Papers by Manjula Magamage
Assessment of milk quality of upcountry dairy farm in Sri Lanka
Ruminant Science, 2018
Journal of Mammalian Ova Research, Apr 1, 2011
In mammals, the mechanisms regulating the initiation of follicle development remain poorly unders... more In mammals, the mechanisms regulating the initiation of follicle development remain poorly understood. We previously reported that testosterone induced the activation of porcine primordial follicles after 7 days of culture. Herein, the effect of KIT ligand (KL) on the viability, activation and development of porcine primordial follicles was examined. Ovarian strips containing primordial fOllicles were cultured for 7 days in a medium supplemented with KL (10, 100, 250 or 500 ng/ml). The percentage of degenerated fOllicles was significantly decreased (39 :f: 2%) in the 100 ng/ml KLtreated group compared to the control (56 :t 1 %) , whereas almost all of the primordial follicles degenerated at higher concentrations of KL. No primordial follicles developed in culture at any concentration of KL. When ovarian strips were cultured in medium supplemented with testo sterone (10-6 M) + KL (100 ng/ml) , primordial follicles developed to early secondary fOlli cles (5 :f: 3%) , however the total percentages of developing follicle s in the testosterone group (2 1 :f: 5%) and the testosterone + KL group (28 :f: 5%) were not significantly different. The se results suggest that KL does not promote primordial follicle activation, although it does promote follicle viability in culture.
Aquaculture Research, 2018
A 65 days feeding trial was conducted to evaluate the potential of black soldier fly larvae (BSFL... more A 65 days feeding trial was conducted to evaluate the potential of black soldier fly larvae (BSFL) as a fish meal (FM) protein alternative in the diet of yellow catfish. Fish meal protein was replaced with BSFL meal protein at 0% (control), 13%, 25%, 37%, 48%, 68%, 85% and 100%. Compared with the control group, increased growth performances (e.g. weight gain rate increased by 21.7%) and immune indexes (e.g. serum lysozyme activity increased by 6.8%) of yellow catfish fed with diets in which a maximum of 48% FM protein was replaced by BSFL meal protein was determined. The diet in which 25% FM protein was replaced by BSFL meal protein resulted in the greatest growth performances (e.g. weight gain rate increased by 29.1%) and immune indexes (e.g. serum lysozyme activity increased by 31.9%) as well as the lowest feed conversion ratio (0.9) among all diets tested. No significant differences in survival rate, body indexes or composition were determined among all treatments. Therefore, BSFL meal protein has the potential to partially replace FM protein in the diet of yellow catfish, and it may also enhance the immunocompetence of the fish. K E Y W O R D S black soldier fly larvae meal protein, fish meal protein, growth index, Hermetia illucens, immune index, Pelteobagrus fulvidraco 1 | INTRODUCTION Proper diet formulation is one of the most important factors in commercial aquaculture as feed production costs and associated impact on subsequent fish growth are major expenses (Haghbayan & Shamsaie Mehrgan, 2015). Fish meal (FM) is the primary source of protein in fish feed (Gatlin et al., 2007). It is produced by processing whole, or parts of, fish and is known to be a highly nutritious and palatable protein source (Ding, Zhang, Ye, Du, & Kong, 2015; Haghbayan & Shamsaie Mehrgan, 2015). However, the continued growth of the aquaculture industry has been limited by a shortage in global production of, and competition for, FM by livestock and poultry. Consequently, the price of FM has increased by more than twofold in recent years (Dalsgaard, Ekman, Pedersen, & Verlhac, 2009). Furthermore, increased production of FM has increased pressure on marine ecosystems (Adelizi et al., 1998; Haghbayan & Shamsaie Mehrgan, 2015). Several studies demonstrated plant-based proteins could serve as an alternative for dietary fishmeal used in aquaculture (Bonaldo
재발성 측두하악관절 탈구의 외과적 교정
대한구강악안면외과학회, Oct 30, 1998
Asian Fisheries Science, 2021
The reliance of aquaculture feed industry on fishmeal has been challenged by ecological, economic... more The reliance of aquaculture feed industry on fishmeal has been challenged by ecological, economic, and ethical limitations leading fish nutritionists to look for viable alternatives, and conventional animal-based protein sources showed varying degrees of success in this regard. However, a non-conventional protein source, black soldier fly Hermetia illucens Linnaeus, 1758 larvae (BSFL), received due attention as a focal point in fish nutrition research. Though many studies were conducted on H. illucens as a potential protein source for fish, a comprehensive review is not available. Therefore, this article aims to review the existing literature on the use of BSFL as a fishmeal replacer in aquaculture. The nutrient composition of BSFL varied with the developmental stage and the composition of growing medium. High crude protein levels (40.4–56.2 %) and high crude fat levels (4.8–24.8 %) made BSFL suitable for high protein and high energy diet. Early prepupa was the best stage for harves...
