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Benefits of waste milk in dairy calves


BY MATTHEW WEDZERAI, FREELANCE CORRESPONDENT C


alves are born with an immature immune system and thus rely on colostrum to acquire passive im- munity during the first days of life. After successful transfer of passive immunity, a liquid feed is the


major nutrient source that can have a significant impact on the growth and development of a calf’s immune system be- fore weaning. Whole milk, milk replacer and waste milk are the most common liquid feed for calves on dairy farms. Al- though whole milk is generally considered the best liquid feed for calves, it is mainly produced for human consumption. On the other hand, milk replacer is made up of high-quality materials that are easy to digest and can meet the nutritional requirements of calves; but it’s not the cheapest source of nu- trients for calves. Most research on calf nutrition has focused on whole milk and milk replacers.


Waste milk study In this study published in the journal Animal Feed Science and Technology, researchers investigated the effect of different liquid feeds on the growth, immunity and gut health of dairy calves. They used 24 Holstein male calves. The calves were fed 4 litres of whole milk twice a day after the successful transfer of passive immunity until 7 days of age. From day 8 to 70, calves received either of three diets: (1) milk replacer (100% milk replacer), (2) mixture (50% milk replacer mixed with 50% pasteurised waste milk), or (3) waste milk (100% pasteurised waste milk). The calves were weaned at day 56 but the experiment continued up to day 70.


Growth performance The researchers found that feeding waste milk gave higher growth performance in Holstein calves compared to milk re- placer. Their results showed that feeding waste milk improved hip width, hip height, heart girth, weight gain and feed effi- ciency compared to feeding milk replacer. Feed efficiency (BW gain/total DMI) was significantly higher in the waste milk group during the whole period. The overall growth perfor- mance was attributed to the lower energy value of the milk replacer (1493.6 MJ/d) compared to waste milk (1547.0 MJ/d). They remarked that calves receiving milk replacer may not have sufficient energy to cope with cold conditions and to


Due to the continuous expansion of dairy farms, a large amount of waste milk including transitional milk, abnormal milk and milk with antibiotic residues has been produced; utilising this waste milk might save costs for most dairies. In a new study, researchers found comparable benefits of waste milk to milk replacers.


support their growth compared with those consuming waste milk. Body skeletal growth is an important indicator reflecting overall development of calves, as well as an intuitive reflec- tion of body growth and feeding level. “Our study showed that calves fed waste milk had greater skeletal growth and development, which may be associated with the change in body weight, as other studies show a significant correlation between body weight and heart girth,” they said.


Immunity Feeding waste milk showed higher levels of plasma immune parameters compared to milk replacer. Plasma concentrations of IgA, IgM, IgG and interleukin 10 (IL-10) were higher, where- as tumour necrosis factor-alpha (TNF-α) was lower in waste milk than in the milk replacer group. The reason for the differ- ences in immune parameters of the liquid feeds was suggest- ed to result from the changes of gut microbiota. Higher


Table 1 – Effects of waste milk on growth performance of dairy calves from day 8 to day 70.


Item


Starter intake (kg) DMI (kg)


Body gain (kg) ADG (kg/d)


BW gain/total DMI


Hip width (cm), day 70 Hip height (cm), day 70 Heart girth (cm), day 70


Milk replacer 48.49 77.64 42.94 0.68 0.54b 33.8b 85.9b


106.8b


Experimental diets Mixture (50:50) 39.83 70.03 41.75 0.66


0.60ab 33.0b 86.4b


106.4b 1: Values in the same row with different superscripts differ significantly (p<0.05). ▶ DAIRY GLOBAL | Volume 9, No. 2, 2022 33


Waste milk 48.95 78.14 49.36 0.78 0.64a 35.6a 88.4a


111.7a


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