Monensin and the prevention of tryptophan-induced acute bovine pulmonary edema and emphysema   总被引：1，自引：0，他引：1  

A C Hammond  J R Carlson  R G Breeze 《Science (New York, N.Y.)》1978,201(4351):153-155

3-Methylindole, a ruminal fermentation product of tryptophan, induces acute pulmonary edema and emphysema in cattle, and 3-methylindole is present in the ruminal fluid and blood of cows with a natually occurring form of this disease. Monensin, a polyether antibiotic and widely used feed additive for beef cattle, prevented tryptophan-induced acute bovine pulmonary edema and emphysema. Monensin acted by reducing the ruminal conversion of L-tryptophan to 3-methylindole both in vitro and in vivo. Lasalocid, also a polyether antibiotic, showed similar effects in vitro. These results provide a promising approach to prevention of this major respiratory disease of cattle.  相似文献   

Single layer centrifugation of fresh dromedary camel semen improves sperm quality and in vitro fertilization capacity compared with simple sperm washing          下载免费PDF全文

C Malo  EG Crichton  JM Morrell  BS Pukazhenthi  JA Skidmore 《Reproduction in domestic animals》2017,52(6):1097-1103

Single layer centrifugation (SLC) through a colloid is a tool for selecting viable mammalian spermatozoa but has not been used previously for fresh dromedary camel sperm. Semen from six camels (2 ejaculates/male) was diluted 1:5 (v:v) or 1:10 (v:v) in a Tris–citrate–fructose buffer for mechanical liquefaction by gentle pipetting. Following liquefaction, semen was processed either by SLC or by centrifugation without a colloid (control). Total and progressive motilities, CASA kinematics, vitality and acrosome integrity (eosin–nigrosin) and plasma membrane integrity (Hypo‐osmotic swelling test; HOST), and fertilizing ability in a heterologous assay (zona‐free goat oocytes) were evaluated. Both total (p = .003) and progressive motilities (p = .003) were higher in SLC‐processed than in control semen samples, irrespective of dilution. Positive HOST values increased when using colloid in 1:5 (p = .001) and 1:10 dilution (p = .010). Colloid‐selected sperm had higher penetration rates than controls (p < .001 and p = .02 for 1:5 and 1:10 dilutions, respectively). However, only the SLC sperm at 1:5 dilution showed higher percentages of pronuclear formation (p = .02) than controls. Dilution effect was only significant for total motility before in vitro fertilization, with higher values for the 1:5 dilution (p = .033). The recovery rates of motile sperm between dilutions were similar (26.1% vs 35.4%; p = .226). In conclusion, SLC is a promising tool for selecting functional dromedary camel sperm and warrants more research.  相似文献   

Zinc is involved in regulation of secretion from intestinal epithelium in weaned piglets     

D. Carlson  J. Sehested  Z. Feng  H.D. Poulsen 《Livestock Science》2007,108(1-3):45-48

The objective was to study the effect of serosal zinc (Zn) on intestinal chloride (Cl⁻) secretion in vitro by the Ussing chamber technique. The secretagogues used to stimulate Cl⁻ secretion were serotonin (5-HT), vasoactive intestinal polypeptide (VIP) and forskolin (FSK). In addition correlations between organ and plasma Zn levels vs. the responses to 5-HT were studied. The results revealed an attenuating effect of serosal Zn on the secretory response to 5-HT, VIP and FSK. Furthermore, negative correlations between secretory responses to 5-HT vs. ADG and plasma Zn concentrations were found, whereas the responses to 5-HT did not correlate to the Zn concentration in liver or intestinal mucosa. It is suggested, that dietary Zn reduces diarrhoea directly through a regulatory role of serosal Zn on Cl⁻ secretion and indirectly by improving the nutritional status, which may stabilize the function of the intestinal epithelium.  相似文献