Milk replacers: To curd or not to curd?

STOCK MILK REPLACERS

To curd or not to curd?

A response to ‘What’s in the bag?’ article, June 2020.

Farmers looking to maximise the profitability of their dairy farm operation understand the importance of high-quality care and nutrition of the young pre-ruminant.

Agricultural scientists and nutritionists understand this too and so researchers around the world have invested substantial resources into quantifying the nutrient requirements of calves and understanding the suitability of different raw materials for inclusion in the diets of these rapidly growing, valuable, young animals.

Finding a suitable alternative to whole milk has been an important focus for over 100 years. Yet, the factors identified in the 1940s as critical for the successful replacement of whole milk are still relevant today: use of high quality, highly digestible ingredients, careful selection of fat sources and homogenisation of fat, plus the addition of essential vitamins and minerals.

While the importance of these factors has not changed, research has proven that the previously “sacred cow” of milk replacers, namely the importance of curding, is not as important as once thought.

Understanding the importance of curd formation in the digestibility of milk replacers has been an area of interest for anyone looking to develop alternative feed sources for young calves. Yet, in their comprehensive 1998 review of this topic, Longenbach and Heinrichs concluded that “The complete function and necessity of abomasal coagulation in calves, beyond colostrum feeding, remains questionable with current feed processing technology”.

More recently, Japanese researchers (Miyazaki, 2010) used ultrasound to assess curd formation in young pre-ruminant calves. These authors reported that abomasal curd formation was absent in eight out of 29 calves fed a curding milk replacer. These authors also reported no significant difference in appearance, appetite, vigour or blood parameters of the calves.

Taking account of this novel and current research and looking back at some of the research published over the last 100 years with a better understanding of the calf development and the digestion of milk, it is becoming increasingly clear that curd formation plays an important physiological role in the success of passive transfer of immunoglobulins in colostrum in the first 24 hours of life, but not in the digestion of milk proteins post colostrum feeding.

And, these research findings are supported by practical experience. Many farmers around the world use wheybased milk replacers as the sole source of nutrition for young calves from as young

SPECIAL REPORT

What’s in the bag?

Words by: Paul Muir

Colostrum and whole milk are always the best feeds to offer young calves. However, if milk feeding is not possible there is a large array of substitute powders available to the rearer. They are not dried milk powders, so using “milk powder” as a name would likely contravene the Fair Trading Act. Instead they are called calf milk replacers (CMRs) and are made up of a range of products blended to meet minimum protein and fat specifications. They can contain a wide range of ingredients, and the lack of clear specifications on the bag means it is almost impossible for rearers to make an informed decision.

In calves up to three weeks of age the digestive system is poorly developed and the calf can digest only a limited range of carbohydrates, fats, and proteins. Curding appears to be necessary to enable full utilisation of complex proteins. When calves are fed whole milk, its casein proteins curd in the abomasum where they break down gradually (over eight hours) and the products of digestion are released slowly into the small intestine where absorption occurs.

as four days of age. Published data (Urie

et al., 2018) from the United States shows REAL PURE EXCELLENT EXCELLENT that more than 30% of heifer calves raised Brytec Calf Milk Powder is produced by a privately owned NZ company, trading since 2015 Quality Milk Powder NZ MILK • Only Real Cows Milk used • Produces excellent results • Protein 28-31% Fat 15-17% Service • Order by Phone or Online • Depots and Agents across NZ • Excellent Back up Service Service • Order by phone or online • Depots and agents across NZ • Excellent back up service Contact: HEAD OFFICE - WAIKATO, BOP Bryson Montgomery 021 0272 3063 in the US are fed only milk replacer, of which more than 95% does not curd. Similarly, market research shows that in the United Kingdom as many as 44% of dairy farmers feed only milk replacer to heifer calves and more than 60% of this is whey-based. What is clear is that, in much the same Dairy Exporter | www.nzfarmlife.co.nz | June 2020 • For use from 4 days old • Easy to mix cold or warm, add hot last • Produces premium results • No Fillers or Vegetable Protein • Cost effective & value for money Brytec Calf Milk Powder • Used by commercial calf rearers through to hobby rearers • Loved by calves, rearers and bank managers Contact Info SOUTH ISLAND & SOUTHLAND TED CHARLTON 020 406 195 34 Depots - Tuatapere and Invercargill CHRISTCHURCH 03 310 0444 Depot - North Canterbury Stockfeeds www.brytecmilk.co.nz 2278023 • Lactose 39-43%• Competitive rates • Free Delivery for 10 bags or more, Pallet of 40, or per tonne (50 bags) June Promo Rates South Island $4250 incl GST per tonne Includes delivery Normal rates $3867.57 excl GST per tonne $4450.00 incl GST per tonne Quality Milk Powder • For use from 4 days old • Easy to mix cold or warm, add hot last • No Fillers or Vegetable Protein Brytec Calf Milk Powder • Used by Commercial Calf Rearers through to Hobby Rearers • Loved by Calves, Rearers and Bank Managers Brytec Calf Milk Powder is produced by a privately owned NZ Company, trading since 2015 • Competitive rates • Free delivery for 10 bags or more, pallet of 40, or per tonne (50 bags) Contact Info SOUTH ISLAND & SOUTHLAND TED CHARLTON 020 406 195 34 Depots - Tuatapere and Invercargill CHRISTCHURCH 03 310 0444 Depot - North Canterbury Stockfeeds 2278023 REAL PURE NZ MILK • Only Real Cows Milk used • Produces excellent results • Protein 28-31% Fat 15-17% • Lactose 39-43% EXCELLENT Service • Order by Phone or Online • Depots and Agents across NZ • Excellent Back up Service • Competitive rates • Free Delivery for 10 bags or more, Pallet of 40, or per tonne (50 bags) June Promo Rates South Island $4250 incl GST per tonne Includes delivery Normal rates $3867.57 excl GST per tonne $4450.00 incl GST per tonne Quality Milk Powder • For use from 4 days old • Easy to mix cold or warm, add hot last • No Fillers or Vegetable Protein Brytec Calf Milk Powder • Used by Commercial Calf Rearers through to Hobby Rearers Brytec Calf Milk Powder is produced by a privately owned NZ Company, trading since 2015 REAL PURE NZ Milk • Only real cows milk used • Produces excellent results • Protein 28-31% Fat 15-17% • Lactose 39-43% Brytec 2020 rates $4250 incl GST per tonne - South Island add $200 www.brytecmilk.co.nz RUAWAI Kaipara Matt Elphick 021 401 67 TARANAKI, MANAWATU Neil Crosse 027 458 5853 EAST COAST Karena Montgomery 027 253 5488 SOUTH ISLAND, SOUTHLAND Ted Charlton 020 4061 9534 way as the book cover only presents a www.brytecmilk.co.nz • Loved by Calves, Rearers and Bank Managers

glimpse of the story, the list of ingredients making up the milk replacer is far less important than the digestible nutrient profile of the product and the performance of the product in your feeding system.

When choosing a suitable milk replacer (curding or non-curding), look beyond the product label and choose a product which is formulated by a qualified nutritionist, based on a thorough understanding of upto-date scientific research, is manufactured to high quality standards, and which is backed by comprehensive local support.

Article supplied by AgriVantage.

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