He aha te DCAD?

Ko te DCAD (Dietary Cation-Anion Difference) he taupū e ine ana i te rerekētanga utu kupenga i waenga i ngā cation me ngā anion kai matua, e whakaatuhia ana i roto i ngā milliequivalents mō ia kirokaramu o te mea maroke (mEq/kg DM). Engari i te ine i tētahi matūkai kotahi, ka whakaata te DCAD i te pānga kupenga o te kai ki te toenga waikawa-pūtake o te kararehe i muri i te nakunaku me te mimiti, ka waiho hei taputapu nui mō te aromatawai me te whakahaere i te kai o ngā kararehe ruminantia.

E rua ngā tātai e whakamahia whānuitia ana hei tatau i te DCAD:

Ngāwari (tino noa): DCAD = (Na⁺ + K⁺) − (Cl⁻ + S²⁻)

Whānui (tae atu ki te Ca, Mg, P): DCAD = (Na⁺ + K⁺ + Ca²⁺ + Mg²⁺) − (Cl⁻ + S²⁻ + P)

I roto i te mahi, ko te konutai, te pāhare pākawa, te pūhaumāota, me te whanariki te nuinga, nō reira ko te tātai māmā te mea e whakamahia whānuitia ana. Ka hurihia ia katote ki ngā milliequivalents (mEq) i mua i te whakakapinga. Ko te whakamaoritanga o ngā hua penei:

Uara pai: he kai kawakore te kai, he pai mō ngā kau e whāngai ana i te u, e pāngia ana rānei e te werawera;

Uara kino: He waikawa te kai, he kai e kaha ana ki te anion, ā, he mea tika mō ngā kau maroke e titiro tata ana hei āwhina i te ārai i te hypocalcemia i muri i te whānautanga.

He aha te hiranga o te DCAD?

Ko te DCAD tētahi o ngā taputapu tino kaha i roto i te whakahaere kai mō ngā kararehe ruminantia, e awe ana i ngā āhuatanga maha o te mahi me te hauora o ngā kararehe:

Taurite waikawa-pūtake:e whakatau ana i te pH o te toto me ngā wai o te tinana, e tautoko ana i ngā pānga ā-tinana katoa o muri mai;
Te kai o te mea maroke (DMI):mā te DCAD tino pai ka whakatairanga i te kai e kainga ana, ā, ka tutuki hoki ngā hiahia pūngao o ngā kau whai hua nui;
Te whakapūkara ruminal:e whakahaere ana i te pumau o te pH o te rumen me te ngāwari o te nakunaku o te muka, e pā ana hoki ki te whakaputanga o te acetate (he matū mua o te ngako miraka);
Te pākia o te konupūmā:ka whakatikatika i te nekehanga konupūmā wheua mā te whakahaere waikawa-pūtake, e hono tata ana ki te hypocalcemia postpartum (kirikā miraka);
Te whānautanga me te hauora:Mā te whakahaere pai o te waikawa-pūtake i te wā e whānau ana ka whakaiti i te maha o ngā mate pāwera me te tautoko i te mahi whakaputa uri i muri mai.

Ko te māramatanga matua: He tino rerekē ngā whakaritenga DCAD i ngā taumata rerekē o te tinana — me whakarite e ngā tohunga kai te kai kia rite ki tēnā.

Ripanga 1. Ngā Whakaritenga me ngā Mahi a te DCAD mā te Wāhanga

Atamira	Whāinga DCAD	Ngā Mahi Matua
Te whāngai ū / Te ahotea wera	+250 ~ +450 mEq/kg DM	Ka whakapūmau i te rumen, ka whakau i te pH; ka whakanui ake i te DMI me te nakunaku muka; ka whakanui ake i te whakaputanga acetate, te nui o te ngako miraka, me te hua miraka
Wā maroke i te wā whānautanga / tirohanga tata	Iti, kino rānei (−50 ~ +100)	Whakaoho i te waikawa pākia ngawari; whakaoho i te nekenekehanga o te konupūmā wheua; ārai i te hypocalcemia postpartum (kirikā miraka); whakapai ake i te kai whāngai i muri i te whānautanga me te tīmatanga o te whāngai ū

Ture matua: TEITEI mō ngā kau e whāngai ana, ITI mō ngā kau e titiro tata ana.

