1. Pre-Weaned Calf Management Dr. Howard Tyler Department of Animal Science

2. Priorities in Calf Management Minimize stress of birth Maximize passive immunity Reduce feed and labor costs Meet nutrient requirements of calf Optimize rumen development Maintain animal health

3. Why Should You Care?? If you can reduce calf mortality from 20% (national average) to 6%, and reduce age at first calving from 27 months to 23 months: –Reduces cost per heifer –More heifers to either sell or to enter herd, increasing voluntary culling rate in herd –Improve NET income by ~$40-50,000 for a 100- cow herd

4. Cost Distribution For Heifers (Hoffman 1998) $1.61/head-day $.20 ($.03-$.55) $.21 ($.08-$.52) $.25 ($.08-$.52) $.95 ($.67-$1.50)

5. Cost Distribution For Calves until Weaning (ICPA Study) $2.78/day $1.19 $.39 $.99 $.20

6. Costs of Pre-Weaned Calves First 2 months of a 24-month rearing period (8% of rearing period): –Take over 50% of vet and medicine costs –15% of feed costs to get 6% of weight gain –25% of labor costs –>90% of mortality losses Risks and costs BOTH drop post-weaning

7. Costs after Weaning (NCSU calculations) Cost per pound of gain drops from $2.46 down to $0.97 Total cost per day drops 50%, from $3.51 down to $1.74

8. Calf Mortality During last 20 years, overall calf mortality increased from 13% to over 20% Stillbirths (mean ~ 9% -- range from 0.5 to 25%) First 48 hours (mostly dystocia-related) (mean ~ 7%) Between 2 days and weaning (combination of passive immunity and dystocia) (mean ~ 4%) –40% of calves severely stressed at birth die within 3 weeks High variance – mortality rates range from 1% to 70% –Suggests it is possible to affect change through appropriate intervention strategies

9. Addressing the Problem 1. Ignore the problem, live with the costs 2. Treat the consequences 3. Prevent the problem –requires understanding of the cause –multifaceted problems more problematic –“dystocia” encompasses many different problems with a single term –to understand dystocia, must first understand normal fetal development and the normal parturition process

10. Costs of calf mortality Direct costs of calf - 20% mortality rate reduces net farm profit by over one-third Indirect costs also critical to consider: –Decrease availability of herd replacements –Decreased voluntary culling –Potential limitation on rate of genetic gain –Decreased potential for marketing valuable animals for profit

11. Dystocia Abnormal or difficult delivery process Subjective scoring system Associated factors often confused with causative factors Short- and long-term implications True economic costs difficult to estimate

12. Calving Ease Scoring System Deliveries scored from 1-5 –Subjective scoring system –Score of 1 represents unassisted delivery not necessarily an easy delivery! unattended always scored as a “1” –Score of 5 represents extreme force not necessarily required force Does not differentiate between causes of dystocia

13. Relationship between dystocia and stillbirth rate in Holsteins

14. CES and Stillbirth Rate (2007)

15. Stillbirth Rate (2007)

16. Effect of dystocia on losses of 305-d milk (kg)

17. Effect of dystocia on increases in days open

18. Days Open for Cows Delivering Stillborn Calves Live calf (ave. 178 days) Stillborn calf (ave. 258 days) Hazard rate for becoming pregnant was 24% lower for cows delivering stillborn calves

19. Culling Rate For Cows Delivering Stillborn Calves Stillborn calf Live calf Cows delivering stillborn calves had a >40% higher hazard rate for culling or death in next lactation

20. Effect of dystocia on percent cow deaths

21. Association with other calving disorders Retained placenta - increased risk with assisted deliveries Metritis - 2- to 3-fold increase Left-displaced abomasum - increased risk Milk fever and dystocia interrelated

22. Relationship between dystocia and incidence of retained placenta in cows without milk fever

23. Relationship between dystocia and incidence of milk fever

24. Cost ($) associated with calving ease scores

25. Sources of dystocia problems Embryo/fetus effects Dam effects Sire effects Breed effects Environmental effects Management effects

26. Factors associated with embryo development IVF-derived and cloned calves have altered fetal development –“Programmed” defects initiated during early embryo development –Prolonged gestation –Placental/umbilical and other circulatory defects –Large Offspring Syndrome (LOS) Size unrelated to physiological maturity –Metabolic defects –Decreased immune competence “Defects” not genetically transferrable The role of embryo effects as a cause of dystocia in “normal” populations not known

27. Breed effects Holsteins have highest dystocia incidence of any dairy breed and highest ratio of calf weight:dam weight (over 10% in many cases) Jerseys relatively unaffected by calving difficulty except in cases of twinning and malpresentation (ratio of calf weight:dam weight ~7%) Other dairy breeds appear to be intermediate

28. Sire effects Holstein sire x Jersey dam decreases incidence of dystocia compared to Holstein x Holstein but dystocia still increased relative to incidence in purebred Jerseys Uterine (maternal) control of fetal growth important but can be overridden by sire effects Use of calving ease sires greatly decreases calving difficulty in first calf heifers primarily by decreasing size of the fetus

