was carried out along egg production and mass of eggs and additionally on the average small diameter of 5 eggs by value of ≥0.5σ from the average for the herd, while the evaluation on the basis of the «small diameter of the egg» was carried out in chickens aged 238 days of life, quails — 70 days of life. Calculated the average for each female and the average for the herd. For further reproduction, chickens carrying eggs with a small egg diameter ≥0.5σ from the average for the herd. Studies were held in SibNIP on quail and on the courses.Results. In the initial period of the egg laying, the individual variability of the small diameter of the egg — more than 10% (in the future, the figure decreased). The close correlation rate of the small egg diameter in the first half of the egg laying with such at the end of the bird's operation period was revealed. It has been established that the large diameter of the egg has a positive reliable connection with a lively mass, but negative with egg production. The reliable correlation rate of the small diameter of the egg with a live weight at a 42-day age, as well as with the derivation of eggs. The inheritance coefficients of the small diameter of the egg are comparable to the inheritance coefficients of the mass of eggs and significantly exceed those for a large diameter of the egg. The selection according to the small diameter of the eggs by ≥0.5σ from the average for the herd led to the fact that the chickens of the experimental groups reliably exceeded the live weight in the SB level of 1.57%, in the line G8 — by 1.35%. The superiority of a lively mass of quail of experienced groups was more pronounced than that of the chickens: the Pharaoh breed — by 4.15%, the Texas white breed is 4.22%. In relation to the derivation of eggs, a similar trend was traced. The derivation of eggs in quails of experienced groups was more than 4.59–4.98%; Country, respectively, 4.57–5.22%. Egg production of females of comparable groups of both chickens and quail was almost on the same level, and the difference was unreliable.Conclusion. It was established that a new method of breeding the poultry of the meat direction of productivity allows without decreasing egg production to increase the living mass of chickens of meat crosses by 1.5%, rewinds of meat breeds — by 4%, the derivation of eggs, respectively, by 4–5%. The method is intended for early prediction of females productivity during breeding selection.

scholarly journals Performance Evaluation of Kuroiler and Sasso Chicken Breeds Reared under On-farm and On-station Management Conditions in Tanzania

2021 ◽  
Vol 3 (2) ◽  
pp. 53-59
Author(s):  
Fadhili S. Guni ◽  
Said H. Mbaga ◽  
Andalwisye M. Katule
Keyword(s):  
Body Weight ◽  
Egg Production ◽  
Linear Models ◽  
Farm Management ◽  
General Effect ◽  
Production Traits ◽  
Gxe Interaction ◽  
Live Body Weight ◽  
Egg Production Rate ◽  
On Farm

A study was conducted to evaluate the effect of management, breed, and their interaction on growth performance, egg production, and survivability under on-station and on-farm management conditions in Tanzania. A total of 1200 chicks, 600 for each breed, Kuroiler, and Sasso of mixed sexes were used. Birds under on-station management were confined and fed commercial ration throughout the experiment while those under on-farm management were allowed to semi-scavenge and supplemented with available feeds in the household. Brooding was carried out on-station for six weeks. Thereafter, birds were sub-divided for on-station and on-farm evaluation where data on body weight, egg production traits, and survival rate were taken at different ages from week 6 up to 52. The General Linear Models procedure fitting management, breed, and interaction between management and breed was used to analyze the data. Results show that management conditions had a significant influence on the performance of the breeds. Birds reared on-station performed better in all traits measured than those reared on-farm. The general effect of the breed was significant only for hen-day egg production (HDEP %) and hen-housed egg production (HHEP) in favour of Sasso chickens. Similarly, Sasso was more efficient at converting feed to live body weight. Interactions between management and breed were observed for all traits except peak egg production rate and mortality rate. While Sasso performance was better than that of Kuroiler on body weight, age at first egg, HDEP, age at peak egg production, and HHEP under the on-station management system, their performance in these traits were similar under the on-farm management except for body weight and age at first egg where Kuroiler was superior to Sasso. The survivability was also higher for Kuroiler than for Sasso under both management systems. It is concluded that genotype by environment (GxE) interaction had significant effects on the performance of the two breeds thus, a need to consider such effect when promoting them for either on-station or on-farm rearing.