Ngā Tikanga o te Whakahaere DCAD

Ko te whakahaere i te DCAD ka taka ki te whakatikatika i te nui o ngā kationa me ngā anion i roto i te kai: mā te tāpiri i ngā kai whai kationa ka piki ake te uara; mā te tāpiri i ngā kai whai kationa ka whakaiti i tōna uara. Ko ngā mātāpono e whai ake nei hei ārahi i te hanganga:

Whakatairangahia te parakore o ngā kai:ka whakaitihia e ngā pūtake parakore teitei ngā takoha katote kāore i te whakahaerehia mai i ngā poke;
Kia iti te Cl me te S i te wā e whakanui ana i te DCAD:Ko ngā tote pāhare pāporo me te konutai e whakamahia ana hei whakanui i te DCAD me iti noa te hauhāora, te whanariki rānei, ki te kore ka heke iho te uara;
Kia mau ki ngā herenga katoa o te whanariki kai:me taurite ngā tote whanariki e whakamahia ana hei whakaiti i te DCAD ki te horomitanga katoa o te S — ka pehia e te whanariki nui te horomitanga o te kai, ā, ka whakararu i te mimiti o te parahi;
Whakakotahitia ki ngā puna konupūmā tuku iho:Ko ngā tote anionic ka whakamahia tahitia me te kōhatu ā-papa, te dicalcium phosphate rānei, kaua hei whakakapinga katoa.

Ripanga 2. Ngā Ahunga e Rua o te Whakahaere DCAD

Te ahunga	Ngā Kai kua Tāpirihia	Tikanga
Whakaara DCAD	Ngā tote K me te Na (ngā warowaihā, ngā paikāponate)	Waikawa rumen whakapūmau; whakakī anō i ngā irahiko; whakau i te pH rumen; whakanui ake i te hanga acetate; whakanui ake i te pH toto
DCAD iti iho	Ngā tote anionic (ngā whanariki, ngā pūhaumāota)	Whakakawahia te kai; whakaohokia te waikawa pākia ngawari; whakahohehia te nekenekehanga o te konupūmā wheua; hangahia he rahui konupūmā i mua i te whānautanga

Ā Mātou Hua Whakahaere DCAD

E whā ngā kai kohuke parakore-teitei e tukuna ana e mātou e kapi ana i ngā taha e rua o te whakahaere DCAD:

Ripanga 3. Tirohanga Whānui mō te Hua DCAD

Hua	Tātai	Te ahunga	Mahi Matua
Pāhare pākawa waro	K₂CO₃	Whakaara	Pūtake K tino parakore; ārai i te rumen; whakanui i te acetate me te ngako miraka; kai matua hei ārai i te ahotea wera
Paikāponate Konutai (houra tunu)	NaHCO₃	Whakaara	Te pūmau o te rumen me te pūtake Na; ka whakau i te pH o te rumen; ka tiaki i te nakunaku muka
Konupūmā Whero i runga i te koiora	CaSO₄	I raro	Tote anionic Ca + S mahi; kai tata-iti-DCAD; ārai i te kirika miraka
Konupora Whanawha	MgSO₄	I raro	Te tote anionic + te pūtake Mg; ka whakaiti i te DCAD i te wā e whakakī ana i te Mg; ka ārai i te hypomagnesemia

Pāhare pākawa waro (K₂CO₃)

