38 research outputs found
Effect of Insulin, Epinephrine, Hydrocortisone and ACTH on the Catheptic Activity of Rat Spleen
In our experiments under in vivo conditions we followed Ā·the
response of spleen on injected insulin, epinephrine, hydrocortisone
and ACTH.
Insulin caused a decrease in spleen weight, a decrease of
protein nitrogen and an increase of catheptic activity 30 min. after
application. Afterwards catheptic activity was significantly above
control value in 60 min. (expressed in E. U./g. tissue) althoughĀ·
decreasing tendency was observed. 30 and 60 min. after epinephrine
application spleen weight and protein nitrogen were increased
whereas catheptic activity remained under the control value (expressed
in E. U./mg.N). After 3 hrs the spleen weight was reduced
(reduced protein nitrogen) whereas catheptic activity was significantly
increased, specially if expressed in E. U./g. tissue. Hydrocortisone
caused a decrease in spleen weight and protein nitrogen.
Catheptic activity was significantly above control value 30 min.
and 3 hrs after application, if expressed in enzyme unit per gram
tissue. Two hours after ACTH administration protein nitrogen was
increased, whereas catheptic activity was under the control value
(expressed in E. U.jmg. N)
SURPLUS OF CRUDE PROTEIN IN RATIONS FOR RUMINANTS PRESSING ON METABOLISM OF ANIMALS AND ENVIRONMENT
THE IMPORTANCE OF THE STANDARD SAMPLE FOR ACCURATE ESTIMATION OF THE CONCENTRATION OF NET ENERGY FOR LACTATION IN FEEDS ON THE BASIS OF GAS PRODUCED DURING THE INCUBATION OF SAMPLES WITH RUMEN LIQUOR
Namen tega dela je bil preveriti, ali je uporaba standardnega vzorca pri izvajanju Hohenheimskega plinskega preizkusa sploh potrebna. V obdobju treh let smo inkubirali z vampnim sokom in vitro 24 serij vzorcev voluminozne krme. Poleg vzorcev krme smo v poskus vkljuÄili tudi standardni vzorec sena, ki so nam ga poslali z univerze v Hohenheimu (HFT-99). Polovico serij smo inkubirali z vampnim sokom krav, polovico z vampnih sokom ovc. Merili smo koliÄino plina, ki se razvije med 24 urno inkubacijo in jo primerjali z
deklarirano vrednostjo vzorca HFT-99. Poleg HFT-99 smo v poskus vkljuÄili tudi 25 preizkusnih vzorcev krme z znanimi in vivo doloÄenimi prebavljivostnimi koeficienti. Na podlagi tvorbe plina pri HFT-99 smo ugotovili, da vrsta živali (govedo ali ovce) ni vplivala na aktivnost vampnega soka (41,4 vs. 42,2 ml plina na 200 mg suÅ”ine, p>0,1). Tudi razlike med leti niso bile znaÄilne (41,9, 41,2 in 42,3 ml plina na 200 mg suÅ”ine, p>0,1). Variabilnost med serijami je bila približno 10%, od 38,9 do 43,7 ml plina na 200 mg suÅ”ine). Tvorba
plina pri HFT-99 je bila v tem poskusu približno 6 % manjÅ”a od vrednosti, ki so jo dobili na Univerzi Hohenheim (41,8 vs. 44,43 ml na 200 mg suÅ”ine). To nakazuje, da obstajajo sistematiÄna odstopanja med laboratoriji. V primeru petindvajsetih preizkusnih vzorcev je korekcija na podlagi standardnega vzorca zmanjÅ”ala povpreÄno razliko in vitro ocenjenih vsebnosti neto energije za laktacijo (NEL) od in vivo doloÄenih vrednosti. Sklepamo, da je glede na variabilnost med serijami in glede na sistematiÄne razlike v aktivnosti vampnega soka med laboratorijema, uporaba standardnega vzorca pri izvajanju Hohenheimskega plinskega preizkusa nujna.The aim of this work was to examine the necessity of using the standard sample at the Hohenheim gas test. During a three year period, 24 runs of forage samples were incubated with rumen liquor in vitro. Beside the forage samples also the standard hay sample provided by the Hohenheim University (HFT-99) was included in the experiment. Half of the runs were incubated with rumen liquor of cattle and half with the rumen liquor of sheep. Gas produced during the 24 h incubation of standard sample was measured and compared to a declared value of sample HFT-99. Beside HFT-99, 25 test samples with known digestibility coefficients determined in vivo were included in the experiment. Based on the gas production of HFT-99, it was found that donor animal (cattle or sheep) did not significantly affect the activity of rumen liquor (41.4 vs. 42.2 ml of gas per 200 mg dry matter, P>0.1). Neither differences between years (41.9, 41.2 and 42.3 ml of gas per 200 mg dry matter, P>0.1) were significant. However, a variability of about 10% (from 38.9 to 43.7 ml of gas per 200 mg dry matter) was observed between runs. In the present experiment, the gas production in HFT-99 was about 6%
