Gökkuşağı Alabalığı Yemlerine Probiyotik ve Antibiyotik İlavelerinin Balıkların Sağlık Karakteristikleri Üzerine Etkileri

Bu çalışmada yeme antibiyotik (amoksisilin+klavulanik asit) ve probiyotik ilavesinin gökkuşağı alabalıklarında (Oncorhynchus mykiss) bazı immünolojik ve serum biyokimyasal sağlık karakteristikleri üzerine etkilerinin araştırılması amaçlanmıştır. Yeme ilave edilen antibiyotik veya probiyotik katkılarının lizozim aktivitesi, myeloperoksidaz aktivitesi, serum total protein, albümin, globülin, trigliserit ve kolesterol değerleri üzerine herhangi bir etkisinin olmadığı belirlenmiştir. Antibiyotik ile beslenen balıkların serum glikoz düzeyleri kontrole göre önemli oranda artmıştır. Bununla birlikte antibiyotik ile beslenen balıkların GOT değeri kontrole göre önemli oranda azalmıştır. Ayrıca LDH ve ALP değerleri antibiyotik ve probiyotik ilavesi ile kontrole göre azaldığı belirlenmiştir. Bu çalışma, tek bir deneysel model olup farklı balık türlerinde ve farklı balık patojenlerinde karşı probiyotik kullanımı farklı dozlara veya zamana bağlı olarak değişebilir. Bu nedenle bu çalışma çeşitli kan parametrelerinin değerlendirilmesi açısından diğer çalışmalara ışık tutmaktadır

Combined Effects of Dietary Bacillus subtilis and Trans-cinnamic Acid on Growth Performance, Whole Body Compositions, Digestive Enzymes and Intestinal bacteria in Rainbow Trout (Oncorhynchus mykiss)

In this study, the combined effects of dietary Bacillus subtilis (BS, 10 7 g/cfu) and different levels (0.025%, 0.050%, 0.075% and 0.150%) of trans-cinnamic acid (CA) on fish growth performance, whole body compositions, digestive enzymes, intestinal bacteria and internal organ index of rainbow trout (Oncorhynchus mykiss) were investigated. Six different experimental groups including control group (C), C+BS, 0.025%CA+BS, 0.050%CA+BS, 0.075CA+BS, 0.150%CA+BS) were established. According to the results obtained, growth performance, whole body compositions and digestive pH were not statistically significant among groups. Further, no significant differences were found between experimental groups in terms of the intestinal enzymes (trypsin, alkaline phosphatase and lipase) and gastric pepsin. Significantly higher levels of intestinal amylase were found in the control+BS, 0.025%CA+BS, 0.050% CA+BS, and 0.075%CA+BS compared to the control and 0.150%CA+BS groups. Moreover, coliform and Enterobacteriaceae counts were highest in the control+B. subtilis and lowest in the 0.150% CA + B. subtilis groups

A preliminary study of the effect of phytoadditive carvacrol on the trace elements (Cu, Mn and Zn) content in fish tissues

Phytoadditives have gained increasing interest as feed additives for fish. The aim of the present study was to determine whether selected dietary phytoadditive can influence the bioavailability of several trace elements (Cu, Mn and Zn), which play an important role in the physiological processes. The experiments were carried out at a commercial trout farm. A total of 420 juvenile rainbow trout (mean weight ± SD = 10.79±0.57), Oncorhynchus mykiss, were randomly allocated into four different treatments with three replicates each. Fish were kept in raceways (3X0.8X0.4 m) at 10±1°C with a natural photoperiod. Proper amount of carvacrol was sprayed on 1 kg of commercial trout diet to prepare four diets with 0 (Control, C0), 1 (C1), 3 (C3) and 5 (C5) carvacrol g/kg diet. Fish were fed to apparent satiation three times per day. The feeding trial lasted four weeks. Then, in different type of fish tissues (muscle, liver and pyloric caeca) from fish fed with diets enriched in carvacrol, beneficial elements (Cu, Mn and Zn) were analysed by atomic adsorption spectrophotometer. Results showed that the levels of Cu, Zn and Mn were especially significantly increase by C1 diet in all tissues (muscle, liver and pyloric caeca) except muscle and pyloric caeca Zn. The results of this experiment indicate that the carvacrol had the ability to potentiate the trace element retention. Although bioaccumulations of Cu, Zn and Mn in the muscle, liver and pyloric caeca are well demonstrated, the exact mechanisms of phytoadditives are still only partially understood. More investigations are required to detail the mechanisms involved in phytoadditives this enhancement

