In ovo carbohydrate supplementation modulates growth and immunity‐related genes in broiler chickens

A study was undertaken to investigate the role of in ovo administrated carbohydrates on the expression pattern of growth and immune‐related genes. In ovo injections (n = 400) were carried out on the 14th day of incubation into the yolk sac/amnion of the broiler chicken embryos. Expression of growth‐related genes: chicken growth hormone (cGH), insulin‐like growth factor‐I & II (IGF‐I & II) and mucin were studied in hepatic and jejunum tissues of late‐term embryo and early post‐hatch chicks. Expression of candidate immune genes: Interleukin‐2, 6, 10 and 12 (IL‐2, IL‐6, IL‐10 and IL‐12), Tumour necrosis factor‐alpha (TNF‐α) and Interferon gamma (IFN‐γ) were studied in peripheral blood monocyte cells of in ovo‐injected and control birds following antigenic stimulation with sheep RBC (SRBC) or mitogen concanavalin A (Con‐A). Glucose injection significantly increased the expression of IGF‐II gene during embryonic period and both cGH and IGF‐II in early post‐hatch period, while ribose‐injected chicks had higher expression of IGF‐II gene during embryonic stage. Enhanced mucin gene expression was also observed in fructose‐injected chicks during embryonic age. Glucose‐injected chicks had higher expression of IL‐6 or IL‐10, while those injected with fructose or ribose had higher expression of IL‐2, IL‐12 and IFN gamma. It is concluded that in ovo supplementation of carbohydrates might help in improving the growth of late‐term embryos and chicks. In ovo glucose could modulate humoral‐related immunity, while fructose or ribose might help in improving the cellular immunity in broiler chickens.     

Effects of supplemental vitamin E in diet of Japanese quail on male reproduction, fertility and hatchability

1. Two experiments were conducted to examine the effect of feeding higher supplemental vitamin E (VE) concentrations on male reproductive variables, fertility and hatchability of quails. 2. In experiment 1, sixty 5-week-old male quails, reared in individual cages, were fed male breeder diets supplemented with 0, 75, 150, 225 or 300 IU alpha-tocopherol acetate/kg. At 10 weeks, observations on cloacal gland size, foam production, testes weight and blood samples for testosterone estimation were taken. 3. In experiment 2, 50 male and 50 female cage-reared quails (5 weeks old) were fed male breeder and layer rations, respectively, supplemented with 0, 75, 150, 225 or 300 IU/kg. At 13 weeks, 9 different mating pairs (5 pairs/group) were formed. Group 1 contained one control male and one control female in each of 5 pens. In groups 2 to 5, control males were paired with females on supplements of 75, 150, 225 or 300 IU/kg. In groups 6 to 9, control females were paired with males on supplements of 75, 150, 225 and 300 IU/kg. During subsequent adaptation and egg collection periods, each of 10 d, control layer ration was fed to all groups. All the eggs laid during the 10-d egg collection period were incubated artificially to estimate fertility and hatchability. The trial was repeated at 15 weeks. 4. Adult male quails receiving moderate supplemental VE (75 and 150 IU/kg) had a higher cloacal gland index, quantity of foam secretion, testicular weight and plasma testosterone than quails fed on either VE-deficient or more highly supplemented diets (225 and 300 IU alpha-tocopherol acetate/kg). 5. It was concluded that a supplement of 75 IU VE/kg in maize/soybean diet could provide the best reproductive performance of male breeder quails. Cloacal gland index, quantity of foam secretion, testicular weight and plasma testosterone can serve as indirect indicators of testicular activity and fertilising ability in quails. Supplemental VE did not affect the fertility and hatchability of male and female Japanese quails.     

Deviation of habitat salinity during seasonal gonad recrudescence affects plasma sex steroid levels and suppresses gonadal maturation in an euryhaline fish Etroplus suratensis

Impact of osmoregulation on plasma sex steroid levels and gonadal histo‐architecture was monitored to elucidate the effects of deviation from habitat salinity on gonadal recrudescence in an active reproductive season of an euryhaline fish Etroplus suratensis (pearlspot). Fish were maintained in three different salinities of 0 ppt Fresh Water (FW), 15 ppt Brackish Water (BW) and 30 ppt Sea Water (SW) for a period of 60 days. Plasma osmolality values were found to be significantly highest in SW‐acclimated fish accompanied by highest levels of plasma K? and Cl¯ ions. The progress of gonadal recrudescence was higher in BW followed by FW and SW as evident from the cellular features of gonads and increased level of plasma sex steroids, such as, in case of female and 11‐keto Testosterone and Testosterone in case of males. Plasma cortisol levels were comparatively higher in fish of both sexes in SW group. Significantly high levels of cortisol in SW suggest its role in hypo‐osmoregulation and associated stress. This study clearly reveals that salinity changes during the active reproductive phase can suppress the steroid‐mediated gonad recrudescence maximally under hypo‐osmoregulation in an euryhaline fish.     

