PARTNER FEATURE ▶▶▶


Low scouring around weaning


Clean and functional enzyme-treated proteins are cost-competitive alternatives to whey and soy products, turning calves into robust and vital animals that grow to their full potential.


BY CHRISTINE BRØKNER, PHD, TECHNICAL MANAGER AT HAMLET PROTEIN


Immature gut system The immaturity of the gastrointestinal system is the reason a calf’s transition to ruminant can be troublesome. From birth, calves have an oesophageal groove, a muscular structure that shunts milk directly into the abomasum, bypassing the ru- men. This means that newborn calves are functional mono- gastrics in terms of their ability to break down feed and ab- sorb nutrients. As is the case for other young animals, the secretion of various digestive enzymes is also limited, empha- sising the need for highly digestible ingredients at this early stage. The luminal surface area of the rumen has a smooth appearance with no papillae development and therefore also no absorption capacity. This is not a problem in the first few


Figure 1 - Faecal consistency improved with HP 100. Faecal score: 1=normal, solid; 2 = semi- formed, pasty; 3=loose, stays on top of bedding; 4=watery, sifts through bedding. Different superscript within the same row is different (P<0.01). 3.0


2,9 a 2.5 2.0 1.5 1.0 0.5 0.0 Dairy protein 20 HP 100 1,7 a


weeks after birth as nutrients are absorbed in the small intes- tine, and the nutritional requirements are met entirely by colostrum and milk products. When starting the transition to solid feed, the pre-starter feed should be introduced gradually. The purpose of this is two- fold: to initiate the development of the rumen and to moti- vate calves to increase their solid feed intake in preparation for weaning. During weaning, where milk feeding is reduc ed and pre-starter feed intake increases, the pre-starter becomes the major contributor of energy and nutrients over time. This naturally emphasises the importance of the bioavailability and utilisation of ingredients used in the pre-starter. The same applies to protein ingredients used in calf milk replacers (CMR): high level of bioavailability and utilisation is essential as long as milk is fed to fulfil nutrient requirements and secure consistent high growth.


How to select protein ingredients Raw unprocessed soy naturally has factors that primarily act as biopesticides, protecting the beans against moulds, bacte- ria and from being overeaten by wild animals. All factors that interfere with the utilisation of nutrients when used as feed should be avoided for maximum utilisation in calves. These factors are collectively defined as anti-nutritional factors (ANFs), and they are harmful to gut physiology and morphol- ogy and subsequently depress animal growth and increase incidence of scouring. The ANFs can be grouped in many ways according to their harmful effects on nutrient utilisation and biological respons- es in animals. In broad terms the most harmful ANFs are those that depress protein digestion and absorption (trypsin, chy- motrypsin inhibitors and lectins), utilisation of minerals (i.e. phytic acid), flatulence factors and osmotic diarrhoea triggers (i.e. stachyose, raffinose and verbascose) and antigenic pro- teins (i.e. beta-conglycinin and glycinin) that activate the im- mune system unnecessarily, causing oxidative stress respons- es which result in villi atrophy locally in the gut system. Processing of soy can reduce the adverse effects caused by ANFs; heat treatment is an often-used method and includes toasting, extrusion and steaming. In fact, heating to excess effectively inactivates ANFs by denaturing protein structures. However, excess heating, besides inactivating ANFs, simultaneously results in loss of nutritional value, including


▶ DAIRY GLOBAL | Volume 8, No. 2, 2021


Fecal score


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