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玛氏宠物护理学院

在中国,为宠物创造一个更美好的世界

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犬的营养需求
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Science Head

科研主管

Dr Lucille Alexander has over 9 years experience working in the field of nutrition across a wide variety of pet species including cat, dog, horse, bird and fish at WALTHAM®. Since joining WALTHAM® Lucille has been involved in research that has generated over 20 peer reviewed publications.
Lucille Alexander医生在威豪®宠物中心从事营养学领域的研究已经有超过9年的历史,研究对象包括多种宠物,包括猫、犬、马、鸟与鱼等。加入威豪®后,Lucille全心投入在科研领域,迄今已发表期刊论文20多篇。

Key Message

关键信息

WALTHAM® has contributed to the understanding of the energy requirements of dogs by:

通过以下方式,威豪®成功地促进了人们对犬的能量需求的认识:

•    Showing that the energy requirement is affected by many factors including body size, breed, and activity level.

•    Demonstrating that energy requirement can be predicted more accurately if the dog’s daily activity level is taken into account using accelerometry.

•    证明犬的能量需求受到多种因素的影响,包括体型大小、犬种与活动程度。

•    证明采用加速度测量术对犬的每日活动程度进行测量能够提高对犬的能量需求预测结果的准确性。

Background

背景

The amount of dietary energy an animal needs to meet its energy requirement has to account for:

动物为满足其能量需求而需要的饮食能量在数量上必须满足下列各项需求:

Basal metabolic rate

基础代谢率

•    动物为保持基本生理功能(包括心率、呼吸与肾功能)所耗费的能量。基础代谢率通常通过休息代谢率测定——即动物在躺卧且清醒状态下维持正常身体功能所耗费的能量。

Thermogenesis

生热作用

•    The energy expended to ingest, digest, absorb and assimilate food

•    The energy expended to cope with stress, including changes in environmental temperature

•    动物摄入、消化、吸收与同化食物所消耗的能量;

•    动物应对压力(包括环境温度变化)所消耗的能量

Activity

活动

•    The energy expended during movement and exercise.

•    动物活动和锻炼所消耗的能量。

Basal metabolic rate depends on factors including body weight, body composition, age and hormonal status. Thermogenesis can vary widely and results in daily fluctuations in energy requirement.

基础代谢率的决定因素包括体重、身体组成、年龄与体内激素状况。生热作用变化的幅度可能非常大,并会导致动物每日能量需求量方面的波动。

Energy expenditure (or requirements) can be measured as heat production (using direct calorimetry). This is affected not only by body weight, but also by body surface area. Body weight that has been corrected mathematically to take account of surface area is known as metabolic body weight (MW), and this allows a comparison of the energy requirements of animals that differ in body size.

能量消耗(或需求量)可以通过热产生的方式测定(使用直接量热法)。能量消耗不仅受到体重的影响,而且还受到身体表面积的影响。经过数学校正以反映身体表面积的体重被称为代谢体重,通过代谢体重可以比较不同体积的动物在能量需求量方面的差异。

The body weight of healthy mature dogs varies over a huge range – from about 1 kg to over 100 kg (Burger 1994). Because of this body weight should be expressed on an allometric basis, but the precise value for the exponent to calculate MW is still a matter of some debate (Burger 1994).

健康成熟犬的体重约为1公斤-超过100公斤(Burger, 1994年)。犬的体重本应以异速生长的形式表示,但目前对用于计算代谢体重的精确指数值尚存在争议(Burger, 1994年)。

Why WALTHAM® is Interested

为何威豪®有兴趣从事该领域的研究

A thorough understanding of energy requirements is essential in order to produce accurate feeding guidelines to help owners feed their dog appropriately and to prevent under-nutrition or obesity. Complete and balanced foods rely on delivering all essential nutrients within the calories the dog requires to maintain a healthy bodyweight.

全面认识犬的能量需求具有至关重要的意义,这有助于制定出准确的喂食指南以帮助犬的主人能够以适当方式喂养犬,从而防止营养不良或肥胖的现象出现。营养成分完全而平衡的狗粮必须能够提供所有必须营养素,并且能够满足犬保持健康体重所需的热量。

Approach

方法

Over time, WALTHAM® has undertaken a great many feeding studies of dogs and routinely collects body weight data. This provides a unique and sizeable dataset for analysing the effect of body size on the amount of food required to maintain body weight, based on the premise that dogs which are maintaining their body weight have an energy intake equivalent to energy requirement.

