A data base was constructed to describe and estimate supplementation effects in nonlactating cattle consuming forage ad libitum. The data base included 66 publications on 126 forages (73 harvested and 53 grazed) and a total of 444 comparisons between a control, unsupplemented treatment and a supplemented treatment. Daily gains were reported for 301 comparisons and voluntary intake for 258. Direct measures of forage digestibility were reported for 202 comparisons, and total diet digestibility for 150. Supplements did not increase gain in all cases. Change in ADG due to supplement was not related closely to intake of supplemental TDN. Lowest increases in ADG were with native forages supplemented with molasses alone or with low intakes of molasses containing high levels of NPN. Greatest increases in gain were with improved forages, supplements with > 60% TDN, and supplemental CP intake > .05% of BW. Supplements decreased voluntary forage intake (VFI) when supplemental TDN intake was > .7% of BW, forage TDN:CP ratio was < 7 (adequate N), or VFI when fed alone was > 1.75% of BW. When supplements increased VFI, forage TDN: CP ratio was > 7 ( N deficit), and VFI when fed alone was often low. There was little relationship between change in VFI and sources of supplemental CP and TDN. Supplements caused total diet TDN concentration to deviate from expected values by −10 to +5% of OM. When supplemental TDN intake was > .7% of BW, diet TDN concentration was always less than expected. There was little relationship between deviation from expected total diet TDN and type or composition of forages or supplements. Empirical multiple regression equations were developed to estimate effects of supplements on VFI and total diet TDN concentration. The most acceptable intake equation estimated VFI when fed with supplement ( r 2 = .84) That equation included VFI when fed alone, supplement intake, CP and TDN concentrations in forage and supplement, and classification codes describing forages and supplemental energy. The most acceptable equation for estimating total diet TDN concentration included only the expected total diet TDN concentration ( r 2 = .87). These equations may be used in nutritional models to account for associative effects.

The objective of this study was to investigate the effect of transportation and commingling on measures of the acute-phase protein response in newly weaned beef calves. Thirty-two (Exp. 1; average BW = 266 +/- 20.8 kg) and thirty-six (Exp. 2; average BW = 222 +/- 34.6 kg) Brahman-crossbred calves were randomly allotted to one of four treatments (2 x 2 factorial arrangement [transportation x commingling] in a completely randomized design). Body weight and jugular blood were collected at weaning, after shipment, and 1, 3, and 7 d after transport for Exp. 1, and at weaning and 1, 5, 9, 13, 17, and 21 d after transport for Exp. 2. Feed intake within pen was recorded daily for Exp. 2. Plasma fibrinogen, ceruloplasmin, haptoglobin, and cortisol concentrations were determined for all collection times. Additionally, serum amyloid-A and alpha-acid glycoprotein concentrations were determined in Exp. 1 and 2, respectively. In Exp. 2, commingled calves tended (P = 0.13) to have a higher DMI than noncommingled calves (5.3 and 4.8 kg/d, respectively). Transported calves lost more BW than nontransported calves from the time of weaning to d 1 (2.0 and 3.1% more BW loss for Exp. 1 and 2, respectively). With the exception of haptoglobin in Exp. 1, each of the acute-phase proteins measured in these studies increased over each sampling day. In Exp. 1, transported calves had higher (P < 0.05) mean serum amyloid-A concentrations than nontransported calves (48.9 vs. 33.4 microg/mL). There was a significant sampling day x transportation interaction (P < 0.01) for fibrinogen, ceruloplasmin, and haptoglobin in Exp. 1; transported calves had higher concentrations of fibrinogen following transport and on d 2 and 3, and ceruloplasmin on d 3. Haptoglobin concentrations were higher (P = 0.04) in nontransported calves on d 1 and 2 of Exp. 1. In Exp. 2, overall mean haptoglobin concentrations were higher in nontransported vs. transported calves. The results of these studies indicate that stressors associated with transportation affect the acute-phase protein response in newly weaned beef calves. More research is needed to determine whether these proteins might be valuable indicators of stress following the weaning process.

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Steers (n = 156) finished on rhizoma peanut (Arachis glabrata Benth.)-tropical grass pasture in Florida and slaughtered at Central Packing, Center Hill were compared with steers (n = 152) finished on a concentrate diet in Texas and slaughtered at Excel, Plainview. Average daily gain during the growing and finishing periods was lower (P < .001) for forage-finished steers (.49 and .94 kg/d, respectively) than for concentrate-finished steers (.78 and 1.33 kg/d, respectively). Forage-finished steers had less fat over the ribeye (8.3 vs 11.4 mm; P < .01), lighter hot carcass weight (280 vs 346 kg; P < .001), and smaller longissimus muscle area (70.8 vs 86.6 cm2; P < .001) than concentrate-finished steers. Yield grade was not different (2.7 vs 2.6; P > .10), but quality grade was slightly better (low Select vs mid Select; P < .01) for concentrate-finished steers. Lean color of forage-finished steers was darker (P < .001) and fat of forage-finished steers had a creamier color (P < .001), but carcasses were not discounted due to yellow fat color. Shear force values were higher (6.8 vs 4.0 kg; P < .001) for forage-finished than for concentrate-finished steers. Off-flavors were detected by trained sensory panelists in 36% of forage-finished and 14% of concentrate-finished carcasses, but all at barely detectable levels. This research indicates that steers can be finished on rhizoma peanut-tropical grass pastures, but with some reduction in quality grade relative to concentrate-finished steers.(ABSTRACT TRUNCATED AT 250 WORDS)