Endokrini i metabolički profil junica holštajna i crvenog holštajna u peripartalnom periodu

The aim of this stady was to examine the relationship between triiodothyronine (T3), thyroxin (T4), insulin-like growth factor-I (IGF-I) and blood serum liver function biomarkers concentrations in Holstein and Red Holstein heifers during the peripartal period. In the first experimental group (I) were heifers of Holstein Friesian breed (n=10), and in the second experimental group (II) were Red Holstein heifers (n=10). Blood samples were taken from the vena coccygea three times during the short peripartal period (5 days before delivery, at delivery and 5 days after delivery), and blood serum samples were separated after spontaneous coagulation. Blood serum T3, T4 and IGF-I concentrations were determinated using radioimmunoassay (RIA). Blood serum concentrations of glucose (G), total protein (TP), albumin, (Alb), urea, total bilirubin (tBil) and aspartate aminotrasferase (AST) were determined using commercial ELISA kits. The statistical significance between means was determined using Student t-test. Blood serum T3 concentration in Group II was significantly lower after delivery, and T4 concentration was significantly higher before delivery (p lt 0.05), compared to Group I. Mean blood serum IGF-I concentrations between the two experimental groups were not significantly different at all time intervals. Relationships between the determined hormones showed a median positive correlation between T3, and T4 (r=0.74) in Group I and highly positive correlation in Group II (r=0.81). Blood serum thyroid gland hormones and IGF-I concentrations in healthy heifers during peripartal period vary considerably, the lowest values being determined immediately after calving in both experimental groups. Blood serum G, TP, Alb and urea concentrations were significantly higher in Group I at all investigated time intervals. Blood serum tBil concentration was significantly higher after partus in Group I (11.02 ± 3.33 : 8.49 ± 3.35 μmol/L, Group I vs. II, respectively), and AST activity was not significantly different at all intervals.Cilj ovih istraživanja je bio određivanje koncentracije triijodtironina (T3), tiroksina (T4), insulinu sličnog faktora rasta-I (IGF-I) i biomarkera, pokazatelja funkcionalnog stanja jetre u krvnom serumu dva varijeteta junica Holštajn rase u peripartalnom periodu. Prvu eksperimentalnu grupu (I) činile su junice crno belog holštajna (n=10), a drugu grupu (II) junice crvenog holštajna (n=10). Krv za analize je uzimana iz repne vene, tri puta u peripartalnom periodu (5 dana pre partusa, na dan partusa i do 5 dana posle partusa), a krvni serum je odvajan nakon spontane koagulacije. U krvnom serumu je radioimunološkom metodom (RIA, INEPZemun) određivanja koncentracija trijodtironina (T3), tiroksina (T4) i insulinu sličnog faktora rasta-I (IGF-I). Koncentracija glukoze (G), ukupnih proteina (TP), albumina, (Alb), ureje, ukupnog bilirubina (tBil) i aktivnost aspartat aminotrasferaze (AST) je određivana upotrebom komercijalnih ELISA kitova. Statistička značajnost razlika srednjih vrednosti ispitivanih endokrinih i metaboličkih parametara je određena Studentovim t-testom. Dobijeni rezultati ukazuju na vrlo različite koncentracije hormona štitne žlezde u krvnom serumu junica oba varijeteta holštajna pre i posle partusa. Koncentracija T3 je bila statistički značajno niža u grupi II nakon partusa, a T4 značajno viša pre partusa (p lt 0.05) u odnosu na nivo hormona u grupi I. Za prosečne vrednosti koncentracija IGF-I, između isptivanih grupa nije ustanovljena statistički značajna razlike ni u jednom od tri perioda ispitivanja. Utvrđena je srednje pozitivna korelacija između koncentracije T3 i T4 (r=0,74) u krvnom serumu junica grupe I, i vrlo visoka pozitivna korelacija u grupi II (r=0,81). Koncentracija TP, Alb i ureje bila je statistički značajno viša kod junica grupe I u sva tri perioda ispitivanja. Nivo tBil u krvnom serumu je takođe bio povišen kod junica grupe I u sva tri perioda ispitivanja, ali su statistički značajne razlike između srednjih vrednosti ustanovljene samo u periodu nakon partusa. Aktivnost AST u krvnom serumu junica oba varijeteta značajno je varirala u svim periodima ispitivanja i nisu ustanovljene statistički značajne razlike između srednjih vrednosti

Određivanje organskih sastojaka mleka kao metoda ocene energetskog statusa mlečnih krava

