补饲对放牧西门塔尔犊牛生长性能及血液指标的影响

为研究放牧加补饲对西门塔尔犊牛生长性能和血液指标的影响,选取内蒙古赤峰草原的放牧犊牛16头,分为放牧组和放牧加补饲组,测量体重、体尺等生长性能指标,用酶联免疫法测定血清中总蛋白(TP)、尿素氮(BUN)、葡萄糖(GLU)、白介素1(IL-1)和白介素2(IL-2)等血液指标。结果表明:1)在正试期的0~30 d 2组犊牛的日增重无显著差异(P>0.05),但在31~60 d放牧加补饲组犊牛日增重显著高于放牧组(P<0.05);在整个试验阶段,放牧加补饲犊牛体尺指标除胸围外,均高于放牧组,但差异不显著(P>0.05)。2)放牧加补饲使犊牛血清中尿素氮(BUN)和葡萄糖(GLU)含量显著提高(P<0.05);而总蛋白(TP)和甘油三酯(TG)含量差异不显著(P>0.05)。3)放牧加补饲犊牛免疫球蛋白G(IgG)和白介素1(IL-1)含量显著升高(P<0.05);而三碘甲状腺原氨酸(T₃)、甲状腺素(T₄)、生长激素(GH)和白介素2(IL-2)含量有高于放牧组的趋势,但差异不显著(P>0.05)。综上,补饲可提高放牧西门塔尔犊牛的生长性能,改善血液生化指标和血清激素水平,并可改善西门塔尔犊牛整体免疫水平。     

Mucosal uptake,mucosal transfer and retention of iron in veal calves

A method for studying iron absorption in humans was adapted to veal calves. Three 10-week-old calves with moderate (calves 1 and 2) or severe (calf 3) iron deficiency were given an abomasal injection of⁵⁹Fe and⁵¹Cr and all their faeces were collected over 15 days in order to measure mucosal uptake, mucosal transfer and retention of iron. The mucosal uptake was 62.2, 53.4 and 71.8% in calves 1, 2 and 3, respectively. The iron retention measured 14 days after administration of the test dose was 57.4, 52.3 and 56.4% in calves 1, 2 and 3, respectively. Maximal plasma activity was found in all three calves between 1 1/2 and 2 h after injection of the test dose. The plasma activity decreased rapidly, with a slight increase between the 5th and the 10th hour. After 21 h, less than 0.25% of the injected dose was still present in 1 litre of plasma. Not all the⁵¹Cr was recovered in the faeces. No⁵⁹Fe was found in the urine but some⁵¹Cr could be detected. The results of this study show that the method described is useful for measuring the different steps of iron absorption in iron-deficient veal calves.Abbreviations Hb haemoglobin concentration - MCV mean corpuscular volume - PCV packed cell volume - PI plasma iron - RBC red blood cell count - R iron retention - TIBC total iron-binding capacity - TIBC-SAT saturation of the total iron-binding capacity - U mucosal uptake     

Bacterial Identity and Characteristics in Healthy and Unhealthy Respiratory Tracts of Sheep and Calves

Barbour, E.K., Nabbut, N.H., Hamadeh, S.K. and Al-Nakhli, H.M., 1997. Bacterial identity and characteristics in healthy and unhealthy respiratory tracts of sheep and calves. Veterinary Research Communications, 21 (6), 421-430The aim of this study was to compare different bacteriological aspects of the respiratory systems of healthy (H) versus unhealthy (UH) animals with respiratory signs. The prevalence of different bacterial species was determined in the upper and lower respiratory tract of H and UH Najdi sheep, Somali sheep and Holstein calves. The characteristics of Pasteurella spp. isolates, and the biotype of Pasteurella haemolytica were identified in H and UH animals. Eighteen out of 28 (64.3%) of the identified bacterial species in the upper respiratory tract were more prevalent in the nasal cavities of UH Najdi and Somali sheep and Holstein calves with respiratory signs than in apparently healthy animals; four of the most prevalent bacteria in the upper respiratory system of UH sheep were Moraxella spp., Pseudomonas pseudomallei, Erysipelothrix spp., and Pasteurella multocida, while three of the most prevalent bacteria in UH calves were Pasturella haemolytica, Actinomyces spp., and Pseudomonas aeruginosa. The prevalence of six different bacterial species was greater in the lungs of UH animals, namely Actinomyces pyogenes, Erysipelothrix spp., P. haemolytica, Pasteurella ureae, Staphylococcus aureus, and Staphylococcus epidermidis, which could be risk factors in the complexity of the prevalent respiratory diseases of the animals surveyed.Of the biochemical, cytological and colonial characteristics studied in the identified P. haemolytica and P. multocida, two characters were significantly different (p < 0.05) in organisms isolated from UH as compared to those from H animals. These were the higher loss of haemolytic power by the strains of P. haemolytica and the decreased fermentation of trehalose by all the strains of P. multocida recovered from healthy animals.The only biotype of P. haemolytica isolated from H animals was biotype A, while both biotypes A (88.0% of the isolates) and T (12.0% of the isolates) were recovered from UH animals.     

Examination of possible transmission of sheep scab mitePsoroptes ovis between host species

Examination of possible transmission of the Irish strain of the sheep scab mite (Psoroptes ovis) of ovine origin between host species involved calves and goats being placed with infected sheep and also directly challenged with live mites. Although mites remained on recipient species for up to a week, they failed to produce disease in either of these species. Calves and goats that had live mites placed on them likewise failed to infect sheep with which they were housed.     

