AI Summary & Key Takeaways
AI InsightFinally, in terms of both growth parameters and survival rate and digestive enzyme activities it is clearly concluded that MD supplementation could be started after 25 DAH in D. labrax larviculture.
📌 3 Key Takeaways
Abstract
In this study, effects of early weaning of sea bass (D. labrax) by microparticulate food on larval development and digestive enzyme activities, acid protease and alkaline protease were investigated until day 40. Larval rearing was conducted in closed sea water systems. Experiments were triplicated on 3 different weaning protocol that introduced on day 15 (MD15), day 20 (MD20) and day 25 (MD25) and also no microparticulate diet (MD) distributed in the control group. At the end of the experiment at 40-day, larval growth was calculated and the best values were obtained from MD25. Statistical differences among groups were not important (P>0.05) whereas MD15 was found different than the other groups (P<0.05). Also, survival rates were calculated as 3.6%, 14.7%, 43.6%, and 34.1% for the experimental groups, respectively. MD15 and MD20 groups were found different than the other groups (P<0.05). Nevertheless, activity of alkaline protease was detected synchronously by mouth opening and exogenous feeding and also increased by larval development. According to histological analysis, pancreas was observed by mouth opening and similarly developed with increasing of larval age. Alkaline protease activity changed by nutritional composition of feed and especially shifting of feed affected the enzymatic activity. There was no differences among the experimental groups (P>0.05) while control group was found statistically different (P<0.05). According to histological analysis, gastric glands and formation of functional stomach were observed on day 24-25 in all experimental groups. Acid protease activity firstly detected at 25 DAH. Control group was found different than the other groups (P<0.05). Finally, in terms of both growth parameters and survival rate and digestive enzyme activities it is clearly concluded that MD supplementation could be started after 25 DAH in D. labrax larviculture.
Özet
Bu çalışmada; levrek (D. labrax) balığının larva kültüründe erken dönemde mikro partikül yemler kullanılmasının, larvaların yaşama ve büyüme oranları ile sindirim enzimlerinden asit proteaz ve alkalin proteaz aktivitesi üzerine olan etkileri 40. güne kadar incelenmiştir. Larval yetiştiricilik kapalı devre sistem kullanılarak gerçekleştirilmiştir. 3 tekrarlı olarak yürütülen denemelede larvalara 15. gün (MD15), 20.gün (MD20) ve 25. gün (MD25) olmak üzere üç farklı dönemde mikro partikül yeme geçilmiş, kontrol grubundaki (K) larvalara herhangi bir yem girişi yapılmamıştır. Denemenin bittiği 40. gün sonunda, larvalara ait total boy ve ağırlık gelişimleri incelendiğinde en iyi değerler MD25 grubundan elde edilmiştir. Deneme grupları arasındaki fark önemsizken (P>0,05) MD15 grubu diğer gruplar ile arasında önemli farklılıklar bulunmuştur (P 0,05) bu grupların kontrol grubu ile arasındaki farklılık önemli bulunmuştur (P<0,05). Histolojik kesitler incelendiğinde, gastrik salgı bezleri ve fonksiyonel mide oluşumu bütün deneme gruplarında 24-25. günlerde tespit edilmiştir. Asit proteaz aktivitesi ilk olarak 25. günde tespit edilmiştir. Deneme grupları ile kontrol grubu arasındaki fark önemli bulunmuştur (P<0,05). Sonuç olarak, gerek büyüme parametreleri ve yaşama oranı gerekse sindirim enzimleri aktivitesi açısından değerlendirildiğinde levrek larvalarında mikro partikül toz yem girişinin 25. günden sonra yapılabileceği tespit edilmiştir.