Potassium diformate(PDF) he tote honohono kua whakamahia hei tāpiringa whāngai kore-paturopi hei whakatairanga i te tipu o ngā kararehe. Heoi, he iti noa ngā rangahau kua tuhia mō ngā momo ika wai, ā, he rerekē tōna whai huatanga.

I whakaatuhia i roto i tētahi rangahau o mua mō te hāmana o te Ataratiki, ko ngā kai kei roto te paraoa ika i tukinotia ki te 1.4v PDF i whakapai ake i te whai huatanga o te whāngai me te tere tipu. I whakaatuhia hoki e ngā hua i ahu mai i te tipu o te tilapia ranu ko te tāpiri o te 0.2 ōrau PDF ki ngā kai whakamātautau i tino whakanui ake i te tipu me te whai huatanga o te whāngai, ā, i whakaitihia hoki ngā mate kitakita.

He rerekē, i whakaatuhia i roto i tētahi rangahau mō ngā tilapia ranu taitamariki, ko te tāpiritanga o te PDF tae atu ki te 1.2 ōrau o te kai kāore i whakaatu i te whakapainga o te mahi tipu, ahakoa te pehi nui i ngā huakita o te puku. I runga i te iti o ngā mōhiohio e wātea ana, ko te whai huatanga o te PDF ki te mahi ika te āhua nei he rerekē i runga i te momo, te wāhanga ora, ngā taumata tāpiritanga o te PDF, te hanganga whakamātautau me ngā āhuatanga whakatipu.

Hoahoa whakamātautau

i whakahaerehia he whakamātautau tipu i te Oceanic Institute i Hawai'i, USA, hei aromatawai i te pānga o te PDF ki te tipu me te ngāwari o te nakunaku o te pāpaka mā o te Moana-nui-a-Kiwa i whakatipuria i roto i te pūnaha wai mārama. I tautokona tēnei e te US Department of Agricultural Research Service, ā, mā te whakaaetanga mahi tahi me te Whare Wānanga o Alaska Fairbanks.

Kōura mā o te Moana-nui-a-Kiwa taitamariki (Litopenaeus vannamei) i whakatōkia ki roto i tētahi pūnaha wai ma e rere ana i roto i te whare, he 31 ppt te tote me te pāmahana 25 nekehanga-C. E ono ngā kai whakamātautau i whāngaihia ki a rātou, he 35 ōrau te pūmua me te 6 ōrau te ngako kei roto te PDF, he 0, 0.3, 0.6, 1.2, 1.5 ōrau rānei.

Mō ia 100 karamu, i hangaia te kai taketake kia 30.0 karamu te paraoa pīni soya, 15.0 karamu te paraoa pollock, 6.0 karamu te paraoa wheke, 2.0 karamu te hinu menhaden, 2.0 karamu te lecithin pīni soya, 33.8 karamu te witi katoa, 1.0 karamu te waikura chromium me te 11.2 karamu ētahi atu kai (tae atu ki ngā kohuke me ngā huaora). Mō ia kai, e whā ngā ipu 52-rita i whakakīia ki te 12 kōura/puna. Me te taumaha tinana tuatahi 0.84-karamu, i whāngaihia ngā kōura ki te ringa e whā ngā wā i te rā kia mākona ai mō ngā wiki e waru.

Mō te whakamātautau nakunaku, i whakatōkia he 120 ngā kōura, he 9 ki te 10 karamu te taumaha o te tinana, ki roto i ia ipu 18, 550-rita me ia ipu e toru/matūkai kai. I whakamahia te chromium oxide hei tohu ā-roto mō te ine i te tauwehenga nakunaku kitea.

Ngā Hua

Ko te pikinga taumaha o te kōura i ia wiki i waenga i te 0.6 ki te 0.8 karamu, ā, i te nuinga o te wā ka piki ake i roto i ngā maimoatanga me ngā kai PDF 1.2 me te 1.5 ōrau, engari kāore i tino rerekē (P > 0.05) i waenga i ngā maimoatanga kai. Ko te oranga o te kōura he 97 ōrau, neke atu rānei i roto i te whakamātautau tipu.

He rite tonu ngā ōwehenga whāngai-huringa (FCR) mō ngā kai he 0.3 me te 0.6 ōrau PDF, ā, he iti iho i te FCR mō te kai 1.2 ōrau PDF (P < 0.05). Heoi, he rite tonu ngā FCR mō te kai mana, 1.2 me te 1.5 ōrau PDF (P > 0.05).

Ko te pāpaka i whāngaihia ki te kai 1.2 ōrau he iti ake te nakunaku (P < 0.05) mō te mea maroke, te pūmua me te pūngao katoa i te pāpaka i whāngaihia ki ngā kai kē atu (Pikitia 2). Heoi, kāore i pāngia te nakunaku o ngā ngako kai (P > 0.05) e ngā taumata PDF.

Ngā Tirohanga

I whakaatuhia e tēnei rangahau kāore te tāpiringa o te PDF tae atu ki te 1.5 ōrau i roto i te kai i pā ki te tipu me te oranga o te kōura i whakatipuria i roto i te pūnaha wai mārama. He rite tēnei kitenga ki tētahi kitenga o mua me ngā tilapia taitamariki ranu, engari he rerekē i ngā hua i kitea i roto i te rangahau me te hāmana o te Moana Ataratiki me ngā tilapia ranu i tipu mai i te tipu.

I roto i tēnei rangahau, i whakaatuhia te whakawhirinakitanga o te horopeta ki ngā pānga o te PDF kai ki te FCR me te ngāwari o te nakunaku. Tērā pea ko te FCR teitei o te kai PDF 1.2 ōrau i ahu mai i te iti o te ngāwari o te nakunaku o te pūmua, te mea maroke me te pūngao katoa mō te kai. He iti noa ngā mōhiohio e pā ana ki ngā pānga o te PDF ki te ngāwari o te nakunaku o ngā matūkai i roto i ngā momo wai.

He rerekē ngā hua o tēnei rangahau i ērā o tētahi pūrongo o mua i kī ai ko te tāpiri o te PDF ki te paraoa ika i te wā rokiroki i mua i te tukatuka whāngai i whakapiki ake i te nakunaku o te pūmua. Ko ngā rerekētanga o te whai huatanga o te PDF kai i kitea i roto i ngā rangahau o nāianei me ngā rangahau o mua, tērā pea nā ngā āhuatanga rerekē, pērā i te whakamātautau momo, te pūnaha whakatipu, te hanganga kai, me ētahi atu āhuatanga whakamātautau rānei. Kāore i te mārama te take tuturu mō tēnei rerekētanga, ā, me rangahau anō.