Chapter 2: Breeds and Life Cycles of Livestock and Poultry

Unit 2b: Dairy Life Cycle - history and general production of dairy cattle

Dairy Cattle in the Americas

: • • •

1607

: Virginia colony, all eaten

1611

: Jamestown colony,

survival!

1625

: Dutch colonies; herds began

Dairy Cattle Genealogy:

• Genus: Bos • Species: taurus(typicus) – Common term: bovine – All 6 major US breeds come from European stock

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

Dairy Cattle Numbers, 2000 State:

California Wisconsin New York Pennsylvania Minnesota

US Total: Number of farms:

2,500 21,000 7,900 10,700 8,500

105,250 Number of dairy cows:

1,523,000 1,344,000 686,000 617,000 534,000

9,210,000 Production per cow:

21,169 17,306 17,386 18,081 17,777

18,204

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

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

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

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

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

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 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

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)