Dairy Cattle Breeding

Dairy Cattle Breeding

 Success with dairy cattle depends upon a well-balanced program of breeding for production and type.

 Conformation, health, and the lifetime level of production are closely associated with breeding.

Management and feeding of heifers

 Puberty

 Age at first breeding

Fertility

Age at first breeding; Breeding efficiency can be lowered seriously by postponing the first breeding to a needlessly late age.

Intervals between pregnancies; Breeding efficiency of a herd or flock as a whole may be seriously lowered by having long intervals between successive pregnancies.

Longevity; The length of life of the parents is important in breeding efficiency, both because it spreads the cost of their rearing over a longer productive life and because it permits more intense selection of the smaller percentage of

replacements needed.

• The number of young produced per female per year is important in determining profits in animal husbandry.

• Calves which die between birth and weaning cause further loss in breeding efficiency. Much of this loss comes from faults of management.

Dairy Cow Unified Score Card

Breed characteristics should be considered in the application of this score card.

MAJOR TRAIT DESCRIPTIONS

There are five major classification traits on which a classifier bases a cow’s score.

 Frame – 15%

The skeletal parts of the cow, with the exception of feet and legs, are evaluated.

 Dairy Character – 20%

The physical evidence of milking ability is evaluated. Major consideration is given to general openness and angularity while maintaining strength, flatness of bone and freedom from coarseness. Consideration is given to stage of lactation.

 Body Capacity – 10%

The volumetric measurement of the capacity of the cow (length x depth x width) is evaluated with age taken into consideration.

 Feet and Legs – 15%

Feet and rear legs are evaluated. Evidence of mobility is given major consideration.

 Udder – 40%

The udder traits are the most heavily weighted. Major consideration is given to the traits that contribute to high milk yield and a long productive life.

Classification traits used for final scores in Holstein cattle

The final score is used in computing predicted transmitting ability for type (PTAT). PTAT identifies genetic differences in sires that can be considered in selection programs to improve dairy cattle type.

Emphasis (%)

Trait Cows Bulls

Frame 15 30

Dairy character 20 25

Body capacity 10 20

Feet and legs 15 25

Udder 40 -

Dairy animals are polyestrus, meaning that they come into estrus (heat) each 21 days throughout the year.

Estrus

Estrus cycle Estrus period Signs of estrus

Methods of Mating (Hand mating, pasture mating, artificial insemination)

The genetic potential of the dairy cow has been

increased through the use of artificial insemination using production-tested bulls. Artificial insemination of dairy cattle became an accepted practice around 1946.

Estrus or heat is the period of time when the female will accept the male for breeding purposes.

The female of each species exhibits some behavior patterns that

demonstrate she is in heat.

When in estrus, dairy cows may show restlessness, enlarged vulvas, and a temporary decline in milk production. Also, when cows are in standing heat they will permit other cows to mount them.

Fertilization; is the union of the male and female germ cells, sperm and ovum. The sperm are deposited in the vagina at the time of service and from there ascend the female reproductive tract. Under favorable conditions, they meet the egg and one of them fertilizes it in the upper part of the oviduct near the ovary.

Gestation period; the average gestation period of cows is 280 (±) days.

Care of the pregnant cow

Care of the cow at calving time Signs of approaching parturition Position of the fetus in the uterus Parturition

Birth weight

Care of the newborn calf The afterbirth

Removing retained placenta

Occurrence of estrus after parturition

The free-martin; In cattle developing fetal membranes of twins usually grow together where they come in contact. If enough of the vessels on the two sets of membranes grow together, the blood of the two twins is mingled and some of that from each twin actually flows in the blood vessels of the other. This does no damage when both are males or both are females; but, when one is a male and the other is a female, the hormones secreted by the male develop first and exert enough influence on the female to prevent her normal sex development.

Presentation

Calving Operations

Dairy cows that are close to calving should be separated from other cows, and each cow should be placed in a maternity stall that has been thoroughly

cleaned and bedded with clean bedding. The cow in a maternity stall can be fed and watered there. A cow that delivers her calf without difficulty should not be disturbed; however, assistance may be necessary if the cow has not calved by 4-6 hours from the start of labor. Extreme difficulties in delivering a calf may require the services of a veterinarian, who should be called as early as possible.

As soon as a calf arrives, it should be wiped dry. Any membranes

covering its mouth or nostrils should be removed, and its navel should be

dipped in a tincture of iodine solution to deter infection. Producers should be sure newborn calves have an adequate amount of colostrum because

colostrum contains antibodies to help the calf resist any invading

microorganisms that might cause illness. The cow should be milked to stimulate her milk production.

• The cow normally will lick the calf immediately after birth and remove any remaining membranes covering it.

• Treat the calf’s umbilical (navel) cord with a strong tincture of iodine as soon as possible after birth to prevent navel infection.

• The calf generally will try to stand within the first 30 minutes after calving and start searching for the cow’s udder.

• The calf should receive colostrum (cow’s first milk) as soon as possible after birth to provide a mild laxative action and protective antibodies that protect the calf from respiratory and gastrointestinal infections early in life.

• The placenta (afterbirth) is usually expelled by continued uterine contractions during the next 2 to 12 hours.

• The placenta should be removed from the calving area immediately after expulsion.

