P. T. Berg

Effect of thiamine concentration on animal health, feedlot performance, carcass characteristics, and ruminal hydrogen sulfide concentrations in lambs fed diets based on 60% distillers dried grains plus solubles

Limited data are available regarding the influence of thiamine supplementation on the incidence of polioencephalomalacia (PEM) in lambs fed diets containing increased concentrations of S in the diet (>0.7%). Therefore, our objective was to evaluate the influence of thiamine supplementation on feedlot performance, carcass quality, ruminal hydrogen sulfide gas concentrations, and incidence of PEM in lambs fed a finishing diet containing 60% distillers dried grains with solubles (DDGS; DM basis). Two studies were conducted using completely randomized designs to evaluate the influence of concentration of thiamine supplementation. Study 1 used 240 lambs fed in 16 pens, whereas study 2 used 55 individually fed lambs. Lamb finishing diets contained 60% DDGS, which resulted in a dietary S concentration of 0.73% (DM basis). Treatments diets were based on the amount of supplemental thiamine provided: 1) no supplemental thiamine (CON), 2) 50 mg/animal per day (LO), 3) 100 mg/animal per day (MED), or 4) 150 mg/animal per day (HI). Additionally, in study 2, a fifth treatment was included, which contained 0.87% S (DM basis; increased S provided by addition of dilute sulfuric acid) and provided 150 mg of thiamine/animal per day (HI+S). In study 1, ADG decreased quadratically (P = 0.04), with lambs fed the CON, LO, and MED diets gaining BW at a greater rate than lambs fed the HI diet. In study 1, DMI responded quadratically (P < 0.01), whereas G:F tended to differ linearly (P = 0.08) to concentration of thiamine supplementation, with MED lambs having greater DMI and decreased G:F. No differences (P > or = 0.17) in lamb performance were observed in study 2. In both studies, most carcass characteristics were unaffected, with the exception of a tendency for decreased carcass conformation (study 1; P = 0.09) and greater flank streaking (study 2; P = 0.03). No differences in ruminal hydrogen sulfide concentration (P > 0.05) among treatments were apparent until d 10, at which point lambs fed the LO diet had less hydrogen sulfide concentrations than all other treatments. Lambs fed HI had the greatest concentrations of hydrogen sulfide on d 31 (1.07 g of hydrogen sulfide /m(3); P < 0.009). Ruminal pH did not differ (P = 0.13) and averaged 5.6 +/- 0.06. No clinical cases of PEM were observed during the course of either study. The use of thiamine as a dietary additive to aid in the prevention of PEM in finishing lambs does not appear to be necessary under the conditions of this study.

Interaction of corn processing and distillers dried grains with solubles on health and performance of steers

Feeding increased concentrations of distillers dried grains with solubles (DDGS) to ruminants has been avoided due to risks of S toxicity and concerns about animal performance. The objective of this study was to evaluate the influence of feeding an increasing concentration of DDGS and corn processing method on animal performance, incidence of polioencephalomalacia (PEM), and concentration of H(2)S gas in feedlot steers. Sixty steer calves (336 ± 13.2 kg) were individually fed for an average of 136 d in a completely random design with a 3 × 2 factorial arrangement of treatments. Main effects included concentration of DDGS (20, 40, or 60% DM basis) and corn processing method [high-moisture (HMC; 71.7% DM) vs. dry-rolled corn (DRC; 86.2% DM)] resulting in treatments of 1) 20% DDGS with DRC, 2) 40% DDGS with DRC, 3) 60% DDGS with DRC, 4) 20% DDGS with HMC, 5) 40% DDGS with HMC, and 6) 60% DDGS with HMC. Ruminal H(2)S gas concentrations were measured on d 0, 7, 14, 21, 28, 35, 49, 63, and 91 via rumen puncture. Animal performance and carcass characteristic data were collected. The day × corn processing × DDGS interaction for H(2)S gas concentrations was not significant (P = 0.91). Ruminal H(2)S concentration increased with increasing DDGS concentration (P < 0.001) and day (P < 0.001), but was not influenced by corn processing method (P = 0.94). Carcass-adjusted final BW decreased linearly (P = 0.009), whereas carcass-adjusted ADG decreased quadratically (P = 0.05) with increasing concentration of DDGS in the diet. Carcass-adjusted G:F was not affected (P ≥ 0.28) by increasing concentration of DDGS in the diet. Carcass characteristics reflected the decrease in final BW with decreased HCW (P = 0.009), as well as decreased fat depth (P = 0.005) with increasing concentrations of DDGS. The combination of decreased HCW and backfat thickness resulted in decreased (P = 0.02) yield grade with increasing DDGS inclusion. There were no confirmed cases of PEM. In conclusion, corn processing did not influence animal performance, incidence of PEM, or H(2)S concentrations under the conditions of this study. Feeding 60% DDGS in beef cattle finishing diets is not recommended due to poor animal performance.

