Fish seed health management in Nepal and potential role of probiotics | |
| Author | Jha, Dilip Kumar |
| Call Number | AIT Diss. no.AQ-15-01 |
| Subject(s) | Fisheries--Management Nepal Fisheries--Nepal--Fishing effort Probiotics Aquaculture |
| Note | A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Aquaculture and Aquatic Resources Management |
| Publisher | Asian Institute of Technology |
| Series Statement | |
| Abstract | Availability of required q uantit ies of high quality seed of the desired species at the stocking season is one of the ma jor factors that lead to success of aquaculture operation. Seed quantity and quality depends on the health management of broodstock and the earlier stages of seed. The research consists of three parts (i) a f ield survey of the c arp seed production system in the private fish hatcheries of Terai and inner Terai of Nepal under different developmental regions , (ii) a series of three consecutive experiments in three developmental stages of rohu were conducted to evaluate the potentials of three different probiotics to enhance survival and growth , and (iii) a series of three experiments conducted with three different dos es of two different probiotics. A tota l of forty private fish hatcheries from different regions of Nepal (Eastern - 9; Central - 19, Western - 6, Midwestern - 3 and Farwestern - 3) representing 15 districts (Morang, Sunsari, Saptari, Siraha, Dhanusha, Mahottari, Bara, Chitwan, Nawalparasi, Rupandehi, Ka pilvastu, Bankey, Bardiya, Kailali and Kanchanpur) of Terai and inner Terai were surveyed. The sources of brood fish were mainly from their own farm. M ajor ingredients for brood stock feed were mustard oil cake, rice bran, soybean flour, maize flour wheat f lour, wheat bran, fish meal and bone meal. More importantly, the percentages of survival of hatchlings were 28.1, 22.2, 26.8, 23.3 and 26.7 recorded by eastern, central, western, mid - western and far western region respectively. Hatcheries of central regio n have variation s in survival of hatchlings ranged from 10% to 35%. The 21.0% owners reported only 10 - 15% survival while 36.8%, 21%, 10.5% and 10.5% owners experienced 16 - 20%, 21 - 25%, 26 - 30% and 31 - 35% survival respectively. The percentage survival of fry were 51. 7 , 52. 4 , 52.5, 50.0 and 53.3 recorded by eastern, central, western, mid - western and far western region respectively. Similarly, the percentage survival of advanced fry were 62. 8 64.7, 62.5, 60.0 and 60.0 recorded by eastern, central, western, mid - western and far western region respectively . Seventy percent hatcheries faced the problem of b acterial ( e specially bacterial ulcer and fin rot), f ungal ( Saprolegniosis ), l ice ( Argulosis ), low dissolved oxygen and d ropsy . About 20% owners reported the problem of Tric h odina sp p while about 5 % faced white and black spot disease s . The survey clearly showed that a mong the problems or challenges of carp seed production systems are the low survival of hatchlings and f ry . T wo, on - station experiments were conducted on the means towards enhancing the survival and growth performance of juvenile r ohu ( Labeo rohita ) . A series of trials were conducted during March 2009 to Octobe r 201 0 to select the most effective probiotics commercially availab le in Nepal. In the experiment - 1, three different probiotics were tested to identify the most effective one. Under this experiment three phases experiment were conducted for 30 day s each to evaluate the potential benefit s of three multi - strain probiotics in thre e different stages of juvenile r ohu (hatchling - 8 days old, fry - 38 days old and advanced fry - 68 days old) on the survival and growth . In this study, four different types of treatments were used; namely, T1: Control, i.e. Fee d without any dietary supplements, T2: Feed with Lactobacilli , Bifidobacteri um , yeast, Spirulina and phytase, T3: Feed with Lactobacillus , yeast, seaweed and amylase, and T4: Feed with Lactobacilli , Bacillus and yeast only. Hatchlings fed with T2 feed show ed highest survival (74.7%), which is about 25% improvement in comparison to the survival of the Control group (49.9%). Similarly, T3(60%) and T4 (61.5%) showed at least 10% increment in survival as compared to that of Control (T1). The hatchlings in T2 g roup had significantly higher (p<0.05) final weight (0.53 g) compared with T1 , T3, and T4 which had final weights of 0.30 g 0.46 g , and 0.39 g respectively. Specific growth rates of T2 and T3 were found significantly higher (p<0.05) in hatchling s. In fry s tage, the feed with all the probiotic mixtures showed significantly higher specific growth than the Control. However, these p robiotics had no clear effect on the survival at the fry stage and afterwards . In advanced fry stage, there was no significant differences (p>0.05) in final weight and specific growth rate among the treatments. This study indicated that positive effects of multi strain probiotics on the survival and growth can be seen only at hatchl ing and fry stages, but not later stages. The experiment - 2 was conducted to determine the optimum doses of the most effective probiotics from the experiment - 1and a new one among the three different doses (low, medium and high). Under this experiment als o three phases experiment were conducted for 30 day s each to evaluate the potential benefit s of doses of two different multi - strain probiotics in three d ifferent stages of juvenile r ohu (hatchling - 8 days old, fry - 38 days old and advanced fry - 68 days old) on the survival and growth . The seven different types of treatments were used; namely, T1: Control, i.e. Feed without any dietary supplements, T2: Feed with Pediococcus acidilactici , Saccharomyces cerevisiae and Bacillus subtilis with low dose, T3: Feed with Pediococcus acidilactici , Saccharomyces cerevisiae and Bacillus subtilis with medium dose and T4: Feed with Pediococcus acidilactici , Saccharomyces cerevisiae and Bacillus subtilis with high dose, T5: Feed with Lactobacilli , Bifidobacteri um , yea st, Spirulina and phytase with low dose, T6: Feed with Lactobacilli , Bifidobacteri um , yeast, Spirulina and phytase with medium dose dose, T7: Feed with Lactobacilli , Bifidobacteri um , yeast, Spirulina and phytase with medium high dose. Hatchlings fed with T7 feed showed highest survival (69.5%), which is about 22% improvement in comparison to the survival of the Control group (47.1%). Similarly, T3 (61.5%) and T4 (63.3%) of probiotics - 1 showed at least 15% increment in survival as compared to that of Contro l (T1). The hatchlings in T 5 of probiotics - 2 and T3 of probiotics - 1 had not differed significantly (p>0.05). All probiotics improved the growth of hatchlings significantly (p<0.05) . In the case of fry (38 – 68 days old), the results showed that probiotics - 1 does not improve survival in low dose while probiotics - 2 improve survival in all the treatments possibly because it has more strains of LAB along with yeat and Spirulina. There was no significant difference in survival of fry were seen between T3 and T4 of probiotics - 1and T5 of probiotics - 2. Also, there were no significant differences between T5 and T6. All treatments of probiotics - 1 and probiotics - 2 had significantly improved the growth of fry than control. There was no significant difference in SGR of fry were seen between T3 and T4 of probiotics - 1 and T5 of probiotics - 2, while T6 and T7 not differed significantly (p>0.05). In the case of advanced fry (68 - 98 days old), the results showed that probiotics does not improve survival except high dose of prob iotics - 2. Though higher dose of probiotics made significant effect on survival but it was very little as compared to medium dose of probiotics - 2. It means advanced stage of fry needs more dose rather usual dose for juvenile Rohu.Similarly, higher dose of p rbiotics improved SGR in probiotics - 1. P robiotics - 2 improved the specific growth rate in all the treatments. There was no significant difference between the medium and higher dos es of all probiotics used in the research. |
| Year | 2015 |
| Corresponding Series Added Entry | |
| Type | Dissertation |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Food, Agriculture and Natural Resources (Former title: Department of Food Agriculture, and BioResources (DFAB)) |
| Academic Program/FoS | Aquaculture and Aquatic Resources Management (AQ) |
| Chairperson(s) | Anal, Anil Kumar;Bhujel, Ram Chandra (Co-Chairperson) |
| Examination Committee(s) | Amararatne Yakupitiyage ;Datta, Avishek ; |
| Scholarship Donor(s) | ASIA-LINK II-EU Funded; |
| Degree | Thesis (Ph.D.) - Asian Institute of Technology, 2015 |