PATHOLOGY - Flock Nutritional and Metabolic Diseases Flashcards
Why is ewe nutrition so important?
Ewe nutrition is key to both ewe and lamb health as nutrition affects susceptibility to disease, dystocia, lamb viability, colostrum and milk quality and production
What body condition score should ewes be at weaning?
Body condition score (BCS) or 2 - 2.5
What body condition score should ewes be at tupping?
Body condition score (BCS) 2.5 - 3.5
What is flushing?
Flushing is a temporary but purposeful increase in the level of nutrition at tupping to boost ewe ovulation and conception rates
What body condition score should ewes be at the second trimester?
Body condition score (BCS) 2 - 3. The placenta develops during the second trimester, and thus nutrition can have an effect on foetal size and birthweight
What body condition score should ewes be at the third trimester?
Body condition score (BCS) 2.5 - 3.5. 75% of foetal growth occurs within the third trimester so ewe nutrition is critical during this period
How should ewe nutrition be altered during the third trimester?
During the third trimester, concentrates may need to be increased for the last 6 - 8 weeks of gestation and dry matter should be reduced to 1.8 - 2% of their liveweight
Grass is very energy dense and thus very useful
Which methods can be used to monitor the nutritional status of ewes?
Body condition scoring (BCS)
Weighing
Lamb birth weights
Metabolic profiling
What are the limitations of body condition scoring (BCS) to monitor ewe nutritional status?
Subjective
Labour intensive (to palpate every ewe)
What are the limitations of weighing to monitor ewe nutritional status?
Cost of weighing equipment
Weight can vary based on urine/faeces stored, wet fleece etc.
How can lamb birth weights be used to monitor ewe nutritional status?
Lamb birth weights can be used to indicate if nutrition should be altered in the ewes still due to lamb
What is metabolic profiling?
Metabolic profiling refers to the analysis of various metabolic markers in the blood to assess the metabolic and nutritional status of an animal. Metabolic profiling can be used to monitor the nutritional status and optimise feeding strategies, as well as identify any metabolic changes that may indicate disease
When should you carry out metabolic profiling in a flock?
Take blood samples for metabolic profiling 2 - 4 weeks prior to lambing. Be aware that the earlier you take samples, the less likely you are to see metabolic changes, however if you do you have more time to rectify them. However, the closer to lambing you take samples, the more metabolic changes you are likely to see as the ewes are under more metabolic stress, however you have less time to correct it
How do you carry out metabolic profiling in a flock?
Take representative blood samples from 5 ewes from each group (i.e. singles, twins and triplets). Or, take 10 - 15 representative blood samples if they haven’t been ultrasound scanned. Make sure to also body conditon score (BCS) the ewes at time of blood sampling
Which blood parameters should you assess in ewes in the pre-lambing period for metabolic profiling?
β-hydroxybutyrate (BHB)
Urea
Albumin
Globulin
Magnesium
Why is it important to measure serum β-hydroxybutyrate (BHB) in ewes in the pre-lambing period?
β-hydroxybutyrate (BHB) is a ketone body released into the bloodstream when the ewe metabolises fat stores to meet their energy demands and these free fatty acids are oxidised in the liver to form ketone bodies. This occurs in periods of negative energy balance which can occur when energy intake is insufficient to meet requirements for maintenance, pregnancy and lactation. Elevated β-hydroxybutyrate (BHB) levels suggest the ewe is mobilising significant fat stores which can indicate a poor energy balance or inadequate nutrition
Why is it important to measure serum urea levels in ewes in the pre-lambing period?
Urea is a byproduct of protein metabolsim, and measuring serum urea levels allows for the assessment of protein intake and utilisation in the rumen. Decreased serum urea levels can indicate inadequate supple of rumen degradable protein, which is important for maintenance, growth, pregnancy, lamb growth, milk production and fertility
Be aware low serum urea levels can also indicative hepatic disease
Why is it important to measure serum albumin levels in ewes in the pre-lambing period?
Decreased albumin levels can indicate chronic disease (such as liver fluke), reduced liver function and/or poor long term protein status
Why is it important to measure serum globulin levels in ewes in the pre-lambing period?
High globulin levels can indicate a chronic inflammatory condition
How does a ewe’s appetite change as lambing approaches?
As lambing approaches, a ewe’s appetite will decrease by 30% as the growing foetuses and increasing uterus size will put pressure on and reduce the space in the rumen. However the energy requirement for the ewe will increase
What is the maintenance energy requirement for a ewe?
8 - 11MJ per day
What is the energy requirement for a ewe in late pregnancy?
19MJ per day
What is the energy requirement for a ewe in peak lactation?
30MJ per day
What are the common periparturient diseases seen in ewes?
Abortion
Pregnancy toxaemia
Hypocalcaemia
Hypomagnesaemia
Septicaemia