In vivo and in vitro 3 x 2 factorial experiments were conducted concurrently to evaluate the incorporation of 0, 15, or 30% sugar beet pulp (SBP) as an energy source in diets fed to growing Holstein steers with either soybean meal (SBM) or alcohol-treated, defatted soybean flakes (ATSBF) as primary supplemental protein sources. Three groups of 42 Holstein steers each were fed six different diets from 54 kg initial BW to 320 kg in three experimental periods. There were no overall SBP level x protein source interactions (P greater than .05). Beet pulp level tended to decrease ADG (linear, P = .05) and increase feed/gain (linear, P less than .05) and DMI (quadratic, P less than .05). Each grower diet was used in a substrate for ruminal microbial metabolism in six dual-flow, continuous-culture fermenters. Organic matter and carbohydrate digestion were similar (P greater than .05) among diets. Increasing dietary levels of SBP caused a concomitant increase (P less than .05) in acetate and decrease (P less than .05) in butyrate and isobutyrate concentrations. Beet pulp level x protein source interactions (P less than .05) were observed for CP degradation, ammonia and nonammonia N, and dietary N flow. Crude protein degradation was higher (P less than .05) for the 0% SBP with SBM diet (81.3%) than for the 30% SBP with ATSBF diet (64.4%). Efficiency of bacterial synthesis was similar (P greater than .05) among diets. Results indicated that SBP is an effective dietary energy source for high-energy grower diets at 15 or 30% of the DM but may cause a decrease in some performance traits. There were no nutritional benefits of using ATSBF vs SBM as the supplemental N source.

No abstract

A trial was conducted to study the effect of supplemental chromium (Cr) levels from a Cr-yeast source on performance, digestibility and carcass characteristics of transport-stressed lambs. Forty-eight Naemi lambs (avg. BW 31.7 kg) were transported by truck for a distance of 1,450 km. On arrival day, the lambs were randomly allocated to four groups receiving diets supplemented with 0.0, 0.3, 0.6 or 0.9 ppm Cr. Each group consisted of four separately housed replicates of three lambs each. The lambs were fed their respective diets ad libitum for 84 d (21 d stress period, followed by 63 d growing period). Road transit of lambs resulted in a decreased (p<0.001) live body weight of 8.5%. Supplementation of Cr-yeast did not alter the performance of lambs during the stress period. Linear and quadratic increases (p<0.05) were observed in DMI and ADG, respectively, with increasing supplemental Cr levels in the diets during the growing period. Values were greater (p<0.05) by 14.7% and 20.8%, respectively, for lambs fed 0.3 ppm Cr compared to control, while those fed on the other two levels were intermediate. Over the 84-d feeding period, a trend was noted towards a slight increase in loin eye area and a decrease in body wall fat thickness for lambs fed Cr supplementation compared to the control group. This study suggests that the supplementation of Cr-yeast, especially at 0.3 ppm level, is beneficial for improving the performance of growing lambs whether the animals are stressed or not.

No abstract

Forty-eight Naemi lambs (avg. BW 31.7 kg) were transported by truck for a distance of 1,450 km from Al-Jouf to Riyadh, Saudi Arabia. On arrival day, the lambs were randomly allocated to four groups receiving diets supplemented with 0.0, 0.3, 0.6 and 0.9 ppm organic chromium (Cr). Each group consisted of four separately housed replicates of three lambs each. The animals were fed ad libitum on a grower diet for 84 days. Blood samples were obtained shortly before transportation, upon arrival and at weekly intervals thereafter from all lambs for analysis of plasma and serum. Plasma glucose and serum cortisol, total protein, albumin, urea-N and total cholesterol concentrations were determined. A cursory clinical examination of the lambs, along with rectal temperature, was undertaken at different intervals during the experiment. The lambs were inoculated each with 2 ml i.v. chicken red blood cells (CRBC) on days 0, 21, and 42. Serum total, IgG and IgM antibody titers were determined at weekly intervals post-immunization. An in vivo intradermal hypersensitivity test was carried out on 6 lambs from each group on days 10 and 70. Transportation of the lambs resulted in a significant (p<0.001) elevation of serum cortisol, total protein and albumin levels, as well as increased plasma glucose concentration, with corresponding decrease in total cholesterol, while blood urea-N remained largely unchanged. These constituents returned to normal levels during subsequent weeks, with no significant differences in their concentrations being observed between the Cr-supplemented groups and controls. Rise in rectal temperature after transportation was reduced to a greater extent (p<0.05) in Cr-supplemented versus control lambs. Total, IgG and IgM antibody titers against CRBC rose significantly (p<0.05) during immunizations in all groups, with significantly and linearly higher (p<0.05) total and IgG titers in Cr-supplemented versus control lambs. By contrast, no significant effect due to Cr supplementation was recorded in IgG titers, which increased equally in Cr-fed and control groups. Skin thickness in response to intradermal inoculation of phytohaemagglutinin (PHA) was also significantly (p<0.01) increased as a result of Cr supplementation. These results indicate that dietary Cr supplementation might be useful during stress especially for enhancing immune responses in transport-stressed lambs.