Aquaculture: improvement of immune system and intestinal health in Nile tilapia and Rainbow trout
The use of pronutrients in tilapia and trout farming led the first session of the 32nd Biovetâ€™s International Symposium
The use of pronutrients applied to the field of aquaculture was the cornerstone of the first session at the 32nd edition of the Biovetâ€™s International Symposium, held on May 27 at the Chamber of Commerce of Tarragona, in Spain.
The session was divided into three talks. The first focused on the use of intestinal conditioners and natural immuno booster pronutrients in Nile tilapia fingerlings (Oreochromis niloticus); the second revolved around the effects of immuno booster pronutrients on productive parameters and general health status in Nile tilapia and Rainbow trout (Oncorhynchus mykiss). The closing talk focused on new microencapsulation techniques applied to the treatment of white spot syndrome virus (WSSV) in shrimp (Litopenaeus vannamei) with thyme essential oil.
Nile tilapia: better performance with intestinal conditioner pronutrients
The opening presentation of the session on aquaculture fell on Dr. Alfredo Palomino, of the Universidad CientĂfica del Sur (UCSUR) in Lima, Peru. With the talk entitled “Productive performance of Nile tilapia fingerlings fed with Alquernat Nebsui”, Dr. Palomino highlighted some of the main challenges faced by the aquaculture industry today: increasing productivity per unit area, reducing feed costs, and getting a high quality product for human consumption.
A field test was carried out in Peru with experimentally farmed tilapia and Alquernat Nebsui, a Biovetâ€™s natural additive rich in intestinal conditioner pronutrients. The aim of the study was to measure the improvement of the intestinal health and the modulation of the gastrointestinal tractâ€™s microbiota, which are key to a better performance of nilotic tilapia fingerlings. The results of the test revealed that the supplementation of the intestinal conditioning additive into the habitual diet in an optimal dose of 1% of total feed intake, resulted in a 9% improvement in the fingerlingsâ€™ feed conversion rateÂ (FCR) during the nursery stage.
By making reference to the results obtained, Dr. Palomino stated that “fish managed to increase their weight by 20 times, which goes in accordance with the established experimental method in order to determine performance evaluations in this stage of cultivation” . In this sense, it is demonstrated that the use of additives with intestinal conditioning properties have a positive impact on the intestinal physiology of tilapias.
The results obtained showed improvements in the intestinal microbiota and in the activity of the digestive enzymes. In general terms, the intestinal morphology presented a better status in the Alquernat Nebsui-treated groups, compared to the untreated group. Therefore, the optimization of the digestive processes allowed a better use of the nutrients present in the diet and, consequently, a higher growth rate in the treated nilotic tilapia specimens.
Immune improvement of Rainbow trout and Chitralate tilapia with natural immuno boosters
The next presentation of the aquaculture session was conducted by the Doctor of Veterinary Medicine Juan B. Battaglia, of Aquaculture Businesses & Technologies Peru S.A.C (AB & T), and in collaboration with the Peruvian Universidad Nacional del Callao (U.Callao). Under the title “Use of liquid Alquernat Immuplus on growth, immunity indicators and nutritional status in Nile tilapia and Rainbow trout“, Dr. Battaglia presented two field studies focused on the use of immuno boosting pronutrients in juvenile Nile tilapias, in its Chitralate variety, and Rainbow trout fingerlings.
Although the lecture was mainly focused on the Peruvian aquaculture industry, Dr. Battaglia made a brief introduction on current sectorâ€™s situation worldwide. Amongst the main exposed facts, there was the exponential growth of the aquaculture industry at the global level, which it is expected to surpass wild caught fish in millions of tons in the following years.
Whilst taking future projections as certain, Dr. Battaglia focused on the problems caused by the emergence of pathologies with important repercussions on productive parameters. In this sense, the growing demand of fish proteins for human consumption has a direct impact on the volume and density of fish farms. In parallel, antibiotics resistance and the possibility that pathogenic bacteria create new resistances in the near future is cause for concern within the industry, which requires new effective products as an alternative to antibiotic therapies.
In this line, Dr. Battaglia presented two field studies conducted with Rainbow trout fingerlings – the most produced species in Peru – and Nile tilapias, which were both supplemented with immuno boosting pronutrients – Alquernat Immuplus in its liquid format â€“ in its usual diet. Thanks to the potentiating effects on the immune cells activity, this Biovetâ€™s natural immunostimulant additive strengthens the specific and non-specific immune system and, in doing so, optimizes the animal’s resistance to infections. In addition, this product has no pharmacological effect, does not create resistances, leaves no residue and does not require a period of suppression.
The results of the test with Rainbow trout revealed that during the 45 days of the experiment there were no significant differences in the growth and other productive parameters shown. However, there was an improvement of 0.8% in the survival rate of the group of trouts treated with a 0.4% of product over total feed input, compared to groups treated with other doses and the control group.
In contrast, the test with Chitralate tilapias did reveal a notable impact on the growth, productive parameters, immunological and nutritional status in treated specimens. Specifically, the optimal dose was also a supplemental 0.4% of product over total feed intake, which corresponded to the treatment group that showed the best feed conversion rate (FCR).
Although all treated groups showed improvements, the immune status of fry tilapias in this experimental group showed a higher concentration of white blood cells, which reduces the risk of contracting diseases and mortality. Regarding the nutritional status, all treated groups experienced improvements but, once again, it was the 0.4% dose group which revealed better results regarding the relationship between nutrient intake and the experienced physiological improvements.