Wild salmon should not be threatened by healthy and non-genetically manipulated escapees

Rungruangsak-Torrissen K. Cultured salmon as escapees should never threaten salmon stocks in the wild as long as they are healthy and are not genetically manipulated. By studying a key digestive protease, trypsin, which is sensitive to environmental changes and influences on food utilisation and growth during the whole life cycle of Atlantic salmon, it is indicated that changes in the phenotypic expression of trypsin can be induced by temperature during egg incubation and the start-feeding period of the alevins. In addition, Atlantic salmon with the same trypsin phenotype showed different feed conversion efficiency and growth rate at different temperatures. Trypsin genes seem to be stable, and although the pattern of expressed genes varies extensively, the expression of trypsinogen mRNA is quantitatively similar between individual salmon in line with the observation that the total trypsin specific activity was similar between the fish with different trypsin phenotypes. However the luminal secretion of the active enzyme, and probably the relative amounts of trypsin isozymes, could be modified by water temperature and food quality. These results indicate that changes in the environmental condition can influence gene expressions of the fish at DNA, RNA and protein levels, regardless of genetic expression of parents. This means that whether the escapees or wild fish is the spawning population, an incidence of the offsprings to have their gene expressions adapted to that environment will be similar. It is the environmental condition that has to be conserved in order to control the genetic structure of animals in the wild. It is naive to think that genetically manipulated escapees such as triploid salmon will not have any impact on wild population, as they are not fertile. Under a more favourable condition for growth, triploid escapees could compete with wild fish on food availability as they have higher consumption rates for higher growth rates, unlike ordinary diploid salmon that could have better food utilisation at a similar consumption rate. This may cause a higher survival rate in triploid escapees and if they spawn, hatching success and survival rate of the offsprings will be low due to low gamete quality for reproduction in triploid fish. This could result in a smaller population of the new generation in that environment in the wild.Wild salmon should not be threatened by healthy and non-genetically manipulated escapeesacceptedVersio

Forbedring av avlsstammer for Atlantisk laks ved bruk av gener som koder for trypsin-like isozymer

Sluttrapport NFR/NFFR- nr. 1402 - 701.30

Artificial hatching substrate and different time of transfer to startfeeding: Effect on growth and protease activities of the Atlantic salmon (Salmo salar).

Groups of Atlantic salmon (Salmo salar) eggs were hatched in a Californian hatching system with and without an astro-turf artificial substrate, and food was presented at four different points in development. Dry weight development and protease activities were studied. Irrespective of time of transfer the astro-turf reared fry were bigger than the flat screen reared fry at the termination of the experiment. In respect of growth the first and the fourth transfers were clearly suboptimal for the fry from both systems

Neural computational model GrowthEstimate: A model for studying living resources through digestive efficiency

Neural computational model GrowthEstimate: A model for studying living resources through digestive efficiencyThe neural computational model GrowthEstimate is introduced with focusing on new perspectives for the practical estimation of weight specific growth rate (SGR, % day–1). It is developed using recurrent neural networks of reservoir computing type, for estimating SGR based on the known data of three key biological factors relating to growth. These factors are: (1) weight (g) for specifying the age of the growth stage; (2) digestive efficiency through the pyloric caecal activity ratio of trypsin to chymotrypsin (T/C ratio) for specifying genetic differences in food utilization and growth potential, basically resulting from food consumption under variations in food quality and environmental conditions; and (3) protein growth efficiency through the condition factor (CF, 100 × g cm–3), as higher dietary protein level affecting higher skeletal growth (length) and resulting in lower CF. The computational model was trained using four datasets of different salmonids with size variations. It was evaluated with 15% of each dataset, resulting in an acceptable range of SGR outputs. Additional tests with different species indicated similarity between the estimated SGR outputs and the real SGR values, and the same ranking of wild population growth. The developed model GrowthEstimate is exceptionally useful for the precise and comparable growth estimation of living resources at individual levels, especially in natural ecosystems where the studied individuals, environmental conditions, food availability and consumption rates cannot be controlled. It is a revelation and will help to minimize uncertainty in wild stock assessment process. This will improve our knowledge in nutritional ecology, through the biochemical effects of climate change and environmental impact on the growth performance quality of aquatic living resources in the wild, as well as in aquaculture. The original GrowthEstimate software is available at GitHub repository (https://github.com/RungruangsakTorrissenManoonpong/GrowthEstimate). All other relevant data are within the paper. It will be improved for generality for future use, and required co-operations of the biodata collections of different species from different climate zones. Therefore, a co-operation will be available.publishedVersio

