ANSC 318 1st Edition Lecture 22 Outline of Last Lecture I. Dairy Nutrition, Feeding Systems, and Body Condition Scores. Outline of Current Lecture II. Nutritional Recommendationsa. Phase IV – Dry Periodb. Phase V – Transition Periodc. Nutritional ManagementIII. Metabolic Disorders Relating to Nutrition in Dairy Cattlea. Milk Feveri. Pre-calving dietii. Preventionb. Ketosisc. Displaced AbomasumIV. Swine Nutrition and Feedinga. Pork ProductionCurrent LectureDairy Cattle Nutrition and FeedingNutritional RecommendationsPhase IV – Dry PeriodGoals to Achieve:•optimize fetal growth•prepare cow for next lactation (regenerate mammary gland)•minimize length of dry period (about 60 days)•feed cows to achieve target BCS at calving  3.5Feeding Recommendations:•separate dry cows from lactating cows•feed higher roughage (lower energy) based diets-energy requirement lowers during this period•avoid high-grain diets to prevent abomasal displacement-twisting of the abomasum or omasum that blocks digestive tracts•avoid feeding excess Ca levels to prevent milk feverThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.Nutritional Recommendations:Phase I – Early Phase II – Mid Phase III – Late Phase IV – DryMilk Production, lb/day74 60 30 0NEl, Mcal/lb, DM 0.78 0.75 0.69 0.57Crude Protein, % 18 16 15 12UIP, % 6.3 5.8 5.4 --DIP, % 10.4 10.0 8.8 --ADF, % 19 20 21 27Calcium, % 0.68 0.62 0.53 0.39Phosphorous, % 0.42 0.40 0.34 0.24Vitamin A, IU/lb 1,450 1,450 1,450 1,800Vitamin D, IU/lb 450 450 450 540Vitamin E, IU/lb 7 7 7 7Phase V – Transition Period•part of the dry periodGoals to Achieve:•acclimate rumen microbes to diet that will be fed during early lactation (high grain)-proper acclimation will allow cows to be switched over with minimal digestive upsets-prevents acidosisFeeding Recommendations:•feed 0.5-1.0% of BW as grain to prevent acidosis•continue to limit intake of Ca to prevent milk fever (ionic salts)•feed negative cation-anion balanced diet•feed high levels of vitamins A & E to prevent mastitisNutritional Recommendations:•minimum nutritional specification for transition cows:-NEl  0.65 – 0.70 Mcal/lb-Crude Protein  13 – 14%UIP  4.3 – 5.3%DIP  8.7 – 9.7%-ADF  30 – 35%-Calcium  0.36 – 0.41%-Phosphorous  0.22 – 0.25%-Potassium  0.70 – 0.80%-Vitamin A  2,200 IU/lb-Vitamin D  600 IU/lb-Vitamin E  15 IU/lbMetabolic Disorders Relating to Nutrition in Dairy Cows•high-producing dairy cows are forced to make major metabolic adjustments at calving•tremendous nutrient shift occurs at calving  cows shift nutrient utilization to support high levels of milk production•cows begin to mobilize body tissue to maintain homeostasis•ability to consume feed stays behind nutrient need for the first 8-10 weeks•cows are very susceptible to nutritional disorders during this time•Nutritional Disorders (some with avg. cost)-Milk Fever  $344-Ketosis  $145-Retained Placentas or Metritis  $266-Fat cow syndrome-displaced abomasum  $340-MastitisMilk Fever•Occurs when:-low blood calcium; 80% of cases happen within 2 days of calving-clinical milk fever cases are between 8-9% Ca-more prevalent in high-producing cows and those with history of milk fever-rarely occurs during a cow’s first lactation•Symptoms:Clinical Cases-hypocalcemia (<5.5 mg Ca/dL)  typical for nonlactating (9/4 mg/dL) and lactating (7.7mg/dL)-usually within 2 days of calving-inactive GIT = less rumination-cows appear dull and listless-uncoordinated walking-“downer” cows = unable to get up-more susceptible to mastitis, ketosis, dystocia, displaced abomasum, and uterineprolapseSub-Clinical Cases-hypocalcemia (< 8 mg Ca/dL)-higher risk for mastitis, ketosis, dystocia, displaced abomasum, and uterine prolapseImpacts of precalving diet on milk fever:•a 1,100 lb dairy cow requires about 30 to 40 g of Ca/day during the dry period to meet daily requirements for maintenance and fetal growth during late gestation•feeding > 100 g of Ca/day during dry period will increase chances of milk fever•when cows are fed excess Ca during late gestation, the mechanisms to absorb Ca from the GIT and mobilize Ca reserves from the bone are reduced•so right after calving, demand for Ca skyrockets and absorption cannot kept up because mobilization is depressed; meaning hypocalcemiaPreventing Milk Fever: Traditional Method•Feed low-Ca (< 0.4%) diets during the dry period:-feeding the cow less Ca than required will cause a negative Ca balance situation,making cow think she is deficient and increasing mobilization ability before calving-enables cow to mobilize Ca digestion and stores more efficiently to meet requirements-formulating low Ca diets for dry cows is difficult and is not always successful inprevention-Remember! Forages are generally high in CaPreventing Milk Fever: Newer Method•Feed negative dairy cation-anion balance (DCAB) during the dry period-DCAB is the sum of the positively charged ions (cations) and the negatively charges ions (anions)Cations  aka alkalogenic ions; Na+ and K+Anions  aka acidogenic ions; Cl- and S—-DCAB [meq/100 g DM] = (Na, %/0.023) + (K, %/0.034) - (Cl, %/0.0355) – (S, %/0.016)-negative DCAB before calving will activate mechanisms to increase Ca mobilization andabsorption-don’t factor in CaCurrent Dry Cow Nutritional Recommendations to Prevent Milk Fever:•DCAB is -10 to -15 meq/100 g diet DM-avoid feeding high-K level forages-add sulfate salts until S is maximized at 0.4 to 0.5% of diet-Add chloride salts until DCAB is lowered to -10 to -15 meq/100 g DMChallenges-anion salts are more expensive-high levels of anions salts decrease palatabilityKetosisOccurrence:•incidence of clinical ketosis cases is about 2-15%•about 50% of cows exhibit borderline ketosis•most cases occur within 60 days of calvingSymptoms:•elevated (about 40 mg/dL) ketone bodies (β-hydroxybutyrate)-normal levels of ketone bodies (<10 mg/dL)•depressed blood glucose levels•distinctive acetone-like odor of the breath and fresh milk•appetite and milk production decrease•ketosis is developed gradually•cows seldom die from ketosisPrevention:•avoid excess BCS at calving•use good transition diet during phase V•maximize DMI during early lactation•feed oral glucose precursors (i.e. propylene glycol or