dairy nutrition Flashcards
what happens during 305 day lactation
- lactation begins after calving
- breeding begins 60 d after calving, most cows become pregnant by 85 to 115 d
what is the dry period
60 day non-lactation
what happens during the dry period
mammary gland involution and regeneration prior to next lactation
what is the average growth rate
1.66 lbs/day
what is colostrum
- first milk produced for the calf
- contains large quantities of immunoglobulins
- excellent source of energy, protein, vitamin A and D
what is the only ingredient in colostrum thats lower vs in whole milk
lactose (2.7 in colostrum vs 5 in whole milk)
what is the importance of colostrum feeding
- no placental transfer of immunity in bovine animals
- absorption of colostrum Ig provides passive immunity
what does early ingestion of colostrum provide
- fluid for post natal circulatory volume
- energy to maintain body temperature
what are the components of colostrum
- large amounts of immunoglobulins (IgG)
- leukocytes (cellular immunity)
- growth factors and hormones
what are the systemic effects of Ig on immunity
- protect against infectious enteric and respiratory diseases
- reduced morbidity and mortality
what are the local gastrointestinal effects of Ig on immunity
- bind to pathogens prior to absorption
- present in intestinal secretions following absorption
what are the two proteins present in colostrum
casein and whey proteins
what are the proteins dependent on in colostrum
protein nutrition of the dam
what are absorbed amino acids used for
colostrum
protein synthesis as well as gluconeogenesis by the newborn calf
what do whey proteins provide
readily available source of AA
what does casein do
clots in abomasum to slow release
what is a fair to good indicator of colostrum quality is
appearance
what does thick and creamy colostrum contain
higher in antibodies and solids
what does thin and watery colostrum contain
lower in antibodies, solids (protein, fat)
what is a colostrometer
- superior (50-140 mg/ml)
- moderate (20-50 mg/ml)
- inferior (<20 mg/ml)
about how much of ingested immunoglobulins are absorbed when colostrum is fed immediately after birth
35%
what are factors affecting passive transfer IG
- IgG intake(g) = colostrum (IgG)
- efficiency of absorption of Ig fed (time after birth)
what are the guidelines for feeding colostrum
- feed 4 quarts of colostrum within 4 hours
- adequate transfer Ig will occur in 90% of calves
- feed 2 quarts again in 12 hours
what percent of body weight should you bottle feed colostrum
10-12% of body weight
esophageal feeder
- slowly pass the tube along the tongue to the back of the mouth
- calf will start chewing and swallowing
what is serum refractometer
- calves 1st week
- centrifuge serum
- leave in car 2-4 hr
within the first week of life, total protein in ____ calves should be > ____ if <5.0 mg/dl FPT
90%; 5.5 mg/deciliter