Reproductive System, Management, and Meat Processing in Cattle and Goats

Functions of the ovary in cattle

1. Production of gametes (ova)

2. Secretion of estrogen

3. Formation of corpus luteum

Uterine measurements for cattle

Uterine horn = 35-40 cm;

Uterine body = 2-4 cm

Uterine measurements for carabao

Uterine horn = 34.5 cm;

Body = 6.2 cm

Cervical and vaginal lengths in cattle

Cervix = 8-10 cm;

Vagina = 25-30 cm

Cervical and vaginal lengths in carabao

Cervix = 6.75 cm;

Vagina = 20-25 cm

Ovary measurements for cattle (700 kg)

Ovary = 2.8-3.8 cm (L), 5.0-9.4 cm (W); CL size = 1.7-3.0 cm; Weight = 1.2-2.5 g

Ovary measurements for buffalo (500 kg)

Ovary = 2.2-2.9 cm (L), 3.0-4.0 cm (W); CL size = 1.3-1.6 cm; Weight = 0.7-1.5 g

Ovum size in both species

169 µm

Phases of the estrus cycle in cattle

1. Proestrus: 3-4 days - Estrogen high 2. Estrus (heat): 12-18 hours - Estrogen low 3. Metestrus: 3-4 days - FSH high, Estrogen low 4. Diestrus: 10-14 days - Progesterone high, FSH low

Function of the cervix

Barrier to pathogens, passageway for semen and fetus

Function of the vagina

Organ of copulation; receives penis and semen; birth canal

Function of the vulva

External genitalia; opening for urinary and reproductive tracts

Stores urine

Function of the bladder

Site of embryo development; Uterine horns receive ova from oviducts; In cows, the uterus is bicornuate (with horns)

Function of the uterus and uterine horn in cows

Proestrus: Endometrial and follicular development; Estrus: Receptive to mating; ovulation follows; Metestrus: CL forms; sexual inactivity; Diestrus: CL is functional; high progesterone

Function of each estrus cycle phase

It degenerates after 10 days into a fibrous structure called corpus albicans.

What happens to the CL if no fertilization occurs?

1. Ovulation 2. Estrus (heat) 3. Gestation 4. Parturition 5. Lactation

Five reproductive stages in cattle

Cattle & Carabao: Puberty = 13-14 months; Breeding = 2-3.5 years

Ages of puberty and breeding in cattle and carabao

Sheep/Goat: Puberty = 5-7 months; Breeding = 8 months

Ages of puberty and breeding in sheep/goat

Estrus period: Cattle = 11-21 hrs; Estrus cycle: 21 days

Estrus period and cycle in cattle

Estrus period: Carabao = 18 hrs; Estrus cycle: 21 days

Estrus period and cycle in carabao

Hormone that prepares the uterus for pregnancy

Progesterone - secreted by CL; suppresses estrogen and new follicle development.

FSH: Stimulates growth of ovarian follicles; LH: Causes ovulation and CL formation.

Roles of FSH and LH in female reproduction

Role of relaxin in parturition

Secreted by CL; softens the pubic symphysis to allow birth.

Cow: 283 days

Gestation periods in days for cow

Carabao: 315 days

Gestation periods in days for carabao

Sheep/Goat: 150 days

Gestation periods in days for sheep/goat

1. Extends use of superior sires 2. Eliminates cost/risk of maintaining bulls

Advantages of A.I.

Artificial Insemination (A.I.)

It is the process of depositing semen into the female genitalia using instruments rather than natural mating.

The method to calculate calving dates based on insemination dates and gestation periods.

Gestation Problem Solving

If a cow is inseminated on July 7, 2019, the calving date is April 15, 2020 (283 days after July 7).

Calving Date Calculation

The ideal temperature of the artificial vagina (A.V.) for semen collection is 40°C to 52°C.

Semen Collection Temperature

A dog (bitch) was the first animal artificially inseminated.

First Animal Artificially Inseminated

The minimum acceptable sperm motility in semen evaluation is at least 60%; below this should be discarded.

Sperm Motility

The average sperm concentration per ml of bull semen is around 800 million sperm per ml (1.5 billion total per ejaculate).

Average Sperm Concentration

Estrus Synchronization

A management tool that manipulates the estrous cycle using hormones (like Prostaglandin) to synchronize the heat periods of multiple cows for timed A.I.

Prostaglandin

is a luteolytic agent that regresses the corpus luteum (CL), reducing progesterone and allowing estrus to occur in 3-5 days.

Liquid Nitrogen Storage Temperature

is stored for semen preservation at -196°C.

The best semen storage temperature in a nitrogen tank is -130°C or lower.

Semen Storage Temperature

Semen Extenders

Common semen extenders used in processing include egg yolk, sodium citrate, glycerol, fructose, and raffinose.

Embryo Transfer Purpose

is to allow superior donor cows and sires to produce offspring carried by surrogate dams, thereby multiplying elite genetics.

MOET: Multiple Ovulation and Embryo Transfer; SOET: Super Ovulation and Embryo Transfer.

MOET and SOET

A.I. Kit Components

Contents of a standard A.I. kit include stainless A.I. gun, disposable sheaths, isopropyl alcohol, paper towels, shoulder-length gloves, lubricant, disinfectant, pail, brush, and liquid nitrogen tank.