很长时间以来,威豪®已经开展了很多犬的喂养试验并在试验中例行性地收集了犬的体重数据。这些数据为分析犬的体积对其维持体重所需食物量的影响提供了独特而充足的数据集(假设前提依据:犬在体重维持期的能量摄取量等于其能量需求量)。

There are several widely accepted techniques for accurately measuring the energy expenditure of an animal. Whole body colorimetry measures energy as heat production (or indirectly calculates this) under carefully defined conditions. Doubly-labelled water measures metabolic rate in the free-living state. Both techniques require considerable experience and expertise, which WALTHAM® has developed. Furthermore, the use of multiple techniques to assess energy requirements is a way to try to overcome the inherent variability in the data.

目前有几种能够准确测量动物的能量消耗的方法已经得到广泛认可。全身比色法能够在精确定义的条件下测定产热能量(或间接计算出产热能量)。双标记水法能够测定自由生活状态下的代谢速率。上述两种方法均要求操作者具有丰富经验和专业技术,而这一点正是威豪®的专家所具备的优势之一。此外,采用多种方法对能量需求量进行评估也是克服数据原有离散性的方法。

Discovery

The energy requirement of dogs is affected by many factors including body size, breed, and activity level

发现与结论

犬的能量需求受到多种因素的影响,包括体型大小、犬种与活动程度。

In a study of 22 dogs representing seven breeds (body weight range 5.8–48.8 kg) at WALTHAM®, whole body calorimetry found a resting energy expenditure of 678 W0.64 kJ/day (Burger and Johnson 1991). These data were taken into account in formulating the NRC 2006 recommendations (NRC 2006).

在一项试验中,威豪®对7个犬种共22只犬进行了全身比色法测定,结果发现,试验犬的静息能量消耗量为678 W0.64千焦/天(Burger与Johnson,1991年)。美国国家研究委员会在制定建议能量供给量时参考了上述试验数据(美国国家研究委员会,2006年)。

A study in collaboration with the College of Veterinary Medicine, Hannover, found that the Newfoundland requires less energy than might be predicted, and great Danes require more, after analysing the body weight data from 78 dogs representing seven breeds (Figure 1) (Kienzle and Rainbird 1991). These data suggest that breed may be a confounding factor when considering energy requirements, perhaps due to coat type, body composition or temperament.

威豪®与汉诺威动物医学学院联合开展的一项研究对78只7个犬种的犬进行了体重数据分析,结果发现,纽芬兰犬的能量需求量低于人们的先前预期值,而大丹犬的能量需求量高于人们先前的预期值(图1) (Kienzle与Rainbird,1991年)。上述数据表明,犬种可能是能量需求的一种混杂因子,并且可能与皮毛类型、身体构成或脾性存在相关性。

Reproduced from Kienzle E, Rainbird A. Maintenance energy requirement of dogs: what is the correct value for the calculation of metabolic body weight in dogs? J Nutr.1991.121(11Supp):39S-40S
摘自:Kienzle E与Rainbird A的“犬在维持阶段的能量需求:怎样才能正确计算出犬的代谢体重?”;选自:《营养学杂志》,1991.121(11Supp):39S-40S。

Figure 1: Relationship between body weight and energy intake for maintenance (Kienzle and Rainbird 1991)

图1: 犬在维持阶段体重与能量摄取量之间的关系(Kienzle 与Rainbird,1991年)

Another of the confounding factors when considering energy requirements is the level of physical activity. A survey of border collies kept as working dogs or pets revealed widely varying energy requirements based on activity level (Table 1 Burger 1994).