lower than the value obtained by the Hohenheim University (41.8 vs. 44.43 ml per 200 mg dry matter). This indicates a systematic error between the laboratories. In the case of twenty-five test samples, correction on the basis of the standard sample reduced the average difference of the in vitro estimates of net energy for lactation (NEL) from the in vivo determined values. It was concluded that, due to variation between runs and systematical differences in rumen liquor activity between two laboratories, the results of Hohenheim gas test
have to be corrected on the basis of standard sample
THE EFFECT OF NITROGEN FERTILIZATION OF MAIZE ON PROTEIN CONCENTRATION AND IN VITRO FEMENTABILITY OF GRAIN
Z in vitro metodo, ki temelji na merjenju plina, ki se razvije pri inkubaciji vzorcev z vampnim sokom, smo preuÄevali vpliv gnojenja koruze z duÅ”ikom na fermentabilnost koruznega zrnja v vampu. Nastajanje plina smo merili kontinuirano do 72 ur, kumulativno nastajanje plina pa opisali z Gompertzovo enaÄbo Y=A*exp(- exp(-d*(t-tm))). Primerjali smo sedem postopkov, od katerih je bil eden negnojen, ostali pa gnojeni s 100 do 250 kg N haā1. Pridelek zrnja in vsebnost surovih beljakovin (SB) v njem, sta se z gnojenjem poveÄevala linearno. Na kg dodanega N se je pridelek zrnja poveÄal za 25 kg suÅ”ine (SS) haā1, vsebnost SB pa za 0,13 g kgā1 SS. Vsebnost SB v zrnju, ki se je gibala od 83 do 115 g kgā1 SS, je bila v tesni povezavi z dinamiko nastajanja plina. NajveÄja stopnja nastajanja plina (MPR) je bila v negativni povezavi z vsebnostjo SB v zrnju (R2 = 0,53; p < 0,06), Äas MPR (tm) pa v pozitivni povezavi s skupno koliÄino dodanega N z gnojenjem (R2 = 0,74; p < 0,05) in z vsebnostjo SB v zrnju (R2 = 0,88; p < 0,01). Izgleda, da intenzivno gnojenje koruze z N omejuje vampno prebavljivost koruznega Å”kroba. Zaradi premestitve prebave Å”kroba iz vampa v nižji del
prebavnega trakta lahko priÄakujemo pri koruznem zrnju intenzivno gnojene koruze boljÅ”e izkoriÅ”Äanje energije kot pri zrnju koruze, ki je pomanjkljivo oskrbljena z N.The effect of nitrogen fertilization of maize on fermentability of maize grain in the rumen was studied by means of in vitro method based on the measurement of gas produced during the incubation of samples with rumen liquor. Gas production was recorded continuously up to 72 h incubation time and cumulative gas
production was described by the Gompertz equation Y=A*exp(-exp(-d*(t-tm))). Seven treatments, one of them unfertilized and others fertilized with 100 to 250 kg N haā1, were compared. Grain yield and concentration of crude protein (CP) in grain increased linearly with nitrogen fertilization. Grain yield increased for 25 kg dry matter (DM) haā1 and CP concentration for 0.13 g kgā1 DM per each additional kg of N. Concentration of CP in grain, which varied from 83 to 115 g kgā1 DM, was closely related to the dynamics of gas production. The
maximal gas production rate (MPR) was negatively related to CP concentration in the grain (R2 = 0.53; p < 0.10) and the time of MPR (tm) was positively related to the amount of added N (R2 = 0.74; p < 0.05) and concentration of CP in the grain (R2 = 0.88; p < 0.01). It is likely that intensive N fertilization of maize limits ruminal digestion of maize starch. Due to the shift of starch digestion from the rumen to lower gastrointestinal tract better utilization of energy can be expected in maize grain of extensively fertilized maize than in the grain of maize, in which supply of N is sub-optimal