To observe the effects of supplemental dietary d-α-tocopherol in relation to dietary energy on growth and immune status in dairy calves, 32 newborn Holstein bull calves were assigned to 1 of 4 treatments for 5 wk in a 2 × 2 factorial, randomized complete block, split-plot design. Calves received moderate growth (MG) or low growth (LG) all-milk dietary treatments, formulated to support daily gains of 0.5 or 0.25 kg/d, respectively, per the dietary energy recommendation for milk-fed calves according to the National Research Council's Nutrient Requirements of Dairy Cattle. Calves in both groups were either injected i.m. with Vital E-A+D (injectable solution of vitamins E, A, and D) on d 1 and supplemented with Emcelle Tocopherol (micellized vitamin E) via milk daily (MG-S and LG-S), or were not supplemented (MG-C and LG-C) during the study period. Total weight gain of MG calves was greater than that of LG calves and tended to be greater in MG-S calves than in MG-C calves. Calves receiving vitamin supplementation demonstrated greater concentrations of plasma α-tocopherol, retinol, and 25-(OH)-vitamin D than did control calves, whereas MG calves demonstrated a lower concentration of plasma α-tocopherol than did LG calves. The apparent increased utilization of α-tocopherol by MG calves was accompanied by a rise in serum haptoglobin, a positive acute-phase protein and indicator of inflammation, especially in MG-C calves. Serum amyloid A, also a positive acute-phase protein, was not different among groups, but was elevated from baseline in all groups during wk 1 through 3. Plasma IgG1 concentrations were higher in MG-S and LG-S calves than in their nonsupplemented dietary counterparts, whereas plasma IgG2, IgA, and IgM concentrations were not different among groups. In summary, dietary supplementation of d-α-tocopherol improved plasma α-tocopherol status and tended to increase growth in calves fed for 0.5 kg of average daily gain. Vitamin supplementation ameliorated the rise of serum haptoglobin associated with acute inflammation in MG calves, and may have improved passive transfer of maternal antibody. These results indicate a role for α-tocopherol in prevention of proinflammatory state associated with greater dietary energy and onset of infectious disease.

Thirty Holstein calves were obtained from 2 dairy farms in central Iowa at birth and randomly assigned to 1 of 6 treatment groups: (1) colostrum deprived (CD), no vitamins; (2) colostrum replacer (CR), no vitamins; (3) CR, vitamin A; (4) CR, vitamin D3; (5) CR, vitamin E; and (6) CR, vitamins A, D3, E, with 5 calves per treatment in a 14-d study. Calves were fed pasteurized whole milk (CD) or fractionated colostrum replacer (CR) at birth (d 0) and injected with vitamins according to treatment group. From d 1 through d 14 of the study, all calves were fed pasteurized whole milk (PWM) supplemented with vitamins as assigned. All calves were inoculated with Mycobacterium avium ssp. paratuberculosis on d 1 and 3 of age. Calves fed CR acquired IgG1 and haptoglobin in serum within 24 h of birth, whereas CD calves did not. The CR-fed calves were 2.5 times less likely to develop scours, and CR calves supplemented with vitamins D3 and E also demonstrated a decreased incidence of scours. Serum vitamin levels of A, D, and E increased within treatment group by d 7 and 14 of the study. Interestingly, synergistic effects of supplemental vitamins A, D3, and E on serum 25-(OH)-vitamin D were observed at d 7, resulting in higher levels than in calves administered vitamin D only. Further, vitamin D3 deficiency was observed in CD and CR calves fed a basal diet of pasteurized whole milk and no supplemental vitamins. Colonization of tissues with Mycobacterium avium ssp. paratuberculosis was negligible and was not affected by colostrum feeding or vitamin supplementation. Results demonstrated passive transfer of haptoglobin to neonatal calves, and potential health benefits of supplemental vitamins D3 and E to calves fed pasteurized whole milk.

Avi-Lution® is a defined, patented, synbiotic product containing Saccharomyces cerevisiae, Enterococcus faecium, and Bacillus spp. Broiler chickens (n = 1,250) were experimentally treated as uninoculated controls (uCon), inoculated controls (iCon) with Clostridium perfringens, or inoculated and treated with bacitracin methylene disalicylate (BMD) at 55 mg/kg as an infected/treated control or Avi-Lution® at 1.0 (AvL1) or 2.0 (AvL2) g/kg in feed for 42 d. Each treatment was applied to 10 replicate pens of 25 straight-run, newly hatched chicks. Pens treated with AvL1, AvL2, or BMD showed improved growth, feed efficiency, or mortality from necrotic enteritis compared with iCon pens at d 14, 28, and 42. No differences in these measurements, however, were observed between pens treated with AvL1 and AvL2, which suggests that Avi-Lution® was effective at 1.0 g/kg in feed. Despite improved performance, BMD, AvL1, and AvL2 treatments did not decrease the severity of intestinal lesion scores through 42 d of age compared with the infected control. These results demonstrate that Avi-Lution® improved growth performance and feed conversion rates in broilers challenged with Clostridium perfringens despite no difference in severity of intestinal lesion scores.

