Raising and Management of Replacement Heifers and Bulls

Importance of Replacement Heifers and Bulls

Replacement heifers and bulls are crucial for the profitability and sustainability of dairy farms. Proper management and care of calves ensure successful dairy enterprises, leading to healthy and productive livestock.

Methods of Raising Calves

Proper calf-rearing practices play a crucial role in ensuring healthy growth and development. There are two primary methods of raising calves:

1. Suckling Method

In this method, the calf is allowed to suckle the mother for a specific period before being weaned.

Advantages:

• Ensures natural bonding between mother and calf.
• Provides fresh, warm, and uncontaminated milk.
• Enhances passive immunity through colostrum intake.
• Reduces labor and feeding management costs.

Disadvantages:

• Difficulty in controlling milk consumption.
• Increased risk of disease transmission (e.g., mastitis, Johne’s disease).
• May cause stress during weaning if done abruptly.

2. Weaning Method

In this method, the calf is separated from the mother and provided with an alternative source of milk or milk replacer. Weaning can be done at an early stage (4-6 weeks) or late (3-4 months).

Advantages:

• Allows better control over milk allocation.
• Reduces the risk of disease transmission.
• Encourages early rumen development if starter feed is introduced.

Disadvantages:

• Requires careful management to prevent stress and growth retardation.
• Initial reluctance of the calf to consume artificial milk or feed.

Care of Newborn Calves

Proper newborn calf care is essential for survival, disease prevention, and optimal growth.

• Birth Weight: The average birth weight of Asian cattle breeds ranges from 24 to 45 kg.
• Clearing Airways: Remove mucus from the nostrils and mouth immediately after birth to ensure proper breathing.
• Artificial Respiration: If the calf does not start breathing, stimulate it by rubbing its chest and splashing cold water on its face.
• Maternal Bonding: Allow the mother to lick the calf to stimulate circulation and promote bonding.
• Cleaning: Wipe the calf’s body with a clean, dry cloth to remove amniotic fluid.
• Hoof Care: Remove the soft, yellow-colored tender hooves, which help in the calf’s movement.
• Naval Care: Cut the navel cord about 3 cm away from the body using a sterile blade. Apply tincture iodine to prevent infections like navel ill and joint ill.
• Colostrum Feeding: Feed colostrum within the first 2 hours of birth at 10% of body weight for enhanced immunity.

Colostrum Feeding

Colostrum (biestings) is the first milk produced by the mother after calving. It is rich in antibodies, proteins, vitamins, and minerals, which are essential for calf survival and immunity. Colostrum is present in the udder for up to six milkings after calving.

Benefits of Colostrum

1. Passive Immunity: Provides immunoglobulins (IgG, IgA, IgM) that protect against infections. Since calves are born without antibodies, colostrum is essential for disease resistance.
2. Essential Nutrients: Supplies vitamins A, D, and E, which do not cross the placenta. Rich in proteins, fats, and minerals for initial growth.
3. Natural Laxative: Helps in the elimination of meconium (the first stool). Prevents digestive issues and constipation.
4. Prevention of Neonatal Diseases: Reduces the risk of scours (diarrhea), pneumonia, navel-ill, and joint-ill.
5. Duration of Feeding: Should be fed for the first 3-5 days after birth for optimal immune system development. The first feeding should be within 2 hours of birth for best antibody absorption.

Weaning of Calves

Weaning is the process of gradually reducing and stopping milk feeding. Calves are weaned either based on age or body weight.

Weaning Schedule

Calf Starter

Calf starter is a balanced concentrate mixture given from day 10 to supplement milk intake and ensure proper growth.

Composition of Calf Starter

Milk Replacer

A milk replacer is a dry feed mixture that is reconstituted with warm water to replace whole milk. It is used to reduce the cost of calf raising.

Composition of Milk Replacer

Housing of Calves

• Calves should be housed separately in well-ventilated calf pens.
• A maximum of 10 calves per group is recommended.
• Provide a minimum space of 25 sq. ft. per calf.
• The calf pen should be near the cow shed for easy monitoring.

Calf Identification and Management

Proper identification and management of calves are essential for maintaining herd records, tracking growth and health, and ensuring effective disease control. Below are the key aspects involved in calf management.

