Granite fines, sand, rice hulls, long wheat straw, and wood shavings were compared as bedding for 60 female dairy calves. Growth, health, stress indices, and behavior of newly born calves, along with physical characteristics and bacterial counts of bedding, were evaluated for 42 d during August to October, 2002. Overall average daily gain and dry matter intake of calves did not differ due to bedding type, although during wk 2 calves housed on rice hulls had the greatest dry matter intake and those housed on wood shavings had the lowest. During wk 2, calves housed on granite fines and sand were treated more often for scours, and calves housed on long wheat straw received the fewest antibiotic treatments (week by bedding material interaction). Granite fines formed a harder surface than other bedding, and calves housed on granite fines scored the dirtiest. When bedding materials were evaluated, sand was scored to be the dirtiest, while pens bedded with rice hulls, long wheat straw, and wood shavings scored cleaner. Long wheat straw had the warmest surface temperature, and rice hulls and wood shavings were warmer than granite fines and sand. Serum cortisol, alpha(1)-acid glycoprotein, immunoglobulin G concentrations, and the neutrophil:lymphocyte ratio were not affected by bedding type. On d 0, coliform counts were greatest in rice hulls. After use, coliform counts were greatest in long wheat straw (week by bedding material interaction). On d 42, the concentration of ammonia at 10 cm above the bedding was lowest for long wheat straw. Growth performance of calves bedded for 42 d with 5 bedding types did not differ; however, the number of antibiotic treatments given for scours was greatest on granite fines and sand; coliform counts in the bedding were highest in rice hulls before use and in long wheat straw after 42 d of use.

Sixty Angus and Angus x Hereford steers (246 kg initial BW) were used to determine the effects of Zn level and source on performance, immune response, and carcass characteristics of growing and finishing steers. Treatments consisted of 1) control (no supplemental Zn), 2) ZnO, 3) Zn proteinate-A (ZnProt-A, 10% Zn), and 4) ZnProt-B (15% Zn). Treatments 2, 3, and 4 supplied 25 mg of supplemental Zn/kg diet. Steers were individually fed a corn silage-based diet during the 84-d growing phase and a high corn diet during the finishing phase. Cell-mediated and humoral immune response measurements were obtained between d 67 and 74 of the growing phase. Equal number of steers per treatment were slaughtered after receiving the finishing diets for 84 or 112 d. Performance and carcass measurements were similar in steers fed the two ZnProt sources. Zinc supplementation, regardless of source, increased (P < 0.05) ADG during the growing phase. In the finishing phase, ADG (P = 0.10) and gain/feed (P = 0.07) tended to be higher for steers fed ZnProt compared with those supplemented with ZnO. Gain and feed efficiency were similar for control and ZnO-supplemented steers during the finishing phase. Steers fed ZnProt had heavier (P < 0.05) hot carcass weights and slightly higher (P < 0.05) dressing percentages than those in the control or ZnO treatments. Quality grade, yield grade, marbling, and backfat were increased by Zn supplementation, but were not affected by Zn source. In vitro response of lymphocytes to mitogen stimulation and in vivo swelling response following intradermal injection of phytohemagglutinin were not affected by Zn level or source. Humoral immune response following vaccination with infectious bovine rhinotracheitis also was not affected by treatment. Soluble concentrations of Zn in ruminal fluid were higher (P < 0.05) in steers fed ZnProt compared to ZnO steers. Results indicate that ZnProt may improve performance of finishing steers above that observed with inorganic Zn supplementation.