Usporedba razrijeđivača za duboko smrzavanje sjemena nerasta temeljenih na dodatku žutanjka jajeta i sojinog lecitina

This study investigated the effects of using egg yolk and/or lecithin combinations in semen extender on frozen-thawed boar sperm quality. A total of 19 ejaculates from 8 Duroc boars were included. Each ejaculate was aliquoted and cryopreserved in three different extenders containing only egg yolk (20.0%; group I), only lecithin (6.0%; group II) and a combination of egg yolk (10.0%) and lecithin (3.0%) (group III). Frozen-thawed sperm motility, motion characteristics, viability, acrosome integrity, membrane permeability and mitochondrial activity were evaluated using a computer assisted sperm analysis system, SYBR-14/ Ethidiumhomodimer-1, FITC-PNA, sHOST test and JC-1 staining. The frozen-thawed sperm motility in groups I and III did not differ significantly (P>0.05), though the combination of extenders was better than group II (P<0.05). Motion characteristics, including straight-line velocity (VSL), linearity (LIN) and wobble coefficient (WOB), were higher in groups I and III than in group II (P<0.05). Likewise, sperm viability, membrane permeability and mitochondrial activity were higher in groups I and III than in group II (P<0.05). In conclusion, the use of lecithin without egg yolk in cryopreserved boar semen extender impaired frozen- thawed sperm quality. Thus, using either 20.0% egg yolk or a combination of 10.0% egg yolk and 3.0% lecithin is recommended for cryopreserved boar semen extender.U ovom su radu istraživani učinci žutanjka jajeta i/ili lecitina u razjeđivačima sjemena na kakvoću smrznute-odmrznute sperme nerasta. Uključeno je ukupno 19 ejakulata od 8 nerasta pasmine Duroc. Svaki je ejakulat bio raspodijeljen i zamrznut u 3 različita razrijeđivača, koji su sadržavali dodatak žutanjka jajeta (20,0 %) (skupina I), lecitina (6,0 %) (skupina II) i kombinaciju žutanjka jajeta (10,0 %) i lecitin (3,0 %) (skupina III). Nakon odmrzavanja vrednovane su: pokretljivost spermija, karakteristike gibljivosti, vijabilnost, integritet akrosome, permeabilnost membrane spermija i aktivnost mitohondrija pomoću računalno podržanog sustava za analizu sperme (CASA), SYBR-14/ etidiumhomodimer-1, FITC-PNA, JC-1 bojenja i HOS testa. Po odmrzavanju, pokretljivost spermija u skupinama I i III nisu se značajno razlikovale (P>0,05), ali su oba razrijeđivača bili bolji od skupine II (P<0,05). Karakteristike gibljivosti, uključujući pravocrtnu brzinu (VSL), linearnost (LIN) i koeficijent kolebljivosti (WOB), bili su viši u skupinama I i III u odnosu na skupinu II (P<0,05). Isto tako, vijabilnost spermija, permeabilnost membrane i aktivnost mitohondrija bili su viši u skupinama I i III u odnosu na skupinu II (P<0,05). Zaključno, uporaba lecitina bez žutanjka jajeta u razrjeđivaču za krioprezervaciju sjemena nerasta pogoršala je kvalitete zamrznuto-odmrznutog sjemena. Stoga se preporučuje uporaba 20,0 % žutanjka jajeta ili kombinacije 10,0 % žutanjka jajeta i 3,0 % lecitina kao dodataka razrijeđivaču za duboko smrzavanje sjemena nerasta

