Ensilage of seaweeds from an integrated multi-trophic aquaculture system

This study aimed to evaluate the feasibility of ensiling preservation of three seaweed species (Gracilaria vermiculophylla, Ulva rigida and Saccharina latissima) produced in an integrated multi-trophic aquaculture system without or with a lactic acid bacteria inoculant after 24–48 hours wilting. The course of silage fermentation for a storage period up to nine weeks was also studied. The characteristics of fresh seaweeds suggested ensiling to be challenging. Overall, seaweeds presented a pH above 7.0, low dry matter (DM) content, and a non-structural polysaccharides content (DM basis) ranging from 14% (U. rigida) to 43% (S. latissima). The highest buffering capacity was recorded for U. rigida while the fermentation coefficient was higher for S. latissima, lower for U. rigida, and intermediate for G. vermiculophylla. The ensiling of S. latissima resulted in a pronounced lactic acid formation and a lower pH in comparison to the red and green seaweed silages. The ensilage of U. rigida and of G. vermiculophylla failed to decrease pH below 5.0 up to nine weeks, fermentation products suggesting the occurrence of a heterolactic fermentation or the promotion of heterofermentative bacteria and clostridia growth, respectively. The use of a lactic acid bacteria inoculant prior to ensiling had only minor effects on fermentation. Composition of seaweeds was generally preserved by ensilage, but in vitro digestibility of G. vermiculophylla was severely reduced. More research is needed to test different inoculants and dosages, and to assess the effects of seaweed silages on animal feed intake and performance. © 2017 ElsevierAuthors are grateful for the financial support received from the European Union (FEDER funds through COMPETE) and National Funds (Funda??o para a Ci?ncia e a Tecnologia, FCT) through projects EXPL/CVT-NUT/0286/2013 - FCOMP-01-0124-FEDER-041111 and UID/QUI/50006/2013 - POCI/01/0145/FEDER/007265 (LAQV). M.R.G.M. was also supported by FCT through a post-doctoral grant (SFRH/BPD/70176/2010). The authors would also like to thank S?lvia Azevedo (ICBAS-UP) and Isabel Azevedo (CIIMAR-UP) for the invaluable technical assistance

Apparent digestibility coefficients of European grain legumes in rainbow trout (Oncorhynchus mykiss) and Nile tilapia (Oreochromis niloticus)

Two trials were carried out to evaluate the apparent digestibility coefficients (ADCs) of dry matter (DM), crude protein (CP), lipids, starch and gross energy (GE) of six European varieties of grain legumes, namely chickpea-type Kabuli (CHK), chickpea-type Desi (CHD), field pea (FP), faba bean (FB), white lupin (WL) and chickling vetch (CV), in rainbow trout and Nile tilapia juveniles. The ADCs were measured using a reference diet and six experimental diets (700 g/kg of the reference diet and 300 g/kg of each raw grain legume) containing 10 g/kg chromic oxide as inert marker. Additionally, grain legumes were analysed for the organic acids profile. In rainbow trout, FP presented the highest ADCs of DM, CP and GE, whereas chickpeas and FB had the lowest DM, GE and starch ADC values. In Nile tilapia, the lowest values of nutrients (except starch) and energy ADCs were found for FP and CV. Nutrients and energy of chickpeas, WL and FB were better digested by tilapia, whereas FP was better digested by trout. Overall results reveal raw grain legumes as promising feed sources for both fish species. © 2017 John Wiley & SonsThis work was financed through Project UID/QUI/50006/2013, receiving financial support from FCT/MEC through national funds, and co-financed by FEDER, under the Partnership Agreement PT2020. S.C.Q. Magalh?es (SFRH/BD/80783/2011) and M.R.G. Maia (SFRH/BPD/70176/2010) are indebted to FCT for the individual grants. The authors thank INIAV, I.P., for supplying the grain legume samples and acknowledge Universidade de Tr?s-os-Montes e Alto Douro (UTAD) for the fish and facilities necessary to develop the trials, Ant?nio Varela (UTAD) for the technical support during both fish experiments and Alexandra Marques (CIIMAR, UP), In?s Campos (CIIMAR, UP), Marcos Taveira (FFUP), S?lvia Azevedo (ICBAS, UP) and Vera Sousa (CIIMAR, UP) for all the help on the chemical analysis of the ingredients, diets and faeces

Dietary protein/carbohydrate ratio in low-lipid diets for Senegalese sole (Solea senegalensis, Kaup 1858) juveniles. Influence on growth performance, nutrient utilization and flesh quality

