Gökkuşağı Alabalığının (Oncorhynchus Mykiss) Performansı Üzerine Sınırlı Yemlemenin Etkileri

Rainbow trout (104.8±0.15g), Oncorhynchus mykiss, were fed a commercial extruded pellet for 7 weeks to investigate the effect of restricted feeding on performances. Th ree restricted feeding were te sted: two day intervals (TDI), every other day (EOD) and twice a day (TD). Fish were held in fresh water at 9-13°C fro m January 16 to March 4, 2004. Feed conversion rate (FCR) were TDI and TD groups 1.33±0.03 and EOD group 1.54± 0.03, protein efficiency ratio (PER) were TDI group 1.88±0.04, EOD group 1. 59±0.03 and TD group 1.85±0.04, respec tively. Although FCR was the same between TDI and TD, there was a significant differences in weight gain, relative growth rate (RGR) and specific growth rate (SGR) between the groups. These group eval uated the food at the same rate but si nce the given food amount were different, the weight gain, SGR and RGR of TD were the highest dependent to the food amount. Although the FCR was good in restricted fed fish, the taken feed amount sigificantly affected the growth parameters of fish. Relative growth rate (RGR), weight gain and specific growth rate (SGR) were lower in TDI and EOD groups. Both specific growth rate and relative growth rate increased with number of restricted feeding. The restricted feeding influenced the chemical composition of the fish. The lipid, moisture and protein content of fish increased when the fish were fd twice a day (TD group). In terms of SGR and RGR, it can be concluded that the best growth rate was obtained from the fish fe d twice a day (TD) and every other day (EOD) feeding for rainbow trout at 9-13ºC.Gökkuşağı alabalığı, (Oncorhynchus mykiss) (104.8±0.15g), performansı üzerine sınırlı yemlemenin etkilerini araştırmak için 7 hafta süresince ticari ekstrüde yemle yemlenmiştir. Her gün (TD), gün aşırı (EOD) ve üç günde bir (TDI) olmak üzere üç farklı yemleme frekansı uygulanmıştır. Balıklar 16 Ocak-4 Mart 2004 tarihleri arasında, 9-13ºC su sıcaklıklarında tatlı suda tutulmuştur. Yem dönüşüm oranları TD ve TDI gruplarında 1.33±0.03 ve EOD grubunda 1.54±0.01, Protein verimlilik oranları TDI grubunda 1.88±0.04, EOD grubunda 1.59±0.03 ve TD grubunda 1.85±0.04 arasında kaydedilmiştir. FCR değerleri TDI ve TD grupları arasında aynı olmasına rağmen, bu gruplar arasında ağırlık kazancı, spesifik büyüme oranı (SGR) ve oransal büyüme oranı (RGR) arasında önemli farklılıklar vardır. Bu gruplar yemi aynı oranda değerlerdirmişler fakat verilen yem miktarları farklı olduğu için yem miktarına bağlı olarak TD grubunda ağırlık kazancı, SGR ve RGR en yüksek kaydedilmiştir. Sınırlı oranda yemlenen balıkların yem değerlendirimi ne kadar iyi olsa da aldıkları yem miktarları balıkların büyüme parametrelerini oldukça önemli bir şekilde etkilemektedir. Oransal büyüme oranı (RGR), ağırlık kazancı ve spesifik büyüme oranı (SGR) EOD ve TDI gruplarında ise daha düşük bulunmuştur. Hem spesifik büyüme oranı hem de oransal büyüme oranı yemleme frekansının artışıyla birlikte artış göstermiştir. SGR ve RGR değerlerine bakılarak, gökkuşağı alabalığın için en iyi büyüme oranının 9-13ºC de her gün iki kez (TD) ve gün aşırı iki kez (EOD) yemlemeden elde edildiği sonucuna varılabilir

Effects of dietary supplementation of different rates of spirulina (Spirulina platensis) growth and feed conversion in guppy (Poecilia reticulata Peters, 1860)

In this study, effect of dietary supplementation of different rates (10% Group B, 20% Group C, 30% Group D, 40% Group E) of spirulina (Spirulina platensis) on growth and feed conversion in guppy (Poecilia reticulata) was compared with a commercial stamp food (Group A). Fish fed 40% spirulina performed better than those fed lower levels. At the end of the experiment, there were no significant differences between the all groups in terms of average final weights (p>0.05). No significant differences were observed in specific growth rate, feed conversion rate and weight gain. However, there were significant differences in terms of feed conversion rate between groups (p<0.05) and it was the highest in Group E (1.090±0.044) and the lowest in Group A (2.312±0.071). Therefore, the best growth rate (1.933±0.009) and live weight gain (0.085±0.006 ) were recorded in Group E. As a result of the study, 40% spirulina supplementation in the diet for guppy has a positive effect on growth and feed conversion rates

Radyonlarda Yem Katkı Maddesi Olarak İki Deniz Yosununun (Ulva lactuca, Enteremorpha linza) Gökkuşağı Alabalığının (Oncorhynchus mykiss) Büyüme Performansı, Yem Değerlendirme ve Vücut Kompozisyonu Üzerine Etkileri