能量需求的另一种复杂因子是身体的活动量。对作为工作犬或宠物的博德牧羊犬的研究表明,其能量需求量随着其身体活动程度的不同而表现出较大的差异性。

Table 1: Survey of food intake in Border collies kept as working dogs or pets (Burger 1994). Data are mean ± SD

表1:作为工作犬或宠物的博德牧羊犬的食物摄取量研究调查(Burger,1994年)。表中数据为平均值±标准偏差。

Reproduced from Burger IH. Energy needs of companion animals: matching food intakes to requirements throughout the life cycle. J Nutr. 1994 Dec;124(12 Supp):2584S-2593S
摘自:Burger IH的“伴侣动物的能量需求:让宠物在整个生命阶段保持食物摄取量与需求量的平衡”。选自:《营养学杂志》,1994年12月,124(12 增刊): 2584S-2593S 。

 

This variation due to activity level may also underlie the effect of age, whereby younger dogs have a higher energy requirement than older dogs (Kienzle and Rainbird 1991). In contrast, gender has no effect on energy requirement (Kienzle and Rainbird 1991).

这种由于身体活动程度不同而导致的数据离散性可能还会受到年龄的影响,即年轻的犬对能量的需求量大于年老的犬(Kienzle与Rainbird ,1991年)。与此相对,性别对犬的能量需求量并无影响(Kienzle与Rainbird ,1991年)。

Discovery

Energy requirement can be predicted more accurately if the dog’s daily activity level is taken into account using accelerometry

发现与结论

采用加速度测量术对犬的每日活动程度进行测量能够提高对犬的能量需求预测结果的准确性。

A study at WALTHAM® evaluated using triaxial accelerometry to measure daily activity as a predictor of individual maintenance energy requirement (MER) in dogs (Wrigglesworth et al. 2011). Triaxial accelerometers are used in humans and other species, and record acceleration in all three orthogonal planes. For this study, triaxial accelerometers were designed and manufactured at WALTHAM, and attached to each dog’s collar.

在威豪®进行的一项研究中,研究人员采用三轴加速度测量术对犬的每日活动量进行了测定,并将测定结果用于预测犬的维持能量需求量(Wrigglesworth等,2011年)。三轴加速度计主要用于对人和其他物种的活动进行测量,能够记录全部三个正交平面上的加速度。该项研究所采用的三轴加速度计由威豪设计和制作。在试验过程中,研究人员将三轴加速度计绑缚在每只犬的颈项上。

In the study, 10 healthy adult Labrador retrievers wore an accelerometer for two 2-week periods. Data on daily activity were successfully collected for 24 to 26 days. Along with body weight, these data were used as independent variables in a multiple linear regression model to predict the dependent variable of daily MER, and the predictive accuracy of the model compared with one that excluded activity. Observed MER was taken to be the dietary energy intake that maintained stable body weight.

在该项研究中,研究人员给10只成年拉布拉多寻回犬均佩戴加速度计,试验分两期进行,每期时间为两周。该试验成功地采集了每只试验犬在24-26天内的每日活动数据。研究人员将上述数据作为独立变量与体重数据一起输入多重线性回归模型中以预测每日维持能量需求量,并将该模型的预测准确度与不包括活动情况在内的模型的预测准确度进行比较。研究人员即以该试验所得出的维持能量需求量作为犬维持稳定体重所需饮食能量供给量。

The model that included both body weight and daily activity predicted observed MER with a mean absolute error of 63.5 kcal and an SE of estimation of 94.3 kcal (Wrigglesworth et al. 2011). In comparison, when activity was removed from the model, the predictive accuracy was reduced to a mean absolute error of 129.8 kcal and an SE of estimation of 165.4 kcal (Wrigglesworth et al. 2011).

包括体重与每日活动量在内的模型所预测出的维持能量需求量平均绝对误差为63.5千卡,估计标准误为94.3千卡(Wrigglesworth 等,2011年)。作为对比,当把活动量从该模型中移除之后,其预测准确度降低至平均绝对误差129.8千卡,估计标准误降低至165.4千卡(Wrigglesworth等,2011年)。

This study showed that triaxial accelerometers provide an independent variable of daily activity that markedly improves the predictive accuracy of the regression model, compared with using only body weight (Wrigglesworth et al. 2011). Improved accuracy in estimations of MER could be made if an accelerometer was used for each dog to record its daily activity.

