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随着饲用抗生素及化学药物广泛的禁用 ,需研究替代方法以确保畜牧业不会受到影响 ;对家禽的研究结果表明 ,被饲料中抗生素抑制的产气芽孢杆菌若大量繁殖将会引起胃肠疾病并导致畜产品产量和品质的下降。因此 ,研制促畜禽生长的抗生素替代品至关重要。1 抗生素的替代品一种抗生素替代品如纤维素酶可增加饲料消化率并促进肠道菌群的平衡。消化后的营养成分被鸡体吸收用于能量代谢和生长而不是被肠道微生物消耗。另一个替代品是甜菜碱 ,它能降低肠道寄生虫如艾美耳球虫引起的损伤 ,抑制球虫的再次感染 ,降低肠炎的发生率。细菌素是由某些细菌…  相似文献   
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To assess the relative bioavailability of bis-glycinate bound Cu, 90 Angus-cross steers (265 ± 21 kg) were blocked by body weight (BW) to pens with GrowSafe bunks and randomly assigned to dietary treatments (14 to 18 steers/treatment): 0 mg supplemental Cu/kg dry matter (DM; CON), 5 or 10 mg supplemental Cu/kg DM as Cu sulfate (CS5; CS10) or bis-glycinate bound Cu (GLY5; GLY10). Steers received a high antagonist growing diet (analyzed 4.9 mg Cu/kg DM, 0.48% S, and 5.3 mg Mo/kg DM). Steers were weighed at the beginning (days 1 and 0) and end (days 125 and 126) of the trial to determine average daily gain (ADG) and gain:feed (G:F). Blood was collected from all steers on days 0, 28, 56, 84, and 126. Liver samples were collected on days −3 or −2 and day 123 or 124. Data were analyzed using ProcMixed of SAS (experimental unit = steer; fixed effect = treatment and block). Plasma Cu was analyzed as repeated measures (repeated effect = day). Plasma and liver Cu concentrations were regressed against total Cu intake using ProcGLM to calculate relative bioavailability of GLY. Final BW and overall ADG were greatest for CS5 and CS10 and least for CON and GLY5 (P = 0.01). Overall, DMI was not affected by treatment (P = 0.14), but overall G:F tended to be greatest for CS5, CS10, and GLY5 and least for CON (P = 0.08). Total and supplemental Cu intake was greatest for steers supplemented either source at 10 mg Cu/kg DM and least for CON (P < 0.01). However, total and supplemental Cu intake was greater for CS5 than GLY5 (P < 0.01). Final liver Cu concentrations were greatest for CS10, least for CON, CS5, and CS10, and intermediate for GLY10 (P < 0.01). Final plasma Cu was greatest for steers supplemented either source at 10 mg Cu/kg DM (P < 0.01). Relative bioavailability of GLY was 82% compared to CS based on liver Cu (P < 0.01) but did not differ based on plasma Cu (P = 0.60). The lesser bioavailability of GLY relative to CS could be due to a high concentration of dietary antagonists and lower solubility of GLY (68.9% relative to CS) in pH conditions (5.2) similar to the ruminal pH of a beef animal consuming a high concentrate diet. Future studies should examine the effects of bis-glycinate bound Cu fed in blended combination with inorganic Cu sulfate to determine the most effective blend of sources for feedlot cattle experiencing varying amounts of dietary Cu antagonists.  相似文献   
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A 2-year-old Dachshund was presented for vomiting and diarrhea. Abdominal ultrasound revealed Dirofilaria immitis in the abdominal aorta and an avascular segment of small intestine. The dog was euthanized. Necropsy revealed D. immitis in the abdominal aorta and widespread necrotizing arteriolitis. This is a unique presentation of aberrant migration of D. immitis.  相似文献   
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Sarcocystidae is a family of coccidian protozoa from the phylum Apicomplexa that includes Toxoplasma, Neospora, Sarcocystis, Hammondia, and Besnoitia spp. All species undergo a 2‐host sexual and asexual cycle. In the definitive host, replication is enteroepithelial, and infection is typically asymptomatic or less commonly causes mild diarrhea. Clinical disease is most frequently observed in the intermediate host, often as an aberrant infection, and is mostly associated with neurologic, muscular, or hepatic inflammation. Here, we review the literature regarding intestinal Sarcocystidae infections in dogs and cats, with emphasis on the life cycle stages and the available diagnostic assays and their limitations. We also report the diagnostic findings for an 11‐year‐old dog with acute neutrophilic hepatitis, biliary protozoa, and negative biliary culture. Although Toxoplasma and Neospora IgG titers were both high, PCR for these 2 organisms was negative for bile. The organisms were identified by 18S rDNA PCR as most consistent with Hammondia, either H heydorni or H triffittae. This is the first report of presumed Hammondia organisms being found in canine bile.  相似文献   
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