Two experiments were conducted to determine the efficacy of mannan oligosaccharides (MOS) fed at two levels of Cu on growth and feed efficiency of weanling and growing-finishing pigs, as well as the effect on the immunocompetence of weanling pigs. In Exp. 1, 216 barrows (6 kg of BW and 18 d of age) were penned in groups of six (9 pens/treatment). Dietary treatments were arranged as a 2 x 2 factorial consisting of two levels of Cu (basal level or 175 ppm supplemental Cu) with and without MOS (0.2%). Diets were fed from d 0 to 38 after weaning. Blood samples were obtained to determine lymphocyte proliferation in vitro. From d 0 to 10, ADG, ADFI, and gain:feed (G:F) increased when MOS was added to diets containing the basal level of Cu, but decreased when MOS was added to diets containing 175 ppm supplemental Cu (interaction, P < 0.01, P < 0.10, and P < 0.05, respectively). Pigs fed diets containing 175 ppm Cu from d 10 to 24 and d 24 to 38 had greater (P < 0.05) ADG and ADFI than those fed the basal level of Cu regardless of MOS addition. Pigs fed diets containing MOS from d 24 to 38 had greater ADG (P < 0.05) and G:F (P < 0.10) than those fed diets devoid of MOS. Lymphocyte proliferation was not altered by dietary treatment. In Exp. 2, 144 pigs were divided into six pigs/pen (six pens/treatment). Dietary treatments were fed throughout the starter (20 to 32 kg BW), grower (32 to 68 kg BW), and finisher (68 to 106 kg BW) phases. Diets consisted of two levels of Cu (basal level or basal diet + 175 ppm in starter and grower diets and 125 ppm in finisher diets) with and without MOS (0.2% in starter, 0.1% in grower, and 0.05% in finisher). Pigs fed supplemental Cu had greater (P < 0.05) ADG and G:F during the starter and grower phases compared to pigs fed the basal level of Cu. During the finisher phase, ADG increased when pigs were fed MOS in diets containing the basal level of Cu, but decreased when MOS was added to diets supplemented with 125 ppm Cu (interaction, P < 0.05). Results from this study indicate the response of weanling pigs fed MOS in phase 1 varied with level of dietary Cu. However, in phase 2 and phase 3, diets containing either MOS or 175 ppm Cu resulted in improved performance. Pharmacological Cu addition improved gain and efficiency during the starter and grower phases in growing-finishing pigs, while ADG response to the addition of MOS during the finisher phase seems to be dependent upon the level of Cu supplementation.

One hundred twenty-five Angus crossbred steers (215 +/- 2 kg initial BW) were blocked by weight and assigned to pens. Pens were randomly assigned to treatment (six pens/treatment). Treatments consisted of 1) control (no supplemental Cr), 2) CrCl3, 3) high-Cr yeast, or 4) Cr nicotinic acid complex. Chromium was added to provide .4 mg of supplemental Cr/kg of DM. Steers were fed diets containing 90% corn silage (DM basis) and 10% soybean meal-mineral-vitamin supplement. Steers were allowed to consume the diets on an ad libitum basis during the 56-d study. Performance was not affected by treatment. On d 52, steers supplemented with high-Cr yeast had a greater response to an intradermal injection of phytohemagglutin (PHA) for 8 h after injection than control steers (P < .10) or those supplemented with CrCl3 (P < .05) or Cr nicotinic acid (P < .05). Peripheral lymphocytes from steers supplemented with Cr nicotinic acid had a greater (P < .05) blastogenic response to 12.5 micrograms PHA/mL than lymphocytes from steers supplemented with CrCl3. After an i.v. infusion of glucose (.25 g of glucose/kg BW), plasma glucose tended (P < .11) to decrease at a faster rate from 15 to 45 min after infusion in steers fed Cr nicotinic acid. Steers supplemented with Cr nicotinic acid had greater (P < .05) serum insulin 15 and 30 min after infusion than those supplemented with CrCl3 and high-Cr yeast. Controls had lower serum insulin than those supplemented with Cr nicotinic acid 30 min after infusion.(ABSTRACT TRUNCATED AT 250 WORDS)

Forty-eight Angus crossbred steers (263 +/- 2 kg initial BW) were blocked by weight and randomly assigned within weight group to treatment. Treatments consisted of control or .4 mg of supplemental Cr as Cr-nicotinic acid complex/kg of DM. Steers were fed diets containing 90% corn silage (DM basis) and 10% of a soybean meal-mineral-vitamin supplement. After 56 d on the dietary treatment, half of the steers in each treatment were transported 343 km and unloaded in an unfamiliar location. The next day, d 58, shipped steers were returned to the feedlot (50 km). On d 58 after shipped steers were returned to the feedlot, all steers were inoculated with infectious bovine rhinotracheitis virus (IBRV) intranasally. Average daily gain from d 0 to 80 was increased (P < .10) by supplemental Cr. There was a shipping x time interaction for serum cortisol concentrations. Shipping increased (P < .02) serum cortisol on d 58, but 7 d after transport there were no effects of shipping on serum cortisol. Transportation increased (P < .05) the ratio of neutrophils to lymphocytes. Supplemental Cr did not affect rectal temperature after the IBRV challenge or the antibody response to IBRV or porcine red blood cells. Immunoglobulin G antibody response to porcine red blood cells was decreased (P < .09) by shipping. Supplemental Cr as Cr-nicotinic acid improved ADG of growing steers, regardless of whether they had been stressed by shipping. Supplemental Cr did not affect any of the immune responses that were measured.