Influence of rearing system on sows' prolificacy during gestation.
In females reared inindividual crates until early control of gestation and in common crates (8-16heads), prolificacy did not reach values that differ depending on the rearingsystem: there is a statistically insignificant difference in t-test(p>0.05). In gestating sows reared in individual crates, the difference wassignificant during the entire gestation period compared to group rearing:11.51±0.85 compared to only 11.13±0.68 in collective rearing. Though there arebetter results from the point of view of sows’ prolificacy when reared inindividual crates during the entire gestation, this rearing system is notrecommendable because of the high financial efforts caused by technology andbecause separation has negative influences on sows’ behaviour depending on reproductionand health state of gestating females.
The influence of differentiated feeding during the early gestation status on sows prolificacy and stillborns
The researches were carried out with the goal to quantify the influence of differential housing and feeding of the pregnant sows until 28 and respectively 56 days of gestation, upon prolificacy and farrowing loss (stillborn). The prolificacy of the sows housed in crates and feed individually, according to the body condition, until 56 days of pregnancy was 10.98±1.58 pigs/sow; with limits from 9 to 13 pigs born alive/sow. For the sows housed in crates and feed individually, according to body condition, until 28 days of pregnancy, prolificacy was 10.92±3.59 pigs/sow; with limits from 4 to 14 pigs born alive/sow. Most of the sows (60.42% of the sows housed inc rates until 56 days and 53.33% of the sows housed in crates until 28 days) farrowed 11 pigs born alive/sow. Regarding the farrowing loss, for the sows housed in crates until 56 days, the number of stillborn was 0.31 pigs/sow; for the sows housed in crates until 28 days, the number of stillborns was 1.14 pigs/sow.
Pharmacokinetics of amikacin and chloramphenicol in the aqueous humor of rabbits
Composite data describing ocular pharmacokinetics are unreliable because of intersubject variation. To address this problem, an animal model was developed in which multiple aqueous samples from single subjects were obtained. Following direct anterior chamber or intravenous administration of amikacin or chloramphenicol, pharmacokinetic analysis of drug concentrations in the serum and anterior chamber was performed by using a nonlinear least-squares regression program. The number of anterior chamber paracenteses performed did not alter the beta elimination rates or percent penetration into the anterior chamber. The aqueous humor and peripheral-compartment terminal slopes were identical. These data indicate that complete ocular concentration-time curves can be obtained without altering antibiotic pharmacokinetics. Following direct injection into the anterior chamber, the elimination rates for both antibiotics followed a one-compartment model, whereas those following intravenous administration best fit an open, first-order, two-compartment model. Following intravenous administration, the anterior chamber elimination rate constants for both drugs were equal to that of the serum and significantly longer than that following direct injection. The elimination rates of both drugs following direct injection were similar. Systemic administration resulted in drug levels in aqueous humor that persisted longer than those following direct injection. Chloramphenicol, a lipophilic compound, gave higher mean concentrations in aqueous humor than did amikacin. Our model provides a new approach which rigorously examines ocular pharmacokinetics and provides data which suggest that for selected compounds the parenteral route of administration is preferable.