1. Chapter 2: Breeds and Life Cycles of Livestock and Poultry Unit 2b: Dairy Life Cycle - history and general production of dairy cattle

2. Dairy Cattle in the Americas: 1607: Virginia colony, all eaten 1611: Jamestown colony, survival! 1625: Dutch colonies; herds began

3. Dairy Cattle Genealogy: Genus: Bos Species: taurus(typicus) –Common term: bovine –All 6 major US breeds come from European stock

4. Historical Perspectives: Early American dairy cattle were dual and triple purpose –Milk –Meat –Draft labor Dairy herds developed around population centers for ease of delivery of fresh product

5. Dairy Cattle Numbers, 2000

6. Dairy Life Cycle: Calving Year-round calving is most common in the US to promote a steady flow of milk for sale Some seasonal calving utilized to reduce milking and calving in the coldest months or to support grazing- based systems Gestation in cattle is about 9 months

7. Newborn Calf Management: Birth weight: 60-100 pounds Colostrum feeding - hand feeding compared to beef nursing Weaning from dam - within first day as compared to 7 months for beef Navel dipping - antiseptic solution Identification - begin record keeping

8. Colostrum Feeding: The first milk produced by the cow around the time of calving Concentrated in preformed antibodies Provides passive immunity to the calf Should be received within an hour of birth Colostrum often bottle fed to assure consumption

9. Other Contrasts to Beef: After colostrum, calves are fed reconstituted milk-replacer and weaned from milk at approximately one month of age Calves are raised in hutches or specialized calf facilities

10. Calf Management: First Month Horn removal - if not genetically polled Males are generally sold at one day of age to specialty growers for beef production Castrate - bull calves for beef will be castrated in the first week to month of age

11. Female Replacements: Goal 1: first calf by 2 years of age –Selected females will be bred at about 15 months of age Goal 2: 12 month calving intervals –Rebred by 90 days post-calving –Full maturity reached at about 5-6 years

12. 12 Month Production Cycle: Lactation is initiated by calving Standard lactation period: 10 months –Peak production reached at 45 days Dry period: 2 months –Cessation of production and rebuilding of body stores and mammary gland Lactation is reinitiated by calving

13. Dairy Bulls: Compared to beef: –Pre-selected via planned matings –Very few bull calves selected –AI organizations (“bull studs”) predominate –Feedlot performance not tested (USA)