1. Cattle Nutrition Ruminant Herbivores Calf- young animal Heifer- female calf that has not given birth and is less than 30 months old Cow- older than 30 months old, or has given birth Bull- intact male Steer- castrated male up to 4 years old Ox- castrated male, more than 4 years old

2. Dairy Cattle Main objective- increase dry matter intake to produce higher levels of milk production Key factors: energy, ration digestibility, rumen fill, palatability, body weight( BCS), environment, frequency of feeding and water

3. Phase feeding program Phase feeding - Changing the nutrient concentration in a series of diets formulated to meet an animal’s nutrient requirements more precisely at a particular stage of growth or production - Based on lactation and gestation cycle

4. Phase 1 First 10 weeks of lactation Peak milk production happens in this phase Negative energy balance develops, so cow uses body stores to make up difference ( can borrow fat, but cannot borrow protein)

5. What to feed in Phase 1 Increased grain for energy ( corn, wheat, soybeans) Protein supplementation to meet amino acid requirements ( dried brewers grain, distillers grain, corn gluten meal) Increased concentrates and fats to increase energy density of feed ( soybeans, sunflower seeds) Sodium bicarbonate “ buffer” to reduce acidosis and maintain ruminal ph

6. Phase 2 Begins 10 weeks post calving and can continue to 20 th week Highest dry matter intake happens here Nutrient intake is finally in balance with nutrient needs

7. What to feed in Phase 2 Lower protein levels because requirement is met by supplementation in Phase 1 Adequate fiber Limited grain intake Frequent feeding ( minimizes digestive upset)

8. Phase 3 “late lactation period”, cow is pregnant again Nutrient intake exceeds requirement for production Main period for restoring body reserves for next lactation

9. What to feed in Phase 2 Easiest phase to manage because cow is pregnant and milk production is declining Increased amount of forage instead of concentrates Lower protein

10. Phase 4 Most of the “ dry” period Final regaining of any lost body weight happens here Goal is to get cow in good condition for parturition, but not excessively fat ( BCS of 3.5 out of 5.O scale)

11. What to feed in Phase 4 High protein, energy, Ca and P needs Combination of legume-grass hay and corn silage ( with added vitamins and P0 Long stem grass hay ( length of hay matters) Limit grain to energy and protein needs

12. Body Condition Scoring A numeric system to subjectively assess and animal’s degree of fatness Fat Cow Syndrome - High blood lipids and fatty liver from eating excess energy from grain or corn silage - Can lead to calving difficulties, displaced abomassum and ketosis

13. Phase 5 Last 1-3 weeks of “dry” period, just before calving Referred to as a “transition period” Increase grain intake to prepare rumen for high energy diets that will be needed postpartum

14. What to feed in Phase 5 Gradual increase in grains Small amounts of all ingredients used in the lactation ration Maybe decrease Ca in “ milk fever” prone cows

15. Beef Cattle Nutrition Most critical factor influencing performance of cattle on forage diet is the amount of Dry Matter Intake Young, growing grass and pasture crops usually have ample nutrients old pastures, crop residues and harvesting methods cause reduction in nutrients

16. Biological Cycle Goal: optimal nutrition at each stage, not maximum nutrition Cycle is made up of 4 periods that span 1 year: 3 trimesters and 1 postpartum period

17. First Trimester ( 95 days) Begins the 1 st day of conception Nutrient needs are for maintenance and lactation if the cow has a calf with her Milk production is declining at this stage

18. Second Trimester ( 95 days) Calf is weaned, lactation requirements end Lowest nutrient requirements at this point Feed minimally Easiest and most economical time to increase a thin cows BCS

19. Third Trimester ( 95 days) Rapid fetal growth causes rapidly increasing nutrient needs Watch BCS carefully, cow gains 1 lb per day Too thin cows experience dystocias, weak calves and decreased milk production

