Ref Code: CAT/SHE39

Category

Teaching – not applicable

Research - 4

Objective

1. The confinement of sheep or cattle to enable the total collection of faeces for estimating the digestibility of a feedstuff for ruminants.
2. The confinement of sheep or cattle to enable the total collection of faeces and urine for determining the nutrient (N, minerals) balance of a feedstuff fed to ruminants.

Details of procedure

Introduction

Animals are generally kept in metabolism pens or crates as part of a larger experiment. As a minimum they have an introductory period prior to the collection period, where they are introduced to confinement in an animal house and to the feedstuff under examination.

They may also be examined in an animal house for longer periods to determine feed intake of the feedstuff and liveweight gain of the animal fed on the feedstuff under examination.

Movement restriction

Metabolism crates can vary in their size and design, which may result in differences in the way they are used during any collection period. 

All animals should be able to stand up, lie down comfortably and stretch within the metabolism pens / crates.

Animals may be required to be tethered in pens for the length of the collection process (generally 10 days) to allow total collection and maintain separation of the faeces and urine. Tethering may also be required to prevent the animals turning around during the collection procedure, where pens are wide enough to permit this.

 If the dimensions of the pen and the size of the animal restrict its forward and backwards movement to a great enough degree that the urine and faeces are not cross contaminated, animals may not need to be tethered. Alternatively some sheep metabolism crates are designed so that animals can not turn around, but are able to move freely forwards and backwards with no cross-contamination of the urine and faeces. Where this is the case, sheep may be left untethered.

Where tethering is required, procedures should follow the relevant NSW Agriculture SOPs for cattle (CAT35) and sheep (SHE06).

Length of confinement

Animals typically have an introductory phase for adjustment to the metabolism pen / crate, which may include several days for the animal to become accustomed to being tethered. The metabolism period requires a minimum of 7 days faecal / urine collection, however this may need to be varied for specific purposes but should not exceed 10 days for cattle over 400 kg confined to crates. Feed intake is generally determined 24 hours prior to the collection period given the lag between feed eaten, and urine / faeces excreted. The total length of time an animal is confined to the metabolism crate is generally no longer than 14 days, unless specifically approved. Animals are not exercised during this period, since faeces and urine would be lost upon removal of the animal from the crates, negating the purpose of the experiment.

Feed, water and environment

Diets should be formulated by experienced nutritionists given the predisposition of ruminants to laminitis, rumenitis, acidosis and other gastrointestinal upsets, however the primary purpose of metabolic studies is feed evaluation. Animals should not be without feed for longer than 24 hours, unless otherwise justified to meet with the experimental design protocol.

Clean, cool, fresh water should be available to the animal at all times.

Food and water troughs in pens should be located to reduce their contamination by faeces and/or urine.

Pens should be designed to be well-drained and minimise the risk of injury or disease to the animal. Flooring should permit excreta to pass through readily without imposing risks of hoof or leg injury.

The building housing metabolism crates and pens should provide adequate ventilation for respiration, removal of excess heat and waste gases and have appropriate lighting. The building should be well insulated and properly sited to reduce high summer temperatures on animals and maintain adequate temperatures during winter.

Faeces and urine should not be allowed to accumulate and present a health risk to the animals. Pens / crates should be cleaned each day. Sheep should be monitored for flystrike and treated if necessary.

Drugs, chemicals or biological agents

Nil

Impact of the procedure on the wellbeing of animal(s)

Depending on the flooring, and the diet, cattle may succumb to ‘sore’ or ‘hot’ feet. This should be monitored daily, and any lame animals returned to the paddock. Prior to entry into metabolism crates, or pens, animals need be examined for symptoms of lameness and those with any indication of ‘stress’ removed from the experiment. Other impacts relate to social isolation and reduced physical activity. To reduce the impact of social isolation animals are housed in close proximity to each other which reduces their stress and abnormal behaviour

Reuse and repeated use

Re-use should be permitted for those animals that have reacted favourably to confinement, however animals should be provided with a break each 14 days, including exercising before commencement of the next metabolism study. Re-use of animals has specific benefits to the researcher by improving the precision of results (change-over designs) and reducing the stress in animals since they are familiar with the environment and procedures.

Care of animals during/after the procedure

Careful observation by an experienced person to ensure the animals’ well-being. Any animals that refuse to eat or become ill, indicated by high rectal temperatures (> 39° C) or by ‘hot’ or inflamed shins, or by persistent lying, should be moved back to a pen or to pasture and be treated appropriately to ensure recovery.

Pain relief measures

Not anticipated

Qualifications, experience or training necessary to perform this procedure

Animal carers should be competent in handling animals and have good knowledge of the husbandry and management of sheep and cattle. The animal carer should also have an awareness of unusual or aberrant behaviour in animals and the ability to administer medicines under veterinary direction and supervision.