Effect of energy source in calf milk replacer on performance, digestibility, and gut permeability in rearing calves

Abstract

Current calf milk replacer (CMR) compositions significantly differ from whole milk in their levels of energy, protein, and minerals. Energy source is one of the major differences, as CMR contains high levels of lactose, whereas whole milk contains higher levels of fat. The aim of this study was to determine the effect of partially exchanging lactose for fat on performance, digestibility, and gut permeability in calves fed twice daily on a high feeding plane. Lactose and fat were exchanged in the CMR formulation on a weight-weight basis. The CMR were isonitrogenous but not isoenergetic. A total of 60 male Holstein-Friesian calves were assigned to 1 of 30 blocks based on serum IgG, body weight, and date of collection after birth. Within each block, calves were randomly assigned to 1 of 2 treatments: high fat and high lactose. The CMR was provided twice daily until 49 d of age, followed by a gradual weaning period of 14 d. Starter, straw, and water were available ad libitum throughout the complete study. Exchanging lactose for fat did not affect growth; intakes of starter, straw, water, crude protein, or total energy; or apparent total-tract digestibility of nutrients. Gastrointestinal permeability was assessed by measuring the recovery of lactulose and Cr in 24-h urine and the Cr concentration and lactulose: d-mannitol ratio in serum following an oral pulse dose. Urinary recoveries of Cr and lactulose were generally low in both treatments but were higher in calves fed the high-fat CMR. Accordingly, the serum lactulose: d-mannitol ratio and serum Cr concentrations were higher in calves fed the high-fat CMR. In wk 1 and during the weaning transition, calves fed the highfat CMR had significantly fewer abnormal fecal scores. In conclusion, exchanging lactose for fat in the CMR did not affect growth performance, total feed intake, or nutrient digestibility. The high-fat CMR was associated with an increase in permeability markers but positively influenced fecal scores in calves.

Effects of exchanging lactose for fat in milk replacer on ad libitum feed intake and growth performance in dairy calves

“…With exchanging lactose for fat, CMR osmolality is reduced and would reduce gut permeability . To the contrary, however, Amado et al (2019) showed a higher gut permeability with HF CMR. The current experiment indicated a reduced occurrence of healthrelated events with HF CMR, although these events were mainly respiratory and not digestive.…”

“…Animals that have low phosphate at birth (<2.26 mmol/L) have been shown to have greater risk for diarrhea, with scouring calves having lower phosphate status than healthy calves up to 20 d of age (Jagoš et al, 1981, citing Cabello et al, 1977. Amado et al (2019) found higher fecal consistency (i.e., less thin) in the first week after birth when feeding high fat.…”

“…In the current experiment, we exchanged lactose for fat. We did not monitor fecal consistency in this experiment; however, Amado et al (2019) indicated a better fecal consistency with HF versus HL CMR. Additionally, Wilms et al (2019) has shown that higher CMR osmolality may lead to higher gut permeability.…”

Strategies for Feeding Unweaned Dairy Beef Cattle to Improve Their Health

“…These authors argued that this hypertonic milk replacer which caused intestinal osmotic pressure was greater than plasma osmolality and that this could exert an osmotic pressure on cell lining and on the tight junctions. Amado et al [ 93 ] studied feeding in male calves high-fat milk replacers, and observed an increased intestinal permeability compared with lactose-rich milk replacers. Curiously, Urie et al [ 94 ] observed a significant association between the amount of fat per day in liquid and increased calves’ mortality; so, the effect of fat content, fat type in the milk replacer and the total amount of fat consumed on gut permeability should be further studied.…”

“…Pisoni and Relling [ 95 ] hypothesized that supplementation with a prebiotic (yeast fermentation products) could stimulate the secretion of the gut hormone glucagon-like peptide 2 (GLP-2) by inducing changes in gut microbiota. GLP-2 is associated with intestinal permeability regulation and could enhance the mitogenic action of IGF-1 to synergistically benefit GIT development [ 93 ]. However, these authors [ 95 ] did not observe benefits of prebiotic supplementation on performance parameters, plasma GLP-2 concentration, intestinal permeability when supplementing these yeast fermentation products in the milk and starter in heifers.…”