该项研究表明,三轴加速度计可以作为每日活动的独立变量值,从而在很大显著改善回归模型的预测准确度(与仅采用体重的回归模型相比较)(Wrigglesworth等,2011)。如果为每只犬均配备加速度计以记录器每日活动情况,则对其维持能量需求的估测准确度能够得到显著改善。

Protein - Key Message

蛋白质-关键信息

WALTHAM® has contributed to the knowledge of the protein requirements of the dog by:

威豪®通过以下方式丰富了关于犬的蛋白质需求量方面的知识:

•    Measuring endogenous nitrogen losses in adult dogs.

•    Assessing the sulphur amino acid requirements of growing puppies.

•    测定成年犬的内源氮损失

•    对发育期幼犬的含硫氨基酸需求量进行评估

Background

背景

Protein consists of amino acids that are classified as essential (because they can’t be synthesised by the body) or non-essential (because the body can synthesise them).

Dietary protein must provide sufficient amino acids to satisfy the body’s metabolic requirement (for example for protein synthesis and the production of other nitrogen-containing compounds). Dietary protein requirements are also dependent on energy intake, life-stage (growth increases the requirement), lifestyle (physical activity increases the requirement) and other factors such as disease.

蛋白质由必需氨基酸(因为身体无法合成这些氨基酸)和非必需氨基酸(因为身体能够合成这些氨基酸)所组成。饮食中的蛋白质必须能够提供足够的氨基酸以满足身体的代谢需求(例如,用于合成蛋白质或其他含氮化合物)。饮食中的蛋白质供给量还取决于能量摄取量、生命阶段(发育期会导致蛋白质需求量的增加)、生活方式(身体活动能够增加蛋白质需求量)以及其他因素(如疾病)。

Why WALTHAM® is Interested

为何威豪®有兴趣从事该领域的研究

Understanding the amino acid and protein requirements of the dog is fundamental to providing optimum nutrition.

了解犬对氨基酸与蛋白质的需求量对于为其制定最佳营养供给方案具有必不可少的作用。

Approach

方法

WALTHAM® assessed the endogenous nitrogen losses of adult dogs, and determined the sulphur-containing amino acid requirements for growth.

威豪®对成年犬的内源氮损失进行了评估,并测定了犬在发育期对含硫氨基酸的需求量。

Discovery (Adult)

The endogenous nitrogen loss of adult dogs reflects their minimal nitrogen requirement

发现与结论(成年犬)

成年犬的内源氮损失反映出成年犬的最低氮需求量。

In an early study at WALTHAM®, the endogenous nitrogen losses (in the urine and faeces) of adult dogs were measured. Daily total endogenous nitrogen output was found to be 273 ± 9 mg/kg0.75 (Kendall et al. 1982). This measurement is a fundamental part of the knowledge of the protein requirement of any species.. It is the obligatory nitrogen loss from the body and hence reflects the minimal nitrogen requirement.

在一项早期研究中,威豪®对成年犬的内源氮损失(通过尿液与粪便损失)情况进行了测定。研究发现,犬每天的内源氮的总生成量为273 ± 9毫克/公斤体重0.75(Kendall等,. 1982年)。该测量值已经成为对所有物种的蛋白质需求量的重要认识。同时,该测量值代表身体的必要性氮损失,因此反映了犬的最低氮需求量。

Discovery (Growth)

Adequate dietary sulphur amino acids result in normal growth of puppies

发现与结论(生长)

饮食中含量适当的含硫氨基酸有助于确保幼犬的健康成长。

A study at WALTHAM® determined the weight gain of puppies fed diets with various levels of methionine and cysteine (Blaza et al. 1982). The study found that the requirement for total sulphur-containing amino acids was 155 mg per 100 kcal metabolisable energy (Blaza et al. 1982). If the puppies were fed diets containing less than this, they gained body weight at a lower rate (Figure 2 Blaza et al. 1982). These data have been taken into account in formulating the NRC 2006 recommendations (NRC 2006).

