scholarly journals Dietary effects on fitness in captive-reared Hawaiian tree snails

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11789
Author(s):  
Evan Strouse ◽  
Melissa R. Price ◽  
David R. Sischo

The native terrestrial snail fauna of the Hawaiian Islands faces numerous threats that have led to severe range reductions, population declines, and extinction of species. With the continued declines of many wild populations, a crucial component of preserving Hawaiian terrestrial snail biodiversity is through captive rearing programs, like that implemented by the Hawai‘i Department of Land and Natural Resources Snail Extinction Prevention Program. Rare and endangered tree snails in the family Achatinellidae, which feed on epiphytic microbial communities, are maintained in captivity with a diet that includes native vegetation brought in from nearby forests, as well as a cultured fungus originally isolated from native host trees. Recent mortality events in lab populations have been attributed to wild-gathered vegetation. These events have increased interest in developing a completely manufactured or cultured diet that would eliminate the need for exposure to wild-gathered plants. This study compared survival and egg production in Auriculella diaphana provided with lab-cultured fungus, and those provided with wild vegetation. We compared the number of eggs laid and number of deaths among three treatments: (1) wild collected vegetation only; (2) wild vegetation supplemented with laboratory-cultured fungus; and (3) laboratory cultured fungus only. Mortality did not significantly differ among treatments, but the number of eggs laid was significantly higher in snails provided wild vegetation and cultured fungus (F = 24.998; P < 0.001), compared with those provided with only wild vegetation (t = 1.88, P = 0.032) or only cultured fungus (t = 4.530, P = 0.004). Our results suggest: (1) the existing strain of cultured fungus alone is not sufficient to maintain captive-reared snail populations; (2) the additional energy or calcium provided by the cultured fungus appears to enhance egg reproduction in captive-reared populations; (3) the presence or absence of live vegetation influences snail behavior, including aestivation and egg laying. These results highlight the importance of ongoing research to culture additional species of fungi at a rate that could support captive-reared populations, as the diversity of fungi present in wild epiphytic microbial communities may be important for snail reproductive health.

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).


Animals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 1108
Author(s):  
Armughan Ahmed Wadood ◽  
Jingyuan Wang ◽  
Liping Pu ◽  
Qaisar Shahzad ◽  
Muhammad Waqas ◽  
...  

Follicles’ development in chicken imparts a major impact on egg production. To enhance the egg-laying efficiency, comprehensive knowledge of different phases of follicular development is a prerequisite. Therefore, we used the tandem mass tag (TMT) based proteomic approach to find the genes involved in the primary follicular development of chicken. The primary follicles were divided into two groups—small primary follicles (81–150 μm) and developed primary follicles (300–500 μm). Differential expression analysis (fold change > 1.2, p-value < 0.05) revealed a total of 70 differentially expressed proteins (DEPs), of which 38 were upregulated and 32 were downregulated. Gene ontology (GO) enrichment analysis disclosed that DEPs were intricate with cellular protein localization, the establishment of protein localization, and nucleoside phosphate-binding activities. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment pathway indicated the involvement of DEPs in different metabolic pathways such as glycolysis, pyruvate metabolism, galactose metabolism, and fructose and mannose metabolism. The current proteomic analysis suggested suitable markers such as Anxa2, Pdia3, and Capzb, which may serve as a potential role for primary follicle development. The present study provides the first insight into the proteome dynamics of primary follicle development and would play a potential role for further studies in chicken to improve egg productivity.


Foods ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 897
Author(s):  
Marianne Hammershøj ◽  
Gitte Hald Kristiansen ◽  
Sanna Steenfeldt

Egg laying genotypes have been selected for generations due to their high yield and egg quality, resulting in efficient feed utilization and low body weight; hence, they are not suitable for meat production. This imposes an issue for the male layer chicks, which are killed at one day old. Because of ethical and food waste concerns, the search for suitable dual-purpose genotypes in order to avoid euthanasia of male day-old chicks has intensified. The aim of the present study is to evaluate potential dual-purpose genotypes for their egg quality compared to a representative egg laying genotype. Three dual-purpose genotypes with divergent characteristics were evaluated: genotype A represented an experimental crossbreed based on a broiler type male and an egg layer female, genotype B was a pure breed, and genotype C was a crossbreed of a layer type. These were compared to a control genotype D, which was an egg layer. Eggs were collected six times during the period of 21–54 weeks of hen age, i.e., a total of 1080 shell eggs were analyzed. Examined parameters were weights of egg, shell, yolk, and albumen, by calculating their relative proportions. Shell quality was assessed by shell strength, shell stiffness, and shell thickness. Yolk quality was determined as yolk color and inclusions of blood and meat spots, and albumen quality was evaluated in terms of pH and dry matter (DM) content. The egg layer genotype produced the smallest eggs with least blood and meat spot inclusions compared to that produced by the three dual-purpose genotypes. Shell quality was superior for the layer genotype. However, the experimental genotype A laid eggs of comparable shell quality, albumen DM, and yolk weight, but also with the darkest and most red-yellow colored yolk. The two other dual-purpose genotypes produced eggs of low-medium quality. In conclusion, the genotype A could serve as dual-purpose genotype from an egg quality perspective.


