Dairy Science and Industry Lecture Notes

Comprehensive vocabulary flashcards covering dairy cow life cycles, breeds, health disorders, milk standards, processing methods, feeding systems, and genetic metrics.

Colostrum

First milk containing antibodies produced during the first 3 days postpartum.

Freshening

The process of calving and starting milk production.

Peak Milk

The stage of maximum milk yield reached $45\text{–}60$ days postpartum.

Dry Period

A $45\text{–}60$ day non-milking interval utilized to prepare the cow for the next lactation.

Lactation Period

The standard milk production period lasting $305$ days in dairy cattle.

Holstein

The most popular dairy breed, characterized by producing the highest milk volume.

Jersey

A dairy breed characterized by producing milk with the highest fat percentage.

Artificial Insemination (AI)

The most common dairy breeding method; benefits include superior sires, decreased STD exposure, and eliminating dangerous bulls, while drawbacks include heat detection demands, training, and equipment costs.

Sexed Semen

Semen modified to increase the proportion of desired-sex calves, especially replacement heifers.

Milk Fever

A disorder marked by low blood calcium levels as calcium is rapidly drawn into milk.

Mastitis

Inflammation of the mammary gland caused by a common infection, with sanitation serving as the first line of defense.

Brucellosis

A bovine reproductive disease also referred to as Bang's disease that results in abortion.

Leptospirosis

A reproductive disease spread through wildlife, rodents, and contaminated urine or water.

Trichomoniasis and Vibriosis

Sexually transmitted reproductive diseases affecting cattle.

Whole Milk

Milk containing a minimum fat level of $\ge 3.25\%$.

Reduced-Fat Milk

Milk containing $2\%$ milk fat.

Low-Fat Milk

Milk containing $1\%$ milk fat.

Skim Milk

Milk containing less than $< 0.5\%$ milk fat.

Pasteurization

A dairy processing method that uses heat treatment to destroy pathogens.

Homogenization

A mechanical process that breaks fat into smaller droplets to prevent cream separation.

Grade A Milk

The regulatory classification meeting strict sanitation standards required for fluid milk.

Grade B Milk

The milk quality classification designated specifically for manufacturing purposes.

Class I Milk

The dairy market category assigned to fluid drinking milk.

Class II Milk

The dairy market category assigned to milk used for manufacturing yogurt and ice cream.

Class III Milk

The dairy market category designated for milk used in cheese manufacturing.

Class IV Milk

The dairy market category designated for milk manufactured into butter and dried milk.

Total Mixed Ration (TMR)

A feeding approach where all feedstuffs are blended together; advantages include balanced nutrition intake and reduced feed sorting, while disadvantages include equipment expense and risk of mixing errors or sorting.

Bovine Somatotropin (bST)

A hormone that increases milk production; routine milk testing cannot differentiate natural bST from recombinant bST.

Predicted Transmitting Ability (PTA)

A genetic evaluation metric representing the genetic merit an animal is expected to transmit to its progeny.

Reliability (%R)

The statistical degree of confidence assigned to a Predicted Transmitting Ability (PTA) value.

Heritability

The measure of the genetic contribution to observable variation; milk traits are generally moderately heritable.