1. Marking of Calves

Marking or identifying calves is important for record-keeping, tracking performance, and monitoring health. The commonly used methods for calf identification include:

• Ear Tagging: A plastic or metal tag with a unique identification number is inserted into the calf’s ear.
• Tattooing: A permanent method where numbers or symbols are imprinted inside the ear using tattoo ink.
• Branding: Hot iron or freeze branding is used to create a permanent mark on the calf’s skin.
• Electronic Identification (RFID Tags): Radio Frequency Identification (RFID) tags help in digital record-keeping and tracking.

2. Castration of Calves

Castration is done to prevent unwanted breeding, improve meat quality, and reduce aggressive behavior in male calves. The common methods of castration include:

a) Open Castration

• The scrotum is cut open using a scalpel, and the testicles are removed.
• It is usually performed on young calves under sterile conditions to minimize infection.
• Proper post-operative care is needed to prevent infections.

b) Burdizzo’s Emasculator

• A bloodless method that uses a special clamp (Burdizzo’s emasculator) to crush the spermatic cord without cutting the scrotum.
• This method reduces the risk of infection as there is no open wound.
• It is best suited for calves younger than three months.

3. Dehorning/Disbudding of Calves

Dehorning or disbudding is done to prevent injuries to other animals, handlers, and to reduce space requirements in housing. The common methods are:

a) Mechanical Method

• Uses dehorning knives, scoop dehorners, or saws to physically remove the horns.
• Effective for older calves but may cause more stress and bleeding.

b) Chemical Method (KOH – Potassium Hydroxide)

• A caustic paste (usually potassium hydroxide or sodium hydroxide) is applied to the horn buds when the calf is 2-3 weeks old.
• This method is bloodless but requires proper handling to prevent chemical burns to other body parts.

c) Electrical Method

• An electric dehorner is used to burn the horn bud and prevent further growth.
• Best performed when calves are less than 2 months old.
• Causes minimal stress and reduces the risk of infection.

4. Deworming and Vaccination of Calves

Proper deworming and vaccination help in preventing major diseases that affect calf growth and productivity.

a) Deworming

• Protects against intestinal parasites (worms) that affect digestion and growth.
• Calves should be dewormed at 3-4 weeks of age and repeated every 2-3 months.
• Common dewormers include albendazole, ivermectin, and fenbendazole.

b) Vaccination

• Essential to protect calves from bacterial and viral diseases.
• Major vaccines recommended for calves include:
  • Foot and Mouth Disease (FMD): Given at 4 months of age, with a booster dose every 6 months.
  • Haemorrhagic Septicaemia (HS): Given at 6 months of age before monsoon season.
  • Black Quarter (BQ): Given at 6 months of age, with annual boosters.
  • Brucellosis: Given to female calves at 4-8 months of age to prevent reproductive issues.

Care and Management of Growing Heifers

Heifers are often referred to as the future dairy cows, and their proper care ensures optimal reproductive and productive performance.

Methods of Raising Heifers

1. Grazing Method (Outdoor System)

• Heifers are allowed to graze on pasturelands.
• The number of heifers should be proportionate to available grazing land.
• Rotational grazing should be practiced.
• Sufficient legumes should be included in the diet.

2. Stall Feeding (Indoor System)

• Heifers are kept indoors and provided green fodder, hay, and concentrates.
• 1–1.5 kg of concentrate mixture should be provided daily.
• Mineral bricks or mineral mixture should be supplied to maintain fertility.
• During the last half of pregnancy, additional 1.5 kg of concentrate mixture should be provided daily (Steaming-Up).

Advantages of Steaming-Up

• Ensures better growth of the pregnant heifer and fetus.
• Prepares the reproductive system for parturition.
• Facilitates proper udder development for lactation.
• Increases milk production post-calving.
• Extends lactation length.

Housing Requirements

• Heifers (6 months to breedable age) should be housed separately.
• Provide 2 sq. meters of covered space and 4 sq. meters of open area per heifer.
• One month before calving, heifers should be housed with milking cows.

General Management Practices

• Deworming every 4-6 months.
• Daily grooming.
• Spraying insecticides to control parasites.
• Vaccination against HS, BQ, Anthrax, and FMD.
• Branding at one year of age for identification.
• Ensuring proper breeding practices based on body weight and reproductive soundness.