1936 ◽  
Vol 26 (1) ◽  
pp. 85-100 ◽  
Author(s):  
R. H. Common

1. Where heavy phosphorus excretion accompanies egg laying in the pullet the excretion of ammonia nitrogen is simultaneously increased. It is probable that this indicates an excretion of excess phosphate in the urine as ammonium phosphate.2. It is shown that heavy phosphorus excretion does not accompany egg laying provided the calcium carbonate intake is sufficiently high.3. The origin of the excess of phosphorus excretion is discussed in relation to calcium-phosphorus metabolism.4. Pullets on a ration containing 5 per cent, calcium carbonate laid eggs containing a higher percentage of P2O5 than pullets receiving a similar ration but from which the calcium carbonate supplement was omitted.5. Some evidence is put forward in support of the view that current standards pitch the requirements of digestible protein for egg production at too high a level.


2021 ◽  
Vol 12 (4) ◽  
Author(s):  
M. S. Doroshenko ◽  
S. O. Kostenko ◽  
P. V. Korol ◽  
A. M. Chepiha ◽  
O. V. Sydorenko ◽  
...  

The consequences of chimerization and its possible influence on the productivity of chimera offspring remain poorly understood. The objects of research were ducks (Anas platyrhynchos) of the Shanma (Shan partridge duck) and Shaoxing breeds kept at the Zhuji Guowei Poultry Development Co, Ltd, P.R.China. The study was conducted in the poultry genetics laboratory of the Zhejiang Academy of Agricultural Sciences on a duck farm of Zhejiang Generation Biological Science and Technology Co., Ltd. (Zhejiang Province, PRC). To create chimeras of ducks, the method described by Aige-Gil, Simkiss, 1991; M.T. Tagirov, 2010 was used. Blastodiscs have been isolated from freshly hatched fertilized eggs using a filter paper ring. Shanma duck embryos have been used as recipients, and Shaoxing duck embryos, homozygous for plumage color gene allele (wild type), have been used as donors. Busulfan (SigmaAldrich, United States) have been used as a chemical agent that suppresses a division of primary germ cells (PGC) of recipient embryos. A hole in an eggshell (window) of recipients (Shanma breed) have been made between a blunt and sharp ends of eggs. (This reduced a distance between an injector and an embryo needle). The recipients havebeen incubated for 8–10 hours at a temperature of 38 °C. After recipient eggs incubation for 8 hours, the windows were opened in them. Busulfan was injected into the subgerminal cavity of the embryo with a micropipette (1.5–3 μl of liquid). After busulfan injection, the empty cavity was filled with culture medium (RPMI-1640) supplemented with antibiotics (ampicillin, streptomycin), the hole was closed by plastic wrap and adhesive tape. The eggs have been incubated at a reduced temperature (+32 °C) for 24 hours with the aim of prolong the duration of busulfan action on the PGC (primary germ cells). More than 50% of embryos have been died in the first 2–3 days (after an incubation start). Head and neck disorders have been observed in the 1.2% of embryos. Busulfan injection at a concentration of 300 ng per egg have been leads to 95.0–96.3% mortality of duck embryos, concentration of 150 ng per egg, a mortality rate of 33.3–75.3% have been observed, concentration to 75 ng led to 18.75–38.5% of embryonic mortality. Analysis of the age of puberty (laying of the first egg) indicates that the chimeras matured later. If in the control group the average age of puberty was 139 ± 9 days, in the group of chimeras - 148 ± 13 days. Thus, we can attest that in our experiment, the chimeras matured later than the control animals, which may be due to the effect of busulfan in the sterilization of recipient embryos. The average weight of ducks in the control group was lower, and the group itself was more consolidated. Thus, in the control ducks weighed 1422.40 ± 57.00 g, the chimeras 1608.80 ± 94.76 g. The advantage of live weight chimeras over the control group may be due to the fact that the control group consisted of recipients served by Shanma animals. Egg production of ducks for the entire study period was 87.5 ± 0.05 % (control) 79.5±0.12 % (busulfan). The weight of eggs of ducks of two groups for the entire period was 70.62±0.199 g (control) and 71.15±0.157 g (p˂0.001). The eggs morphometric parameters of the studied ducks groups were: the average values of egg length were 6.056±0.0564 cm (control) and 6.269±0.1341cm (busulfan); egg breadth were 4.520±0.0053 cm (control) and 4.529±0.004 cm (busulfan). There were no statistical intergroup differences in the morphometric parameters of the eggs of the studied groups. In fact, we obtained results similar to the previous ones, which concerned the egg production of daughters of drake chimeras.


Author(s):  
E. Rehleckaya ◽  
A. Dymkov ◽  
L. Lazarets ◽  
A. Maltsev

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.