He tino parakore (≥99%), he iti noa te nui o te hauhā me te whanariki — kāore he anion ārai-hua e pehi ana i te DCAD;
Hei pūtake cation kaha, ka whakanuia te DCAD me te pupuri i te rumen, ka whakapai ake i te nakunaku o te muka, ka whakanui ake i te whakaputanga acetate, ka whakanuia ā-kore te ōrau ngako miraka me te hua ngako miraka;
He kai matua i roto i ngā kaupapa kai mō te wera me te ahotea raumati; he mea whakakotahi ki te konutai paikāpōnate me te konupora waikura hei hanga i tētahi pūnaha ārai rumen whānui;
Te tāpiringa e taunakitia ana: 100–250 karamu/upoko/rā mō ngā kau whai hua nui; tae atu ki te 300 karamu/upoko/rā i raro i te ahotea wera nui. Ngā Whāinga: kai K 1.5–1.8% DM; DCAD +300 ki te +450 mEq/kg DM.

Paikāpōnate Konutai / Houra Tunu (NaHCO₃)

He pūtake pūmau o te rumen me te puna konutai e tere ana te whakakore i te waikawa rumen, e tiaki ana i te nakunaku muka me te whakaiti i te mōrearea o te waikawa rumen subacute (SARA);
Ka whai wāhi ki te puna cation, ka tautoko i te pikinga o te DCAD me te taurite whānui o ngā electrolytes;
He pai mō ngā kai tino kukū, mō ngā wā tino pukumahi o te whāngai ū, me ngā wā ahotea wera; he maha ngā wā ka honoa ki te pāhare pākawa waro hei tautoko i te pēpi.

Konupūmā Whanawha (CaSO₄) e ahu mai ana i te koiora

I ahu mai i ngā pūtake koiora; he pumau te waimeha, he tino parakore, he iti hoki ngā taumata poke — he tote anionic mahi-rua e tuku ana i te konupūmā me te whanariki;
I hangaia mō ngā kai iti-DCAD tata: mā te whakakawa i te kai ka whakaoho i te nekenekehanga konupūmā, ka taea ai e ngā kau te hanga kaha whakahaere konupūmā i mua i te whānautanga, ā, ka ārai pai i te hypocalcemia postpartum (kirikā miraka);
I te wā kotahi ka whakarato i te whanariki mō te hanga pūmua moroiti rumen me te whakapūtanga muka; kua whakaatuhia hoki ka whakapai ake i te kounga o te anga hua manu i roto i ngā mahi heihei.

Konupora Whanawha (MgSO₄)

Ka whakakotahi i te tote anionic me te pūtake konupora i roto i te kai kotahi — ka whakaiti i te DCAD me te whakarato whai hua i te konupora kai;
He mea nui te konupūmā mō te mahi uaua-io, ā, he mea tautoko hoki mō ngā pūnaha whākōkī maha; he mea nui rawa atu i roto i ngā kaupapa ārai i te kirika miraka i te wā e whānau ana, me te ārai i te hypomagnesemia (tetany tarutaru);
Me aroturuki te katoa o te whanariki i roto i te kai — tae atu ki ngā takoha mai i ngā pūtake whanariki katoa — ā, me pupuri i te nuinga o te wā ki te 0.4% DM, ki raro iho rānei, kia kore ai e nui rawa te kai, ka pā kino pea ki te mimiti me te whakamahinga o te parahi.

Ngā Pātai Auau

P1: He aha rawa te DCAD? Ka taea e koe te whakamārama mārama?

Ae. He tau noa iho tēnei e whakaatu ana mēnā he nui ake ngā kationa (konutai, pāhare pākawa) he anion rānei (hauora, whanariki) kei roto i tō kai. Ka pāngia te pH toto o te kau e taua tau. Ā, ina heke te pH toto, ka kitea ngā raruraru ki te kai, te nakunaku, te whakaputa miraka, tae atu ki te tūnga o te kau i muri i te whānautanga. Nō reira, he mea nui tēnei.