29. Effects of fetus Calf weight - dystocia rate increases 5% for each 5 pounds increase in calf birth weight Sex of calf - males have increased risk Inbreeding decreases calf birth weight but increases incidence of dystocia Malpresentation - increases with parity Multiple births - increase risk of dystocia with twins

30. Effects of dam Body weight or condition score - minimal effect except at extremes –Increasing energy intake of dam in late gestation does not increase dystocia unless BCS of dam increases Intrapelvic fat increases and effective pelvic area decreases –Decreasing energy intake decreases birth weight and increases incidence of dystocia Fetopelvic incompatibility often identified as most important factor Parity - dystocia most frequent in first calf heifers Age at first calving - young heifers (< 22 months) have increased difficulty

31. Genetic effects Tendency for small calves to become small cows and large calves to become large cows Daughters of cows with calving problems also had above average calving difficulty Daughters of calving ease sires, although smaller at the time of calving, had a lower risk of dystocia than their larger herdmates

32. Effects of environment Season effects - higher in fall and winter months but highly variable May be related to heat stress effects (placental restriction) Stillbirth rates of calves highest in winter and summer

33. Management factors Aggressive assistance - premature assistance associated with increased difficulty Inattention - Lack of timely assistance also associated with increased difficulty Calving site - temperament of cow and(or) stressful environment

34. Umbilical cord rupture Premature rupture of umbilical cord in calves decreases placental blood transfer (~1 pint) Most drastic effects on systems that received least amount of blood perfusion in the fetus –Brain, lungs, gut, liver, kidneys Slow to stand, loss of suckling reflex Rectal temperature drops, respiration irregular Lung function compromised at least until weaning Same behavioral responses that are normally associated with dystocia

35. Recommendations Liberal use of calving ease sires - especially on heifers Allow time for cow to adapt to calving environment –Amount of time needed depends on temperament and experience of the dam Observe all calvings possible and check position of calf early in calving process Assist only when signs of maternal or fetal distress apparent

36. Experience is crucial in determining timing of assistance and type of assistance (???) Important to differentiate between experience vs. expertise

37. Signs of distress Uterine inertia (undistracted cow!!) Responsiveness of cow Color of calf tongue –Observe both the change in color and timing of changes Responsiveness of fetus (tongue or eye reflex) Appearance of meconium, blood, or placental pieces

42. Force of Assistance Pulling force should not exceed 150 pounds for Holstein and 75 pounds for Jersey –Assist in dilation prior to pulling (5 minutes) –Use appropriate lubricant (not soap and water) –watch your time and assess the calf condition –One person pulls with ~100-150 pounds of force –Two people pull with ~300 pounds of force –600 pounds of force will fracture femur –Calf jack can generate 1500-2000 pounds of force Apply delivery force during contractions, restraining force between contractions Pull calf straight out until head delivered Deliver shoulders and body at 30 to 40 0 angle Stop assistance after last rib and allow dam to expel fetus

43. Excessive assistance Assistance prior to full cervical dilation or the use of excessive force is associated with a high incidence of rib fractures (~40%) and a lower incidence of front leg and vertebral fractures (~10%)

45. Self-fulfilling prophecies Large hooves indicate large calf Earlier intervention suggested based on this finding Overly aggressive assistance (prior to full cervical dilation) will result in injuries and “weak calf” syndrome –In the field, this is often interpreted as a need for more aggressive intervention in the future –Patience and restraint often alleviate the need for intervention The cervix has incredible potential for dilation 126 pound calf from an 1150 pound heifer Twin Guernseys simultaneous delivery

46. Newborn calf care Clear amnion from nose area If not breathing: –Do not hang calf upside down Does not clear fluids from trachea Does compress digestive organs against diaphragm –Stimulate first gasp if necessary Use gasp reflexes (stimulate nostril, rub chest, cold water in face) Respiratory stimulants as last resort –Initial stimulation of respiration, eventually depress respiratory center

47. Calf care, continued Remove calf from dam Move to warm (60-75 F) environment until calf is completely dry - then move to calf housing –Hot environment interferes with respiration –Even a warm environment will cause brown fat stores to regress within a few days Dry briskly and completely with towel Clip and dip navel (iodine, chlorhexadine) Feed adequate high-quality colostrum

48. Calf survival rates by level of serum IgG Source: USDA NAHMS Report, National Animal Health Monitoring System, 1993 2x the death losses

49. Calf Serum IgG vs Calf Health Costs Southern Research & Outreach Center Waseca (Outside hutches - 1993 vs 1994 birth to 49 days of age) 1993 - Serum IgG 4.2 mg/ml; 2.5 days/calf treated for scours; $7.17/calf treatment costs 1994 - Serum IgG 10.9 mg/ml; 1.4 days/calf treated for scours; $2.75/calf treatment costs For every 100 calves you raise per year, you can save $432/year PLUS other potential benefits and savings…