Impact of crop and nutrient management on crop growth and yield,nutrient uptake and content in rice

Paddy and Water Environment - System of rice intensification (SRI) together with appropriate nutrient management holds promise in increasing rice productivity with micronutrient enriched grains....     

The colonization processes of Myrtus communis by strains of Pseudomonas savastanoi with a differential ability to produce phytohormones

The ability to produce indole-3-acetic acid (IAA) through the indole-3-acetamide (IAM) pathway as well as cytokinins is a common trait of Pseudomonas savastanoi populations causing disease on oleander and olive. These phytohormones are required for the induction and development of an outgrowth of plant cell tissue termed a knot. However, in myrtle orchards of Sardinia (Italy), strains of P. savastanoi unable to produce cytokinins were found coexisting with cytokinin-producing strains. Data presented here show that the ability to produce IAA through the IAM pathway is also a variable trait within this population, raising questions on the exact role of these plant growth substances in the disease process on myrtle. Three P. savastanoi strains were selected based on their differential ability to produce phytohormones in vitro, and their interaction with the host was investigated over a period of 8 months using histological methods. All strains successfully invaded the infected twigs, moving systemically (unhalted by host defences) upward and downward from the inoculation point, both by completely degrading the cell walls and by taking advantage of the xylem vessels and intercellular spaces. Moreover, all strains induced the development of cankers, which slowly evolved into typical knots only on the twigs inoculated with the phytohormone-producing strains. This study further demonstrates that cytokinins and IAA are essential for knot development; moreover, it ascertains that bacterial production of cytokinins is not necessary for host colonization and for the expression of pathogenicity (i.e. the ability to cause disease) of P. savastanoi on myrtle.     

Host plant resistance through physico-chemical characters against major insect pests of okra occurring in the Gangetic plains of eastern India

Okra production in the tropics is threatened by attack of insect-pests, fruit and shoot borer (FSB), jassid and whitefly causing severe loss in marketable yield particularly in the Gangetic plains of eastern India. No developed varieties/hybrids are free from attack of these pests. However, improved lines of okra have potential to broaden the genetic variability may improve resistance to these pests. Therefore, the population dynamics of these pests were recorded from 24 advance breeding lines/varieties of okra during peak infestation period over two consecutive years. Morphological leaf traits and biochemical parameters were assessed as potential mediators of resistance. The population of these pests reached above economic threshold levels during the month of September. Significant genotypic differences in terms of infestation of these pests were observed. Negatively correlated physico-chemical characters might be considered as important indices for selection of genotype tolerant to these pests. As indicated by the low infestations, the tolerance of BCO-1 to FSB, whitefly and that of Arka Anamika to jassid is based on both antixenotic properties of the genotypes. The donor parents BCO-1 and Arka Anamika should, therefore, be introduced into okra breeding programs to enhance tolerance against these pests.     

Identification of RAPD‐SCAR marker linked to white spot syndrome virus resistance in populations of giant black tiger shrimp,Penaeus monodon Fabricius

White spot disease (WSD) caused by white spot syndrome virus (WSSV) creates severe epizootics in shrimp aquaculture industry worldwide. Despite several efforts, no such permanent remedy was yet developed. Selective breeding using DNA markers would be a cost‐effective strategy for long‐term solution of this problem. In the present investigation, out of 30 random primers, only one primer produced a statistically significant (P < 0.01) randomly amplified polymorphic DNA (RAPD) marker of 502 bp, which provided a good discrimination between disease resistant and disease susceptible populations of Penaeus monodon from three geographical locations along the East coast of India. Because RAPD markers are dominant, a sequence characterized amplified region (SCAR) marker was developed by cloning and sequencing of 502 bp RAPD fragment, which generates a single 457 bp DNA fragment after PCR amplification only in the disease resistant shrimps. Challenge experiment was also conducted to validate this 457 bp SCAR marker, and the results suggested that the WSSV loads were 2.25 × 10³ fold higher in disease susceptible than that in disease resistant shrimps using real‐time PCR. Therefore, this 457 bp DNA SCAR marker will be very valuable towards the development of disease‐free shrimp aquaculture industry.     

A Microsatellite DNA Marker Developed for Identifying Disease‐resistant Population of Giant Black Tiger Shrimp,Penaeus monodon

White spot disease caused by white spot syndrome virus (WSSV) poses major problems that result in huge economic losses each year in shrimp aquaculture throughout the world. In the present study, microsatellite‐based DNA fingerprints have been compared between naturally occurring WSSV disease‐resistant and susceptible populations of giant black tiger shrimp, Penaeus monodon, to find DNA markers. For the first time, we report here a microsatellite locus, which, after amplification by polymerase chain reaction, provides a highly statistically significant DNA fingerprint of 71 bp, only in disease susceptible populations but not in disease‐resistant shrimp populations, whereas a 317 bp band is common in both. The absence of the former DNA marker will be very useful to identify disease‐resistant broodstock of P. monodon for marker‐assisted selection in breeding programs to generate disease‐free shrimps (P. monodon) in the aquaculture industry.