肉种鸡的维生素D3需要量

本研究以25～66周龄的Ross肉种鸡为试验对象,在无紫外光照射的环境中,检测不同维生素D3摄入量对于母鸡每日产蛋量、孵化率、子代雏鸡初生重、入孵种蛋胚胎发育各阶段死亡率（早期：入孵1～10d;中期：入孵11～15d;后期：入孵16～21d）、蛋重、蛋比重、1日龄雏鸡躯体灰分含量等的影响。母鸡从25～66周龄分别饲喂5个浓度水平的维生素D3（每千克饲料的含量分别为：125IU、250IU、500IU、1000IU和2000IU）。另加一组母鸡在36周前饲喂不添加维生素D3的饲料,36周后开始饲喂添加维生素D34000IU/kg的饲料。预测母鸡每日产蛋量最大值相对应的维生素D3水平,产蛋高峰期和高峰后分别为1424IU/kg和2804IU/kg。预测孵化率最大值相对应的维生素D3水平,产蛋高峰期和高峰后分别为1390IU/kg和2708IU/kg。早期胚胎死亡率最小相对应的维生素D3水平,产蛋高峰期值1288IU/kg,然而高峰后未现显著的影响。胚胎中期死亡率最小相对应的维生素D3水平,产蛋高峰期和高峰后分别为1130IU/kg和2568IU/kg,以及胚胎后期死亡率最小相应的维生素D3水平,产蛋高峰期和高峰后分别为1393IU/kg和2756IU/kg。蛋重最大相应的维生素D3水平,产蛋高峰期1182IU/kg,比重最大相应的维生素D3水平,产蛋高峰期为1337IU/kg,高峰后大于2000IU/kg。1日龄雏鸡躯体灰分含量最大相应的维生素D3水平〉2000IU/kg。27～36周龄的母鸡（每千克饲料提供维生素D3水平分别为0、125、250、500、1000和2000IU）从原始设计试验得到的数据分析显示,肉种鸡母鸡饲料需要维生素D3约1400IU/kg。37～66周龄母鸡的试验,包括提供维生素D3水平0至4000IU/kg的不同饲料,高峰后修正设计得到的数据分析显示,饲料需要维生素D3约2800IU/kg。     

Expression of behavioural signs of oestrus during mid-cycle in a dairy cow

Abstract

Extract

Routine monitoring of commercial dairy herds has confirmed the occurrence of oestrus during the luteal phase of the cycle in a small proportion (<5%) of cows (Royal et al 2000 Royal, MD, Darwash, AO, Flint, APF, Webb, R, Wooliams, JA and Lamming, GE. 2000. Detecting fertility in dairy cattle: changes in traditional and endocrine parameters of fertility. Animal Science, 70: 487–501.  [Google Scholar]). One such event occurred in one of four Friesian dairy cows being intensively monitored for progesterone and luteinising hormone (LH) concentrations in daily milk samples and 6-hourly blood samples collected from the jugular vein, throughout the postpartum period (Peters et al 1981 Peters, AR, Lamming, GE and Fisher, MW. 1981. A comparison of plasma LH concentrations in milked and suckling post-partum cows. Journal of Reproduction and Fertility, 62: 567–573.  [Google Scholar]; Fisher 1983 Fisher, MW. 1983. “The control of reproduction in the post-partum cow”. In PhD thesis, Sutton Bonington, , UK: Nottingham University.  [Google Scholar]). Consequently, the endocrine parameters associated with heat during the luteal phase were noted (Figure 1). Although an observation on a single cow, the intensive sampling data available for this animal warrant publication.     

Incidence of lameness requiring veterinary treatment in dairy cattle in Queensland

A survey of the incidence of lesions causing lameness in dairy cattle was conducted by veterinarians in 9 practices in Queensland between November 1984 and July 1985. One hundred and eighty five cases were treated in 83 dairy herds. The average incidence of lameness which required treatment by veterinarians was 2.7 cases per 100 cows per 9 months, with a range of 1.4 to 5.5% in the 9 practices. Foot lesions constituted 83.2% of all lesions; the most common being interdigital necrobacillosis (15%), deep sepsis (8.9%), white line disease (8.4 per cent), axial groove fissure (8.4%), bruised sole (5.6%) and foreign body in the sole/heel (5.6%). Sixty-five per cent of foot lesions occurred in the hind feet and 63% of these lesions occurred in the lateral claw, while 37% of foot lesions occurred in abnormally shaped claws. Limb lesions accounted for the remaining 16.8% of lesions, and 50% of these lesions occurred in the hip and stifle, while trauma was the main cause of limb lesions.     

Duration of the QT interval in healthy cats

OBJECTIVE: To develop a clinically useful model for predicting QT interval duration as a function of heart rate in healthy cats. ANIMALS: 20 healthy cats. PROCEDURE: For all cats, results of a physical examination, electrocardiography, and echocardiography were normal. Twenty-four hour heart rate and rhythm data were collected by means of ambulatory electrocardiography. Hourly ECG segments were obtained from the 24-hour recordings. Mean heart rate and the mean of 5 QT interval measurements were calculated for each of 479 usable ECG segments. Analysis of covariance was used to develop models to describe variability in QT interval duration. RESULTS: Prediction equations (R2 = 0.81) including terms for heart rate, (heart rate)2, age group (1 to 4 vs 8 to 14 years old), and their interactions were developed. Sex, individual cat, and time of day were of little value in predicting QT interval duration. A simplified prediction equation without age group (R2 = 0.71) also was developed and had better predictive ability than reported correction formulas for QT interval duration. CONCLUSIONS AND CLINICAL RELEVANCE: Prediction equations with 95% prediction intervals for expected QT interval duration in healthy cats were generated. Abnormal QT interval duration can be associated with cardiac electrical instability, yet QT interval duration is greatly influenced by heart rate. Results of the present study provide reference ranges for expected QT interval duration as a function of heart rate in healthy cats.     

Biodiversity assessment and conservation strategies

The efficient representation of all species in conservation planning is problematic. Often, species distribution is assessed by dividing the land into a grid; complementary sets of grids, in which each taxon is represented at least once, are then sought. To determine if this approach provides useful surrogate information, species and higher taxon data for South African plants and animals were analyzed. Complementary species sets did not coincide and overlapped little with higher taxon sets. Survey extent and taxonomic knowledge did not affect this overlap. Thus, the assumptions of surrogacy, on which so much conservation planning is based, are not supported.     

High-pressure liquid chromatographic method for the determination of patulin in apple butter.

Patulin is extracted from apple butter samples with ethyl acetate and the extract is cleaned up on a silica gel column, using benzene-ethyl acetate (75+25) as the eluant. High-pressure liquid chromatography, using a 25 cm ZorbaxSil column, isooctane-ethyl ether-acetic acid (750+250+0.5) as the mobile solvent, and a 254 nm ultraviolet detector, is used for the determinative step. Under these conditions, patulin is eluted before 5-hydroxymethylfurfural, a component of apple butter which interferes with other liquid chromatographic and thin layer chromatographic methods. Recoveries of patulin added at levels of 34.6, 138.4, and 276.8 mug/kg ranged from 89.0 to 112.1%.