50. Low (0-9.9 mg/ml) vs High IgG (at least 10 mg/ml) (Fowler, 1999) Benefit of High IgG: 2.2 lbs more weight gain……. (+ $1.53); 12 lbs less feed/calf …………...(+ $5.70); 12.1% less mortality ………….(+ $12.10); Lower health treatment costs...(+ $3.74) Potential benefit …………………+ $23.07

51. Clinic threshold: Amount of organisms needed to cause recognizable sickness

52. IgG Production by the Calf (Active Immunity) IgG, IgM, and IgA concentrations begin to increase within a few days after birth in colostrum deprived calves Not enough of a response to be effective in preventing disease –Poor response to vaccinations for first few months Also need to consider that maternal antibodies (from colostrum) will inhibit response to calfhood vaccines

53. Colostrum-fed calves show poor response to vaccines until about 4 months of age

54. PASSIVE Immunity vs. ACTIVE Immunity (Great Colostrum Management) TOTAL IgG stays adequate throughout rearing period – hold off vaccinating until 4 months of age!!!

55. PASSIVE Immunity vs. ACTIVE Immunity (Average Colostrum Management) Total IgG leaves animal “at risk” throughout most of the pre-weaning period – vaccinations still not effective prior to weaning

56. PASSIVE Immunity vs. ACTIVE Immunity (Poor Colostrum Management) Total IgG leaves animal “at HIGH risk” throughout most of the pre-weaning period – you should vaccinate these calves earlier!!

57. Vaccines Increase antibody levels against a specific pathogen –Can’t vaccinate against “scours” – you must identify the problem pathogen to know which vaccine to use Questions to consider… –Is the vaccine effective? – not all of them are!! –What is the cost of the vaccine? – more expensive than the disease? –What is the risk of the disease? – 5% of calves or 50% of calves? –What is the cost of the disease? – more expensive than the vaccine?

58. Vaccines don’t protect against overwhelming pathogen loads!!

59. Vaccinate the calf or vaccinate the cow? – depends on colostrum management!!

60. Failure of Passive Transfer (FPT) Low IgG levels greatly increase risk for death and disease –40% of calves classified as FPT (<10 g IgG/L) –Colostrum-deprived calves 50-74 times more likely to die before 3 weeks of age –FPT calves are twice as likely to get sick as non- FPT calves NAHMS estimates suggest 22% of all calf deaths could be prevented by better colostrum management

61. Colostrum Sources Identify cows that will be best colostrum sources and those that are questionable –Older cows provide better colostrum Typically, more antibodies produced against more pathogens Heifers colostrum should be checked –Colostrum quality lower with high colostrum production (18-pound rule) –Johne’s suspect animals colostrum should be dumped Hard to pasteurize effectively (reduce Ig along with organism) –Colostrum from BLV-positive animals should be frozen or pasteurized –Vaccinations can be used to increase levels of specific antibodies

62. Fig 35-1. Cows with Johne's disease can potentially shed the pathogen into colostrum and milk. (Courtesy of Mark Kirkpatrick)

63. Colostrum Sources – During Farm Expansion Expansion creates passive immunity issues –colostral quality typically lower in heifers –mixed source heifers provide variety of pathogens to their new environment colostral antibodies no longer farm-specific –potential for dam-calf disease transmission Can vaccinate to protect against specific pathogens of concern –Must vaccinate early enough to allow antibodies to be secreted into mammary gland

65. Colostrum Harvesting and Storage Cow’s teats should be thoroughly cleaned and dried –First time in 30-60 days Equipment should be well-cleaned and sanitized Minimize pathogen load in colostrum at first milking Colostrum should be rapidly fed or cooled –Bacterial loads double in 20 minutes –Within 6 hours, bacterial loads are over 10 million cells per ml of colostrum

66. Fig 45-15. On farm pasteurizers drastically decrease pathogen loads in colostrum and therefore enhance performance of calves (Courtesy of Mark Kirkpatrick)

67. Colostrum Freezing and Thawing Can refrigerate for about 1 week Can freeze for years –Freezer cannot be “frost-free” Can only freeze for weeks in frost-free freezer Freeze in ½ gallon or 1 gallon zip-lock bags –Double-bag to prevent leaks –Lay flat in freezer to help thawing process –Label with dam ID, date, and quality Thaw in warm water (120 degrees F) Thaw in microwave on defrost (never on high) –Pour out thawed colostrum frequently!

68. Colostrometer A specific gravity measuring device that can be used to estimate Ig content of colostrum Available from vet supply houses, Nasco for about $40

69. Colostrometer measurements High quality colostrum (> 50 g/L) is GOOD Moderate quality (20 to 50 g/L) is FAIR Colostrum < 20 g/L is POOR Do measurement at room temp! –Quality “appears” to increase in cooled colostrum Affected by fat content (issue with Jerseys)

70. On-farm Monitoring of Colostrum Quality Visual assessment –Clean, thick, and yellowish Colostrometer –Specific gravity correlated with Ig content Refractometer –Measure light reflectance in a solution Correlates with IgG content

71. Refractometers Can assess colostrum quality AND assess passive transfer in calves – different cut- points for different breeds