在威豪®进行的一项研究中,研究人员向幼犬喂食蛋氨酸与半胱氨酸含量不同的各种饲粮并对幼犬的体重进行了测定(Blaza等,1982年)。该研究发现,幼犬所需要的含硫氨基酸总量为155毫克/100千卡代谢能(Blaza等,1982年)。如果喂给幼犬的饲粮中含硫氨基酸的含量低于上值,则幼犬的体重增重率会有所降低(图2 Blaza 等,1982年)。美国国家研究委员会在制定含硫氨基酸建议供给量时也参考了上述试验的数据(美国国家研究委员会, 2006年)。

Reproduced from Blaza SE, Burger IH, Holme DW, Kendall PT. Sulfur-containing amino acid requirements of growing dogs. J Nutr. 1982 Nov;112(11):2033-42.
摘自:Blaza SE、Burger IH、Holme DW与Kendall PT的“发育期的犬对含硫氨基酸的需求量”。选自:《营养学杂志》,1982年11月:112(11):2033-42。

Figure 2: Body weight gain of six individual littermate beagles fed on three levels of methionine (Blaza et al. 1982)

图2:喂食三种蛋氨酸含量不同狗粮后6只同窝比格猎犬幼犬的体重增重情况(Blaza 等,1982年)

Zinc - Key Message

锌-关键信息

WALTHAM® has contributed to the knowledge of the zinc requirements of dogs by:

威豪®通过以下方式丰富了关于犬的锌需求量方面的知识:

•    Showing the levels of dietary zinc that supports healthy growth of puppies.

•    确定出能够支持幼犬健康成长的饮食中的锌含量

Background

背景

Zinc is an essential nutrient that must be provided in the diet. Its functions are multiple and include catalytic (zinc is a cofactor in many enzymes) and structural (zinc helps to stabilise some protein structures [zinc fingers]) roles.

锌是饲粮中必须提供的一种必需营养素。锌在机体内的承担多种功能,其中包括催化(锌是多种酶的辅因子)与构成多种化合物(锌有助于稳定部分蛋白质结构的作用[锌指结构])的作用。

Zinc deficiency in dogs has been reported. It is termed zinc-responsive dermatosis (Colombini 1999) and manifests as poor growth rate and skin lesions.

已经有文献对犬缺锌的情况进行了报告。缺锌所导致的症状称为“锌反应性皮肤病” (Colombini,1999年),具体症状为生长速度缓慢和皮肤损伤。

The NRC 1985 recommended requirement for zinc in puppies was thought to be very low – close to that reported to cause deficiency (Booles et al. 1991).

美国国家研究委员会在1985年给出的犬的建议锌供给量被认为过于偏低,该值甚至与被报告会导致锌缺乏症状的锌供给量相接近(Booles等,1991)。

Why WALTHAM® is Interested

为何威豪®有兴趣从事该领域的研究

Zinc is an essential nutrient for puppies, and it is important to understand how much they need in order to grow and develop normally.

锌是幼犬的必需营养素,因此了解幼犬对锌的需求量对于确保幼犬的正常生长和发育具有正要意义。

Approach

方法

WALTHAM® fed two levels of zinc to puppies and monitored their growth and development.

威豪®的工作人员分别向幼犬喂食两种锌含量的狗粮,并对幼犬的生长与发育情况进行监测。

Discovery

Adequate dietary zinc results in normal growth of puppies

发现

饮食中适当的锌含量有助于幼犬实现健康生长

In a study in collaboration with the University of Liverpool, Labrador retriever puppies were fed diets containing 50 or 200 mg zinc/kg diet (Booles et al. 1991). All the puppies grew normally (Figure 3) and had normal plasma zinc values (Booles et al. 1991). This study showed that 50 mg zinc/kg diet was sufficient to support the healthy growth of puppies, and these data were subsequently taken into account when formulating the NRC recommendation for zinc (NRC 2006).

在威豪®与利物浦大学联合进行的一项研究中,研究人员向拉布拉多犬幼犬喂食含锌量分别为50或200毫克/公斤的饲粮(Booles 等,1991年)。研究发现,所有的幼犬均可以正常生长(图3),其体内血浆中的锌浓度也保持正常(Booles 等,1991年)。该研究表明,50毫克/公斤饲粮的锌含量足够支持幼犬的健康生长。美国国家研究委员会在制定幼犬对锌的需求量时也参考了该项研究的数据(美国国家研究委员会,2006年)。

