DSpace Collection:

Comparative Study of Egg Characteristics of White Leghorn and Naked Neck Chicken for Table Eggs

2025-06-03T09:11:52Z

Title: Comparative Study of Egg Characteristics of White Leghorn and Naked Neck Chicken for Table Eggs Authors: Mohamed Thariq, M.G.; Nikzaad, R.M. Abstract: The quality of hens’ eggs is central in purchasing for consumption. The present study investigated the egg weight and the shell characteristics of White Leghorn and Naked neck chickens for table eggs from the coastal areas of Ampara district of Sri Lanka. The egg weight, shell thickness, and shell weight were recorded from White Leghorn (n=60) fed with commercial feed and Naked neck chicken fed on free range (n=60) using recommended methods. The data were analyzed statistically using SPSS (version 25) software. The mean egg weight was significantly higher (p<0.05) in White Leghorn (60.23 ± 3.57g) compared to Naked neck chickens (42.70 ± 5.17g) while shell thickness was significantly higher (p<0.05) in Naked neck chickens (0.75 ± 0.14mm) compared to White Leghorn (0.24 ± 0.10mm). No significant difference (p<0.05) was observed in shell weight between the two breeds. The correlation of egg weight with shell weight (-0.068) and shell thickness (0.020) as well as the correlation of shell thickness with shell weight (-0.061) was negligible in White Leghorn. However, in Naked neck chickens, the correlation of the egg weight with shell thickness (0.266) and shell weight (0.28) was significant (p<0.05) and weak positive. Likewise, the correlation of the shell thickness with shell weight was significant and weak positive (0.281, <0.05). The study concludes that the egg weight was higher in White Leghorn and falls under the category of extra-large (60 g and above) and in Naked neck chickens small (38 g – 44 g) according to the Sri Lankan Standards. In White Leghorn, the shell thickness and shell weight were independent of egg weight, while in naked neck chickens, with the increase of egg weight, the shell thickness and shell weight tend to increase. It is recommended that for larger sizes, consumers can select White Leghorn’s eggs while naked neck chicken eggs can be chosen for their thicker shell.

Initial Crossbreeding to Develop Fancy Hybrids Using Threatened Endemic “Cyprinid” Species

2025-06-03T09:08:12Z

Title: Initial Crossbreeding to Develop Fancy Hybrids Using Threatened Endemic “Cyprinid” Species Authors: Chathuranga, H.A.N.P.; Thanusan, S.; Jeyaweera, B. P. A.; Shirantha, R. R. A.R. Abstract: There are two economically important ornamental freshwater fish species found in Sri Lanka; Dawkinsia filamentosa and Dawkinsia srilankensis. Combination of several factors directly caused those freshwater fish species to threatened levels. Due to that, their export was currently regulated, highlighting immediate need of conservation. The objective of this study was to develop a new fancy hybrid variety for ornamental fish industry. Wild caught brooders of those species were separated into male and female and reared in cement tanks until they attained sexual maturity. Afterwards 2:1 ratio male and female brooders were introduced into the breeding tank, provided with submerged aquatic plants. The water quality parameters were recorded every week during the culture period. During this culture period offspring exhibited average length, average weight and average width of 17.29 mm, 0.047 mg and 2.55 mm, respectively. During this period, the water temperature, water pH, dissolved oxygen, alkalinity, hardness, nitrate, nitrite, ammonia, phosphate, turbidity and total suspended solids (TSS) in experiment tank was 27-29 oC, 7-9, 5-7 mg/L, 110-142 mg/L, 100-123 mg/L, 0.0099- 0.0016 mg/L, 0.0015-0.0094 mg/L, 0.022-0.076 mg/L, 0.0123-0.0854 mg/L, 0.45-1.72 NTU, and 4-9 mg/L, respectively. Fulton condition factor (K) values ranged from 0.85 to 1.43, indicating varied fish health and body condition. Length frequency distribution displayed a right skew of 1.77, suggesting growth pattern variations. Therefore, we can conclude that, cross-breeding these D. filamentosa and D.srilankensis can create a successful hybrid variety. Often, produced new hybrids variety, showed the color preference of the D.filamentosa cultivar. Therefore, the newly found hybrid variety can be exported instead of pure D. filamentosa and this will also prevent the bio-piracy of D. filamentosa and conserve their stocks.