72. Distribution of IgG concentration

73. How are we doing at feeding quality colostrum? Percentage of samples with above and below industry recommended adequate IgG concentration IgG (mg/ml)Samples(%) <5024329.38 50 - 8030336.64 80 - 10015618.86 100 - 120759.07 >120506.05 Total827100 Percentage of samples with above and below industry recommended total plate count Samples(%) Range (CFU/ml) < 100,00042753.8 100,000 - 300,00010012.6 300,000 - 500,000486.0 500,00 - 1,000,0008510.7 >1,000,00013416.9 Total794100 IgG > 50 mg/mlTPC < 100,000 CFU/ml

74. Colostrum Feeding Recommendations ALWAYS test quality (>50 g/L) For calves over 100 pounds –four quarts at birth, two quarts at 12 hours For calves between 50 and 100 pounds –three quarts at birth, two quarts at 12 hours For calves under 50 pounds –two quarts at birth, two quarts at 12 hours

75. Colostrum Feeding Recommendations In order to make sure the calves ingest enough colostrum, they must be hand-fed –Nipple feeders or esophageal feeders Total amounts of immunoglobulins absorbed depend on several factors –Amount of ingested colostrum –Concentration of colostrum –Time elapsed between birth and first feeding

76. Efficiency of Ig absorption

77. How is colostrum fed?

78. Fig 45-11. Feeding colostrum via nipple bottle, although time consuming, also helps train calves to nurse from a bottle (Courtesy of Howard Tyler)

81. Fig 45-13. Feeding positions where the head is extended on the neck helps ensure complete closure of the esophageal groove (Courtesy of Iowa State University)

82. Fig 45-12. Calves that won't voluntarily consume colostrum are force fed with an esophageal feeder (Courtesy of Emily Barrick)

84. On-Farm Monitoring of Passive Immunity in Calves Zinc sulfate turbidity –Not typically used on farms –Qualitative, not quantitative Refractometry –Measures plasma proteins –Loosely correlated with IgG levels Can be misleading in some cases (especially in older calves) –Only test calves over 1 day and less than 3 days old –Dehydrated calves are abnormally high (over 8 g/dl in some cases) More accurate at diagnosing failure than success >5.5 g/dl is good, <5.0 g/dl is bad Calf-side IgG tests

85. What Can You Do When Colostrum is Poor Quality or in Short Supply? Colostrum supplement = < 100 g IgG/dose Colostrum replacer = > 100 g IgG/dose + addition nutrients AEA affected by IgG source –Serum > colostrum > milk-derived IgG

86. Issues With Colostrum Supplements Whey-, colostrum, or plasma-derived immunoglobulin sources Mass of Ig varies between products –efficiency of absorption also varies Antibodies not farm-specific for pathogens Missing other nutrients, growth factors, etc. –use as adjunct to good colostrum program

87. What Can You Do After 24 Hours of Age for FPT Calves? Injectable immunoglobulins –Utilized after intestinal closure –Routes include SQ, IP, and IV –IV infused IgG half-life = 18-23 d 68% transferred to GI tract –Clinically ill animals require more IgG than healthy animals

88. Reactions to IVIG Unfortunately, adverse reactions to IVIG are an issue In humans, adverse reactions occur in 5% of patients –25-50% reaction rate in foals Often rate and concentration dependent Clinical signs: –Blood pressure changes –Rapid heart rate –Rapid, shallow breathing –Weakness, collapse, death Banamine will prevent most problems

89. Good Colostrum Management Colostrum as a band-aid –Masks other problems –Allows more mistakes Nutritional Environmental Management Problems are still there and affect productivity and profitability – just easier to overlook

90. Specific Risks of Poor Colostrum Management Four-fold more scours cases –More shedding of cryptosporidia, coronavirus, and rotavirus in feces Three-fold more all other illnesses –Greatly increased risk of pneumonia Decreased growth rate 1 st 6 months (50 pounds on same feed) Decreased milk production in first lactation –20% greater culling rate during first lactation

91. Sick Calves A higher percentage of calves show signs of clinical disease than at any other time in the life cycle Many factors affect the risk of disease during this period The basic premise of disease prevention is still the same as at any other stage of life

94. Most common site for calves to pick up pathogens – calving site!! - they often don’t show signs of infection until later – depends on incubation period of the pathogen

95. Costs of Calf Morbidity Pneumonia reduces pre-weaning growth by 8% Diarrhea reduces pre-weaning growth rates by 18% –Effects are additive (29% total reduction) Calf morbidity incidence increases age at first calving, reduces milk yield in first lactation and increases risk of culling in first lactation

96. Pathogen Issues Most diarrhea in calves is not bacterial –Antibiotics should not always be first option Most diarrhea cases become a pathogen mixture over time –Diagnose and treat promptly –Fecal samples obtained EARLY in disease outbreak Dehydration is common among all diarrhea pathogens and contributes greatly to the risk of death