The objective of the investigations described in this work was to determine the energy status and to make recommendations for correcting the cow diet at a farm of high-yield dairy cows, on the grounds of values for the concentration of organic components of milk and their ratios in individual milk samples. A total of 147 cows were examined, including 97 in the first and 50 in the second lactation. Average concentrations of milk fat and urea were within the physiological values. Namely, the milk fat concentration in cows in the first lactation was 38.88±5.07 g/l, and it was 36.47±4.82 g/l in cows in the second lactation, while the urea concentration in cows in the first lactation 3.16±0.58 mmol/l and it was 3.72±0.64 mmol/l in cows in the second lactation. The protein concentration in both groups of cows was below the physiological values, being 30.33±2.35 g/l in cows in the first lactation and 30.17±2.27 g/l in cows in the second lactation. Based on the ratio of urea and protein concentrations, as well as of fat and proteins in the individual milk samples, it was concluded that in most examined cows, both in those in the first and those in the second lactation, there is a deficit of energy, along with a deficit or relative surplus of proteins. On the grounds of the obtained results, recommendations were given for correcting the feed rations in the coming period. .Cilj istraživanja u ovom radu je bio da se na farmi visokomlečnih krava, na osnovu vrednosti za koncentraciju organskih sastojaka mleka i njihovog odnosa u pojedinačnim uzorcima mleka, utvrdi energetski status i daju preporuke za korekciju ishrane krava. Ukupno je ispitano 147 krava, od kojih je 97 bilo u prvoj, a 50 u drugoj laktaciji. Prosečne koncentracije mlečne masti i ureje bile su unutar fizioloških vrednosti. Naime, koncentracija mlečne masti kod krava u prvoj laktaciji bila je 38,88±5,07 g/l, a kod krava u drugoj laktaciji 36,47±4,82 g/l. Koncentracija ureje kod krava u prvoj laktaciji bila je 3,16±0,58 mmol/l, a kod krava u drugoj laktaciji 3,72±0,64 mmol/l. Koncentracija proteina kod obe grupe krava je bila ispod fiziološke vrednosti, jer je kod krava koje su bile u prvoj laktaciji bila 30,33±2,35 g/l, a kod krava koje su bile u drugoj laktaciji 30,17±2,27 g/l. Na osnovu odnosa koncentracija ureje i proteina, kao i masti i proteina u pojedinačnim uzorcima mleka zaključeno je da kod većine ispitanih krava, kako onih koje su bile u prvoj tako i onih u drugoj laktaciji, postoji deficit energije, uz deficit ili relativni suficit proteina. Na osnovu dobijenih rezultata date su preporuke za korekciju obroka u narednom periodu.

Influence of housing conditions, number of farrowing and number of pigs in litter on weight loss in sows during lactation

The objective of this work was to investigate the influence of housing conditions, number of farrowing and number of pigs in litter on weight loss in sows during lactation. The experiment included 60 sows, half breed developed by cross breeding of Big Yorkshire and Swedish Landrace in lactation. Body weight of the sows (kg) was determined 2nd, 7th, 14th, 21st and 28th day after farrowing. On the basis of the obtained values, there was calculated the difference in body weight between two consecutive investigation periods. The sows were divided into two groups and held in different housing conditions: 30 of them were held in extensive, and other 30 sows in intensive way of farming. In regard to number of farrowing, the sows were divided into three groups: sows with one or two farrowing (group P1, n=20), with three or four farrowing (group P2, n=20), and sows that farrowed five or more times (P3,n=20). In regard to number of pigs in litter, the sows were divided into two groups: the first (Group I, n=30) with sows that had up to eight pigs, and the second (Group II, n=30) with sows that had nine or more pigs in litter. The obtained results showed that in all perids of the investigation during lactation, body weight in sows held in extensive farming conditions was statistically significantly higher compared to those from intensive farming conditions. On the other hand, the loss of body weight during lactation was significantly higher in sows from extensive in regard to intensive farming conditions in the first two weeks of lactation. The sows with bigger number of farrowing had greater body weight, compared to those with smaller number of farrowing. There was no statistically significant difference in body weight loss during lactation, between sows with different number of farrowing, but considering that the sows with less farrowings had significantly lower body weight, they consequently lost more weight in percentage. The sows with greater number of pigs had significantly smaller body weight in the end of lactation, that is on 21st and 28th day of lactation. The results of this investigation point out to the fact that mainly housing conditions, that is nutrition influence body weight loss, and after that comes the number of pigs in litter