Porcine primordial follicle activation in vitro
Journal of Agricultural Sciences, 2018
Journal of Animal Reproduction and Biotechnology, 2021
Research infrastructure and manpower support by NIAB to SV is acknowledged. AUTHOR CONTRIBUTIONS ... more Research infrastructure and manpower support by NIAB to SV is acknowledged. AUTHOR CONTRIBUTIONS MPSM conceived the idea, designed and performed experiments, compiled and analyzed the data; SS assisted in culture experiments, performed qPCR and Western blot, and assisted in microtome sectioning; KA collected samples, and assisted in culture experiments; DNNM assisted in data analysis; SV compiled and analyzed the data, prepared the figures and wrote the manuscript.
International Journal of Entomological Research, 2019
A recent outbreak of FAW (Spodoptera frugiperda) caused a substantial yield loss in corn was reco... more A recent outbreak of FAW (Spodoptera frugiperda) caused a substantial yield loss in corn was recorded in Sri Lanka especially from Uva, Eastern and North Central provinces. This was first reported in Sri Lanka in August 2018 and over the last six months, the livelihood of the majority of small-scale farming families was greatly affected. National mobilization of resources, agriculture related institutions together with university academia actively participated with the government campaign of combating the pest and improving the livelihood of affected people all over the country. The effort of this short communication is to describe the magnitude of FAW infestation, its implications in Ratnapura District, Sri Lanka and the contribution of the inter-institutional support towards the sustainable management of the Fall ArmyWorm epidemic in Sri Lanka. Amount of land extent used for corn cultivation in Ratnapura district was estimated as 292.65ha, while 32.95 ha were infected with the pes...
Journal of Agricultural Sciences – Sri Lanka, 2019
Purpose: The quality of DNA and reliability of molecular markers are crucial for the success of P... more Purpose: The quality of DNA and reliability of molecular markers are crucial for the success of Polymerase Chain Reaction (PCR) based genetic sex determination. This study was aimed at investigating the optimum conditions for isolation of DNA from chicken blood and the reproducibility of dominant and co-dominant sex markers to be validated as a tool for successful sexing in avian research. Research Method: Effi cacy of six diff erent extraction procedures including manual and solution based commercial purifi cation kit were evaluated with diff erent combinations of initial blood, lysis buff er and protein denaturant in relation to the DNA yield and purity. Three primer sets namely CHD1, HUR 0423 and HUR 0424 were evaluated by PCR. Findings: The study results showed that 10µl of initial blood volume yields a signifi cantly high DNA yield with high purity. Dominant marker HUR0424 showed to be a reliable marker system for the genetic sexing of domestic chickens over co-dominant markers. Research Limitation: For the accuracy of the results, protocols had to be followed at the same time and using same sample to avoid any errors. Originality/ Value: PCR based sexing is considered, the most accurate and inexpensive method and hence validation of the method is important for success of future avian research.
July-2019, 2019
Background and Aim: Estrogen activity, a central component of reproductive growth, is regulated b... more Background and Aim: Estrogen activity, a central component of reproductive growth, is regulated by the receptor proteins, estrogen receptor alpha (ERα), and ER beta (ERβ) in chickens as in many other species. ERα expresses predominantly in gonads. Although the expression of ERα in embryonic gonads has been studied in detail, the expression of ERα in post-hatching male gonads has not been studied adequately. Therefore, the current research was conducted to determine the post-hatching changes in the expression of ERα in the left gonads of male chickens with age. Materials and Methods: Shaver Brown male chickens were raised and cared for according to the management guide and sacrificed at the intervals of 1, 4, and 8 weeks of age. The total RNA was extracted from the left gonads using the Trizol method and reverse transcribed using a pair of gene-specific primers. Following polymerase chain reaction amplification, the expression of ERα was quantified relative to the expression of the r...
