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This study evaluated the effects of soy protein ratio, lipid content and the minimum dietary level of krill meal in plant-based diets over the growth performance and digestibility of Litopenaeus vannamei. Nine plant-based diets varied the soybean meal ( SBM) and soy protein concentrate ( SPC) inclusion ratio at 1 : 2.3, 1 : 1 and 2.5 : 1, and their dietary lipid content at 121.4 ± 9.4, 102.3 ± 1.2, and 79.9 ± 1.2 g kg−1 (in a dry matter basis). An additional diet containing 120 g kg−1 of fish meal (salmon by-product) was used as a control. Krill meal was included at 0, 5, 10, 20 and 30 g kg−1 in a new set of plant-based diets. After 10 weeks in clear-water tanks of 0.5 m3, no effect of SBM: SPC ratio and dietary lipid content was detected on shrimp survival. However, dietary lipid levels of 80 and 121 g kg−1 combined with a high SPC to SBM resulted in the lowest final body weight and the poorest apparent crude protein digestibility, respectively. Krill meal increased feed intake at only 10 g kg−1, while at 20 g kg−1, it accelerated shrimp growth, increased yield and reduced food conversion ratio. [ABSTRACT FROM AUTHOR]

This work aimed to determine whether a minimum provision of marine oil in practical diets for Litopenaeus vannamei is required when replacing fish meal ( FM) by soy protein concentrate ( SPC). The study consisted of three growth experiments conducted in 500-L tanks with 70 shrimp m−2. In experiment #1, FM was progressively replaced by SPC as fish oil ( FO) levels increased with a consistent input of whole squid meal ( WSM). In experiment #2, FM was replaced by SPC under two levels of FO (10 or 20 g kg−1) without the presence of a feeding effector. In experiment #3, three dietary levels of krill meal ( KRL) and WSM (5, 10 and 20 g kg−1) were included in a basal diet containing SPC and low levels of FM. Results showed that under a clear-water condition, the dietary levels of FO in practical diets for L. vannamei have a significant impact on the amount of FM that can be replaced by SPC. As much as 31% replacement of FM/ SPC was possible with 20 g kg−1 FO. Whenever dietary fat was adjusted by using FO as a lipid source, complete replacement of FM by SPC was achieved with no negative effect on shrimp growth. [ABSTRACT FROM AUTHOR]

This work evaluated the performance of Litopenaeus vannamei to low fish meal diets supplemented with 2-hydroxy-4-(methylthio)butanoic acid (HMTBa). A basal diet with 150.0 g kg−1 of anchovy fish meal was designed. Two positive control diets were formulated to reduce fish meal at 50% and 100% with 1.0 and 2.0 g kg−1 of MERA™ MetCa (calcium salt with 84% HMTBa activity), respectively. Two nearly equivalent diets acted as negative controls, without HMTBa supplementation. A total of 50 clear-water tanks of 500 L were stocked with 2.22 ± 0.19 g shrimp under 70 animals m−2. Shrimp survival (92.3 ± 5.1% and 81.4 ± 8.0%), yield (808 ± 12 and 946 ± 17 g m−2) and FCR (2.17 ± 0.19 and 3.12 ± 0.37) showed no differences among diets after 72 or 96 days, respectively. A significantly higher shrimp body weight and weekly growth were observed for those fed with the basal diet or diets supplemented with HMTBa compared with non-supplemented ones. This study has shown that L. vannamei growth, body weight, survival, yield and FCR were supported by HMTBa supplementation when 150.0 g kg−1 of fish meal was replaced by soybean meal and other ingredients, at 50% and 100%. [ABSTRACT FROM AUTHOR]

Litopenaeus vannamei were stocked in 25 clear-water 500-L tanks at 100 shrimp m and in 25 green-water 1000-L tanks at 60 animals m. Four diets were formulated to include krill meal at 10, 50 or 110 g kg; or krill oil at 25 g kg by replacing fish meal, fish oil, soybean lecithin and cholesterol. Diets had similar levels of crude protein, total energy and essential amino acids. After 72 days, shrimp reared in clear and green water showed no differences in performance among diets. In clear water, shrimp attained 13.1 ± 0.59 g body weight, 1.00 ± 0.06 g week growth, 81.4 ± 7.3% survival, 780 ± 118 g m yield, 16.9 ± 1.8 g shrimp apparent feed intake (AFI), and 2.18 ± 0.29 food conversion ratio (FCR). In green water, shrimp attained 14.3 ± 0.81 g body weight, 1.04 ± 0.09 g week growth, 91.4 ± 5.4% survival, 569 ± 69 g m yield, 20.9 ± 3.2 g shrimp AFI, and 2.22 ± 0.34 FCR. Diets containing krill meal or krill oil were able to fully replace the protein and lipid value of fish meal, fish oil, soybean lecithin and cholesterol at no cost to performance. [ABSTRACT FROM AUTHOR]