Plasma Concentrations,Pharmacokinetics and Urinary Excretion of Gatifloxacin after Single Intravenous Injection in Buffalo Calves

The pharmacokinetics and urinary excretion of gatifloxacin were investigated after a single intravenous injection of 4 mg/kg body weight in buffalo calves. The therapeutic plasma drug concentration was maintained for up to 12 h. Gatifloxacin rapidly distributed from blood to tissue compartments, which was evident from the high values of the distribution rate constant, α₁ (11.1 ± 1.06 h⁻¹) and the rate constant of transfer of drug from central to peripheral compartment, k ₁₂ (6.29 ± 0.46 h⁻¹). The area under the plasma drug concentration–time curve and apparent volume of distribution were 17.1 ± 0.63 (μg.h)/ml and 3.56 ± 0.95 L/kg, respectively. The elimination half-life (t _{1/2 β}), total body clearance (Cl_B) and the ratio of drug present in tissues and plasma (T/P) were 10.4 ± 2.47 h, 235.1 ± 8.47 ml/(kg.h) and 10.1 ± 2.25, respectively. About 19.7% of the administered drug was excreted in urine within 24 h. A satisfactory intravenous dosage regimen for gatifloxacin in buffalo calves would be 5.3 mg/kg at 24 h intervals. Abbreviations for pharmacokinetic parameters are given in the footnote of Table I     

Study on Production of White Veal with Holstein Bull Calves Fed on Different Milk Replacer and Feeding Methods

The objective of this experiment was to study the effects of production of white veal with Holstein bull calves fed on the liquid milk replacer (containing mainly dairy products) feeding and the dry milk replacer (containing mainly plant diet, etc)feeding.20 healthy male calves with similar birth date and body weight were selected, and randomly divided into two groups (10 calves per group), for a period of 120 d white beef production fattening test.GroupⅠfed with milk replacer (commercial, 22% CP, 16% EE), groupⅡ fed with milk replacer (formulated, 22% CP, 16 MJ/kg DE).The results showed as follows:① 0 to 90 d ADG of group Ⅱ were higher than groupⅠ, 91 to 120 d ADG of group Ⅱ were significantly lower than groupⅠ (P< 0.05), but there were no significant differences in 0 to 120 d ADG and 120 d weight between two groups (P> 0.05).② There were no significant differences in the nutrient apparent digestibility of Holstein bull calves with different milk replacer and feeding methods (P> 0.05).③ Carcass weight, dressing percentage and eye muscle area of groupⅠcalves were significantly higher than those of group Ⅱ (P< 0.05), increased by 11.88%, 11.04% and 8.12%, respectively, but there was no significant difference in carcass meat production rate between two groups (P> 0.05).There was no significant differences in pH, shear force, cooking lose and meat color of longissimus between two groups (P> 0.05), but compared with group Ⅱ, the water lose rate of groupⅠincreased by 20.83% (P< 0.01).The content of EE of groupⅠwas significantly higher than group Ⅱ (P< 0.01), but there were no significant differences in the contents of moisture, CP, Ash, Ca, P and Fe of longissimus between two groups (P> 0.05).④Compared with groupⅠ, the feed cost of group Ⅱ was reduced by 45.38%.In summary, the growth performance and meat quality of two groups calves were similar, feeding cost was reduced significantly.     

Genetic and non-genetic factors associated with health and vitality traits in beef calves

Awareness and interest in calf health and wellbeing is intensifying, prompting change in the management and breeding decisions of producers and associated policy-makers. The objectives of the present study were to 1) quantify the risk factors associated with subjectively measured scores of vigor and birth size as well as diagnoses of scour and pneumonia in a large national dataset of beef calves, and 2) to estimate the contribution of genetic variance to such phenotypic measures. After edits, the data consisted of health and birth size data subjectively scored by producers on 88,207 calves born in 6,126 Irish beef herds. Vigor was recorded on a scale of 1 (very poor) to 5 (very good). Birth size was also scored on a scale of 1 (very small) to 5 (very large). Scour and pneumonia were both scored independently based on the suspected number of occurrence of each (0 = no occurrence, 1 = one occurrence, or 2 = more than one occurrence). On average, 14.7% of calves were recorded as having had at least one occurrence of scour within the first 5 mo of life, whereas 6.4% of calves were recorded as having had at least one occurrence of pneumonia within the first 5 mo of life. Relative to female calves, male calves had a worse vigor score and a suspected greater incidence of both scour and pneumonia. Relative to singletons, twins were, on average, smaller at birth, they had a worse vigor score, and they were more prone to scour. Calves born in the later periods of the calving season (i.e., late and very late) had a greater incidence of scour relative to calves in the herd born earlier in the calving season. Heritability estimates for vigor, birth size, and pneumonia were 0.12 (0.02), 0.33 (0.03), and 0.08 (0.02), respectively; no genetic variance was detected for scour. Breeding for vigorous calves that are less susceptible to pneumonia could provide producers with an additional strategy to ensure consumer concerns regarding food quality, safety, and calf wellbeing are being met.     

使用酵母培养物AYC-X6防治犊牛腹泻效果

[目的]犊牛腹泻是犊牛最常见的消化道疾病,是由饲养管理和多种感染性病原微生物共同作用引起。为研究在犊牛日粮中添加酵母培养物防治犊牛腹泻效果。[方法]在宁夏固原现代农业园区肉牛繁育基地随机选取120头2.5月以下犊牛作为试验牛群,对照组和试验组各60头,试验组犊牛每头每天添加30 g酵母培养物AYC-X6,对照组不添加。[结果]结果表明,试验组犊牛腹泻发病率减少35%,死亡率减少8%;平均每头治疗成本节省8.4元/头。[结论]犊牛日粮中添加酵母培养物AYC-X6,有利于建立健康稳定的瘤胃微生物菌群,对犊牛腹泻有很好的防治效果。