Reproduced from Booles D, Burger IH, Whyte AL, Anderson RS, Carlos GM, Robinson IP. Effects of two levels of zinc intake on growth and trace element status in Labrador puppies. J Nutr.1991;121(11 Supp):79S-80S
摘自:Booles D、Burger IH、Whyte AL、 Anderson RS、Carlos GM与Robinson IP的“两种不同的新摄取量对拉布拉多犬幼犬生长及其体内微量元素含量的影响”;选自:《营养学杂志》,1991年;121(11 Supp):79S-80S

 

Figure 3: Mean body weights of Labrador puppies receiving either 50 (◊ n=8) or 200 (□ n=10) mg Zn/kg diet (Booles et al. 1991)

图3:被喂食锌含量为50毫克(◊ n=8)或200毫克(□ n=10)/公斤饲粮的拉布拉多犬幼犬的平均体重(Booles等,1991年)

This study also found that the zinc metalloprotein, metallothionein, reflected zinc status in the dog, as had been found in other species (Booles et al. 1991).

该项研究还发现,与其他物种的相关研究结果相同,犬的锌金属蛋白与金属硫因参数能够反映出其体内的锌含量状况。

Another study in collaboration with the University of Liverpool measured the zinc, copper, iron, and calcium concentrations of bitch milk to understand how much of these minerals puppies were receiving prior to weaning (Anderson et al. 1991).

在另外一项与利物浦大学合作开展的研究中,研究人员对犬乳中锌、铜、铁与钙的浓度进行了测定,以了解幼犬在断奶前对上述矿物质的摄取量(Anderson等,1991年)。

Vitamin A - Key Message

维生素A-关键信息

WALTHAM® has contributed to the knowledge of the vitamin A requirements of dogs by:

威豪®通过以下方式丰富了关于犬的维生素A需求量方面的知识:

•    Establishing the safe upper level for dietary vitamin A in growing puppies.

•    确定出生长期幼犬饲粮中维生素A的安全上限值。

Background

背景

Vitamin A is an essential fat soluble vitamin. It must be provided in the diet, but as in other species, excessive vitamin A intake in dogs is undesirable. Excessive vitamin A results in severe adverse effects including abnormal bone development, pain, and reduced growth (Cho et al. 1975). It is therefore important to understand the safe upper limit of dietary intake.

维生素A是一种必需的脂溶性维生素,是饮食中必须供应的营养素。但与其他物种相同,犬也不宜摄入过量的维生素A。摄入过量的维生素A会导致犬出现多种不良反应,包括骨发育异常、疼痛以及生长速度减缓等(Cho 等,1975年)。因此,了解饲粮中维生素A含量的安全上限值具有重要意义。

The safe upper limit for inclusion of vitamin A in complete diets for growing dogs is uncertain. There are few published data available, and since the metabolism and excretion of vitamin A in the dog differs from that of other species (see Morris et al. 2012), this makes cross-species extrapolation problematical.

营养成分完全的狗粮对于发育期犬的维生素A安全上限值目前尚未确定。这方面的已发表资料非常有限,而且由于维生素A在犬体内的代谢机制与排泄与其他物种有所不同,因此对维生素A的安全上限值进行跨物种推断并不适用。

A lack of published data has resulted in a lack of consensus on the safe upper limit for vitamin A in complete diets for growing dogs, with recommendations ranging from 5.24–104.80 μmol retinol (5000–100,000 IU vitamin A)/1000 kcal (4184 kJ) metabolisable energy (Morris et al. 2012).

相关出版资料的匮乏导致有关研究人员对完全狗粮中维生素A的安全含量上限值难以取得一致意见,相关建议供给量从5.24微摩尔至104.80微摩尔视黄醇(5000–100,000 国际单位维生素A)/1000千卡(4184千焦)不等(Morris等,2012年)。

Why WALTHAM® is Interested

为何威豪®有兴趣从事该领域的研究

Vitamin A is an essential nutrient for puppies, and it is important to understand how much they need in order to grow and develop normally. As a fat soluble vitamin, it is essential that dietary levels are sufficient but not excessive.

维生素A是幼犬的必需营养素,因此了解幼犬对维生素A的需求量对于确保幼犬的正常生长和发育具有正要意义。维生素A是一种脂溶性维生素,因此是狗粮中必须含有的营养素,但维生素A的含量同样不宜过量。

Approach

方法

WALTHAM® fed different amounts of vitamin A to puppies and monitored their health in order to establish a safe upper level.