The European Climate Law recently codified the goal for European climate neutrality by 2050, highlighting the need for sustainable farming practices within a robust and transparent carbon dioxide equivalent (CO2e) accounting system. In the present study, a series of equations were proposed for the estimation of CO2e emissions from corn silage fermentation. Systematic review of previous meta-analyses of corn silage fermentation identified the mean and standard deviation statistics for key model inputs of acetic acid, ethanol, lactic acid, ammonia, and volatile-corrected dry matter loss. Estimates of CO2e emissions were determined for a mock dataset comprising 1,000 iterations of randomly-generated values for each metric in accordance with mean and variance statistics of the source data. Estimates for CO2e emissions of corn silage based on meta-analysis review of laboratory experiments were 1.9 ± 5.6% (GWP20) and 0.2 ± 5.5% (GWP100) of silage dry matter. Furthermore, model results demonstrated a precedent for CO2 recycling by silage microorganisms, which was supported by genome annotation of strains belonging to common silage species. Linear model equations for GWP20 and GWP100 with inputs and outputs in mg kg−1 silage dry matter were developed, where inputs are acetic acid (A), ethanol (E), lactic acid (L), and volatile corrected dry matter loss (DV). Linear equations are (for GWP20; Eq. 11):GWP20=−3626.1−0.04343A+0.8011E−0.03173L+1.46573DVand for GWP100; Eq. 12:GWP100=−8526.10−0.22403A−0.11963E−0.03173L+1.46573DV.

Bacillus subtilis subsp. subtilis American Type Culture Collection deposit number PTA-125135 has recently been studied by our laboratory as a potential probiotic strain for avian species. The objective of the present study was to evaluate growth performance and feed efficiency in broiler chickens in response to a dose titration of the Bacillus strain in feed. In addition to a nonsupplemented control, Bacillus spores were supplemented into broiler chicken diets at 4 levels, which were 8.1 × 10 4 , 1.6 × 10 5 , 2.4 × 10 5 , and 3.2 × 10 5 CFU per g of feed. The titration was applied to two different dietary regimes of standard or low metabolizable energy (ME), which differed in ME by 22, 56, and 110 kcal/kg in starter, grower, and finisher dietary phases, respectively. All diets contained 249 g per metric ton of a previously patented synbiotic feed additive. Performance data were collected at day 14, 26, and 40 of age, and the effects of Bacillus and ME treatments were evaluated by factorial ANOVA. Treatment group means were further examined for significant ( P < 0.05) pairwise differences among treatments and for significant ( P < 0.05) linear and quadratic effects. At day 14 of age, significant linear effects for decreased feed conversion ratio (FCR) with higher CFU of Bacillus supplementation were observed within the standard ME diet. At day 26, a linear trend was observed for increased mortality with increased dose within the standard ME diet only. Bacillus supplementation at day 26 also significantly affected FCR and mortality-adjusted FCR, where supplementation with 3.2 × 10 5 CFU per g feed produced lower FCR and mortality-adjusted FCR than supplementation with 1.6 × 10 5 CFU per g feed. We conclude from linear effects related to feed efficiency observed at day 14 and from the significant separation of Bacillus treatment means within the titrated range of supplementation at day 26 that further evaluation for effects on performance should be made of doses at 2.4 × 10 5 , 3.2 × 10 5 , and greater CFU per g in feed.

Peripheral blood mononuclear cells (PBMC) and mesenteric node lymphocytes (MNL) were obtained from 30 calves that were assigned randomly at birth to 1 of 6 treatment groups with 5 calves per treatment in a 14-d study: (1) colostrum-deprived (CD), no vitamins; (2) colostrum-replacer (CR), no vitamins; (3) CR, vitamin A; (4) CR, vitamin D; (5) CR, vitamin E; (6) CR, vitamins A, D, E. Calves were injected with appropriate vitamin supplements and fed pasteurized whole milk (CD calves) or fractionated colostrum replacer (CR calves) at birth. Thereafter, all calves were fed pasteurized whole milk fortified with vitamins according to treatment group. Calves were orally inoculated with 10 cfu of Mycobacterium avium ssp. paratuberculosis (MAP) on d 1 and 3. The PBMC and MNL harvested on d 13 were analyzed by flow cytometry as fresh cells, after 3-d culture with phytohemagglutinin (PHA), and after 6-d culture with a whole-cell sonicate of MAP (MPS). Peripheral γδ T cells were a predominant lymphocyte subset in neonatal calves, with a decreased percentage noted in CD calves compared with CR calves. As well, CD25 expression was higher in γδ T cells compared with other cell subsets, regardless of treatment group. Stimulation of PBMC with PHA resulted in increased CD4 and CD8 subsets, whereas MNL response was dominated by expansion of B-cell subpopulations. Stimulation with PHA and MPS decreased the relative abundance of PBMC γδ T cells, but MNL γδ T cells increased upon stimulation with MPS. These results identify γδ T cells as key early responders to intracellular infection in neonatal calves and suggest that colostrum may be an important mediator of this response.

No abstract

In the present study, 30 Holstein calves were acquired at birth and were randomly subjected to one of six treatments. One treatment group was colostrum deprived (CD) and five other treatment groups were fed colostrum replacer (CR). Of the five CR groups, one group was not further supplemented (CR), one received vitamin A (CR-A), one received vitamin D (CR-D), one received vitamin E (CR-E), and one received vitamins A, D, and E (CR-ADE). Additionally, all calves were inoculated with Mycobacterium avium, subsp. paratuberculosis on d 1 and d 3 of age. One d after birth, CD calves exhibited lower IgG1, haptoglobin, and serum amyloid A concentrations in serum compared with the other five CR groups. These findings point to an endogenous early inflammation disorder in calves that are not fed colostrum.