ABSTRACT. Eleven late-pregnant Jersey cows were assigned to two groups; a group (PO-RBVD group) consisting of five cows treated with an oral administration of 10 million I.U. of an encapsulated form of vitamin D 3 ("rumen-bypass" VD3; RBVD3) and another group (IMVD group) consisting of the other six treated with an intramuscular injection of 10 million I.U. of vitamin D 3 (VD3). The cows received the RBVD 3 or VD3 administration at 7 days before the expected parturition. The changes in the plasma concentrations of vitamin D metabolites, ionized Ca (Ca ++ ) and inorganic phosphorus (iP) were evaluated. Of the vitamin D metabolites, the plasma 25-hydroxyvitamin D concentrations in PO-RBVD group increased significantly after the RBVD 3 administration and remained in high levels that were significantly higher than those in IMVD group. This suggested that RBVD 3 was absorbed rapidly and excellently from the post-ruminal digestive tract without the degradation by ruminal microorganisms. The plasma Ca ++ and iP concentrations in PO-RBVD group tended to be higher after the administration and around parturition than those in IMVD group. From these observations, it was suggested the oral RBVD 3 administration had more potent ability to prevent parturient paresis compared with the VD3 injection used widely in Japan.-KEY WORDS: calcium, cattle, parturition, "rumen-bypass", vitamin D3.J. Vet. Med. Sci. 62(4): 403-408, 2000 continuous feeding of extremely massive doses of VD is needed for maximum protection against milk fever [10]. Several studies have reported that dietary proteins, amino acids and vitamin AD3E premix encapsulated by hydrogenated oil or polymer can bypass the rumen with minimization of the ruminal degradation in cows [1,15,16,23]. Therefore, we suspect that VD in a form that prevents the degradation by ruminal microorganisms will bypass the rumen and provide the prophylactic effect against parturient paresis. In the present study, cows received a single oral administration of an encapsulated form of VD3 ("rumenbypass" VD3; RBVD3) before calving. The objective of this study was to determine the effects of RBVD3 on VD and Ca metabolism after the oral administration and around parturition. These effects were compared with a single intramuscular injection of VD3 that was one of the popular prophylaxis in Japan. MATERIALS AND METHODS Animals:Eleven late-pregnant Jersey cows (aged 3 to 8 years) were assigned to two groups; a group (PO-RBVD group) consisting of five cows treated with an oral administration of RBVD3 and another group (IMVD group) consisting of the other six treated with an intramuscular injection of commercial VD3 preparation. The cows stayed in an outside paddock during dry period until 8 days before the expected parturition. They were housed in an individual pen until 3 days after calving. They thereafter stayed in another outside paddock during 9 a.m. to 3 p.m., and wereThe use of vitamin D (VD; general name of vitamin D2 and D3) has been popular in attempt to prevent parturient paresis in cow...

The genetic polymorphism of apolipoprotein C in normal plasma of four European sheep breeds (Suffolk, Corriedale, Cheviot, and Finn) was first detected using one-dimensional polyacrylamide gel isoelectric focusing (pH 2.5-5.0) followed by immunoblotting with antihuman apolipoprotein CII antibody. Six phenotypes (1-1, 2-1, 2-2, 3-1, 3-2, and 3-3) were identified in the 4.3-4.8 pH range, consisting of the combination of three isoform groups. On the basis of family and population data, these phenotypes were controlled autosomally by three codominant alleles, designated APOC*1, APOC*2, and APOC*3, the first being the most common allele. The frequency distributions of these alleles were similar between the Suffolk and Corriedale sheep, and between the Cheviot and Finn sheep. The former breeds had a significantly lower APOC*2 frequency than the latter breeds (P < 0.001). The mean plasma total-, HDL- and LDL-cholesterol levels of type 3-1 animals were significantly higher compared to type 1-1 animals in the Suffolk sheep (P < or = 0.04). However these differences were not seen in the Corriedale sheep.