Steps in Embryo Transfer

1. Superovulatory treatment to donor cow; 2. A.I. of donor; 3. Embryo collection; 4. Synchronization of surrogate.

1. Remove fetal membranes from mouth; 2. Cut the navel cord 2-3 inches from base using sterilized scissors; 3. Tie the cord and apply tincture of iodine or Negasunt.

First Steps After Calf Birth

should be given immediately after birth to ensure the calf receives essential nutrients and antibodies.

Colostrum Administration

Ideal physical traits of a good semen sample include color: grayish white to pale cream, pH: 6.4 to 6.8, and volume: 5 to 10 ml.

Semen Sample Physical Traits

1. Poor technique can spread disease; 2. Limited to areas with good transport; 3. Careless use lowers breeding efficiency.

Disadvantages of A.I.

1. Remove from tank (not beyond frost line) within 3-5 seconds; 2. Thaw at 37°C for 17 seconds (0.5 ml straw); 3. Do NOT return to tank once removed.

Semen Thawing Steps

Examples include Oestrophan (Fenprostalene) - 2.0 ml, Lutalyze (Dinoprost) - 5.0 ml, Estrumate (Cloprostenol) - 2.0 ml.

Prostaglandin Drugs and Doses

Tincture of iodine

A solution of iodine used for disinfecting wounds.

Colostrum

The first milk produced by a cow after giving birth, providing passive immunity and nutrients.

Signs of calving (Parturition)

Behavioral and physical indicators that a cow is close to giving birth.

Diving position — two forelimbs come first, followed by the head, body, then hindlimbs.

Normal position of the calf during delivery

Retained placenta

Condition when the placenta is not expelled within 12 hours after birth.

The water bag appears.

First visible sign during actual calving

Surgical, rubber band (elastrator), Burdizzo (emasculatome - crushes spermatic cord).

Castration methods

Around 3 months.

Age for castrating male cattle

Calves can be dehorned at 6 weeks.

Dehorning age

Hot iron cautery, mechanical saw, KOH or chemical paste.

Methods of dehorning

Ear tags and ear notches

Other methods of cattle identification.

As early as 10-14 days old.

Earliest age for deworming calves

Broad-spectrum oral anthelmintics such as Pyrantel, Thiabendazole, Tetramisole.

Anthelmintics used for deworming

Four key periods: Preconditioning, During transport, Quarantine upon arrival, Weaning period.

Preventive health periods in cattle operations

Should be done 2-3 weeks before or after weaning.

Vaccination against Hemosep and HMD

Iron dextran injection

Given 4-5 days after birth.

Prevent overgrazing, control animal movement, enable rotational grazing, adapt to land topography and water distribution.

Importance of fences in cattle production

Should be 5.0 meters apart and 1.5 meters above the ground.

Fence post placement

Squeeze chute

A device used for safely restraining cattle for veterinary procedures.

Feed containing 16-18% crude protein (CP).

Concentrates for calves

Soilage/roughage introduction age

Starting at 2 weeks.

Weaning age for beef cattle

4-5 months.

Weaning age for dairy cattle

3-5 days, then given whole milk or milk replacer.

Hot iron branding

The most common method of cattle identification in the Philippines.

Iron: 6.4 cm long, 5.0 cm wide, 1 cm thick; Handle: 65 cm long.

Hot iron brand dimensions

1. Strict quarantine, 2. Early disease diagnosis, 3. Proper sanitation, 4. Accurate record-keeping, 5. Isolation/treatment facilities, 6. Responsible use of drugs and antibiotics.

Key elements of disease prevention

General cause of slow cattle industry growth in the Philippines

Low conception rate (<50%), high pre- and post-weaning mortality (>10%), high annual death losses in mature cattle (>2%).

5 sq. m/head

Space requirement for heifer/steer

6 sq. m/head

Space requirement for milking and dry cows

10 sq. m/head

Space requirement for maternity stall

4 sq. m/head

Space requirement for mature carabaos

1.2-1.5 m

Pen height for mature carabaos

Around 45 liters per day

Standard water consumption of mature cattle

0.8 sq. m

Feeding space needed for 35 kg animal

1.1 sq. m

Feeding space needed for 50 kg animal

1.4 sq. m

Feeding space needed for 70 kg animal

3.0 sq. m/head

Space requirement for Buck/Ram

0.4-0.5 sq. m/head

Space requirement for Kid/Lamb

Central area for stock movement

Purpose of a working corral

No. of head × Animal Unit (A.U.) = Total A.U.

Stocking rate formula

0.5 A.U./ha

Feasible stocking rate of pasture for cattle

Total DM = 250 × 0.025 = 6.25 kg

Total DM calculation for 250 kg steer

Concentrate DM = 6.25 × 0.30 = 1.875 kg

DM requirement using 70:30 roughage:concentrate ratio

An extensive system where cattle graze freely on natural pastures.

What is ranching?

A system where breeding cows are maintained to produce calves.

What is a cow-calf operation?

An intensive production system where animals are confined and fattened with a high-energy diet.

What is feedlot fattening?

Less than 50% — may indicate poor herd health, improper A.I. timing, or poor nutrition.

What is considered a low conception rate in cattle?

Weight (kg) = (Heart Girth² × Body Length) ÷ 11,880

Formula for estimating live weight using heart girth and body length

Mass treatment against external parasites for herds with 200+ animals.

Function of a dipping vat

To facilitate safe loading/unloading of cattle into trucks or trailers.

Function of a loading chute