scholarly journals EGG PRODUCTION BY SAND CRABS (EMERITA ANALOGA) AS A FUNCTION OF SIZE AND YEAR CLASS (DECAPODA, HIPPIDAE)

1987 ◽  
Vol 172 (2) ◽  
pp. 225-235 ◽  
Author(s):  
ADRIAN M. WENNER ◽  
DAVID M. HUBBARD ◽  
JENIFER DUGAN ◽  
JULIE SHOFFNER ◽  
KERRY JELLISON
2020 ◽  
Vol 70 (4) ◽  
pp. 417-425
Author(s):  
Ritindra N. Bhaduri

Abstract Parasites can dramatically influence fecundity of their hosts, so for any host species it is important to establish whether parasite infections affect host reproduction. The Pacific mole crab, Emerita analoga, commonly harbors metacercarial cysts of the trematode Microphallus nicolli and cystacanths of the acanthocephalan Profilicollis altmani. Although these helminths are known to infect primarily larger female mole crabs, they may do so disproportionately when tied to their host’s reproductive condition. This study was undertaken to examine differences in parasite prevalence and abundance between non-ovigerous and ovigerous hosts. Crabs from Del Monte Beach, Monterey, California were collected, carapace length measured, sexed, examined for parasites, and had their reproductive state noted. The vast majority of the crabs sampled were infected with at least one parasite, and over half of the crabs had both M. nicolli and P. altmani. Ovigerous females were significantly larger than non-ovigerous crabs. Prevalence of both trematode metacercarial cysts and acanthocephalan cystacanths was significantly higher in ovigerous females than in non-ovigerous ones. Egg-bearing females were also more heavily infected by both parasites than non-egg-bearing individuals. These results suggest that larger ovigerous crabs may provide greater resources and thus are able to support higher levels of infections. This study shows that neither parasite prevalence nor abundance seemed to affect egg production in E. analoga.


2009 ◽  
Vol 7 ◽  
pp. 31-43 ◽  
Author(s):  
AAV Flores ◽  
CC Gomes ◽  
WF Villano

Intermittent Lighting Improves the Efficiency of Artificial Insemination in Cage Housed Laying Hens Kavtarashvili A.Sh., Kolokolnikova T.N. Federal Scientific Center “All-Russian Research and Technological Poultry Institute” of Russian Academy of Sciences Omsk Agrarian Scientific Center Summary: The effects of different lighting regimes on the oviposition schedule, productive performance, and reproductive efficiency in cage housed laying hens of layer parental flock (Hisex White-R) were studied; the reasonable regime of artificial insemination (AI) under intermittent lighting is proposed. It was found that intermittent lighting regime 1L:4D:4L:1D:4L:10D compared to the constant lighting significantly alters oviposition schedule: under this regime 82.3% of all daily eggs were laid until 9 am (vs. 66.6% in control). This regime and AI at 10 am improved the productive and reproductive performance compared to control (constant lighting 16L:8D and AI at 12 am): mortality by 1.9%, egg production per initial hen by 3.8%, egg weight by 1.1%, percentage of eggs suitable for incubation by 1.9%, egg fertility by 0.9%, hatchability by 2.3%, hatch of chicks by 2.9%, feed conversion ratio (kg of feed per 10 eggs) by 5.3%, the expenses of electric energy for lighting (per 1000 eggs suitable for incubation) by 54.5%. Key words: INTERMITTENT LIGHTING, CAGE HOUSED LAYERS, ARTIFICIAL INSEMINATION (AI), OVIPOSITION SCHEDULE, AI TIMING, PRODUCTIVE PERFORMANCE, REPRODUCTIVE PERFORMANCE


Author(s):  
Arda Yıldırım ◽  
Ergin Öztürk

This study was conducted to determine the effect of cottonseed meal (CSM) incorporated into laying rations in place of soybean meal (SBM) at different ratios on yield traits. The birds began to lay at 6th week, 180 female and 45 male quails were used in laying period experiment. Birds were fed with rations containing 20% CP and 3000 Kcal/kg ME up to 20-week age (Laying period). CSM as a substitute, five different rations of the protein content (0, 30, 58, 86 and 100%) for SBM to basal diets based on corn-soybean meal were used. The results showed that there were no differences in terms of egg yield traits, cumulative feed consumptions and viabilities during the laying period. The highest dry shell rate and shell thickness were obtained from 5th group and 1st group, respectively. As a result, adding CSM instead of SBM in laying period were no significantly differences in terms of egg production and egg quality in laying period.


Author(s):  
O. Merzlyakova ◽  
V. Rogachyev ◽  
V. Chegodaev

The efficiency of introducing probiotics based on strains of Bacillus subtilis, Bacillus licheniformis and their consortium in the amount of 150 g/t of feed into the diets of laying quails has been studied. The experiment lasting 182 days has been carried out on four groups of quails with 30 heads in each. The quails have been housed in the broiler battery in compliance with the required microclimate conditions. Quails of all groups have been received the main diet (compound feed) developed taking into account their age and physiological characteristics. The quails of the 1st, 2nd and 3rd experimental groups in addition to the main diet received probiotics (150 g/t compound feed) based on strains Bacillus subtilis, Bacillus licheniformis and their consortium, respectively. It has been found that feeding the laying quails of the consortium of strains Bacillus subtilis and Bacillus licheniformis had the most significant positive impact on their productive performance, it allowed to increase egg production by 7,81 %, egg laying intensity by 5,0 %, egg mass yield by 9,77 %, while reducing feed expenditures for 10 eggs by 13,35 %. The yield of hatching eggs has been increased by 7,03 %, hatchability of chickens from laid and fertilized eggs by 8,33 and 8,35 %, brooding waste decreased by 21,74 %. Hematological parameters of quails during the whole experiment were within the physiological norm. The economic effect calculated on the basis of data on the cost of compound feed, probiotics and the cost of sold eggs of quail laying was 14,56 % in the 3rd experimental group (in relation to the control group).


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