Abstract This research is aimed at determining the impact of supplementing extensively reared lambs with a limited amount of flax seed enriched-concentrate on the fatty acid profile of the lamb meat (omental fat depot). A total of 96 60-day old Pramenka breed lambs (23.85±3.98 kg live body weight; 60±10 days of age; 42 males and 54 females) raised on pasture with their dams were randomly divided in three experimental groups: control (CON) or extensive rearing group, which did not receive any supplementary feed; concentrate (CC) group, receiving 300 g of a conventional commercial concentrate feed per animal daily, and concentrate-flax seed (CC-FS) group, receiving 300 g/day of the concentrate supplemented with 5% of flax seed. After 60 days of experimental period, 10 lambs were selected (5 males and 5 females) from each group and slaughtered. Omental fat samples were taken and analyzed to determine their fatty acid profile. Significant (P>0.05) differences in the fatty acid profile between CON and CC groups were small. However, enrichment of the concentrate with 5% flax seed increased the percentages of PUFA and n-3 PUFA when compared to both CON and CC groups and thus slightly improved the nutritional characteristics of the omental fat. The effect of sex on the fatty acid profile was only observed for C20:4 n-6 and C20:5 n-3 (P < 0.05).

The process of gluconeogenesis in ruminants is under the direct influence of insulin and glucocorticoid hormones. The goal of this study was to determine the effects of added Napropionate on the neuroendocrine regulation of blood glucose in calves at three specific physiological periods: on exclusive milk nutrition; on mixed milk and forage nutrition; and with established ruminant digestion. The influence of Na-propionate on blood glucose, insulin and cortisol concentrations was examined in the same 20 female Holstein calves at different stages of forestomach development (15 days, 2 months, and 4 months of age of calves). Group 1 of calves (n = 10) received Na-propionate intravenously; group 2 (n = 10) received Na-propionate mixed in milk. Blood sampling was performed 1 and 3 h after Na-propionate administration. After i.v. administration of Na-propionate, a significant increase (P < 0.05) in blood glucose concentration was observed 1 h after administration only in calves aged 2 and 4 months; blood insulin concentration was significantly higher (P < 0.01) 1 and 3 h after i.v. administration in 2-month-old calves; and cortisol concentration increased (P < 0.01) 1 h after administration in each selected calf in all testing periods. Orally administered Na-propionate led to a significant increase (P < 0.01) of insulin concentration 1 and 3 h after administration in 15-day-old calves, and 3 h after administration in 2-month-old calves. Based on these results it could be assumed that i.v. and p.o. administration of Na-propionate affects the neuroendocrine regulation of glycaemia in calves of different age. Cattle, Na-propionate, neuroendocrine regulation, gluconeogenesis

Cilj rada bio je da se ustanovi povezanost rezultata higijenskog skora proizvodnog procesa na farmi i parametara kvaliteta sirovog mlijeka (broj somatskih celija i ukupni broj mikroorganizama). Vrijednost higijenskog skora proizvodnog procesa na ukupno 25  ispitanih farmi podijeljenih u tri grupe (grupa A, n=5, velike farme; grupa B, n=10, manje farme, i grupa C, n=10, individualni proizvođaci) ustanovljena je uz pomoc upitnika datog u radu, a vrijednosti broja somatskih celija i ukupnog broja mikroorganizama uz pomoc aparata Fossomatic TM Minor i Bactoscan TM TC50. Prosjecne vrijednosti higijenskog skora bile su najvise na farmama grupe A (88.25±3.68 poena, ocjena vrlo dobar), a najniže na farmama grupe C (55.67±4.94 poena, ocjena ne zadovoljava). Broj somatskih celija bio je statisticki znacajno visi na farmama grupe C u odnosu na grupe A i B (505027±89990 naprema 167728±35780, p<0,05, i 236045±38712,  p<0,01). Ukupan broj mikroorganizama u ispitanim uzorcima mlijeka bio je najvisi na farmama grupe C (207786±74859), a najniži na farmama grupe B (90423±14828). Rezultati ovog istraživanja ukazuju na znacajan uticaj redovnog sprovođenja higijenskih mjera u procesu proizvodnje na parametre higijenske ispravnosti, a time i kvalitet sirovog mlijeka.