20. Postpartum Period ( 80 days) High lactation requirements Feed intake is 35-50% higher than non- lactating cow Nutritional stress at this point causes problems during the cow’s next breeding ( usually 80 days post partum)

21. Energy Requirement Energy is considered first in balancing diet for beef cattle, it’s the largest portion of the ration Energy utilization determines cow’s ability to use other nutrients Good quality forage satisfies adult energy requirements Poor quality forages need to be supplemented with concentrates

22. Protein Requirements 50% of all protein and amino acid needs are met by microbial protein synthesis Protein deficiency is common when cows consume straw and low quality hay Urea is commonly used as a protein supplement

23. Beef Cattle, Water requirements Need abundant supply at once daily Range cows consume 2 ½ gallons daily in winter and up to 12 gallons per head in summer When salt is added, water need is increased Fresh succulent feeds or silage help reduce need

24. Beef Cattle mineral requirements Salt- need more when eating succulent forages than when eating drier forage Calcium- depends of Ca concentration in soil, higher needs in growing and lactating cows Phosphorus- Low P levels in roughage, so P is often offered free choice in a mineral mix Cobalt- required for rumen microorganisms to synthesize vitamin B 12

25. Minerals continued Copper- Simental and Charlois have a higher requirement than Angus Iodine- deficiencies in Northwest and Great Lakes area soil; supply via iodized salt

26. Beef Cattle Vitamin Requirements C, D, E, K and B complex- no need for supplementation; ruminal microflora synthesizes B complex and K, Vitamin C is synthesized in tissues, Sun dried forages contain lots of Vit D and E A- roughage and grains are low in Vit A, causing a deficiency. Cattle on pasture can store large amounts of Vit A for 2 months in liver, so deficiency isn’t immediately apparent. Look for signs of rough coat, diarrhea, excessive lacrimation

27. Grazing Systems and Management 1. Continuous Grazing - Most common type of grazing scheme - Cow grazes 1 area for the entire season up to 1 year - Low maintenance, but production suffers

28. Grazing systems continued 2. Deferred rotational grazing - 4 pasture system - 1 pasture would not be grazed from spring to mid summer in order to allow desirable plants to flower and reach seed maturity - The following year another pasture would not be grazed - After 4 years, all four pastures will have had time to rest

29. Grazing systems continued 3. Rest rotation - Uses 3-5 pastures - 1 pasture is not grazed for an entire year, while herd uses other pastures

30. Grazing Systems continued 4. Short duration grazing - Developed in France - 8-40 pastures grazed intensively for 2-3 days, then not grazed again for several weeks

31. Nutritional Disorders 1. Pasture bloat - Comes from consuming lush legumes ( alfalfa, red clover) - Relieve bloat by inserting stomach tube into rumen and giving anti-foam material ( ex vegetable oil) - A trocar is used in extreme cases to release pressure ( large “needle” puncture through skin and gas rushes out)

32. Nutritional disorders continued Grass tetany - Low Mg levels in blood from grazing lush green grass pastures - Common in cows nursing calves under 2 months - Symptoms: excitability, cows act blind - Fix by feeding free choice mineral supplement containing Mg, early in grazing season

33. Nitrite toxicity - Caused when intake of nitrite is in excess of the rumen’s ability to convert it to ammonia - Causes hemoglobin in blood to change into a form which cannot transport oxygen to the tissues - Cow dies from asphyxiation - Treat with injection of IV methylene blue

34. Fescue toxicity - Caused by grazing or consuming harvested hay from tall fescue pastures - Cow eats the endophytic fungus that grows between the fescue cells - signs: soreness in hind limbs, “ fescue foot” hooves and tail slough off, hypersalivation and polyuria

35. Acute Pulmonary Emphysema “ Asthma’ - Occurs in western US when cattle are moved from dry rangelands to lush meadow pastures abruptly - Signs seen in 4-5 days after diet change - Symptoms: labored breathing, extended neck, open mouth breathing, grunting - Prevention: ( no treatment) slowly introduce cattle to new pasture and supplement with monensin