Dairy Heifer Growth

What is colostrum? How is it different than other milk secreted?

First milk at parturition, contains more lactalbumin & lactoprotein

Name 3 immunoglobulins present in dairy colostrum, from greatest to least concentration

IgG, IgM, IgA, IgE

Colostrum with have _____ the protein than other milk production

4x

Name 3 cytokines present in colostrum that will aid in antimicrobial activity for the calf?

Lactoferrin, lactoperoxidase, lysozyme

What molecule in colostrum will protect IgG from proteolytic degradation?

Trypsin inhibitor

Name 1 cytokine & 1 hormone present in colostrum to promote growth in calves

TGF-b2, Growth hormone

Calf serum that measures less than _______ mg/mL of IgG within 24-48hrs post partum will constitute failure of passive transfer

10

Name one economic factor in 2yr old dairy heifers that will be caused from failure of passive transfer

Decreased milk production in first lactation

Due to the presence of a pooling bank, dairy cattle that have calved 3-4 times will have their colostrum mixed with _________ colostrum to increase the quality

Heifer

100% of passive transfer will be possible if a calf receives colostrum within _____ hours

6

After 12hrs, what will prevent full transfer of maternal antibodies?

Trypsin production, endothelial membrane thickening in GIT

In order to reach over 50g/L of immunoglobulins in colostrum, how should a dairy heifer be managed?

Vaccinate dam 3-6w pre-partum, dry period (60d)

In order to reach over 50g/L of Ig in colostrum, how much should a newborn dairy calf be fed during their first feeding?

15%BW

What is the preferred method of feeding colostrum to newborn dairy cattle?

Esophageal feeder

How should preserved colostrum be stored?

Frozen within 1 hour of collection

To ensure protein degradation does not occur, how should colostrum be defrosted?

Slowly (no microwave)

Give 2 reasons that farmers may chose colostrum supplementation rather than source from the dam

Death of dam, biosecurity (BVDV)

During the first 2-3w of life, dairy heifers should be fed milk & dry feed ad lid True/False

False, milk is only utilized by heifers

During the transitional period of young dairy heifers, feeding some grain along with milk will promote what GIT changes?

Rapid expansion of volume, differentiation of rumen epithelium

Describe how casein proteins will react in the abomasum of calves

Casein proteins will denature, coagulation of casein protein plus fat will make coagulant

When a calf starts to consume starter concentrates, what VFAs will be produced from greatest to least?

Acetic acid, butyric acid, propanoic acid

Until the pH of the rumen is greater or equal to _____, the ability of cellulolytic bacteria to thrive is limited

6

Availability of Metabolizable Energy is influenced by _________ in calves less than 21 days old

Temperature

During the winter months in Montana, name 3 changes a dairy farmer may make to ensure dairy calves are well fed?

Increase volume of milk, introduce 3rd feeding, switch to higher fat milk replacer

Name 3 deficiencies of practical whole milk

Iron, manganese, selenium

Calves do not have a dietary requirement for what vitamin?

C

Aside from water, what is the most important vitamin a calf must receive in order to grow to their potential?

Vitamin B1

During the liquid feeding phase of a conventional feeding approach, what % of BW should be offered from the 1st week of life? What else should be included?

8-10%, starter

During the liquid feeding phase of an accelerated feeding approach, what % BW should be feed during week 1? What about after week 1?

12%, 16%

Name 2 benefits of improved nutritional status during the first 2-3w of life

Better immunity, reach breeding age sooner

Name 3 examples of nonsaleable milk from a dairy farm

Colostrum, transition milk, drugs with residue

Name 4 benefits of milk replacer additives compared to traditional milk

Probiotics, prebiotics, antibiotics, coccidiostats

At what age are calves considered a true ruminant?

42-45d

Weaned calves will be maintained on the ______ ration until moving to the transition pen at ___-____ weeks

Starter, 10-14

Moving heifers onto TMR in the ______ _____ phase by mixing starter grain with small amount of the high-group lactation TMR is common practice

Early grower

For Holstein heifers, the target BW gain pre-breeding is ______ kg/d

0.87