97. Other Health Issues to Consider!!!

98. This drug is unusual in that the law expressly forbids any extra-label use under any circumstances by anyone Species Approved: Cattle only (not for use in cattle intended for dairy production or in calves to be processed for veal) Disease: Only for treatment of bovine respiratory disease associated with Pasteurella haemolytica, P. multocida, Haemophilus somnus Dosage: Only the approved dosage rates on the label Frequency of Treatment: Only those listed on the label Route of Administration: Subcutaneous injections only Withdrawal Time: Animals must not be slaughtered within 28 days of the last treatment Warning: Do not use in cattle intended for dairy production or in calves to be processed for veal Cannot be given intramuscularly, or intravenously Cannot be used at different dosage rates or frequency from those listed on the label Cannot be used to treat calf scours or other diseases not listed on the label Baytril

99. Banamine Meat witholding time established by FDA during summer, 2006 at 4 days (for animals treated intravenously with recommended dosage) –Withholding not established for IM or SQ use, but would be longer than 4 days! Banamine has been the number one source of violative residues in meat since that time

100. Dehydration Issues More dehydration leads to: –Sicker calves –More acidosis (more concentrated blood) –Longer time to recovery –Weaker immune system Maintaining hydration –Reduces treatments –Helps keep calves on feed –Saves calves

101. Fig 45-23. Calves with severe diarrhea will rapidly dehydrate, often requiring oral rehydration therapy to restore fluid and electrolyte balance (Courtesy of Iowa State University)

109. Considerations with Intubation No rumen by-pass Direct effect on rumen environment –Electrolytes Amount of glucose is a concern –Rapid fermentation, high acid production –Milk Amount of lactose is a concern –Ferments to lactic acid »pH drops from 6.5 to 4.5 within hours »Poorly absorbed, slow rumen recovery

110. Electrolyte Composition

111. Oral Rehydration Strategies FEED CLEAN WATER FROM BIRTH –Even healthy calves will dehydrate in hot weather Keep feeding milk –Calves need the protein and energy Feed electrolytes at least 15 minutes after milk feeding –Less important if bicarbonate is not in electrolyte solution –Sodium citrate instead of sodium bicarbonate Electrolytes should have no more than 20-25 grams of glucose if milk is being fed as well

112. The depressed calf you find in the morning, and WAIT to treat --- --- may not need treatment by the evening

113. Fluids, Nutrition, Comfort Start oral electrolyte fluids EARLY – even before scours is observed –Non-toxic, no withdrawal period, very low risk of overtreatment Maintain energy & protein to calf with milk feedings + oral electrolytes Be patient & persistent – the intestinal lining takes time to heal– keep the fluids coming! Keep calf warm and dry – requires MUCH more bedding than healthy calf –Strip old bedding to remove pathogen load

114. Biosecurity Goals for Your Farm 1. Minimize disease transmission 2. Minimize treatments 3. Minimize pathogen load 4. Maximize immune function

115. Specific Risks From First Day of Life Calves surviving a stressful birth: –6-10% stillbirth rate (can be reduced by good management) –40% of calves that are stressed at birth die by 3 weeks of age –3-fold more likely to become sick (scours, pneumonia) –Decreased growth rate and feed efficiency Calves receiving inadequate colostrum: –Four-fold more scours cases More shedding of cryptosporidia, coronavirus, and rotavirus in feces –Three-fold more all other illnesses Greatly increased risk of pneumonia –Decreased growth rate 1 st 6 months (50 pounds on same feed) –Decreased milk production in first lactation 20% greater culling rate during first lactation

116. Practical calf feeding programs

117. Meeting Nutrient Requirements A nutritionist’s nightmare Entire pre-weaning period is transition period –proportions of nutrients provided by liquid vs. solid feeds in constant flux –physical capacity of digestive system increases potential for dry matter intake also increases –fermentative capacity increases –absorptive capacity increases –therefore, digestibility of solid feeds also changes

118. Energy Intake One pound of milk replacer (4 quarts/day): –20:20 milk replacer = 2000 kcal/day ($0.85/day) –Holstein milk (25:30) = 2,600 kcal/day –Jersey milk (30:35) = 3,000 kcal/day One pound starter –Provides 1300-1500 kcal/lb ($0.18/lb)

119. Liquid Feed Options Bulk tank (saleable) milk –Consistent, high quality feed source –High cost to producer Milk replacer –Less expensive –Most consistent –Starts out with low risk of disease transmission –Many options Waste milk –Cheap –Inconsistent quality –Inconsistent quantity (availability depends on number of cows with mastitis) –Must be pasteurized

120. Benefits of Pasteurization Compared to unpasteurized milk –Reduced bacterial loads –Improved weight gain –Fewer days with diarrhea and pneumonia –Reduced calf rearing costs by $8.13 Does not include additional costs associated with pasteurization Must be managed properly –Increased total plate counts –Disease outbreaks

121. Increasing Energy Intake Through Milk Replacer 20:24 adds 150 kcal/day ($0.90/day) 4 ounce fat supplement adds 750 kcal/day ($1.04/day) Increase DM by 25% increases 525 kcal/day ($1.05/day) 3 feedings increases 1000 kcal/day ($1.27/day) Increasing energy does not efficiently increase lean tissue gain

