甘南玛曲不同年龄欧拉型藏羊放牧采食量季节动态研究

为确立高寒地区天然草地欧拉型藏羊放牧采食量的季节动态变化,本试验采用TiO₂外源指示剂法和瘤胃尼龙袋法分别测定欧拉型藏羊不同季节排粪量和牧草消化率从而计算放牧采食量。结果表明:玛曲高寒草地牧草干物质消化率(DMD)和粗蛋白(CP)含量夏季显著(P < 0.05)高于冬春季与秋季;欧拉型藏羊各年龄段排粪量3季差异显著(P < 0.05)且秋季 > 夏季 > 冬春季;随着年龄增长,欧拉型藏羊三季牧草采食量均有增大的趋势,同年龄段不同季节的藏羊采食量和代谢采食量(除4岁母羊)差异显著(P < 0.05)且秋季 > 夏季 > 冬春季;各年龄段藏羊累计牧草消耗量(AFC)差异显著(P < 0.05)分别为339.37,757.58,1185.93和1655.61 kg。由此可见,牧草干机物质消化率、排粪量和采食量夏秋季较高、冬春季较低,随着年龄增大排粪量和采食量有增高的趋势。因此,在高寒牧区应提倡草地季节性畜牧业,充分考虑牧草营养与动物营养需求之间的耦合性来提高经济和生态效益。     

Peripheral blood lymphocyte subsets in fleece rot-resistant and -susceptible sheep

Objective To compare haematological values and lymphocyte phenotypes in the peripheral blood of fleece rot-resistant and -susceptible sheep.
Procedure Experiments were conducted on 2- and 3-year-old Merino rams, flock 1 (17 rams) and flock 2 (32 rams), respectively. Within each flock, individual rams were classified as fleece rot-resistant or -susceptible, based on established criteria. Total and differential white cell counts, and indirect fluorescent antibody tests specific for B cells and T cells were performed on all sheep. The concentration of various subsets of circulating lymphocytes was then determined in each sheep.
Results There were no significant differences between fleece rot-resistant and -susceptible sheep from either flock in the mean total or differential white cell counts. However, fleece rot-resistant rams in flock 1 did have a significantly higher concentration of circulating SBU-T1⁺ cells than fleece rot-susceptible rams from the same flock. No such difference was noted in the rams from flock 2. While all rams in flock 1 were free of clinical fleece rot, 24 rams in flock 2 (comprising all 17 fleece rot-susceptible and 7 of 15 fleece rot-resistant animals) had clinical signs of the disease. Fleece rot-free rams in this flock (irrespective of their classification as fleece rot-resistant or -susceptible) had significantly higher concentrations of circulating SBU-T1⁺ cells compared with fleece rot-affected animals. They also had significantly higher concentrations of circulating B cells, and total lymphocytes.
Conclusions An examination of peripheral blood lymphocyte subsets in fleece rot-resistant and -susceptible sheep revealed a possible association between resistance to fleece rot and the concentration of circulating SBU-T1⁺ cells.     

Preliminary Studies on Cryopreservation of Common Tench (Tinca tinca) Embryos (Work in Progress)

Vitrification could provide a promising tool for the cryopreservation of fish embryos. However, to achieve cryopreservation using vitrification, chilling sensitivity and cryoprotectants toxicity were determined using tench embryos at four developmental stages (11, 17, 23 and 29 h). Embryos treated with alcalase (2 ml/998 ml, 2 min at 22°C) were exposed to chilling with/without warming. Other embryos were exposed to methanol and glycerol at the concentration of 10% and 20% for periods of 20 min. At last, embryos were incubated at special incubator cages where hatching rates were counted. Regarding chilling sensitivity and exposure to chilling followed by warming, the hatching rates of embryos decreased significantly (p < 0.001) after exposure to 0°C at all developmental stages except the 29-h stage compared with the controls. The embryo stage most sensitive to chilling was 11-h stage. The 29-h stage exhibited the least sensitivity to low temperature while 17-h and 23-h stages were intermediate in their sensitivity to chilling. The toxicity of methanol increased significantly (p < 0.001) with developmental stage for 11, 17 and 23-h stages. The highest hatching rates of tench embryos were obtained with 29-h embryos using various concentrations of methanol. The hatching rates of tench embryos exposed to glycerol concentrations were approximately similar to those embryos exposed to methanol concentrations except for 11-h embryos that showed no hatching. Unfortunately, we could not obtain living embryos in any of the conditions examined after vitrification. In conclusion, it was quite difficult to vitrify the tench embryos during this study using various vitrifying solutions and the method reported by Chen & Tian (2005) and further studies are needed to achieve successful cryopreservation.     