A preliminary study on the preparation method of soya milk feed and its effect on the survival rate of common carp (Cyprinus carpio) post-larvae

2025-06-03T09:04:46Z

Title: A preliminary study on the preparation method of soya milk feed and its effect on the survival rate of common carp (Cyprinus carpio) post-larvae Authors: Anitha, G.; Perera, H.A.C.C. Abstract: Common carp plays a major role in inland fish production. However, seed supply for culture-based fisheries remains inadequate due to the low survival rate during their nursery stages. During their first week of nursery stage, they were fed with soya milk. Normally, soya comprises over 30% crude protein, but unfortunately, soya contains few anti-nutritive factors such as trypsin and amylase inhibitors. There are many practices developed for deactivating those inhibitors, including applying and overnight soaking in hot water, frying seed powder, and overnight soaking in water. The study was conducted using a completely randomized block design with in four cement tanks each measuring 18m2 and 1.2 m deep over a period of 15 days. The post- larvae stocking density was 2777 post larvae/m2 (50000/18m2). Soya milk was administered as feed at a total volume of 0.5 liters, distributed over three times per day. The post larvae were fed with soya milk prepared according to the above three methods, while soya milk prepared using normal powdered soya was taken as a control treatment. Body weight and total length of post-larvae were recorded at stocking (Initial mean length (5.68 mm), Initial mean weight (4.25 mg)) and water quality parameters were also recorded twice a day in each treatment. The survival rate, body weight and total lengths of the post-larvae were recorded at the end of the 15 days of rearing period. The data were analyzed using a one-way ANOVA followed by Turkey’s test at the 5% significance level. Soya milk prepared by using hot water (P = 0.001) showed a significant difference, while other methods showed no significant difference between each other. A significantly high survival rate of 87% was observed with the hot water soaking method compared to the control. In contrast, frying seed powder and the overnight water soaking method demonstrated lower survival rates of 43% and 35%, respectively, when compared to the control. Soya beans contain anti nutritional factors such as inhibitors and lectins, which can interfere with digestion and nutrient absorption. Therefore, the present study revealed that soaking in hot water helps to deactivate these compounds, making the soya milk more suitable and safe for the post larvae.

Assessing Water Quality and Plankton Abundance in Jaffna Lagoon

2025-06-03T09:00:25Z

Title: Assessing Water Quality and Plankton Abundance in Jaffna Lagoon Authors: Karthika, P.; Chandrasekara, C.M.P.V.; Gobiraj, S.; Ragavan, N.; Gunaalan, K.; Kuganathan, S. Abstract: Jaffna Lagoon, located on the Northern coast of Sri Lanka, is a significant habitat for marine life, yet its water quality and the role of environmental parameters on plankton distribution and abundance remain unknown. The present study aims to investigate the water quality of Jaffna Lagoon, plankton diversity, abundance, and their relationship with water quality parameters. Water samples were collected from 20 different locations between September 2021 and March 2022, and water quality parameters and plankton samples were analyzed. The results revealed that the water quality of Jaffna Lagoon was highly variable, with pH ranging from 7.67 to 8.52, dissolved oxygen ranging from 5.34 to 8.76 mg/L, salinity ranging from 20.5 to 29.5 PSU, temperature ranging from 26.06°C to 29.98°C, total nitrate ranging from 10x103 mg/L to 21.9x106 mg/L, and total phosphate ranging from 0.01 mg/L to 0.32 mg/L. A total of 13 species belong to 12 families of planktons were identified, viz., Coscinodiscus granii, Leptocylindrus minimus, Gyrosigma balticum, Woronichinia elenkin, Acartia sp., Gastropod larvae with ciliated foot, Chaetoceros vanheurckii, Melosira sp., Cymbella cuspidata, Cymbella lanceolata, Chaetoceros costatus, Closterium limneticum and Protoperidinium pellucidum. Gyrosigma balticum was the most abundant plankton species (13%) in the lagoon, followed by C. granii (10%) and C. vanheurckii (10%). The total phytoplankton abundance fluctuated from values of <104 cells L−1 to values >2 × 106 cells L−1. The regression analysis was performed to examine the relationship between plankton abundance, temperature, and nitrate content. These findings contribute to the understanding of the ecological status of Jaffna Lagoon and can inform the development of sustainable management strategies for the lagoon ecosystem.