Effects of increasing dosages of zeranol implants on lamb growth, carcass characteristics, blood hormones, and nitrogen metabolism1

The objective of this research was to compare the growth performance, incidence of prolapse and mortality, carcass characteristics, blood hormone concentration, and N balance of lambs implanted with increasing dosages of zeranol. One hundred forty-four crossbred lambs (29.6 ± 4.9 kg) were used in a completely random design and placed into 16 feedlot pens (4 pens/treatment) for a 116 d finishing study. Lambs were fed an 84.7% corn and 15.3% market lamb pellet (DM basis) diet ad libitum. Treatments were 0, 12, 24, and 36 mg zeranol (Ralgro; Schering-Plough), and lambs were implanted in the ear according to treatment on d 0. Lambs were weighed. Thirty lambs (67.6 ± 3.4 kg) and 96 lambs (65.8 ± 5.1 kg) were harvested on d 84 and d 118, respectively. Carcass data were collected 24 h after chill. Blood samples were collected on d 0, 28, 56, 70, 82, 99, and 116 from 64 lambs (29.6 ± 2.1 kg) in the feedlot study (subsample of 4 lambs per pen) and analyzed for thyroxine, triiodothyronine, and IGF-I. A second study was conducted to compare effects of 0, 12, 24, or 36 mg zeranol on N balance in 16 crossbred lambs (34.8 ± 2.1 kg). There were no differences among treatments for BW, ADG, DMI, and G:F (P > 0.05) in the feedlot study. However, there was a linear increase for incidence of prolapse (P = 0.006; 2.78, 5.55, 24.98, and 27.75%, respectively) and mortality (P = 0.005; 0.00, 5.55, 11.10, and 13.88%, respectively) as zeranol dosage increased. Carcass characteristics, blood hormone concentrations, and N balance were not affected by treatment (P > 0.05). These results indicate zeranol increases incidence of prolapse and mortality without increasing growth performance.

Influence of level of dried distillers grains with solubles on feedlot performance, carcass characteristics, serum testosterone concentrations, and spermatozoa motility and concentration of growing rams

The objective of this study was to evaluate the effects of dried distillers grains with solubles (DDGS) on ram lamb feedlot performance, carcass characteristics, serum testosterone concentration, and semen quality. One hundred twenty ram lambs (40.4 ± 9.1 kg; Suffolk × western white face) were used in a completely randomized design to determine the effects of DDGS on feedlot performance and carcass characteristics. Rams were allotted into one of three dietary treatments (n = 4 pens/treatment; 10 rams/pen): 1) 0DDGS: 85% corn and 15% commercial market lamb pellet, 2) 15DDGS: 15% DDGS substituted for corn (DM basis), and 3) 30DDGS: 30% DDGS substituted for corn (DM basis). Rams were weighed on consecutive days at the beginning (d 0 and 1) and end (d 96 and 97 and d 116 and 117) of the trial. Scrotal circumference was measured on all rams on d 84, 96, and 116. Semen and blood samples were collected on a subset of 48 rams (4 rams/pen; 16 rams/treatment; n = 4) to evaluate semen quality. Blood samples were collected every 14 d throughout the study. Semen samples were collected on d 84, 98, and 112. Rams were fed to market weight, shipped to a commercial abattoir, and harvested for carcass data collection. Initial BW, final BW, change in scrotal circumference, days on feed, carcass characteristics, serum testosterone concentrations, and spermatozoa motility score were not different (P ≥ 0.23) due to dietary treatment. However, DMI increased linearly (P < 0.001) as DDGS increased in the ration, resulting in a linear increase (P = 0.02) in ADG. Additionally, spermatozoa concentration decreased linearly (P = 0.05) as DDGS concentration increased in the ration. Increasing DDGS in the diet did not have a negative impact on ram feedlot performance or carcass characteristics; however, spermatozoa production may have been negatively affected, necessitating the need for additional research on the impact of DDGS on ram development.