Heat Stress in Dairy Cattle: Summer Care Guide

Dairy animals feel heat much earlier than people do. A high-yielding crossbred cow starts to struggle on days that feel only warm to us, especially when the air is humid. Buffaloes have dark skin and few sweat glands, so they suffer in direct sun. In north Indian summers, heat stress quietly cuts milk, feed intake and fertility for months.

Signs of heat stress

• Fast breathing and panting. Open-mouth breathing with the tongue out is serious.
• Drooling.
• Eating less, especially dry fodder, and chewing the cud less.
• A drop in milk.
• Standing instead of lying down, and crowding around the water.
• Animals in heat showing weak or no signs, and fewer conceptions.

Shade and the shed

• Give every animal shade all day. A high roof with open sides lets hot air escape.
• A bare tin or asbestos roof gets very hot. Insulate it, cover it with straw or thatch, or paint the top white.
• Fans help a lot, and fans with water sprinklers or foggers help most. Wet the animals, then let the fan dry them, and repeat.
• Let buffaloes wallow, or splash water on them two or three times a day.

Water first

• Clean, cool water should be available all the time. A milking animal can drink well over twice as much in summer as in winter.
• Put water troughs in the shade and keep them clean.
• Offer water right after every milking.

Feeding in summer

• Feed in the cool hours: early morning, evening and night.
• Give more green fodder and good-quality feed, because the animal eats less in total.
• Animals lose sodium and potassium through sweat and urine in heat. An electrolyte supplement helps them drink and stay hydrated. Bictro Cool is an oral rehydration mix with dextrose and vitamin C.
• Live yeast supports the rumen when feed intake drops, as in Hazmino.
• Keep the daily mineral mixture going. Heat increases the need for some minerals.

Handling and breeding

• Do not move, transport or treat animals in the midday heat.
• Cool animals before and after insemination, and check for heat in the early morning and at night, when signs are easier to see.
• Animals near calving need extra care, because heat stress at this time affects the calf and the next lactation.

Heat stroke: act fast

If an animal is breathing very hard with its mouth open, staggering or collapses, move it into shade, pour cool (not ice-cold) water over the whole body, especially the head and neck, keep a fan on it and call the vet.

Quick checklist

• Shade all day, with fans and sprinklers if possible.
• Cool water always available.
• Feeding moved to cool hours.
• Electrolytes and minerals through the hot months.

This guide is general information for farmers and dairy owners. Blackmango products are animal feed supplements, not medicines. For a sick animal, call your veterinarian.