Chapter 2: Breeds and Life Cycles of Livestock and Poultry

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Chapter 2 Breeds and Life Cycles of Livestock
and Poultry

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

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Dairy Cattle in the Americas

• 1607 Virginia colony, all eaten
• 1611 Jamestown colony, survival!
• 1625 Dutch colonies herds began

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Dairy Cattle Genealogy

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

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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

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Dairy Cattle Numbers, 2000
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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

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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

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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

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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

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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

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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

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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

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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)