Causes of variation in carcass traits of Atlantic salmon (Salmo salar)

The aim of the present study was to reveal causes of variation in carcass traits of farmed Atlantic salmon (Salmo salar). During slaughtering of one year class Atlantic salmon, composed of half sib and full sib groups, samples for determination of carotenoid levels in flesh and ovaries were collected. Also the hepatosomatic and viscerosomatic indexes as well as relative visceral fat content were determined. As expected it was found that these traits were influenced by several factors. The material is too limited for firm conclusions, but evidently the carotenoid level depends largely on stage of maturity and possibly also on genetic factors. Genetic factors seem to influence the visceral fat content. In hepatosomatic and visceral indexes, and possibly in visceral fat content, a strange and still unexplained interaction between sex and stage of maturation was observed

Komparativna studija dviju različitih metoda određivanja integriteta akrosome smrznute pa odmrznute sperme nerasta: bojanje s FITC-PNA/EthD-1 u usporedbi s bojanjem Coomassie plavom

Coomassie blue staining has been reported as an effective and inexpensive method for evaluating the acrosome integrity of spermatozoa, though to date its use to evaluate cryopreserved boar sperm has not been reported. Moreover, there is no information concerning the agreement between Coomassie blue staining and fluorescein isothiocyanate conjugated peanut agglutinin and ethidium homodimer (FITC-PNA/EthD-1) methods for assessing sperm acrosome integrity for any species. The current study was performed to determine the efficacy and agreement between Coomassie blue and FITC-PNA/EthD-1 staining methods for evaluating the acrosome integrity of frozen-thawed boar sperm. A total of 25 semen samples were cryopreserved using lactose-egg yolk-based extender and loaded into 0.5 PVC-French straws. Sperm motility and motion characteristics were determined using a computer-assisted sperm analysis system. Sperm viability and plasma membrane integrity were evaluated using the SYBR-14/EthD-1 and hypo-osmotic swelling test, respectively. Acrosome integrity of frozen-thawed boar sperm was evaluated using both FITC-PNA/EthD-1 and Coomassie blue staining to assess the association between sperm acrosome integrity and agreement between these two methods. The average percent acrosome integrity of frozen-thawed boar sperm as determined by FITC-PNA/ EthD-1 and Coomassie blue staining was 48.8 ± 12.6% and 52.6 ± 13.6%, respectively (P>0.05). Interestingly, Coomassie blue staining found a correlation between sperm viability and acrosome integrity (r=0.609, P=0.002), while FITC-PNA/EthD-1 staining did not (P>0.05). However, the acrosome integrity of frozen-thawed boar sperm evaluated by FITC-PNA/ EthD-1 and Coomassie blue staining was significantly correlated (r=0.448, P=0.025, n=25). The Bland-Altman plot determined that this agreement was acceptable. In conclusion, the acrosome integrity of the frozen-thawed boar sperm assessed via Coomassie blue staining was significantly correlated with that obtained via the FITC-PNA/EthD-1 staining method, and the two methods showed good agreement. Moreover, the significant association between the acrosome integrity of frozen-thawed boar sperm determined by Coomassie blue staining with other sperm quality parameters indicates that this is an effective method for assessing the acrosome integrity of frozen-thawed sperm in pigs.Postoje izvješća da je bojanje Coomassie plavom učinkovita i jeftina metoda procjene integriteta akrosome spermija. Međutim, ne postoje izvješća o bojanju Coomassie plavom za procjenu integriteta akrosome krioprezervirane sperme nerasta. Nadalje, informacije u svezi podudarnosti između bojanja Coomassie plavom i fluorescein izotiocijanatom konjugiranim s aglutininom kikirikija i etidij homodimerom (FITC-PNA/ EthD-1) za procjenu integriteta akrosome spermija nisu dostupne niti za jednu vrstu. Stoga je ova studija provedena za određivanje učinkovitosti i podudarnosti između metoda bojanja Coomassie plavom i bojanja FITC-PNA/EthD-1 za procjenu integriteta akrosome smrznute pa odmrznute sperme nerasta. U eksperiment je uključeno ukupno 25 uzoraka sjemena. Sjeme je krioprezervirano uporabom razrjeđivača na bazi laktoze i žumanjka i pohranjeno u 0,5 PVC-pajete. Svojstva pokretljivosti i gibanja spermija ustvrđena su uporabom sustava za računalno potpomognutu analizu spermija. Vijabilnost spermija i integritet njihove stanične membrane procijenjeni su uporabom SYBR-14/EthD-1, odnosno hipoosmotskim testom bubrenja. Integritet akrosome smrtznute pa odmrznute sperme nerasta procijenjen je uporabom bojanja FITC-PNA/EthD-1 i Coomassie plavom. Procijenjena je povezanost između integriteta akrosome sperme ustvrđene pomoću bojanja FITC-PNA/EthD-1 i Coomassie plavom te podudarnost između dviju metoda mjerenja. Prosječni postotak integriteta akrosome smrznute pa odmrznute sperme nerasta ustvrđene bojanjem FITC-PNA/EthD-1 i Coomassie plavom bio je 48,8 ± 12,6 %, odnosno 52,6 ± 13,6% (P>0,05). Zanimljivo, vijabilnost spermija korelirala je s integritetom akrosome procijenjenom uporabom Coomassie plavom (r=0,609, P=0,002), ali nije korelirala kada je procjenjivana uporabom FITC-PNA/EthD-1 bojanja (P>0,05). Međutim, integritet akrosome smrznute pa odmrznute sperme nerasta procijenjen bojanjem FITC-PNA/EthD-1 i Coomassie plavom značajno je korelirao (r=0,448, P=0,025, n=25). Uz to, podudarnost između bojanja Coomassie plavom i FITC-PNA za procjenu integriteta akrosome smrznute pa odmrznute sperme nerasta ustvrđena Bland- Altmanovim grafikonom bila je prihvatljiva. Zaključno, integritet akrosome smrznute pa odmrznute sperme nerasta procijenjena bojanjem Coomassie plavom značajno je korelirao s onim dobivenim FITC-PNA/EthD- 1 metodom bojanja te su te dvije metode pokazale dobru podudarnost. Uz to, značajna povezanost između integriteta akrosoma smrznute pa odmrznute sperme nerasta koja je ustvrđena bojanjem Coomassie plavom i drugih parametara kakvoće sperme ukazuju na to da je bojanje Coomassie plavom učinkovita metoda procjene integriteta akrosome smrznute pa odmrznute sperme u svinja