Growth And Feed Consumption Of Young Rainbow Trout (Oncorhynchus Mykiss) Exposed To Different Photoperiods

A feeding experiment was carried out in a brackish water (18 ppt) flow-through system to deter- mine the effects of different photoperiods (light hours/dark hours; L/D) on feed intake and growth performance of young rainbow trout (Oncorhynchus mykiss). Duplicate groups of fish (35.32 g avg body wt) were exposed to a natural photoperiod, a long photoperiod (16L/8D) or a continu- ous photoperiod (24L/0D) for 60 days and fed to satiation twice a day. The growth rate, daily feed intake and feeding rate in the natural photoperiod were significantly lower (p0.05) from the natural photoperiod. Survival was not significantly (p>0.05) affected by the treatment. For better growth and a lower food conversion rate, the long photoperiod is recommended for young rainbow trout

Enhancement of Growth Performance and Pigmentation in Red Oreochromis mossambicus Associated with Dietary Intake of Astaxanthin, Paprika, or Capsicum

Diets for tilapia, Oreochromis mossambicus, were supplemented with astaxanthin, paprika, or capsicum to determine their effects on growth performance and pigmentation. Seven isonitrogenous (37% crude protein) and isoenergetic (18 kJ/g) diets were formulated to contain 40 or 60 mg carotenoid per kg diet. Triplicate groups of 210 fish were stocked in 21-l plastic boxes and fed one of the three experimental diets or the control diet for 45 days. Significantly better final weight, weight gain, specific growth rate, and food conversion ratio were obtained with the diets containing 40 or 60 mg/kg paprika than with control diet (p<0.05). In general, the carotenoid-supplemented diets significantly increased the values of redness (a*), yellowness (b*), and chroma (C*), and decreased the values of lightness (L*) and hue (Hoab) on the tail, body, and head areas (p<0.05). Results show that paprika or capsicum oleoresin can be used as an alternative natural carotenoid source in O. mossambicus diets to ensure good pigmentation, better growth, and feed utilization

Effects of Cumin-Supplemented Diets on Growth and Disease (Streptococcus iniae) Resistance of Tilapia (Oreochromis mossambicus)

The effects of dietary cumin (Cuminum cyminum) as a feed additive on growth performance and disease resistance of tilapia (Oreochromis mossambicus) were studied. Five isonitrogenous (37% crude protein) and isocaloric (18.6 kj/g) diets were formulated to contain 0% (control), 0.5%, 1.0%, 1.5%, or 2.0% cumin. Fifteen aquaria (80 l) were stocked with 15 fish (0.56±0.02 g), each, and fish were fed one of the five diets for 75 days. The cumin supplementation did not affect the feed conversion rate (FCR) or specific growth rate (SGR). Cumulative mortality was 60% in fish fed the 0% control diet and challenged with Streptococcus iniae. However, in fish fed the 1.0%, 1.5%, or 2.0% supplemented diets, mortality was only 10.42%, 31.25%, and 37.50%, respectively. In conclusion, a dietary cumin level of 1% provides the best survival rate for tilapia, O. mossambicus, without adversely affecting growth performance or feed utilization

Changes In Blood Ion Levels And Mortality Rates In Different Sized Rainbow Trout (Oncorhychus Mykiss) Following Direct Transfer To Sea Water

