Exam Notes - Section 4

Exam Notes - Section 4 - 5 Cows in the herd?...

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Unformatted text preview: 5 Cows in the herd? Dry,Transition, Early, Mid-late Lactation. ◦ Heifers vs. Older cows? ◦ & The dry cow Goals? ◦ & Body condition &#2; Rest for the rumen Overview of the lactation cycle development – late gestation &#2; Energy - .57 - .66 Mcal/lb. &#2; Protein - 12% - RUN? &#2; Minerals Ca - .4% (<100g/day) - ~21 g of absorbable ◦ Ca/d P - .25% ◦ Na - .1% ◦ Se - .3 ppm***** ◦ Fiber - >30% ADF, Form of fiber?***** ◦ Vitamins - A – 2,740 I.U./lb., D - 750/lb. ◦ E - 40 / LB. ****** &#2; Rest and rejuvenation of rumen Bulky, high fiber diet ◦ Encourage cud chewing ◦ High pH. ◦ & Rumen absorptive surface shrinks in response to lower VFA? ◦ & “Calm before the storm” &#2; Dry cow diet - Fiber digesting bacteria - high pH, dietary substrate? &#2; High producing cow diet - Concentrate digesting bacteria - low pH, dietary substrate? Rumen function of transition cow? &#2; Achieve high intake as quickly as possible? - Cow driven – Management driven. Goal for transition? Do cows milk more because they eat more? ◦ Do cows eat more because they milk more? ◦ & Adapt rumen to new feeds Bacterial ◦ Rumen papillae? ◦ & Critical to determining success in ensuing lactation. Peak DMI, low incidence of metabolic disorders ◦ Peak milk ◦ & Protein 12 – 15% ◦ Fiber ADF – 23 – 27% ◦ NDF – 32 – 35% ◦ Quality and form of fiber. ◦ Nutrient Levels? Close up cow (<20d prepartum &#2; Goal? High peak dry matter intake, peak milk yield, ◦ healthy. Each lb. of peak yield = 300 lb. of lactation ◦ yield. &#2; Negative nutrient balance - first ??? days of lactation? Early lactation- the first 100 days WHY? ◦ DMI is inadequate. ◦ & Energy - 100 lb. of body fat = 600 - 1,000 lb. lactation milk yield Mobilize stores of energy - body fat. ◦ fine line between “normal” and disease state. ◦ & Protein Body stores? ◦ & Minerals Body stores ◦ Challenge is attaining peak dry matter intake, peak milk yield, early in lactation &#2; HOW???? &#2; Individual cow care &#2; Monitor &#2; Prepartum ration &#2; ENVIRONMENT !!!!!!!!!!!!!! Prepartum – close up group &#2; Energy - High energy forages - Which? ◦ & Alfalfa - <30%ADF &#2; Corn silage - <25% ADF High energy concentrates - >.88Mcal/lb. ◦ & ground or flaked corn or barley &#2; dried distillers grains &#2; whole cottonseed Maximizing nutrient intake – post partum &#2; roasted soybeans &#2; Protein Amt. and quality - Amino acid content ◦ Correct amt. of degradable and undegradable ◦ protein &#2; Meet the needs of rumen microbes first. ◦ Optimizes rumen microbial amino acid synthesis &#2;...
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This note was uploaded on 03/30/2008 for the course DASC 3274 taught by Professor Rejames during the Fall '07 term at Virginia Tech.

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Exam Notes - Section 4 - 5 Cows in the herd?...

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