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Nutritional Considerations for the Cow Herd . (based on calving season). What do they need? When do they need it?. Energy. Result of CHO and Lipid metabolism ( eg . Converting hay to VFA) Requires the majority of feed intake Most commonly deficient nutrient for the brood cow.
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Nutritional Considerations for the Cow Herd (based on calving season)
What do they need? When do they need it?
Energy • Result of CHO and Lipid metabolism (eg. Converting hay to VFA) • Requires the majority of feed intake • Most commonly deficient nutrient for the brood cow
Estimated Net Energy Requirementsfor 2-, 3-, and 5-year old Cows Breeding Season Calving Wean Mcal/d Months Since Calving 1996 Beef NRC
Protein • Cattle have 2 protein requirements • N needs of rumen bacteria • Amino acids of the animal • Degradable Intake Protein (DIP) • Breakdown in rumen and supply N to bacteria • Undegradable Intake Protein (UIP) • Escape rumen, digested in gut, supply AA
Protein Needs for Cows 30 lb peak milk production
Macro Salt (NaCl) Calcium (Ca) Phosphorous (P) Magnesium (Mg) Potassium (K) Sulfur (S) Micro Copper (Cu) Selenium (Se) Zinc (Zn) Manganese (Mn) Cobalt (Co) Iron (Fe) Chromium (Cr) Molybdenum (Mo) Iodine (I) Nickel (Ni) Macro & Micro Minerals
Mineral Content of Forages • Grasses are low in P, Mg, Se, Cu, Zn, Mn and others • Grasses are high in Ca and K • Grains are low in Ca, K, and many TM
Vitamins • Fat Soluble • A, D, E and K • Water Soluble • B complex and C • For the cow, A is the only vitamin deficient under normal circumstances
Water • Factors affecting water intake • Temperature • Feed moisture • Body size • Production status
Objective Meet the nutritional needs of the cow herd as economically as possible….
…generally on fescue-based pasture systems which minimize the need for stored (hay, silage) or purchased (supplements) feeds.
Critical Critical
Goals(Spring Calving Cows) • Feed a least-cost, balanced ration • Have healthy, vigorous calves and a good milk supply • Cycle early and rebreed before extreme heat (in July)
Goals(Fall Calving Cows) • Feed a least-cost, balanced ration • Rebreed in December/January • Extra feed for calves during February 15 to April 15 (creep graze or feed)
Quality of Hay High Low Classes of Cattle Young Calves Weaned Calves Replacements Yearlings Bred Heifers 2-year old Cows Lactating Cows Mature Cows, last 1/3 of gestation Mature Bulls Mature Pregnant Cows, first 2/3 of gestation Allocation of Hay to Various Classes of Cattle Based on Quality
Or use your forage analysis to estimate dry matter intake…120 / NDF (%) = DMI (% BW)
Find out how much hay the cow will consume and make up a deficiency with energy or protein supplement
Energy Deficiencies Affect • Cow Rebreeding • Calf Health/Survival • Calf Growth Rate
Timing of Deficiency Influences Effect • Pre-calving deficiency days of post partum interval • Post-calving deficiency % conception
How do you monitor the nutrition adequacy of your feeding program?
Beef Cattle Body Condition Scoring • Reflects adequacy of feeding program • BCS is a visual assessment of body fat • Scoring range of 1 to 9, 1=thin, 9=obese • A score = 4 to 5% empty body fat and 65 to 85 lbs of body weight
Body Condition Score (BCS)in Beef Cows • Highly related to reproductive efficiency • Calving time BCS very important • Thin cows at calving have days return to heat and pregnancy rate
Forage System 2 (High) = creep gate
Forage System 3 (Low) = creep gate
Forage System 4 (High) = creep gate
Forage System 5 (High) = creep feeder (soyhulls)
Parameter Evaluated Affects Animals Mineral Requirement Immunity > Fertility > Growth > Maintenance
Factors influencing mineral intake from forage • Forage mineral content • Forage mineral availability • Antagonists • Dry matter intake
Organic vs. Inorganic Minerals • Absorbed by a different system • Use in presence of antagonists • Better at immune stimulation
Situation: Selenium (a trace mineral) is presently supplied as sodium selenite at 3X NRC recommended level, yet deficiencies seem to appear (impaired immunity, etc.) FDA max. daily allowable is 3mg/hd/da in supplement