In the present study, it was aimed to determine to effects of diet containing two seaweed species, Ulva lactucaand Enteromorpha linza , on the growth performance, feed utilization and body composition of rainbow trout. Two experimental diets were formulated with the usage of 10% U. lactuca meal and 10% E. linza meal in feed and control group had no seaweed ingredients. Each experiment was triplicate and each group had fourteen fish specimens with an average weight of 32.96±0.29 g. Fish were hand fed three times per day for 60 days. Significant differences were determined in weight gain, specific growth rate, relative growth rate and feed utilization between experimental and control groups (P<0.05). Fish fed with the diet containing 10% E. linza meal had the poorest feed utilization. The survival rate ranged from 96% to 98% in all groups during trial period. Apparent net protein retention, protein efficiency rate, daily dry feed intake and total feed intake were significantly lower in fish groups which fed with the diet containing U. lactuca and E. linza than control group (P<0.05). The final levels of crude protein, crude lipid and crude ash were in higher rates in the body composition all the groups compared when compared to the initial level (P<0.05). The results of the experiment revealed that a diet with U. lactuca and E. linza inclusion at 10% levels resulted in a poorer growth and feed utilization for rainbow trout when compared to those of control group. Hence, more defined experiments seem to be necessary in order to determine the optimum dietary inclusion level of these seaweeds in rainbow trout diets.Bu çalışmada, iki deniz yosunu ( Ulva lactuca and Enteromorpha linza) içeren rasyonun gökkuşağı alabalığının büyüme performansı, yem değerlendirmesi ve vücut kompozisyonu üzerine etkisinin belirlenmesi amaçlanmıştır. İki deneme rasyonu % 10 U. lactuca ve %10 E. linza unu içerecek düzeyde formülüze edilmiş, kontrol grubuna ise hiçbir deniz yosunu ilave edilmemiştir. Her bir deneme grubu üç tekerrürden oluşmuş, her bir tekerrürde ortalama ağırlığı 32.96±0.29 g olan 14 balık yer almıştır. Balıklar günde üç kez elle yemlenmiş ve çalışma 60 gün sürmüştür. Deniz yosunu içermeyen Kontol grubu ile U. lactuca ve E. linza unu ihtiva eden gruplar arasında ağırlık artışı, spesifik büyüme oranı, nispi büyüme oranı ve yemden yararlanma yönünden farklılık istatistiki olarak önemli bulunmuştur (P<0.05). % 10 E. linza unu içeren grupta, yem değerlendirmenin en düşük olduğu tespit edilmiştir (P<0.05). Yaşama oranı tüm deneme gruplarında % 96’dan %98’e değişim göstermiştir. Görünür net protein alımı, protein etkinlik oranı, günlük yem ve toplam yem alımı U. lactuca ve E. linza içerikli rasyonlarda kontrol grubuna nazaran nispeten daha düşük bulunmuştur (P<0.05). Deneme sonunda, balıketinde yapılan ham protein, ham yağ ve ham kül oranı deneme başıyla karşılaştırıldığında tüm deneme gruplarında daha yüksek bulunmuştur (P<0.05). Bu çalışma sonuçları, gökkuşağı alabalığı rasyonlarında %10 seviyesinde U. lactuca ve E. linza kullanmanın kontrol grubuna göre, balıkların daha düşük bir büyüme ve yem değerlendirmesine neden olduğunu ortaya çıkarmıştır. Bu yüzden, alabalık rasyonlarında bu deniz yosunlarının,optimum kullanımı için daha fazla araştırma yapmaya gerek vardır

Evaluation of extruded chickpea, common bean and red lentil meals as protein source in diets for juvenile rainbow trout (Oncorhynchus mykiss)

An experiment was conducted to evaluate, the use of extruded chickpea, common bean and red lentil meals as dietary protein source for juvenile rainbow trout. Three experimental diets were formulated based on a reference diet, which composed of 70% reference diet and 30% test ingredient. The diets were given as triplicate groups of juvenile rainbow trout (initial weight of 50 g) to apparent satiation twice daily. There were no significant differences among the groups fed chickpea, common bean and reference diet, for weight gain, specific growth rate and feed conversion ratio, but there were significant differences among these groups and red lentil group in these respects. There were no significant differences in digestibility of protein between the fish fed chickpea and reference diets and chickpea and common bean diets, but the red lentil diet gave lower protein digestibility. Apparent protein digestibility coefficients of the ingredients were determined high for extruded chickpea (80.65%), mid-range for extruded common bean (72.91%) and low for extruded red lentil meals (50.07%). The results indicated that extruded chickpea and common bean meals have higher potential than red lentil meal for use as dietary protein source in diets for juvenile rainbow trout

Fatty acid composition in the fillets of rainbow trout grown in different conditions

The aim of this study was to determine the influence of different feed composition and cultivation on the composition of fatty acids, their relationships, and the cholesterol content in the tissue of rainbow trout (Oncorhynchus mykiss). Trout were reared in ponds at two different altitudes and raised on different feeds. The total amount of monounsaturated fatty acids in fillets of both groups showed no statistically significant difference. However, higher levels of n-6 fatty acids were found in Pond I trout fillets than in Pond II fillets, while Pond II fillets contained almost even amounts of n-3 and n-6 fatty acids. Total cholesterol content in Pond I trout fillets was significantly lower (p<0.05) than in Pond II fillets. The results indicate that the final composition of the trout fillets was mostly dependent on the feed the live fish had consumed; the altitude of the ponds had less effect. Also, both groups of trout could be used in the human diet as biologically valuable foods. Practical application: Our results show influence of altitude, feed, and fatty acid composition of feed on trout fillets. The average fatty acid level in the trout fillets increased in the order SFA <MUFA <PUFA. Trout fillets contain low levels of cholesterol but high levels of EPA, DPA, and DHA. These facts are important for fish industries and aquaculture producers to design a healthy food