Critical aspects of sheep mineral nutrition. Critical aspects of sheep mineral nutrition

Transcription

1 Critical aspects of sheep mineral nutrition Critical aspects of sheep mineral nutrition

2 Agenda Identification of Mineral Problem Mineral Sources Macro Mineral Related Issues Trace Mineral Related Issues 2

3 Sheep are not Performing Is there enough grass? Is there adequate energy intake Is there sufficient protein and quality protein? Health Issues Parasite issues 3

4 If minerals are the Issue Diet fed Mineral supplementation History of supplementation/treatment Clinical signs Analysis Forage & Feed Water Bloods Liver 4

5 Minerals and Vitamins Calcium Phosphorous Sodium Magnesium Sulphur Potassium Chloride Macro Minerals (g or %) Trace Minerals (mg) Copper Zinc Cobalt Manganese Selenium Iodine Iron Vitamin A Vitamin D3 Vitamin E B Vitamins Vitamins (iu) Antagonists (g) Lead Aluminium Molybdenum Iron

6 Mineral Sources Forages (natural presence/background) Feed materials (natural presence/background) Moist feeds Concentrate feeds (background +/- supplementation) Mineral Supplements Powder minerals Bucket & Block minerals Drench Bolus Injections Water application 6

7 Responsible Mineral Nutrition: Challenges 1. Complexities of mineral nutrition: antagonistic effects 2. Knowledge and hence confidence by the nutritionist to consider minerals and vitamins. Confusing labeling 3. Broad range of sources 4. Failure of any single person to take responsibility: further exacerbated by lack of forthcoming information on all sources from the farmer 5. Rationing programmes not used to enable a full review of inputs in this critical nutritional area.

8 Forage Sampling (FAA Sampling Procedure) Core samples: 3 full depth samples from the top diagonal of the clamp. Face samples Samples from 6-9" behind the face following a 'W' pattern Total of 9-15 samples taken along the W A different horizontal and vertical position for each sample. No not sample mouldy patches as are not fed/eaten Mix thoroughly the sub samples in a suitably sized container A minimum of 0.5 kg should be sent to the laboratory Quickly transferred to a clean self sealing polythene bag Remove as much of the air as possible by squeezing the bag

9 Grass Silage Mineral Analysis (n=40) Macro Minerals Average Range Grass silage (National Survey) Ca (%) P (%) Mg (%) Na (%) K (%) S (%) Cl (%) CAB (meq/kg)

10 Grass Silage Mineral Analysis (n=40) Trace Elements Average Range Grass silage (National Survey) Mn (mg/kg) Co (mg/kg) Zn (mg/kg) Se (mg/kg) Cu (mg/kg)

11 Grass Silage Mineral Analysis (n=40) Antagonists Average Range Grass silage (National Survey) Fe (mg/kg) Al (mg/kg) Pb (mg/kg) Mo (mg/kg)

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14 Mineral Levels in Raw Materials Average Cu No. samples Barley Distillers Hi-pro Soya Maize Maize Distillers Palm Kernal Rapemeal Soya Hulls Sugarbeet Sunflower Wheat Wheat distillers Wheatfeed

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16 Sheep Mineral Specs Analysis Product Name Sheep Intensive Lamb** Ewe + Vit E Vitamin A iu/kg 400, , ,000 Vitamin D3 iu/kg 80, ,000 Vitamin E iu/kg 600 1,000 6,000 Vitamin B12 mcg/kg Vitamin B1 mg/kg Iron mg/kg 2,000 1,333 2,000 Cobalt mg/kg Manganese mg/kg 2,000 1,333 *2,400 Zinc mg/kg 2,000 1,667 *2,400 Iodine mg/kg Selenium Mg/kg *12 Calcium % Phosphorus % Salt % Magnesium % Pack size Kg 25kg 30kg 25kg Ammonium Chloride 5kg/ton 16

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19 Macro Mineral Related Issues Hypocalcaemia Hypomagnesaemia Urinary Calculi 19

20 Milk Fever (Hypocalcaemia / Lambing sickness) Occurs during the last 6 weeks of pregnancy (sporadically during early lactation) Usually older ewes, occurs in any condition Milky breeds may be more susceptible Due to increased calcium demand in late pregnancy Risk Factors Sudden changes in diet Associated with stress such as housing, moving, gathering for vaccination, bad weather Incorrect mineral supplementation 20

21 Clinical Signs of Hypocalcaemia Calcium is needed for muscle contraction and muscle tone Ewe becomes depressed, weak, stagger and unable to stand Rumen stasis and bloat Green rumen contents around nostrils and mouth Vaginal prolapse Rapid progression to coma and death within 48 hrs 21

22 Prevention of Hypocalcemia Prevention is important Due to the rapid progression of hypocalcaemia, deaths may occur Providing adequate nutrition for pregnant ewes is key Balanced mineral mix in late pregnancy Calcium supplements in late pregnancy (5-10g Ca/day) Prevent stress in pregnant ewes 22

23 Calcium Requirement Calcium Requirement Total Requirement Early Gestation Late Gestation Early Lactation Merck 6.5g/d 8.8g/d 7.9g/g 6.5g/g INRA 7-8g/kg DMI Supplemental Prelambing PostLambing Teagasc 2.9g 3.6g Calcium Supply PreLambing Grass Silage 1kg DMI 5g/d Concentrate (no min) 0.75kg 3.3g Mineral (20%Ca) 5.0g/kg@0.75kg 3.8g Mid Lactation 12g or 7g/kg DMI * Requirement for 70kg Twin Bearing Ewes: Merck Vet Manual. (no mineral = 5g/kg DMI) 23