Retained placenta

Retentio secundinarium

Disease Prevention

A sound basis for maintaining a healthy herd is provided by the following:

•Good care of animals

•Adequate feed

•Adequate shelter

•Isolation or elimination of diseased animals

•Purchase of only healthy animals

•Guarding against disease carriers

•Breeding for disease-resistant qualities

•An adequate testing program

•An adequate vaccination program

•Sanitary practices and premises

•Proper use of veterinary services

Management of Calves

• Management in birth

• Feeding with colostrum

• Feeding with milk

 A few rules which are important in feeding calves are:

 Feed warm milk at a uniform temperature

 Feed from clean pails

 Feed regularly

 Do not overfeed

 Make changes in feed gradually

 Weigh or measure milk for calves

• Methods of feeding with milk

• Milk Replacer

• Weaning (five factors influence weaning weight of calves: inbreeding, sex of calf, age of dam, size at birth, and milking ability of the dam. Since gains in cattle during the suckling period are largely under environmental rather than genetic influences, one would not expect a high relationship between suckling and post-weaning gains)

Growth and Development in Calves

Growth could be regarded as protein synthesis, but in actual studies that are being made with farm animals, most of the work is based on gains in body weight. Some gain in weight can be made without any increase in body tissue simply by an accumulation of water. Fattening, which might not be considered as growth, can result in increased gains. True growth can be accomplished only by an increase in cell size, by an increase in cell number, or by a combination of the two.

Growth begins as soon as the egg is fertilized and continues until maturity is reached.

•Growth Period

The growth period is divided into prenatal and postnatal periods.

•Pre-natal Growth (is controlled in part by additive genetic influences)

^Breed

Age of dam Sex of calf

Calving number Gestation length Management etc…

•Post-natal Growth (vital organs used for maintenance of life develop first, while other parts develop later. The order of development is: 1) digestive and endocrine systems, 2) skeletal system, 3) musculature, and 4) fat deposition)

Month Weight (kg)

Prenatal Growth Graph in Cattle

The female calves she produces are used for

replacement animals, while the male calves are used for

the production of veal or

finished out as beef-type.

Baby beef production;

The first requirement for baby beef production is superior breeding.

Secondly, the calves intended for such use should never be allowed to lose their baby fat.

In finishing the baby beef animal at so early an age,

unstinted use must be made of palatable and highly nutritious feeding stuffs.

Well-finished baby beeves command top prices.

Embryo Transfer

Embryo transfer (ET) is sometimes referred to as ova transplant or embryo transplant. In this procedure, an embryo in its early stage of development is removed from its own mother’s (the

donor’s) reproductive tract and transferred to another female’s (the recipient’s) reproductive tract.

The first successful embryo transfer was accomplished in 1890.

In the past several decades, successful embryo transfers have been reported in sheep, goats, cattle.

Calf Pens and Maternity Stalls

 Calves can be housed satisfactorily in an open shed even in cold climates if they are provided with dry bedding and protected from drafts.

 An open shed is ideal for older heifers and dry cows.

 Calves frequently are kept in movable pens.

 Losses due to disease and parasites are minimized by moving the pens to clean areas periodically.

Shelter of calves

 Marking or Identifying Method of Identification

 Dehorning; should be dehorned as early in life as possible.

• The objective of dehorning is to reduce the possibility of injury and bruising of animals.

• Less shed and feeding space is required for dehorned cattle

• Dehorned cattle are less likely to inflict injury upon other cattle or upon the attendant

• Dehorned cattle are quieter and easier to handle

• Prefer to buy dehorned cattle

• Dehorned cattle suffer fewer bruised carcasses and damaged hides in shipment to market

• Reduce carcass value in beef and milk production in dairy Methods of Dehorning

Caustic stick or paste Bell-shaped dehorners Surgical or cutting method Spoon (gouge), tube, or knife Barnes-type dehorners

Dehorning clippers and saws

 Removal of Supernumerary Teats

Some Management Practices of

Calves

Electrocautery

Application of electrocautery

Calf Diseases

• Mortality rate 5-20 %,

• Septicemia,

• Pneumonia,

• Diarrhea,

• Coccidiosis,

• Parasites,

• Tympany

• Calf Biosecurity Programme

• Sanitation and Disinfection

Effect of blood Ig levels to calf mortalities (Johnson ve Harpestad, 1970).

Breed Mortality Rate (%) Blood Ig Level

Ayrshire 4.2 High

Brown Swiss 10.5 Medium

Holstein 13.1 Medium

Jersey 16.9 Low

Guernsey 18.2 Low

Hereditary Disorders of Dairy Cattle

There are several inherited abnormalities known in dairy cattle.

Some of these abnormalities include achondroplasia (short bones), weavers, limber legs, rectal-vaginal constriction, dumps, flexed pastern (feet turned back), fused teats (teats on same side of udder are fused),

hairlessness (almost no hair on calf), and syndactylism (only one toe on a foot). Many of these inherited abnormalities are lethal and most are recessive in their mode of inheritance.

Usually the occurrence of inherited abnormalities is infrequent. However, occasionally an outstanding sire might carry an abnormality or a specific dairy herd may have several genetically abnormal calves. As most inherited abnormalities result from recessive genes, both the sire and dam of genetically abnormal calves carry the undesirable gene. Breeding stock should not be kept from either parent.