|Carroll, Jeffery - Jeff Carroll|
|LAWHON, S - Texas A&M University|
|BRYAN, L - Texas A&M University|
|GART, E - Texas A&M University|
|O'CONNOR, D - Kemin Industries, Inc|
|ROUNDS, W - Kemin Industries, Inc|
Submitted to: American Society of Animal Science Southern Section Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 11/21/2016
Publication Date: 12/23/2016
Citation: Broadway, P.R., Carroll, J.A., Sanchez, N.C., Callaway, T.R., Lawhon, S.D., Bryan, L.K., Gart, E.V., O'Connor, D., Rounds, W. 2016. CLOSTAT® reduces the negative impacts of a Salmonella challenge in weaned Holstein steers. American Society of Animal Science Southern Section Meeting. 2017. J.Anim.Sci. 95(Supplement 1):31-32.
Technical Abstract: To evaluate the effects of a patented Bacillus subtillus probiotic (CLOSTAT®), weaned Holstein steers, (n=200; ~90kg) were supplemented (CLO) or not (CON) with CLOSTAT® (13 g/hd/d; Kemin Industries, Des Moines, IA) in a starter ration at a calf ranch for 35 d (n=50 head per pen; 2 pens/trt.). A subset of 40 calves was selected for an oral Salmonella challenge based on body weight, treatment records, and lack of Salmonella shedding. The calves were transported to Lubbock, TX (105 km) and assigned to 1 of 4 treatments in a 2x2 factorial design with CLO and CON calves that were orally administered Salmonella (STM) or not (CLOSTM, CLONoSTM, CONSTM, CONNoSTM). Calves assigned to receive Salmonella were challenged with 1.6 x 106 Salmonella Typhimurium (resistant to 50µg/ml nalidixic acid) in 1 L of milk replacer on d 0. Blood samples for serum and hematology were collected via jugular catheters every 8 h for 96 h, and body temperature was collected every 5 min via indwelling rectal temperature recording devices. Five calves from each treatment were harvested 48 h post-challenge, and the remaining calves were harvested 96 h post-challenge. During necropsy, tissues were collected for the isolation and quantification of the inoculated STM from various tissues. The CLO group had reduced STM concentrations in the jejunum, ileum, and transverse colon 48 h after the challenge (P=0.03) and numerically reduced STM concentrations in all gastrointestinal tissues 96 h post-challenge. There was a difference in rectal temperature (P<0.001) in which CLOSTM calves displayed decreased rectal temperatures after the challenge when compared to CONSTM calves. White blood cells and lymphocytes were increased (P=0.05) in CLOSTM calves after the challenge in comparison to other treatments. Calves in the CLO treatment maintained greater numerical BW throughout the study; however, there was no difference (P = 0.89) in BW change during the study. In calves given STM, the CLO group had greater feed disappearance before and after the challenge (P=0.006) in comparison to the CON group. Increased serum IL-6 and IFN' was observed in the CONSTM group compared to other treatments. There was no difference (P=0.42) in circulating cortisol between the treatments. Overall, CLO reduced Salmonella presence and concentrations in gastrointestinal tissues while simultaneously reducing the severity of the salmonellosis as indicated by blood parameters and the reduced febrile response.