威豪®的工作人员向幼犬喂食维生素A含量不同的狗粮,并对其健康状况保持监测,从而确定出维生素A的安全上限值。

Discovery

There are no adverse effects when puppies are fed a diet containing 104.80 μmol retinol (100,000 IU vitamin A)/1000 kcal (4184 kJ) metabolisable energy

发现与结论

视黄醇含量为104.80微摩尔(100,000国际单位维生素A)/1000千卡(4184 千焦)代谢能的狗粮不会导致幼犬出现不良反应

This study compared the effect of feeding four concentrations of vitamin A to puppies from weaning until 1 year of age (Morris et al. 2012). The hypothesis was that feeding dietary retinol concentrations up to 104.80 μmol retinol/1000 kcal (that is, the highest currently recommended maximum) to puppies would not affect biomarkers associated with health. The study was a collaboration between WALTHAM® and scientists from the Freie Universität Berlin and the University of Potsdam, Germany.

在该项研究中,工作人员向幼犬(刚断奶至1周岁)分别喂食添加4种维生素A含量各不相同的饲粮,然后对幼犬的相关情况进行比较(Morris 等,2012年)。该研究的假定前提是向幼犬喂食最高视黄醇含量为104.80微摩尔/1000千卡(当前维生素A最高建议供给量)的狗粮不会对幼犬健康方面的生物指标构成影响。该项研究由威豪®的研究人员与柏林自由大学和波茨坦大学的科学家共同开展。

The 49 puppies (Labrador retriever and miniature schnauzer) were randomly assigned to one of four groups following weaning at 8 weeks of age and fed a complete diet supplemented with retinyl acetate to achieve an intake of 5.24, 13.10, 78.60 or 104.80 μmol retinol/1000 kcal metabolisable energy (vitamin A equivalent 5000, 12,500, 75,000 and 100,000 IU/4184 kJ).

在该项研究中,工作人员将刚断奶的8周大的49只(拉布拉多寻回犬与迷你雪纳瑞)幼犬随机分成4组,并分别喂食添加了视黄醇乙酸酯的完全狗粮,狗粮中的视黄醇含量分别达到5.24、13.10、78.60 与104.80微摩尔/1000千卡代谢能(维生素A当量分别为5000、12,500、75,000和100,000国际单位/4184千焦)。

Markers of vitamin A metabolism and safety (including clinical examination, haematology and biochemistry, and dual-energy X-ray absorptiometry) were monitored repeatedly up to 52 weeks of age.

在试验期间(到幼犬年龄达到52周为止),研究人员对维生素A代谢与安全性指标(包括临床检查、血液学与生化以及双能X射线吸收测量参数)保持重复监测。

No dose-effects were seen (with the exception of total serum retinyl esters), and there was no effect of dose on adverse events (number, type, and duration) (Morris et al. 2012). Poor faeces quality was the most commonly reported adverse event, occurring in 20 dogs, all resolving within 3 days. Two Labradors exhibited lameness without apparent cause (one in the 5.24 μmol group and one in the 78.60 μmol group); both cases resolved in less than 7 days following treatment.

试验未发现幼犬出现剂量效应(总血清视黄酯除外),也未见任何剂量产生任何不良事件(数量、类型与持续时间)影响(Morris 等,2012年)。试验期间最常见的不良反应是粪便质量较差,共计有20只试验幼犬出现这一情况(所有症状均在3天内消失)。试验中发现两只拉布拉多犬(分别属于被喂食5.24微摩尔与78.60微摩尔视黄醇狗粮的试验组)出现跛行症状,但原因尚不清楚;这两例症状均在接受治疗的7天内痊愈。

This study supports the adoption of 104.80 μmol retinol (100,000 IU vitamin A)/4184 kJ (1000 kcal) as a suitable safe upper level for puppy growth diets (Morris et al. 2012).

该项研究的结果证明104.80微摩尔视黄醇(100,000国际单位维生素 A)/4184千焦(1000千卡)饲粮的维生素A含量标准可以作为发育期幼犬狗粮中的维生素A含量上限标准(Morris等,2012年)。

 

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