Comparison of Biochemical Values of Paired Serum and Plasma Samples from American Flamingos (Phoenicopterus ruber), Indian Runner Ducks (Anas platyrhynchos), and Hyacinth Macaws (Anodorhynchus hyacinthinus)

Single blood samples from 8 clinically normal adult Indian runner ducks (Anas platyrhynchos), 8 clinically normal American flamingos (Phoenicopterus ruber), and 3 blood samples from each of 4 clinically normal hyacinth macaws (Anodorhynchus hyacinthinus) were collected to compare the biochemical values of paired plasma samples from heparinized blood with those of serum samples from clotted blood. Small but significant differences (P < 0.05) were found between paired serum and plasma samples for some biochemistries. In flamingos, potassium (P = 0.001), albumin (P = 0.03), and alanine aminotransferase (P = 0.02) were significantly higher in serum compared with plasma, whereas total protein (P = 0.04) and globulin (P = 0.01) were significantly lower in serum compared with plasma. In Indian runner ducks, potassium (P = 0.0002), chloride (P = 0.02), and alanine aminotransferase (P = 0.0005) were significantly higher in serum compared with plasma, whereas total CO₂ (P = 0.02) and globulin (P = 0.007) were significantly lower in serum compared with plasma. Serum total protein was lower than plasma levels, but it was not significant (P = 0.05). In hyacinth macaws, total protein (P = 0.02) and the albumin:globulin ratio (P = 0.02) were significantly lower in serum compared with plasma. Although statistically significant, these differences were small and appear unlikely to be of any clinical relevance. There is minimal loss of plasma volume from heparinized blood samples compared with serum volume from clotted blood samples. This allows collection of smaller blood volumes from small or sick birds in a single lithium heparin anticoagulant tube to perform a hemogram on whole blood and a biochemical profile on the separated plasma that provides values similar to those of serum.     

反刍动物甲烷排放调控的研究进展

甲烷是导致温室效应的重要因为,反刍动物是甲烷气体的重要释放者,因此减少反刍动物甲烷排放对提高饲料利用率和改善环境具有重要的意义.本文主要对甲烷的生成机制,甲烷排放量调控,粪便甲烷的回收等方面的研究进展进行概述.     

Acute lymphocytic leukemia in a six-month-old western lowland gorilla (Gorilla gorilla gorilla).

A 6-mo-old hand-raised male western lowland gorilla (Gorilla gorilla gorilla) was diagnosed with acute lymphocytic leukemia based on complete blood count and bone marrow cytology. Clinical signs of the disease were pyrexia, abdominal distention, splenomegaly, and lethargy. Acute lymphocytic leukemia has rarely been reported in this species, and therapy was based on human oncologic protocols. Remission induction chemotherapy resulted in complete clearing of leukemia cells from the bone marrow. Consolidation and maintenance chemotherapy followed. Therapy was facilitated by the use of an infusion port for i.v. treatments and an indwelling lumbar catheter for intrathecal therapy. Side effects associated with chemotherapy were inappetence, moderate alopecia, pancytopenia resulting in sepsis, and bleeding tendency. In spite of initial success, the leukemia reappeared 120 days into treatment. The gorilla was euthanized 7 days later when respiratory distress developed. Intensive care by the animal staff was a key factor in the treatment of this gorilla.     

The use of vascular access ports in nonanesthetized green iguanas (iguana iguana) to collect baseline arterial blood gas parameters.

The green iguana, Iguana iguana, is used as a model in reptile anesthesia research because of its size, availability, and the body of knowledge characterizing its physiology. Arterial blood gas values in nonanesthetized green iguanas have not been determined because of the technical difficulty involved. Vascular access port (VAP) placement to facilitate blood sampling has been described in other species, but not lacertilians. This abstract describes the technique for placement of VAPs and the values for arterial blood gas parameters in seven 1 kg adult green iguanas. Using sterile technique, a 1.5 cm incision was made on the lateral side of the neck. Blunt dissection ventral to the external jugular vein revealed the internal and external carotid arteries near their bifurcation. The catheter was inserted into the internal carotid artery and then guided to the common carotid artery. The other end of the catheter was tunneled below the skin to a subcutaneous location, caudal‐dorsal to the iSPSilateral scapula. The skin was closed and the port was flushed twice a week with heparinized saline. Post‐operatively, the VAPs were well tolerated by the iguanas. Difficulties included port disconnection (n = 1), inability to aspirate blood after a few weeks (n = 2), and infection (n = 1). The iguanas were breathing room air prior to and during blood collection. From the five functional VAPs, the blood pH, PCO₂, PO₂, HCO^‐₃, and BE (measured at 37 °C) were 7.45 ± 0.06; 37.5 ± 7.0 mm Hg, 99.0 ±16.6 mm Hg, 25.4 ± 2.5 mmol L^–1, and 1.5 ±2.4 mmol L^–1 respectively (mean ± SD). VAPs can be successfully used to facilitate collection of arterial blood gas samples in green iguanas. These values are similar to those reported for most mammalian species. This technique should facilitate research in anesthesiology and respiratory physiology of iguanas and other lacertilians.