Effects of supplementing milk replacer with essential amino acids on blood metabolites, immune response, and nitrogen metabolism of Holstein calves exposed to an endotoxin.
In: Journal of Dairy Science, Jg. 106 (2023-08-01), Heft 8, S. 5402-5415
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Zugriff:
This study evaluated the effects of supplementing calf milk replacer with essential AA on immune responses, blood metabolites, and nitrogen metabolism of 32 Holstein bull calves [28 d of age, 44 ± 0.8 kg of body weight (BW)] exposed to lipopolysaccharide (LPS). Calves were bottle-fed a commercial milk replacer (20% crude protein and 20% fat, dry matter basis) twice daily along with a calf starter (19% crude protein, dry matter basis) for 45 d. The experiment was a randomized complete block design and treatments were a 2 × 2 factorial arrangement. Treatments were milk replacer (fed twice daily at 0.5 kg/d of powder) supplemented with or without 10 essential AA (+AA vs. −AA), and subcutaneous injection of sterile saline with or without LPS (+LPS vs. −LPS) at 3 h after the morning feeding on d 15 (4 µg LPS per kg of BW) and 17 (2 µg LPS per kg of BW). Calves also received a 2-mL subcutaneous injection of ovalbumin (6 mg of ovalbumin/mL) on d 16 and 30. Rectal temperature and blood samples were collected on d 15 before LPS injection and at h 4, 8, 12, and 24 thereafter. From d 15 to 19, total fecal and urinary output were collected, and feed refusals were documented. Rectal temperature was greater in +LPS than −LPS calves at h 4, 8, and 12 after LPS injection. Serum cortisol was greater for +LPS than −LPS at h 4 after LPS exposure. At d 28, serum antiovalbumin IgG level was greater in +LPS +AA calves compared with +LPS −AA. Serum glucose was lower for +LPS than −LPS at h 4 and 8. Serum insulin was greater in +LPS than −LPS calves. Plasma concentrations of Thr, Gly, Asn, Ser, and hydroxyproline were lower for +LPS versus −LPS calves. Plasma concentrations of Met, Leu, Phe, His, Ile, Trp, Thr, and Orn were greater in +AA calves than −AA calves. Plasma urea N and N retention were not different among LPS and AA treatments. The lower concentrations of AA in +LPS than −LPS calves indicate higher demand for AA in immuno-compromised calves fed milk replacer. Additionally, higher concentration of ovalbumin-specific IgG level in +LPS calves supplemented with +AA compared with +LPS calves with −AA suggests that supplementing AA to immune-compromised calves might improve immune status. [ABSTRACT FROM AUTHOR]
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Effects of supplementing milk replacer with essential amino acids on blood metabolites, immune response, and nitrogen metabolism of Holstein calves exposed to an endotoxin.
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Autor/in / Beteiligte Person: | Zubia, K.M. ; Akter, A. ; Carter, B.H. ; McDaniel, M.R. ; Duff, G.C. ; Löest, C.A. |
Zeitschrift: | Journal of Dairy Science, Jg. 106 (2023-08-01), Heft 8, S. 5402-5415 |
Veröffentlichung: | 2023 |
Medientyp: | academicJournal |
ISSN: | 0022-0302 (print) |
DOI: | 10.3168/jds.2022-22708 |
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