Four isoenergetic (21 kJ/g dry matter, DM) and isolipidic (65 g/kg DM) diets containing different crude protein/total carbohydrate (CHO) ratios: 60/26, 56/30, 52/34 and 48/38, were tested in 22 g Senegalese sole for 104 days. Apparent digestibility coefficients (ADC) were not affected by the treatments, and all groups presented extremely low starch ADC values (22.8%\u201336.5%). Replacement of dietary protein by CHO did not affect daily growth index (0.9\u20131.0), but significantly increased voluntary feed intake of fish. Regression analyses demonstrated that digestible protein content, rather than digestible energy, was the main dietary factor influencing such feeding activity (R2 = .952). A significantly increased feed conversion ratio was observed in sole fed increasing CHO contents. The dietary protein/CHO ratio did not influence whole-body composition. Sole fed the 48/38 diet showed the lowest efficiency in terms of N and energy utilization. PUFA were the most represented fatty acid fraction in fillet, regardless of the dietary protein/CHO ratio, mainly due to the high content of DHA. Senegalese sole increase feed intake under low dietary protein/CHO ratios to ensure an adequate N intake. Such compensatory mechanism seems to be triggered to satisfy a specific protein metabolic requirement for energy purposes as tissue accretion remained unchanged

Dietary protein/carbohydrate ratio in low-lipid diets for Senegalese sole (Solea senegalensis, Kaup 1858) juveniles. Influence on growth performance, nutrient utilization and flesh quality

Four isoenergetic (21 kJ/g dry matter, DM) and isolipidic (65 g/kg DM) diets containing different crude protein/total carbohydrate (CHO) ratios: 60/26, 56/30, 52/34 and 48/38, were tested in 22 g Senegalese sole for 104 days. Apparent digestibility coefficients (ADC) were not affected by the treatments, and all groups presented extremely low starch ADC values (22.8%–36.5%). Replacement of dietary protein by CHO did not affect daily growth index (0.9–1.0), but significantly increased voluntary feed intake of fish. Regression analyses demonstrated that digestible protein content, rather than digestible energy, was the main dietary factor influencing such feeding activity (R2 =.952). A significantly increased feed conversion ratio was observed in sole fed increasing CHO contents. The dietary protein/CHO ratio did not influence whole-body composition. Sole fed the 48/38 diet showed the lowest efficiency in terms of N and energy utilization. PUFA were the most represented fatty acid fraction in fillet, regardless of the dietary protein/CHO ratio, mainly due to the high content of DHA. Senegalese sole increase feed intake under low dietary protein/CHO ratios to ensure an adequate N intake. Such compensatory mechanism seems to be triggered to satisfy a specific protein metabolic requirement for energy purposes as tissue accretion remained unchanged. © 2017 John Wiley & SonsThis work was partially supported by NORTE-07-0124-FEDER-000038, comprised in the North Region Operational Programme (ON.2?O Novo Norte), under the project Sustainable Aquaculture and Animal Welfare (AQUAIMPROV) directed by L.M.P. Valente, and from Ministerio de Econom?a y Competitividad and European Fund for Regional Development (AGL2013-46448-3-1-R and FEDER) to J.L. Soengas. Dr. Salas-Leit?n was partially sponsored by Andalusian Operational Program-European Social Fund (2007?2013), Axis III. Individual grants to M. Conde-Sieira (SFRH/BPD/84251/2012) and M.R.G. Maia (SFRH/BPD/70176/2010) from FCT, Portugal, are gratefully acknowledged. There are no conflicts of interest in connection with the present study

Influence of fish oil in the concentration of conjugated linoleic acid and omega 6 and 3 in buffalo milk

The aim of this research work was to investigate the influence of fish oil supplementation on the concentration of conjugated linoleic acid (CLA) and omega 6 and 3 in samples of buffalo milk. A total of 24 female buffaloes separated at random into three groups were fed for 49 days with: natural pasture (group I), supplemented with 70mL of fish oil (group II) and 140mL of fish oil (group III). In the experiment the concentration of CLA showed differences (P<0.05) among the three groups, with a maximum of 7.14mg/g fat in group II. No significant differences were found in omega-6 among the three groups. The highest value of 3.82mg/g fat corresponded to group I, whicht had not been supplemented with fish oil. Significant differences were observed in omega 3 (P<0.05) in groups II and III with respect to group I. The highest average value of 2.42mg/g fat was obtained in group III. The closest relationship omega 6/3 (1.37:1) was observed in group III. As a result, the diets of groups II and III, which included fish oil, increased significantly the content of CLA and omega 3 with reductions in levels of omega 6