Plasma ion values and mortality rates were compared for 450 rainbow trout (Oncorhynchus mykiss) of three sizes following direct transfer from fresh water to Black Sea water of about 18 ppt. In fish of 14.29±0.30 g, plasma Na+, Cl- and K+ levels significantly (p<0.05) rose above ini- tial values five days after the transfer and peaked at 178.6±5.66, 153.9±0.14 and 1.14±0.04 mM/l, respectively. In 20.45±0.48 g fish, these values also rose significantly, reaching 172.4±4.24, 151.8±6.65 and 0.98±0.04 mM/l by day 5. In fish of 29.91±0.99 g, however, plasma Na+ and Cl- concentrations peaked 19 days after transfer, reaching only 165.5±6.43 and 142.9±8.34 mM/l, while plasma K+ reached its highest concentration of 1.02±0.06 mM/l on day 12, All three concentrations dropped to near initial values on day 26. In all groups, the plasma Ca2+ level rose significantly (p<0.05) above the initial value five days after transfer and then declined while the plasma P5+ concentration dropped on day 5, reaching a minimum on day 12 and recovering the initial level on day 26. The lowest mortality (8.0±1.89%) was recorded in the 30 g group, followed by 19.3±0.94% and 24.7±0.94% in the 20 g and 14 g groups. The failure of the smallest fish to adapt after direct transfer to sea water was likely due to excessively high plasma Na+ and Cl- concentrations and tissue dehydration, indicating that fish of 30 g best adapt to a seawater environment of 18 ppt

Effects of the levels of astaxanthin in the diet on the flesh pigmentation of Rainbow trout

A feeding trial was conducted to study the effects of dietary astaxanthin concentration on muscle pigmentation of rainbow trout ( Oncorhynchus mykiss) with a mean initial weight of 270 g fed diets supplemented with astaxanthin in diet concentrations of 60 (group II) and 90 mg/kg (group III) for 35 days. A control (I) group received a diet without astaxanthin. At the end of the experiment, the trout showed average body weight increases of 250.660g, 261.675 g and 234.410 g, and the flesh reached a level of 0.695 mg/kg, 10.539 mg/kg and 11.954 mg carotenoid/kg in groups I, II and III, respectively (initially, 0.595 mg/kg). Fish pigmentation increased with increasing dietary carotenoid concentration. But the retention coefficients decreased as the pigment dose in the diet increased. Key Words : Rainbow trout ( Oncorhynchus mykiss), pigmentation, astaxanthi

Incorporation of Soybean Meal and Hazelnut Meal in Diets for Black Sea Turbot (Scophthalmus maeoticus)

The effects of soybean and hazelnut meals as partial replacements of fishmeal were studied in Black Sea turbot (Scophthalmus maeoticus). Juvenile fish (mean 26 g) were fed six isoenergetic (19.1±0.18 kJ/g diet) and isonitrogenous (511±0.48 g protein/kg diet) diets for 60 days. The con- trol diet contained fishmeal as the sole protein source. In two of the six experimental diets, soy- bean meal replaced 20% and 35% of the fishmeal. The other three diets contained 65% fishmeal plus soybean and hazelnut meal at ratios of 25/10, 15/20, 5/30. There was no significant differ- ence (p<0.05) in growth performance between the groups fed the diet containing 20% soybean meal and those fed the control diet. Fish fed the 10% or 20% hazelnut meal diets had similar results as fish fed the diet containing 35% soybean meal. Growth performance, feed utilization, protein efficiency, and nitrogen retention were significantly lower in the group fed the 30% hazel- nut diet. Total nitrogen excretion and retention were similar in all groups except the 30% hazel- nut group. Results indicate that soybean meal can replace up to 20% of the fishmeal without causing reduction in growth performance, nutrient utilization, or nitrogen retention and that hazel- nut meal can be incorporated with 20%, but not 35%, soybean meal at a level of no more than 20% of the diet