122. Factors Affecting Energy Requirements Approximately 20 kcal/pound of body weight in a thermoneutral environment for maintenance for calves Requirements increase 1% for every degree below 50 0 F –High surface area:body mass ratio –Require 450 kcal more at 20 0 F (2800 kcal/day total) –Difference between small and large calves Requirements increase with increasing lean tissue deposition –Protein synthesis is energetically expensive requires about 5 ATP per one peptide bond

123. NORMAL FEED Dry coat – calm wind5°C9°C Dry coat – windy12°C17°C Wet coat – windy13°C17°C LOW FEED Dry coat – calm wind12°C18°C Dry coat – windy17°C20°C Wet coat – windy19°C23°C Temperature at Which Calves Started Shivering HolsteinJersey

124. Factors Affecting Protein Requirements Rate of gain determines amount of protein required –If facilities, genetics, and calf source/management permit rapid gain, then high levels of protein and energy required in diet –If facilities, genetics or calf source/management LIMIT rate of gain, then protein and energy must be reduced accordingly The size of the animal affects the protein requirements at any given level of intake –Less energy needed from maintenance in lighter animals, so more energy available for growth Therefore, more protein required to support lean growth Frequency of feeding affects digestive efficiency –Natural suckling frequency allows greater intake than most “hand- feeding” systems can achieve –Required protein:energy ratio changes accordingly

125. Imbalanced Protein:Energy Ratios If energy diverted to immune function (poor facilities), then it is NOT available for growth –Excess protein must be de-aminated and ammonia detoxified and excreted Energy required (3 ATP per molecule of urea) and therefore even LESS energy available for growth and immunity Overfeeding protein (in this case by underfeeding energy) impairs growth and may impair immunity

126. Accelerated Growth Programs in Dairy Calves Programs mimic “natural” milk composition and calf intake levels –Suckling calves consume ~20% BW in whole milk per day –8-10 suckling bouts per day vs. twice daily bottle-feeding Free choice water at all times –Relatively high nitrogen excretion in urine –Challenging requirement in hot and cold conditions –Can lead to higher death losses if not met Excellent colostrum management –Poor passive immunity reduces growth response, reduces needs for protein Excellent sanitation –High protein intakes in a poor environment may alter immune response –Higher death loss in challenging environment Low potential for growth leads to problem with excess protein

127. Is Mortality Rate an Issue? First study: –120 calves from sale barns shipped to an extremely challenging environment Half on conventional program (22:20 with starter) Half on accelerated program (28:20 with starter) –Morbidity 53% higher in accelerated group –14 “accelerated” calves died vs. 3 “conventional” –Growth rate 1.3 lbs./day vs. 1 lb/day

128. Is Mortality Rate an Issue? (Part 2) Second study: –Forty three calves on home facility, excellent colostrum management, but marginal facility Old tie stall barn, marginal ventilation, poor drainage, but less than 1% mortality rate over previous 18 months –15 “accelerated” calves, 14 “early-weaning” calves, and 14 “modified accelerated” 6 “accelerated” calves died, 1 each on other treatments died Growth rates 1.45 lbs/day vs. 1.15 lbs./day for accelerated and conventional, respectively

129. Is Mortality Rate an Issue? (Part 3) Average age at death for accelerated calves on both studies was during second week of life –This corresponds to increase in feeding rate –This also corresponds to age at highest risk of disease Is timing of changes in feeding rates a issue? –“Nutritional stress” at same time as “pathogen stress”?

131. Is Mortality Rate an Issue? (Summary) Under excellent management conditions, there is no evidence that calves on accelerated programs are at more risk or less risk for dying Under marginal conditions, calves on accelerated programs may be at somewhat of a higher risk Under highly challenging conditions, calves on accelerated programs are at higher risk of dying than calves fed conventionally This begs the question – do calves on a higher plan of nutrition have a stronger immune system or a weaker immune system?

132. Does Higher Plane of Nutrition = Higher Functioning Immune System?

136. Comparison of Economic Efficiencies VARIABLE NATIONAL AVERAGE ACCELERATED Birth weight, lb95 Weaning Age, d56 ADG, lb.982.1 8-Wk Weight, lb150212 MR Intake, lb64121 Starter Intake, lb7445 Gain:Feed Ratio.40.70 MR Cost, $54121 Starter Cost, $139 Total Feed Cost, $67130 Feed $/lb Gain$1.20$1.12

137. Comparison of Economic Efficiencies VARIABLE NATIONAL AVERAGE EARLY WEANING ACCELERATED Birth weight, lb958795 Weaning Age, d563156 ADG, lb.981.52.1 8-Wk Weight, lb150165212 MR Intake, lb6430121 Starter Intake, lb7413045 Gain:Feed Ratio.40.49.70 MR Cost, $5425121 Starter Cost, $13249 Total Feed Cost, $6749130 Feed $/lb Gain$1.20$0.63$1.12

138. Other Economic Considerations Labor costs –drop over 50% after weaning in conventional program greater labor costs associated with accelerated programs –early weaning (~30 d) cuts total labor costs associated with rearing to 56 d by about 40% Housing costs –Reduce number of hutches or stalls required by ~45%