Parasitology ◽  
1941 ◽  
Vol 33 (1) ◽  
pp. 40-46 ◽  
Author(s):  
A. J. Haddow

1. Isolated unmated female body-lice were worn in pillboxes between the skin and the clothes. They were kept constantly on the body but, by a simple device, groups of ten were permitted feeding periods of different length. These groups were fed for 4, 8, 12, 16, 20 and 24 hr. per day respectively. Another group of ten were never allowed to feed after the last moult.2. Some of the figures for egg yield were high. Lice in the 24 hr. group were able to maintain a rate of ten eggs per day for 4−5 days at a time.3. No significant difference in longevity or rate of egg-laying was found to exist between the 12, 16, 20 and 24 hr. groups nor between the 4 and 8 hr. groups but a pronounced and significant difference exists between the 8 and 12 hr. groups. Below 12 hr. there is a sharp fall in longevity and rate of egg production. The unfed group all died, without laying, on the third day.4. The rate of laying as shown by the mode increases progressively with increase in time allowed daily for feeding.5. With regard to the mean eggs per louse the position is less clear. It is felt that the 24 hr. group may differ significantly from the 12, 16 and 20 hr. groups but this is uncertain.


Author(s):  
Manuel Colas ◽  
Edmundo Oliver Pérez ◽  
Yanet Támbara

The objective of this study was to evaluate the influence of protein hydrolysates (PH), as a nutritional supplement, in the bioproduction performance of White Leghorn hens. Thirty-nine-week old light line hens were assessed during six weeks. Two treatments (T) were designed involving 320 hens each (three replications of 40 hens each). In T1, each bird received 2 ml of PH daily; the birds in T2 were not offered the product. The following variables were controlled: bioproduction (total egg production, egg-laying percentage, total feed intake, mass conversion, viability, and caused mortality); incubation indicators (eggs to plant, incubation percentage, hatchability, and top quality chicks) and; quality (feed intake by top quality chicks, and top quality chicks per hen). The hens that received the PH showed significant differences in the laying, incubation, and hatchability percentage, as well as mass conversion, and the egg to plant ratio. They showed better performance in quality indicators. It is concluded that the use of PH in light line hens improves their bioproduction performance, as well as the indicators of to incubation, egg to plant ratio, and hatchability; its use also reduces by approximately 100 grams the necessary food intake to obtain top quality chicks.


1990 ◽  
Vol 68 (3) ◽  
pp. 493-497 ◽  
Author(s):  
R. C. Plowright ◽  
C. M. S. Plowright

The hypothesis that proximal factors associated with high worker density in a bumble bee (Bombus terricola) colony trigger laying of male eggs by the queen was examined in a series of four experiments. Neither the age of workers, the presence or absence of laying workers, nor the amount of pollen available to the colony affected the date of first male egg laying. Moreover, queens that had begun laying male eggs did not revert to laying female eggs after being removed from their colonies and placed in isolation. Instead, onset of male egg production appeared to be associated with the date of attainment of a critical worker/larva ratio in the colony. Functional considerations lead to the new hypothesis that queens monitor their egg-laying performance and begin to lay male eggs when it can be predicted that their female eggs will be raised as young queens.


Nematology ◽  
2002 ◽  
Vol 4 (3) ◽  
pp. 381-386
Author(s):  
Christopher Steel ◽  
John Kirkegaard ◽  
Rod McLeod

AbstractThe effects of seed treatments with pesticides, soil temperature at sowing, cutting of plants with and without glyphosate herbicide, root disruption and age of crop at inoculation on reproduction of Meloidogyne javanica on Brassica napus were investigated. When inoculated at sowing, plants grown from fodder rape cv. Rangi seed treated with fenamiphos (0.35 g a.i. per 100 g) and from fodder swede cv. Highlander seed with a coating including imidacloprid had fewer galls than plants from seed untreated or treated with omethoate (0.7 g a.i. per 100 g). When nematode inoculation was delayed until 4 weeks after sowing, omethoate and the imadacloprid treatments had no effect while fenamiphos (0.7 g a.i. per 100 g seed) suppressed galling but also impaired seedling emergence and induced chlorosis. Green manure rape plants cvs Rangi and Humus transplanted into infested soil in the field in mid-autumn (soil temperature 17°C) remained nematode and gall-free, but tomato cv. Grosse Lisse plants were heavily galled. All three cultivars were gall-free when transplanted and grown in early winter (soil temperatures 8-14°C). Cutting off the tops of cv. Rangi plants at from 6 to 11 weeks after sowing and inoculation had no effect on egg production compared to that on intact plants. Predominant nematode stages in cut plants ranged from developing juveniles to egg-laying females. Application of glyphosate to freshly cut stems had no effect on egg production at any stage. Infesting soil with roots of cv. Rangi, finely chopped while nematodes in them were still juveniles, resulted in a low incidence of infection of bioassay tomato plants compared with infesting soil with rape roots chopped later, when females and females with eggs predominated. Young females in tomato roots laid eggs despite fine chopping of the roots. When cv. Rangi plants were inoculated at 3, 5 and 7 weeks after sowing, the 7-week-old plants were the least invaded and fewer eggs were produced on the 5 and 7-week-old plants than on the 3-week-old ones.


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