Procedia Food Science, 2016
Emergence of babesiosis in both public health and food security concern in global perspectives ca... more Emergence of babesiosis in both public health and food security concern in global perspectives cannot be ignored. The dairy farming plays an important role in food industry that, fulfilling the protein requirement through producing both milk and meat. The farming operations may get hampered due to non-infectious and infectious diseases. Infectious diseases also cause huge production losses in all farming operations in time to time. Babesiosis becomes a major concern in public health and animal production specialists in recent years both locally and internationally due to severity of out breaks, carrier animals and zoonotic nature. Babesiosis as an emerging zoonotic disease and also causing heavy production losses due to the both clinical diseases and carrier animals. Babesia parasites, mainly Babesia bovis and B. bigemina, are tick-borne hemoparasites inducing bovine babesiosis in cattle globally. Babesiosis is known to occur in tropical and subtropical regions of the world and it is one of the major constraints to the livestock industry which adversely affects economic return and food security by reducing milk, meat production and if not treated leads to the death of the animal. Babesia parasites are considered to be endemic in central Sri Lanka and the prevalence of babesiosis is high in other areas. Carrier cattle infected with babesiosis have low number of parasites in circulation. Babesiosis is difficult to detect and is a challenge to conventional diagnostic methods. However, diagnosis of carrier animals in herd is important for preventing outbreaks by transmission through vector ticks to healthy animals and for obtaining epidemiological data of the disease. Here, we have conducted nested PCR detection of Babesia bovis in carrier cattle (Jersey crosses, Friesian crosses and Australian milking zebu) of selected localities of Sri Lanka. For this study, 30 blood samples were collected from suspected carrier cattle and analyzed using light microscopy and nested PCR. Screening by light microscope indicated that 47% of the samples to be positive. PCR analysis of samples brought to you by CORE View metadata, citation and similar papers at core.ac.uk
KIT ligand promotes the viability but not the activation of porcine primordial follicles in vitro
In mammals, the mechanisms regulating the initiation of follicle development remain poorly unders... more In mammals, the mechanisms regulating the initiation of follicle development remain poorly understood. We have reported that testosterone induces the activation of porcine primordial follicles after 7-day culture. Herein, the effect of KIT ligand (KL) on the viability, activation and development of porcine primordial follicles was examined. Ovarian strips containing primordial follicles were cultured for 7 days in a medium supplemented with KL (10, 100, 250 and 500 ng/ml). The percentage of degenerated follicles was significantly decreased (39 ± 2%) in 100 ng/ml KL-treated group compared to the control (56 ± 1%), whereas almost all of the primordial follicles degenerated at the higher concentrations of KL. No primordial follicles developed at any concentrations of KL in this culture condition. When ovarian strips were
Journal of Mammalian Ova Research, 2011
In mammals, the mechanisms regulating the initiation of follicle development remain poorly unders... more In mammals, the mechanisms regulating the initiation of follicle development remain poorly understood. We previously reported that testosterone induced the activation of porcine primordial follicles after 7 days of culture. Herein, the effect of KIT ligand (KL) on the viability, activation and development of porcine primordial follicles was examined. Ovarian strips containing primordial fOllicles were cultured for 7 days in a medium supplemented with KL (10, 100, 250 or 500 ng/ml). The percentage of degenerated fOllicles was significantly decreased (39 :f: 2%) in the 100 ng/ml KLtreated group compared to the control (56 :t 1 %) , whereas almost all of the primordial follicles degenerated at higher concentrations of KL. No primordial follicles developed in culture at any concentration of KL. When ovarian strips were cultured in medium supplemented with testo sterone (10-6 M) + KL (100 ng/ml) , primordial follicles developed to early secondary fOlli cles (5 :f: 3%) , however the total percentages of developing follicle s in the testosterone group (2 1 :f: 5%) and the testosterone + KL group (28 :f: 5%) were not significantly different. The se results suggest that KL does not promote primordial follicle activation, although it does promote follicle viability in culture.