139. Other Long-Term Considerations Early feeding programs can have long-term consequences –Colostrum ingestion affects feed efficiency, rate of gain, and lactation potential –Milk vs. milk replacer also affects long-term performance in similar ways Nutrient intake, growth factors, immune factors –Different rates of milk replacer feeding also have long-term effects Underfeeding and overfeeding are both detrimental to the profitability of a dairy farm

140. Other Long-Term Considerations The added weight gain through 8 weeks for calves on accelerated programs appears to be maintained throughout the growing period If breeding on weight rather than age, then this should allow earlier calving and save ~$50 in feed costs –Helps offset additional costs in pre-weaning period Potential for improved lactational performance?

141. So What IS the Ideal Liquid Feeding Program? Clearly, the ideal feeding program would be individualized for each animal, or at least for each management scheme –Varying protein:fat by age, by growth goals and maybe by management intensity - Varying frequency of feeding with age –Varying intake by age and management intensity Clearly, this is not practical in most situations Understand the biology and the economics behind the different programs, assess your animals (source, passive immunity, housing, etc.), and create your own program –Sometimes it is better to listen to what the animals tell you rather than listen to what the experts tell you…

142. Dr. Tyler’s Liquid Feeding Recommendations Feeding up to 2% BW of a 25:15 to 28:20 milk replacer through 10-14 days (voluntary intake – only force-feed up to 1%) Reducing intake of MR to 1% to encourage starter intake –timing dependent on health status –abrupt vs. gradual change? –economics of feeding programs –“best guess” program from one person’s perspective

143. Recent Liquid Feed Research Alternative protein sources –Plasma, red cells, egg proteins, etc. Antibiotic alternatives and functional proteins –Antibodies from plasma or eggs, lactoferrin, probiotics, fructooligosaccharides or mannan oligosaccharides, beta-glucans or other immune stimulants, garlic derivatives, botanicals, etc. Group feeding vs. individual feeding –Once a day vs. ad lib feeding

144. Challenges with Liquid Feeding Strategies High energy intake from liquid feed delays initiation of starter intake and suppresses appetite for starter –high fat inclusions during cold weather –higher solids in the same volume of milk replacer –higher volume intakes Must balance accelerated growth with accelerated rumen development

145. Factors Required for Rumen Development Establishment of bacteria Water-based environment Muscular development Absorptive ability of tissue (rumen papillae) Substrate availability

146. Rumens of 4-Week-Old Calves Milk, Grain, and Hay Milk and Hay

147. Rumens of 6-Week-Old Calves Milk, Grain, Hay Milk and Grain Milk

148. Effect of Starter Diet Concentrates –provide proprionate and butyrate energy for calf rumen papillae growth and development Forages –scratch factor papillae function –rumen buffering –muscular development –calves WILL find a source of “roughage” What is the right balance?

149. Importance of Texture Textured Commercial textured starter Ground CP - 23.58% ADF - 6.39% CP - 25.44% ADF - 6.44%

150. Role of Forage Coarse + 7.5% Hay Hay of consistent particle size Coarse + 15% Hay Hay of consistent particle size CP - 23.08% ADF - 6.47% CP - 22.60% ADF - 7.43%

151. Calf Starter Basics Textured calf starter –Increased intake –Increased weight gain –Increased feed efficiency Calf starter with 7.5% chopped hay –Increased body weight –Increased feed intake (especially post-weaning!!!) –Increased feed efficiency –Alters rumen VFA production increased acetate:propionate –Creates a more stable rumen environment –4 lbs chopped hay per 50 lb bag of starter

152. Recent Dry Feed Research Increased protein content (above 18%) Altered rumen degradability –Based on book values, not measured degradability in pre-weaned calves Cheaper protein sources Strategies to encourage intake –Molasses level –Flavoring agents –Bucket size and shape Color?? Height??

153. Water, Water and More Water!!! Water availability may limit starter intake –free water necessary for development of rumen fermentative capacity water in milk replacer bypasses rumen Hot weather greatly increases water consumption Cold weather increases difficulty in providing water free choice –rotate the use of multiple buckets per calf Provide 3x daily in extreme conditions

154. Table 11-1. Percentage of Bovine Stomach Tissue Contributed by Each Compartment Age in Weeks Compartment048121610 - 1634 - 38 Reticulo-Rumen38%52%60%64%67%64%64% Omasum13%12%13%14%18%22%25% Abomasum43%36%27%22%15%14%11% http://www.afns.ualberta.ca/drtc/dp472-5a.htm

155. Weaning Strategies Level of calf starter intake correlates with maturity of rumen fermentative function as well as physical development of rumen Weaning should be intake-based Weaning reduces labor costs by 50% and costs of gain by 3 to 5-fold –earlier weaning of healthy calves is most profitable

156. Costs after Weaning (NCSU calculations) Cost per pound of gain drops from $2.46 down to $0.97 Total cost per day drops 50%, from $3.51 down to $1.74

