Protein quality and utilization of timothy, oat-supplemented timothy, and alfalfa at differing harvest maturities in exercised Arabian horses

To evaluate the protein quality and postgut N utilization of full-bloom timothy hay, oat-supplemented timothy-hay diets, and alfalfa hay harvested at different maturities, apparent whole tract N digestibility, urinary N excretion, and serum AA profiles were determined in light to moderately exercised Arabian horses. Six Arabian geldings (16.0 ± 0.3 yr; 467 ± 11 kg of BW) were randomly allocated to a 6 × 6 Latin square design. Diets included full-bloom timothy grass hay (G), G + 0.2% BW oat (G1), G + 0.4% BW oat (G2), mid-bloom alfalfa (A1), early-bloom alfalfa (A2), and early-bud alfalfa hay (A3). Forages were fed at 1.6% of the BW of the horse (as-fed). Each period consisted of an 11-d adaptation period followed by total collection of feces and urine for 3 d. Blood samples were taken on d 11 for analysis of serum AA concentrations. During the 3-d collection period, urine and feces were collected every 8 h and measured and weighed, respectively. Approximately 10% of the total urine volume and fecal weight per period was retained for N analyses. Fecal DM output was less (P < 0.05) in A1, A2, or A3 compared with G, G1, or G2. Apparent whole tract N digestibility was greater (P < 0.01) in A1, A2, and A3 compared with G, G1, or G2, and was greater (P < 0.05) in G1 and G2 compared with G. Nitrogen retention was not different from zero, and there were no differences (P > 0.05) in N retention among diets. Urinary N excretion and total N excretion were greater (P < 0.05) in A1, A2, and A3 compared with G, G1, or G2. Plasma concentrations for the majority of AA increased curvilinearly in response to feeding G, A1, A2, and A3 (quadratic, P < 0.05), with values appearing to maximize 2-h postfeeding. Although alfalfa N digestibility increased with decreasing harvest maturity, N retention did not differ and urinary volume and N excretion increased, indicating that postabsorptive N utilization decreased. In contrast, inclusion of oats at either 0.2 or 0.4% of the BW of the horse to timothy hay markedly enhanced N digestibility without increasing N excretion, indicating improvement in postgut N utilization. These findings indicate that feeding oat-supplemented timothy hay is more environmentally sustainable than feeding alfalfa to the horse at maintenance or under light to moderate exercise.

Analysis of potential causes of positive microbiological cultures in tissue donors

The purpose of this statistical analysis is to determine what factors are the major contributors to bacterial contamination of recovered human cadaveric tissue. In this study we analyzed factors that could contribute to an increased bacterial bioburden from recovered tissues using the following independent variables: (1) the physical recovery environment; (2) recovery before or after an autopsy; (3) the length of time from death to recovery; (4) the cause of death; (5) the length of time to complete recovery; (6) the number of staff involved with the tissue recovery; and (7) the impact of organ and skin recovery on musculoskeletal contamination rates.In these analyses we used analysis of variance of main effects on data from seven tissue banks. The scale of the analysis included 1036 donors each having multiple cultures to better control for the inherent large variation in this type of data. We looked at several dependent variables. The dependent variable that was most useful was 'percent positive cultures'.The results of the combined data differed from analyzing the tissue banks individually. The differences in each tissue bank's procedures and techniques were responsible for most of the variability. Depending on how the data was organized, statistically significant increases in bioburden were seen with: (1) recoveries after autopsy; (2) location of the recovery; (3) length of time taken for a recovery; (4) size of the recovery team; and (5) the impact of organ and skin recovery on musculoskeletal contamination rates.In conclusion, statistical analysis of recovery cultures can be a powerful tool that may be used to indicate problems within any bank's recovery procedures or techniques.

Effect of serum magnesium and feed intake on serum growth hormone concentrations

Concentration of serum growth hormone was increased and feed intake was reduced in lactating dairy cows fed an 84% concentrate diet supplemented with either 100.8 g MgO or 121.2 g of Mg(OH)2. Analysis of serum growth hormone, feed intake, and serum Mg showed an interaction of serum Mg and feed intake, which suggests low concentrations of serum Mg lessen the increase of concentration of serum growth hormone caused by reduced feed intake. Also, compared with control, treatments with Mg supplementation and reduced feed intake increased growth hormone concentration 12 d into the subsequent treatment.