Reproductive Medicine and Biology, 2010
Purpose The mechanism underlying primordial follicle activation is poorly understood. In this stu... more Purpose The mechanism underlying primordial follicle activation is poorly understood. In this study, in-vitro culture and subsequent xenotransplantation were conducted to determine whether testosterone promotes the activation of porcine primordial follicles. Methods Prepubertal porcine ovarian cortical strips containing primordial follicles were cultured in the presence of testosterone for 7 days, and subsequently transplanted to immunodeficient mice for 2 months. After culture and transplantation, development of follicles was examined histologically. The presence of androgen receptors in oocytes was assessed by use of western blot and immunohistochemical analyses. Results Testosterone at 10-6 M induced the primordial follicle transition to the intermediate (19 ± 4%) and primary (3 ± 1%) stages after 7-day culture, while 56 ± 5% of primordial follicles remained in the initial pool. Higher concentrations, above 10-5 M, or lower concentrations, below 10-6 M, did not induce follicle transition to the primary stage. After 7-day culture with 10-6 M testosterone, ovarian cortical strips were transplanted to immunodeficient mice. Some of the follicles developed to the secondary (15 ± 3%) and antral (10 ± 3%) stages, whereas 44 ± 7% of primordial follicles remained in the initial pool. In the culture experiment, estradiol-17b (10-7-10-5 M) had no significant effect on follicle activation. The androgen receptor antagonist, cyproterone acetate, inhibited the stimulatory effect of testosterone on primordial follicle activation, suggesting an androgen receptormediated action of testosterone. Western blot and immunohistochemical analyses revealed that androgen receptors were present in the oocytes of primordial follicles. Conclusions These results suggest that testosterone at 10-6 M promotes the activation of porcine primordial follicles in vitro through the androgen receptors in the oocytes.
Effect of Vascular Endothelial Growth Factor 121 Adenovirus Transduction in Rabbit Model of Femur Head Necrosis
The Journal of Trauma: Injury, Infection, and Critical Care, 2011
Our objective was to observe the role of vascular endothelial growth factor (VEGF) 121 gene trans... more Our objective was to observe the role of vascular endothelial growth factor (VEGF) 121 gene transfer in promoting vascular reconstruction and bone repair in femur head necrosis of rabbits. The femoral head necrosis model was induced by injection with ethanol. The necrotic femoral head was transfected with a human adenoviral vector expressing VEGF (Ad-hVEGF121). Bone formation in the subchondral necrotic region was analyzed using histology, by measuring the bone mineral density value, and by observing bone trabecular morphology using image analysis. Revascularization level, bone formation rate, bone quality and quantity, and mineralization level in the subchondral necrotic region of the gene transfection group were significantly higher than the control groups. The control groups had more subchondral bone resorption compared with the gene transfection group. VEGF might promote bone formation and revascularization in the subchondral necrotic region of the femoral head, indirectly protecting the necrotic bone trabecula from absorption and avoiding a reduction in the mechanical function of the subchondral region.
Biology of Reproduction, 2019
Follicular progression during peripuberty is affected by diet. Vascular endothelial growth factor... more Follicular progression during peripuberty is affected by diet. Vascular endothelial growth factor A (VEGFA) induces follicle progression in many species; however, there are limited studies to determine if diet may alter the effects of angiogenic VEGFA165-stimulated follicle progression or antiangiogenic VEGFA165b follicle arrest. We hypothesized that diet affects the magnitude of angiogenic and antiangiogenic VEGFA isoform actions on follicular development through diverse signal transduction pathways. To test this hypothesis, beef heifers in our first trial received Stair-Step (restricted and refeeding) or control diets from 8 to 13 months of age. Ovaries were collected to determine follicle stages, measure vascular gene expression and conduct ovarian cortical cultures. Ovarian cortical cultures were treated with phosphate-buffered saline (control), 50 ng/ml VEGFA165, VEGFA165b, or VEGFA165 + VEGFA165b. The Stair-Step heifers had more primordial follicles (P < 0.0001), greater me...