Different expressions of trypsin and chymotrypsin in relation to growth in Atlantic salmon (Salmo salar L.)

The expressions of trypsin and chymotrypsin in the pyloric caeca of Atlantic salmon (Salmo salar L.) were studied in three experiments. Two internal (trypsin phenotypes, life stages) and three common external factors (starvation, feeding, temperatures) influencing growth rates were varied. Growth was stimulated by increased temperature and higher feeding rate, and it was depressed during starvation. The interaction between trypsin phenotype and start-feeding temperature affected specific activity of trypsin, but not of chymotrypsin. Trypsin specific activity and the activity ratio of trypsin to chymotrypsin (T/C ratio) increased when growth was promoted. Chymotrypsin specific activity, on the other hand, increased when there was a reduction in growth rate whereas fish with higher growth had higher chymotrypsin specific activity resulting in lower T/C ratio value. During a rapid growth phase, trypsin specific activity did not correlate with chymotrypsin specific activity. On the other hand, a relationship between specific activities of trypsin and chymotrypsin could be observed when growth declined, such as during food deprivation. Trypsin is the sensitive key protease under conditions favouring growth and genetically and environmentally affected, while chymotrypsin plays a major role when growth is limited or depressed. Trypsin specific activity and the T/C ratio value are shown to be important factors in the digestion process affecting growth rate, and could be applicable as indicators for growth studies of fish in captive cultures and in the wild, especially when food consumption rate cannot be measured