Title

Dietary protein and chromium tripicolinate in suffolk wether lambs: Effects on production characteristics, metabolic and hormonal responses, and immune status

Document Type

Article

Publication Date

1-1-1999

Abstract

Thirty-two Suffolk wether lambs were fed for 84 d in a 2 × 2 factorial experiment using two levels of dietary protein (9.0 to 12.1% CP, low protein, LP; or 12.8 to 14.4% CP, high protein, HP) and supplemental Cr (none, C; or 400 ppb Cr as chromium tripicolinate, Cr). At 14-to 21-d intervals, lambs were weighed, and jugular blood samples were collected. Mean ADG and carcass weight (P > .10) did not differ. In lambs fed HP, Cr reduced liver weight and increased kidney weight (P < .01). Lambs fed HP had elevated plasma urea N (PUN; P < .01) and albumin (P < .04). During an i.v. epinephrine challenge on d 43, plasma cortisol declined in lambs fed Cr (Cr × time, P < .03) and in lambs fed LP (CP × time, P < .001). An i.v. glucose tolerance test conducted 3 h later showed that supplemental Cr decreased glucose clearance rate in lambs fed HP (CP × Cr, P < .10) but not in lambs fed LP. On d 62, PUN was increased in lambs fed HP (P < .001) between 0 and 3 h postprandial, and there was a Cr × CP interaction (P < .04). Postprandial plasma NEFA declined with Cr vs C (Cr × time, P < .07) and with HP vs LP (CP × time, P < .10). By d 66, lambs fed Cr had an elevated (P < .03) blood platelet and fibrinogen content. Chromium increased erythrocyte count in lambs fed HP (Cr × CP, P < .08), and isolated peripheral lymphocytes had greater blastogenic response to 4 μg/mL of phytohemagglutinin (Cr × CP, P < .001). The lymphocyte response to pokeweed mitogen (.2 μg/mL) was reduced in lambs fed Cr (P < .10). In the present experiment, Cr supplementation had minimal and inconsistent effects on production and metabolic criteria of lambs.

Publication Source (Journal or Book title)

Journal of Animal Science

First Page

1284

Last Page

1294

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