157. Dr. Tyler’s Weaning Recommendations Calves >100 pounds at birth –consume 1.25 pounds of starter daily for 3 consecutive days Calves 50 - 100 pounds at birth –consume 1 pounds of starter daily for 3 consecutive days Calves <50 pounds at birth –consume 0.75 pounds of starter daily for 3 consecutive days Adjust for health and environmental factors

158. Assumptions: 100-cow herd 400 day calving interval 91 calves born each year = 45 heifers born Annual removal rate for milking cows is 30% = needs 30 replacements per year Average age at first calving 26.5 months = feeding 99 heifers on farm at any one time SCENARIO: Raise only best 35 heifers (sell remaining 10 at 1 week of age) SAVINGS FIRST YEAR SAVINGS SECOND YEAR SAVINGS THIRD YEAR Forage 31,080 lb $1,398.60 132,000 lb. $5,940.00 156,625 lb. $6,868.13 Shelled corn 170 bu. $680.00 210 bu. $840.00 210 bu. $840.00 Soybean meal 1,500 lb. $202.50 1,700 lb. $2.29.501, 700 lb. $229.50 Dical 300 lb. $49.5 0 600 lb. $99.00 687.5 lb. $113.44 TM salt 240 lb. $25.25 490 lb. $51.55 533.75 lb. $56.15 Milk replacer 400 lb. $336.00 400 lb. $446.00 400 lb. $336.00 Total feed cost savings $2,691.85 $7,496.05 $8,443.21 Livestock costs: Bedding 6,500 lb. $195.00 10,000 lb. $300.0010, 750 lb. $322.50 Veterinarian & medicine $157.40 $237.40 $252.40 Breeding $250.00 $250.00 $250.00 Total livestock cost savings $352.40 $787.40 $824.90 Labor savings 170 hours $1,105.00 270 hours $1,755.00 291 hours $1,890.00 TOTAL FARM SAVINGS YEAR 1 $4,149.25 YEAR 2 $10,038.45 YEAR 3+ $11,158.53 Alternative Strategy for Cost Savings

159. On Raising Calves The first four weeks of its life the calf must receive the whole of its mother’s milk, because in this period the nutrition contained in the milk in so small volume can be replaced by no other equally nutritious and as easily digestible means of food. After four weeks the milk may be replaced by that means of fodder which nutritious substance next to it in equal weight of dry volume, in the greatest possible amount. USDA, 1847

160. Summary of Calf Nutrition Consider the nutritional needs of the calf, the metabolic needs of the rumen, and the optimal conditions for rumen microbial growth when creating your calf nutrition program Provide an environment that permits maximal response to your nutrition program

161. Housing Options for Calves Balance needs of calves with comfort of the calf feeders –Strict ventilation requirements –Isolation to prevent pathogen transfer Some producers prefer indoor facilities while other prefer cold housing –If warm barn, it should be well ventilated –Minimum of 24 square feet of pen space for individual calves –Calves from birth to 1 week post-weaning should be housed individually

162. Fig 42-5. Indoor facilities provide a difficult challenge to maintain isolation without compromising ventilation (Courtesy of Iowa State University)

163. Fig 42-6. Open stalls for calves enhance ventilation but permit disease transmission via nose-to-nose contact (Courtesy of Iowa State University)

164. Fig 42-7. An elevated floor in the calf pens enhances ease of cleaning for this calf facility (Courtesy of Iowa State University)

165. Fig 42-8. Using wire panels between calves enhances ventilation but allows nose-to-nose contact (Courtesy of Mark Kirkpatrick)

166. Fig 42-9. An open air calf facility in southern California (Courtesy of Iowa State University)

167. Fig 42-10. Ideally, pens are spaced 18-24 inches apart to minimize the transmission of airborne pathogens (Courtesy of South Dakota State University, Brookings)

168. Fig 42-11. Plastic calf hutches are a popular choice for housing pre-weaned calves (Courtesy of South Dakota State University, Brookings)

169. Fig 42-12. Old tires can be used as weights to keep plastic hutches in place during high winds (Courtesy of Mark Kirkpatrick)

170. Fig 42-13. Although less expensive than individual hutches, calf condos are more difficult to move and sanitize between calves. (Courtesy of Mark Kirkpatrick)

171. Fig 42.14. Dome-style plastic hutches are another popular choice for housing individual calves. (Courtesy of Mark Kirkpatrick)

172. Fig 42-15. Wood hutches are less expensive than plastic, but also heavier and more difficult to sanitize properly (Courtesy of Monsanto)

173. Monitor growth Record birth weight Record weaning weight or when they move to new group

174. Managing Risk Calves can be raised successfully in many facilities and using many management schemes –Maternity pens vs. bedded pack vs. pasture-based calving systems –Colostrum vs. colostrum replacers vs. colostrum supplements –Indoor vs. outdoor housing –Milk replacer vs. milk Pasteurized waste milk vs. unpasteurized milk –Type and amount of bedding Some facilities or management practices carry greater risk - must balance costs and benefits and then manage the risks associated with those choices