Nutritional effects of including different levels and sources of protein in milk replacers for calves

Abstract

Two digestibility and nitrogen balance experiments were carried out with groups of young calves given high-fat milk replacers reconstituted with water and fed in liquid form. In the first experiment six different milk replacers with crude protein contents ranging from 12.7 up to 27.6% in the dry matter were compared, the differences in protein content being brought about by adjustments to the level of separated milk protein used in the replacers. The apparent digestibility of organic matter was very high on all the treatments and unaffected by level of protein. Although the crude protein fraction showed an increase in apparent digestibility with increase in level of protein, its true digestibility was estimated to be virtually 100% on all the treatments. Retention of nitrogen expressed as a percentage of total intake remained fairly constant for diets containing from 18.8 to 27.6% of crude protein and the weight of nitrogen retained increased with each successive increase in level of dietary protein.In the second experiment the effects of replacing half of the milk protein in a control milk replacer by different forms of animal protein were studied. The true digestibilities of the total dietary protein on the treatment containing only separated milk protein and on the other treatments containing partial substitution by dried delactosed whey, dried blood, white fish meal and meat meal were found to be 94.1, 90.9, 85.4, 91.1 and 86.6%, respectively. Their biological values were 74.7, 70.3, 69.1, 66.0 and 65.5%, respectively. A sixth treatment in which the meat meal was provided with an enzyme supplement did not effect any significant change in either digestibility or biological value. Retentions of nitrogen expressed as percentages of intake were significantly lower on all the treatments containing partial replacement of separated milk protein by the other sources of protein than on the control treatment.

A note on the effect of feeding calves on fish-protein-based milk replacers

“…Despite the linearly decreasing tendency, the differences in N retention were not significant. The results of this investigation are similar to those reported by Huber and Slide (1967), Raven (1972) and Opstvedt et al (1977). In all the investigated treatments, N balance was positive and N retention decreased with higher level of fish protein.…”

Fish Protein in the Nutrition of the Young Calf

“…These figures are in line with the digestibility found for the protein in other types of fish protein concentrates (Hellcmond, 1967;Huber & Slade, 1968;Sleiman & Huber, 1971;Gorrill et al, 1975;Raven, 1972;Sniits et al, 1974), and somewhat higher than those found for milk protein substitutes of vegetable, animal and single cell origin (Paruelle et al, 1973;Raven, 1972). The ability of the calf to digest protein of non-milk origin, therefore, improves with age.…”

“…In a separately conducted digestibility test (unpublished data) the apparent digestibility of the protein in Norsamin" was 73% when fed as the sole source of protein to calves between 1 and 4 weeks of age. Since the total protein content was different in milk replacers without and with Norsaniins in the present study, the apparent digestibility of the protein in Norsaniin" cannot be calculated directly by difference (Raven, 1972). However, assuming a n apparent digestibility of 93:/0 for the milk protein revealed that the protein in Norsaniin" was digested to about 80% for the younger calves (Expts.…”

Analysis of Nitrogen Utilization and Excretion in Growing Dairy Cattle

“…Applying these restrictions allowed data from 16 published papers to be used. Of these, 6 studied calves were fed milk or milk protein-based milk replacer (milk-fed group) with 37 different dietary treatments, with animals ranging from 30 to 81 kg of BW (Blaxter and Wood, 1951b;Brisson et al, 1957;Roy et al, 1970;Raven, 1972;Donnelly and Hutton, 1976;Blome et al, 2003). For animals in the milk-fed group, all nutrition was derived from the milk or milk replacer and no additional feed was offered (either starter grain or hay).…”