1. Selenium (Se) Only nutrient whose level is controlled by FDA Has smallest optimal range (difference between requirement and toxicity) Toxicity can be a regional problem in Montana

2. Selenium (Se) There are Se accumulating plants Can be indicators of toxicity Can result in acute toxicity – sudden death Astragalus species (locoweed) Vetches Some native range plants

3. Selenium (Se) Toxicity Originally called Alkali disease Chronic toxicity Affects keratin of hair/hooves Rough hair coat “Bobbed” tail Sloughed hooves Affects adult animals

4. Se Deficiency Se deficiencies that affect young animals Nutritional Muscular Dystrophy White Muscle Disease Affects ability to stand and nurse

5. Se Deficiency In reproductive females Retained placenta Decreased fertility

6. Iodine (I) Not high in feeds Therefore we use Iodized salt (even for humans) Regional deficiency – Great Lakes, Montana

7. Iodine Deficiency At any age = Goiter Enlargement of thyroid gland Thyroxine contains Iodine In reproductive females = stillbirths Weak, hairless young

8. Mn Deficiency Symptoms: Lameness Abnormal bone growth Immune dysfunction

9. Mn Deficiency In reproductive females: Delayed estrus Reduced ovulation Embryonic mortality Decreased fertility

10. Cobalt (Co) Required for rumen microbes to synthesize Vitamin B 12 Part of Vit. B 12 ’s chemical structure

11. Cobalt (Co) Deficiency regional grazing

12. Wasting Disease (Co deficiency) First discovered in Australia Australia – extreme emaciation Because Vit B 12 important in energy metabolism

13. Wasting Disease (Co deficiency) To cure: Cobalt must be provided to rumen Injection of Co won’t work (because Co needed in rumen to synthesize Vit. B 12 ) Injection of Vitamin B 12 will work

14. “Organic” Minerals Chelated Attached to amino acids Proteinated Attached to peptides Complexed Attached to other organic compounds

15. “Organic” Minerals Usually Zn, Cu, Mn, & Co are included in organic form Hypothesis: Increased availability

16. Example feed tag containing organic minerals

17. “Organic” Minerals Are they effective? Conflicting research results Positive results with animals that are: High producing Stressed Immune-compromised

18. “Organic” Minerals Organic forms are more expensive than sulfates, chlorides, etc. Therefore, they must be cost effective

19. “Organic” Minerals Recommendation for organic mineral use: If high S, Fe and/or Mo (antagonists)

20. “Organic” Minerals Recommendation If problems occur such as: Calf/lamb scours Increased reproductive failure Change in hair color Increased foot rot Increased respiratory infections

21. “Organic” Minerals Due to cost, recommendation is: 70% inorganic + 30% organic Supplementation during strategic (stressful) times: Cows – prior to calving through breeding Ewes – prior to lambing, during breeding Calves/lambs – prior to weaning