Two maize based diets containing 2.3 g phytic P and 38 mg Zn/kg (P+) or 1.3 g phytic P and 25 mg Zn/kg (P−) were formulated. A third diet (P+/Phytase) was P+ supplemented with 3-phytase (500 FTU/kg). Each of these three basal diets, supplemented or not with 15 mg Zn/kg, was given during 20 days to weaned piglets and to 1-day-old chicks. Chicks fed the P− diets were removed from the data set because of an abnormally low feed intake.
In piglets, added Zn increased bone (P < 0.05) and plasma Zn (P < 0.01) irrespective of the basal diet (basal diet × Zn, P > 0.05). Supplementing P+ with phytase was more efficient in improving these indicators of Zn status than replacing P+ by P−. In chicks, supplemental Zn improved Zn status in a higher extent when added to P+ than to P+/Phytase (basal diet × Zn, P < 0.05). Phytase increased Zn status in a lesser extent than 15 ppm supplemental Zn. More Zn was soluble in gizzard than in stomach which corresponded to the differences in pH (4.2 vs 5.0). Phytase increased soluble Zn in stomach (P < 0.05) but not in gizzard. These results suggest a higher availability of Zn in chicks than in piglets in the absence of phytase. This may explain the higher efficacy of phytase for improved Zn availability in piglets than in chicks. 相似文献
At weaning, low feed intake level is a major factor responsible for gut disorders. However, less is known on adaptation of the antibacterial activity of pancreatic juice in response to variations in feed intake level. Moreover bovine colostrum has been demonstrated to decrease coliform counts in duodenal digesta and to improve health status of weaned piglets. Aims of the present study were to evaluate effects of feed intake level and of a bovine colostrum-supplemented diet on the pancreatic secretion of antibacterial activity in piglets at weaning. At 33 days of age, twenty-eight piglets fitted with two permanent catheters (for pancreatic juice collection and reintroduction) were weaned and allocated to one of the following three dietary treatments for 5 days: low feed allocation with a starter diet (L), gradually increased feed allocation with a starter diet (Ctrl), or gradually increased feed allocation with a starter diet supplemented with bovine colostrum (Col). In Ctrl piglets, the post-weaning secretion of antibacterial activity did not significantly differed from pre-weaning values. The pancreatic secretion of antibacterial activity in L piglets was higher than that in Ctrl piglets at day 5 (+ 300%; P < 0.05). Moreover in Col piglets the secretion of the antibacterial activity tended to increase by 55% (P = 0.08) compared to Ctrl piglets. Variations in the pancreatic secretion of antibacterial activity could constitute an adaptive phenomenon to maintain bacterial homeostasis in the upper small intestine during the early post-weaning period. 相似文献
A tissue cage (TC) model was used to evaluate the pharmacokinetics and ex vivo pharmacodynamics of cefquinome after intravenous (IV) and intramuscular (IM) administration to piglets at 2 mg/kg bodyweight. The mean values of area under the concentration–time curve (AUC) were 21.28 (IV) and 21.37 (IM) μg h/mL for serum, and 17.40 (IV) and 16.57 (IM) μg h/mL for TC fluid (TCF), respectively. Values of maximum concentration (Cmax) were 6.15 μg/mL (serum) and 1.15 μg/mL (TCF) after IM administration. The elimination half-lives (t1/2β) in TCF (10.63 h IV and 11.81 h IM) were significantly higher than those in serum (2.33 h IV and 2.30 h IM) (P < 0.05). The values of AUCTCF/AUCserum (%) after IV and IM administration were 82.4% and 80.7%, respectively.The ex vivo time-kill curves were established for serum and TCF samples using Escherichia coli ATCC 25922. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration values of cefquinome against E. coli were 0.030 and 0.060 μg/mL in Mueller–Hinton broth, and 0.032 and 0.064 μg/mL in both serum and TCF, respectively. The ex vivo growth inhibition data of TCF after IM administration were fitted to the sigmoid Emax model; AUC24h/MIC was 35.01 h for bactericidal activity and 44.28 h for virtual eradication, respectively. The findings from this study suggest that cefquinome may be therapeutically effective in diseases of pigs caused by E. coli when used at a dose rate of 1.33 mg/kg administered every 24 h for organisms with MIC90 ⩽ 0.50 μg/mL. 相似文献
“Sperm mediated gene transfer” (SMGT) is based on the ability of sperm cells to bind exogenous DNA. The main objective of this study was to improve the production of transgenic pigs by SMGT. Taking into account that there is a lack of repeatability in studies of SMGT and that the mechanism of binding and internalization of exogenous DNA is a question that has not been solved, different factors involved in the production of transgenic animals by SMGT method were evaluated. Here we set out to: (1) evaluate the sperm capacity to bind exogenous DNA after DMSO treatment; (2) determine the location of the transgene–spermatozoa interaction; and (3) evaluate the efficiency of production of transgenic piglets by deep intrauterine artificial insemination (AI) with sperm incubated with DNA. The percentage of DNA binding was higher than 30% after 2 h of co-culture, but it was not affected by sperm treatment with DMSO (0.3% or 3%). The integrity of the sperm plasma membrane plays a critical role in DNA interaction, and altered plasma membranes facilitate interactions with exogenous DNA. DNA bound mainly to spermatozoa with reduced viability. DNA molecules were found to be mainly associated to the post-acrosomal region (61.9%). After deep intrauterine AI a total of 29 piglets were obtained, but none of them integrated the transgene. In conclusion, although it has been confirmed that DNA can associate with boar spermatozoa, the efficiency of producing transgenic pigs by AI was not confirmed by the present experiments, mainly due to a reduced DNA binding to functional spermatozoa. 相似文献