Journal of Agricultural Sciences – Sri Lanka
Ruminant Science, 2018
Quality of the milk has a significant effect on the economic return and sustainability of the dai... more Quality of the milk has a significant effect on the economic return and sustainability of the dairy farm. Present study was
conducted to assess the milk quality of the New Zealand Farm, Ambewela, Sri Lanka with respect to milk instability and microbial
activity. Alcohol test (to determine milk instability) for milk obtained from New Zealand farm, Ambewela in three times of the day
from the lactating cows (164) in the herd was performed and cows with all three positive and all three negative results were selected
for further analysis. The milk from the selected cows was subjected to Resazurin test (RT), Californian mastitis test (CMT) and
Portable somatic cell count (PSCC) with three replicates. The alcohol test resulted 34 and 86 all positive (P) and all negative (N) for
three trials, respectively. A significant difference was observed for both Resazurin test and somatic cell count test (P = 0.029 and
P=0.020 respectively) among the tested groups (P and N). P and N groups showed 38% and 11% positive results respectively for
CMT. In conclusion, study revealed that the instability of the milk studied was relatively high and the alcohol test results were more
precisely analyzed with a combination of RT, CMT and PSCC test. Hence it can be suggested that subclinical mastitis induced
microbial activity has caused the instability of raw milk in New Zealand Dairies, Ambewela.
The present study was conducted to elucidate the applicability of body condition score (BCS) and ... more The present study was conducted to elucidate the applicability of body condition score (BCS) and locomotion score (LMS) to predict the reproductive and health performance of cows in intensive manage dairy herd in upcountry dairy farm in Sri Lanka. BCS and LMS were scored using 1 to 5 point score system. Forty three (n=43) pregnant cows and forty six (n=46) early lactating cows were selected for the study. Fertility was measured from farm records based on conception rate and length of postpartum anestrus of the selected herds. BCS level 2 to 4 has shown the lowest postpartum length. Under the given conditions, BCS<2 level has shown 70.75±4.09 days of post-partum length, where BCS 2-4 level has shown 34.4±2.15 days of post-partum anestrus length. This was the lowest recoded postpartum anestrus length during the study period. Low LMS was also associated with the lowest post-partum length compared to other groups (56.29±5.29 in LMS<2, 47.16±5 in LMS >2, 36±1.15 in control). There was significant (P<0.0075) effect of BCS on retained placenta condition. LMS has significant (P<0.0098) impact on retained placenta condition. There was no significant effect (P>0.2547) of body condition score on dystocia. A significant effect (P<0.0163) of lameness condition was observed on dystocia. Higher lameness condition score has shown significant effect (P<0.0098) on increasing incidents of endometritis. Poor body condition score has recorded significant effect to the lowering conception rate (P<0.0026). In conclusion, BCS and LMS have direct relationship with the reproductive performance and herd health parameters of dairy cattle, therefore the BCS and LMS can be effectively used to predict the reproductive performance in dairy cattle in the herds under intensive management system.
Keywords: Body condition score, locomotion score, postpartum anestrus length, reproductive performance
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Papers by Manjula Magamage
conducted to assess the milk quality of the New Zealand Farm, Ambewela, Sri Lanka with respect to milk instability and microbial
activity. Alcohol test (to determine milk instability) for milk obtained from New Zealand farm, Ambewela in three times of the day
from the lactating cows (164) in the herd was performed and cows with all three positive and all three negative results were selected
for further analysis. The milk from the selected cows was subjected to Resazurin test (RT), Californian mastitis test (CMT) and
Portable somatic cell count (PSCC) with three replicates. The alcohol test resulted 34 and 86 all positive (P) and all negative (N) for
three trials, respectively. A significant difference was observed for both Resazurin test and somatic cell count test (P = 0.029 and
P=0.020 respectively) among the tested groups (P and N). P and N groups showed 38% and 11% positive results respectively for
CMT. In conclusion, study revealed that the instability of the milk studied was relatively high and the alcohol test results were more
precisely analyzed with a combination of RT, CMT and PSCC test. Hence it can be suggested that subclinical mastitis induced
microbial activity has caused the instability of raw milk in New Zealand Dairies, Ambewela.
Keywords: Body condition score, locomotion score, postpartum anestrus length, reproductive performance