Effects of Increased Dietary Protein and Energy on Composition and Functional Capacities of Blood Mononuclear Cells from Vaccinated, Neonatal Calves

Abstract

Effects of increased protein and energy provided by an intensified milk replacer on the antigen-specific, cell-mediated immune response of the neonatal calf were examined. Calves were fed a standard (0.45 kg/day of a 20% crude protein, 20% fat milk replacer; n=11) or intensified (1.14 kg/day of a 28% crude protein, 20% fat milk replacer; n=11) diet from 0 to 6 weeks of age. All calves were vaccinated with Mycobacterium bovis bacillus Calmette-Guerin (BCG) at 1 week of age. The daily weight gain of intensified-diet calves (0.62 kg/day) was greater than the weight gain of standard-diet calves (0.29 kg/day). Liver, kidney, heart, thymus, and subcervical lymph nodes from intensified-diet calves were heavier than the same organs from standard-diet calves. Flow cytometric analysis of peripheral blood mononuclear cell (PBMC) populations indicated that CD4+ cells, gamma delta TCR+ cells, and monocyte percentages, although unaffected by diet during the first 5 weeks of the study, were higher in intensified-diet calves at week 6. The decline in gamma delta TCR+ cell percentages and increase in B cell percentages with increasing age seen in all calves are characteristic of the maturing immune system of the calf. CD8+ T cell or B cell percentages were not affected by diet. In intensified-diet calves, percentages of CD4+ expressing interleukin-2 receptor increased and percentages of gamma delta TCR+ cells expressing interleukin-2 receptor decreased with time. The same populations in standard-diet calves did not change with time. Percentages of CD4+ and CD8+ T cells, and B cells expressing MHC class II antigen, were unaffected by diet or age. Although mitogen-induced interferon (IFN)-gamma and nitric oxide (NO) secretion increased with age for all calves, PBMC from intensified-diet calves produced less IFN-gamma and more NO than did cells from standard-diet calves at week 6 of the study. Antigen-induced secretion of IFN-gamma and NO also increased with age but was unaffected by diet. Antigen-elicited delayed-type hypersensitivity was unaffected by diet, suggesting increased dietary protein and energy did not alter adaptive immunity in vivo. Overall, these results suggest that feeding calves a commercially available, intensified milk replacer affects minimally the composition and functional capacities of PBMC populations. Additional research is necessary to determine whether these subtle effects influence the calf's susceptibility to infectious disease.

Mortality in Holstein-Friesian calves and replacement heifers, in relation to body weight and IGF-I concentration, on 19 farms in England

“…Conversely, small calves with a low IGF-I concentration, indicative of low energy intake, were perhaps more susceptible to infections and thus at an increased risk of dying. The effect of increased protein and energy on the antigen-specific, cell-mediated immune response of the neonatal calf has previously been examined (Foote et al, 2005). Increased dietary protein and energy had subtle effects on the composition and functional capacities of peripheral blood mononuclear cell populations; further research is needed to determine if these minimal effects influence the calf's susceptibility to infectious disease, as speculated in our study.…”

Stress, immunity, and the management of calves

“…In another meta-analysis, a calf's motivation to feed was a better predictor of health and performance than its colostrum passive transfer status (Bateman et al, 2012). This motivation to consume solid foods at an early age may influence HPN-calves' immune systems because they had less ex vivo innate immune responses before weaning, but after weaning, ex vivo immune measures did not differ from conventionally fed calves (Nonnecke et al, 2003;Foote et al, 2005Foote et al, , 2007Ballou, 2012;Obeidat et al, 2013;. Once HPN calves were no longer on a milk replacer diet, they also showed less signs of clinical sickness, faster inflammatory responses, and speedier recovery than conventionally fed calves when challenged with aerosolized Mannheimia haemolytica or oral Salmonella enterica serotype Typhimurium Sharon et al, 2015).…”

Influence of therapeutic use of feedgrade tetracyclines in combination with tulathromycin metaphylaxis on animal health and performance of Holstein steer calves1

“…Not only do dairy cattle possess different performance characteristics than typical beef breeds, such as a slightly lower ADG and greater DMI across the feeding period due to larger maintenance requirements, Holsteins are also more susceptible to environmental stressors because of their thinner hide and hair coat and less subcutaneous fat ( Hulbert and Moisa, 2016 ). However, multiple studies have examined ex vivo immune factors and observed that after weaning, Holstein calves did not differ immunologically from their conventionally fed beef animal counterparts ( Nonnecke et al, 2003 ; Foote et al, 2005 , 2007 ; Ballou, 2012 ; Obeidat et al, 2013 ; Ballou et al, 2015 ). Nonetheless, we are not aware of any studies to date that have compared the effects of feedgrade CTC or OTC, or in combination with tulathromycin metaphylaxis, on Holstein steers entering the feedlot.…”