Factors affecting egg production in the selfing mangrove rivulus ( Kryptolebias marmoratus )

Zoology ◽  
2017 ◽  
Vol 122 ◽  
pp. 38-45 ◽  
Author(s):  
Justin L. Lomax ◽  
Rachel E. Carlson ◽  
Judson W. Wells ◽  
Patrice M. Crawford ◽  
Ryan L. Earley
Keyword(s):  
Egg Production ◽  
Factors Affecting ◽  
Kryptolebias Marmoratus ◽  
Mangrove Rivulus

Composition changes of phototrophic microbial communities along the salinity gradient in the solar saltern evaporation ponds of Eilat, Israel

Hydrobiologia ◽  
2009 ◽  
Vol 636 (1) ◽  
pp. 77-88 ◽  
Author(s):  
Klára Řeháková ◽  
Eliška Zapomělová ◽  
Ondřej Prášil ◽  
Jana Veselá ◽  
Hana Medová ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Salinity Gradient ◽  
Solar Saltern ◽  
Evaporation Ponds ◽  
Composition Changes

scholarly journals Breeding for the improvement of indigenous chickens in Bangladesh: performance of second generation

2017 ◽  
Vol 3 (1) ◽  
pp. 66-71
Author(s):  
Shakila Faruque ◽  
AKFH Bhuiyan ◽  
Md Yousuf Ali ◽  
MSK Sarker ◽  
Ziaul Faruque Joy
Keyword(s):  
Body Weight ◽  
Egg Production ◽  
Second Generation ◽  
Breeding Value ◽  
Genotype 3 ◽  
Indigenous Chicken ◽  
Egg Weight ◽  
Slaughter Age ◽  
Dressing Percentage ◽  
Egg Production Rate

The improvement of productivity of indigenous chicken is a long desire in the country. Present research is a part of the long-term selection program being undertaken to evaluate the carcass characteristics and expected response to selection of second generation (G2) of indigenous chicken under intensive management in Bangladesh. A total of 1643-day-old chicks comprising of 3 types of chicken namely Naked Neck (NN), Hilly (H) and Non-descript Desi (ND) were hatched in a two batches for this study. In second generation (G2), selection was practiced at 3 (three) stages of birds life, firstly and secondly at 8 and at 16 weeks of age, selection was performed on the basis of breeding value for 8 and 16 week body weight. Thirdly, at 40-week of age, on the basis of an index comprising the parameters of age at sexual maturity (ASM), body weight (BW), egg production (EP) and egg weight (EW). Improvement target of egg weight was to increase by 1g and improvement target of egg production rate was to increase by 2 % per generation. The main target was the mean body weight in H, ND and NN chicken has to be gone up from the initial eight-week body weight of 375, 342 and 331g to 500 g at eight weeks of age. At 8, 10 and 12 weeks of age, six birds from each genotype were slaughtered to analyze the meat yield traits. Slaughter data were analyzed in a 3(genotype)×3(slaughter age) factorial arrangement in CRD by General Linear Model (GLM) Univariate Procedure in SPSS Computer Program. Genotype and slaughter age had significant effect (p<0.001) on dressing percentage. Body weight at 8 weeks of age was expected to improve by 51.21 vs. 24.03; 37.74 vs. 15.47 and 26.26 vs. 9.65g; respectively for ND, H and NN males and females. In terms of body weight H genotype was superior and NN genotype was for dressing percentage. As a result of selection; EP, BW increased and ASM reduced in second generation than that of the foundation stock.Asian J. Med. Biol. Res. March 2017, 3(1): 66-71

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