P2: Me rerekē ngā taumata DCAD mō ngā kau maroke me ngā kau e whāngai ana i te u?

Rerekē rawa atu.

Mō ngā kau miraka (ina koa i te werawera o te raumati), me nui te DCAD – tata ki te +250 ki te +450 mEq/kg DM. Mā tēnā ka pumau te pH o te rumen, ka āwhina i a rātou ki te kai nui ake, ki te nakunaku pai ake te muka, ā, ka whakanui ake i te ngako o te miraka.

Mō ngā kau maroke e tata ana te titiro (he torutoru wiki i mua i te whānautanga), me iti te DCAD, ahakoa he kino. Ka puta he waikawa ngawari ka akiaki i te kau ki te tango i te konupūmā mai i ōna wheua i mua i te wā, kia kore ai ia e pāngia e te kirika miraka i muri i te whānautanga.

Ko te tino take: he teitei mō te whāngai u, he iti mō te whakamaroke – kaua e whakaranua.

Q3: He aha ngā hua DCAD e tukuna ana e SUSTAR?

E whā ā mātou kai kohuke parakore teitei, e kapi ana i ngā taha e rua:

Hei whakaara ake i te DCAD:

Te pāhare pākawa waro (K₂CO₃) me te konutai paikāpōnati (houra tunutunu). He ≥99% te parakore o tā mātou pāhare pākawa waro, ā, kāore rawa he pūhaumāota, he whākawa waro rānei, nō reira e kore e whakakore i te pānga.

Hei whakaiti i te DCAD:

Te konupūmā whanariki (CaSO₄) me te konupūmā whanariki (MgSO₄). He tote anionic ēnei e whakakawa ana i te kai, e whakaoho ana hoki i te nekenekehanga o te konupūmā. Ka whakaratohia hoki e te konupūmā whanariki te konupūmā me te whanariki, ā, ka homai e te konupūmā whanariki he konupūmā tāpiri hei ārai i te mate tarutaru.

He hua paerewa ēnei e whā e whakamahia ana e te nuinga o ngā kamupene whāngai kai matua.

P4: Kia pehea te nui o te pāhare pākawa waro me whāngai e au, ā, he aha te whāinga?

Mō ngā hua nui, whāngaihia kia 100–250 karamu/upoko/rā, ā, kia 300 karamu i raro i te ahotea wera nui. Whai kia 1.5–1.8% te pāhare pākawa o te kai maroke, ā, kia tata ki te +300 ki te +450 te DCAD. He tino parakore te pāhare pākawa waro, nō reira ka whiwhi koe i te pikinga me te kore he pūhaumāota, he whanariki rānei e hiahiatia ana, e tōia ana te uara ki raro – koinei te mea nui.

Q5: He tūpato kei te whakamahia ngā whākawa hei whakaiti i te DCAD?

Āe – kia mau tonu te whānariki katoa o te kai (mai i ngā pūtake whānariki katoa) ki te 0.4% o te mea maroke, ki raro iho rānei. Ki runga ake i tēnā, ka iti ake te kai a ngā kau, ā, ka heke te mimiti o te parahi. Ka memeha haere te konupūmā whānariki koiora, ā, he iti hoki ngā poke, nō reira he māmā ake te whakahaere.

P6: Kei te tuku tohutohu hangahanga koe, kei te hoko noa rānei i ngā rauemi mata?

E rua ā mātou mahi. Ka mahi tahi mātou me ngā tohunga kai o te whare wānanga, ā, ka taea e mātou te āwhina ki ngā tūtohutanga mō te ranunga, te tere tāpiri, me te karo i te whakahē a ngā kohuke.

Kua roa mātou e mahi tahi ana me CP Group, Cargill, DSM, ADM, Nutreco, New Hope, Haid, Tongwei, me te maha atu o ngā kamupene whāngai kai rongonui 100 – nō reira, ko te tautoko hangarau tētahi wāhanga o te kete.