24 Grass Tetany (Hypomagnesaemia / Grass staggers) Low blood magnesium levels Most common during the 6 weeks following lambing Risk Factors There are little/no body stores of magnesium Therefore a daily dietary intake of magnesium is essential Risk times Lush grass is low in magnesium and high potassium Lush grass also has a reduced gut transit time Stressed animals and reduced Intakes Poor weather, disease, lameness, malnutrition, weaning, 24

25 Clinical Signs of Hypomagnesaemia Magnesium is needed for nerve function Excitability /nervous Muscle tremors / shaking Collapsed and Convulsions / Seizures Rapidly followed by death often found dead Stress handling/movement/dogs can induce this Other sheep within the flock will also be suffering from low blood magnesium levels 25

26 Grass Tetany: Prevention Watch closely after moving onto lush pasture Minimize stress Provide shelter and feed during bad weather Provide a daily intake of magnesium Magnesium rich concentrates Rumen bullets Licks Buckets 26

27 Magnesium Requirement Magnesium Requirement INRA g/kg DMI Supplemental Prelambing PostLambing Tetany Times Teagasc 0.5g (3% mineral) 1.2g (5% mineral) 4g (14% min) Elbex Avoid high Mg 0.7% Mg in concentrate General g/kg DMI 0.6%Mg Conc Magnesium Supply Post Lambing Grass 2.2kg DMI 3.5g/d Concentrate (no min) 0.75kg 1.9g/d * Requirement for 70kg Twin Bearing Ewes: Merck Vet Manual. Cal Mag (7.5kg/ton) 3.75g/kg@0.75kg 2.8g 8g or 2.7g/kg DMI 27

28 Urolithiasis / Urinary Calculi / Watery Belly Urinary calculii is a risk when intensive feeding lambs, primarily ram lambs (whether or entire) Important to have diet checklist Ca:Phos ratio 2:1 Calcium level % finished feed Magnesium max level 0.25% Increase salt level (max %) Add ammonium chloride 5-10 kgs/tonne (7-10gs/head) Clean fresh water in adequate quantities Ammonium chloride acts to acidify urine and disrupts magnesium-ammonium-phosphate crystal formation 28

29 Trace Mineral Related Issues Trace Mineral Issues: Deficiency causes issues Complex Interactions Toxic Levels Deficiency elements Toxic elements Excessive elements Se, I, Mn, Co, Zn, (Cu) Cu, Se, I Co Fe, S, Mo, Al, Se 29

30 Cobalt Cobalt: Required for its role is as the central component of vitamin B12. Vitamin B12: is essential for enzymes involved in energy and amino acid metabolism. Cobalt Deficiency: Occurs in areas of low soil cobalt Worm burden can exacerbate cobalt deficiency Deficiency in growing lambs Poor thrive (Pine) Failure of vaccinations (e.g. pulpy kidney, pneumonia) Deficiency in ewes - poor mothering ability 30

31 Minutes Effect of cobalt in ewe diet on lamb vigour Standing Finding udder Sucking Mortality in 1st 4 Weeks Fisher; 1992 No Cobalt + Cobalt

32 Cobalt and B12 32

33 Cobalt and B12 Cobalt Requirement Total Teagasc Supplemental 0.3mg/kg DMI 2mg/d Cobalt Supply Post Lambing Grass 2.0kg DMI 0.30mg/d Co in Concentrate 0.75kg 0.75mg/d 1.05mg or 0.38mg/kg DMI Cobalt Supply Post Lambing Grass 2.0kg DMI 0.10mg/d Co in Concentrate 0.5kg 0.5mg/d 0.6mg or 0.24mg/kg DMI 33

34 Copper deficiency Copper deficiency seen when sheep are grazing pastures low in copper True deficiency rare, most is locked up by molybdenum sulphur and iron Some breeds more susceptible (variation in the efficiency of absorption) Deficiency in mid to ate pregnancy causes swayback in lambs Incoordination /swaying on their back legs (lambs are bright) Subclinical disease (marginal levels) - poor weight gains, poor fleece steely wool Treatment Minerals Drenches Injections 34

35 Copper Poisoning Symptoms: Liver damage Animals become increasingly weak. Wandering aimlessly or head-pressing. Jaundice develops and breathing becomes shallow and rapid. Most animals die following a short period. Prevention : Avoid feeding diets high in copper Treatment response is poor in animals showing clinical signs. Use of Copper antagonists such as molybdenum or sulphur. Blood sampling is not always reliable Liver sampling more reliable as copper is stored in the liver Diet < 10 ppm

36 Iodine Certain soils are deficient in iodine Feeding brassicas - impair iodine uptake Sheep more susceptible than cattle Iodine deficiency late abortions Birth of weak lambs Goitre enlarged thyroid poor growth low fertility, poor embryo survival Over supplementation of the ewe in late pregnancy reduces the lambs ability to absorb antibodies from colostrum 36

37 Selenium and Vitamin E deficiency Important for immune function in rapidly growing young animals Certain soils are deficient in selenium Vitamin E generally found in green crops Clinical disease white muscle disease (sudden stiffness) in rapidly growing lambs Subclinical/marginal deficiency birth of weak lambs, poor growth rates Diagnosis blood sample for GPx Excess selenium is toxic 37

38 Summary Establish Mineral Problem & Conduct Analysis Variation in mineral supply from forages & feeds Mineral Related Issues - Fatal Mineral Related Issues Thrive & Vitality 38

39 Thanks for the Attention! 39