Forty-six nonlactating beef cows were used to examine effects of dried distiller's grains plus solubles (DG) supplementation strategies to cows fed grass hay during mid- to late gestation on BW, ultrasound body composition characteristics, concentrations of serum NEFA and urea, feeding behavior, and calf birth weight. Cows were assigned to dietary treatments in a completely randomized design: 1) control, where hay was fed each day of the week (CON), 2) both hay and DG fed daily during the week (DG7), 3) hay fed daily but DG fed 3 d of the week (DG3), and 4) hay fed 4 d of the week alternating with DG fed on the remaining 3 d (DGA). Hay was offered ad libitum on days it was fed. The DG were fed at 0.40% of BW when offered daily and 0.93% of BW when offered 3 d per week (Monday, Wednesday, and Friday). Feed intake was monitored continuously over the 84-d feeding period. Hay intake and total DMI were reduced (P < 0.05) in DGA compared with DG7 and DG3. Gain and G:F were decreased (P < 0.05) for CON compared with other treatments. No differences (P > 0.05) were observed among treatments for change in BCS, intramuscular fat, rib fat, or rump fat from d 1 to 84. On a day when DG7, DG3, and DGA all received DG (Friday), DGA had reduced (P < 0.05) concentrations of urea compared with DG3 and DG7. On a day when only DG7 received DG (Saturday), urea was greater (P < 0.01) for DG3 and DGA compared with DG7, and concentrations of NEFA were greater (P < 0.01) in CON and DGA compared with DG7. On the second consecutive day when only DG7 received DG (Sunday), concentrations of NEFA were less (P < 0.001) for DG7 compared with other treatments. On days when all cows received hay, DGA spent more time eating (P < 0.05) compared with DG7 and DG3. Cows fed DGA had greater (P < 0.05) hay intake per meal and time per meal compared with other treatments. On days when DG7, DG3, and DGA all received DG, cows in the DG3 and DGA treatments had greater (P < 0.05) number of DG meals, time spent eating, intake per meal, and time per meal but a slower (P < 0.05) rate of DG intake compared with DG7. No differences (P > 0.05) were observed in calf birth weights among treatments. The alternate-day feeding strategy reduced hay and total intake, altered concentrations of serum urea and NEFA, and altered feeding behavior compared with other supplementation methods.

Four ruminally and intestinally cannulated steers were used in a 4 × 4 Latin square to evaluate effects of rumen-protected Arg supplementation or intravenous Arg injection on small intestinal delivery of AA, site and extent of digestion, and ruminal fermentation. Steers were fed grass hay (7.2% CP, 67.6% NDF, 0.29% Arg) for ad libitum intake with no additional Arg (CON), 54-mg L-Arg/kg BW injected intravenously (Arg-INJ), 180-mg rumen-protected L-Arg/kg BW daily (Arg-RP180), or 360-mg rumen-protected L-Arg/kg BW daily (Arg-RP360). Half of each treatment dose was administered twice daily. Each period had a 7-d washout of hay only followed by a 14-d treatment and collection period. Ruminal disappearance (%) of Arg was greater (P &lt; 0.001) for both Arg-RP treatments than CON and Arg-INJ, although the amount of Arg disappearing was greatest in Arg-RP360, followed by Arg-RP180, and least in CON and Arg-INJ (P &lt; 0.001). Duodenal flow and small intestinal disappearance (g/d) of Arg was greatest in Arg-RP360, followed by Arg-RP180, and least in CON and Arg-INJ (P &lt; 0.004). Ileal flow of Arg was greatest in Arg-RP360, intermediate in Arg-RP180, and least in CON (P = 0.01) because the proportional small intestinal disappearance of Arg was not different (P = 0.96). Steers fed Arg-RP360 had greater (P = 0.01) ileal flow of Orn and tended to have greater (P = 0.09) ileal flow of Glu than all other treatments. There were no differences in hay or total DMI, microbial efficiency, or OM, NDF, or ADF digestibility (P ≥ 0.10). Total N intake and duodenal N flow were greater in Arg-RP360 than all other treatments (P ≤ 0.02). Total tract N digestibility was greatest in Arg-RP360, followed by Arg-RP180, and least in CON and Arg-INJ (P = 0.003). Ruminal ammonia was greater (P = 0.004) in Arg-RP360 compared with CON and Arg-INJ and greater (P = 0.06) in Arg-RP180 than CON. There was no effect of treatment (P ≥ 0.37) on total VFA, acetate, propionate, or butyrate concentrations. Results indicate that feeding rumen-protected Arg increases small intestinal Arg flow with minimal effects on ruminal fermentation and total tract digestibility of OM and fiber.

Four ruminally and duodenally cannulated Holstein steers (BW = 449 ± 7.3 kg) were used to examine the effects of feeding either dried distiller's grains plus solubles (DG) or grass hay on alternate days (every other day) on intake, ruminal fermentation and passage rates, and serum NEFA in forage-fed steers. Steers were assigned to 1 of 4 dietary treatments in a 4 × 4 Latin square: 1) only hay (CON), 2) hay and 0.4% of BW as DG DM daily (DG7), 3) hay daily and 0.8% BW DG every other day (DG2), and 4) alternate day feeding of hay and 0.8% of BW as DG (DGA). Treatment periods consisted of 13 d of adaptation and 8 d of collecting digesta and blood. Over the entire collection period, DMI was decreased ( = 0.004) for DGA compared with other treatments (13.0 ± 0.8, 12.7 ± 0.8, 13.3 ± 0.8, and 10.9 ± 0.8 kg/d for CON, DG7, DG2, and DGA, respectively). Immediately after feeding on days supplement was fed to DG2 and DGA (supplemented days [SUP]), ruminal pH of DGA was less than other treatments but by the end of the day was greater than other treatments (treatment × time, < 0.001). At feeding time on nonsupplemented days (NSUP), ruminal pH of DGA steers was greater than other treatments but was similar (treatment × time, < 0.001) to DG2 and CON by 5 h after feeding. Total concentrations of VFA were similar ( = 0.09) among treatments on SUP; however, on NSUP, total VFA concentrations were least in DGA from feeding until 4 h after feeding (treatment × time, = 0.02). No differences ( ≥ 0.06) were observed among treatments for apparent ruminal, total intestinal, and total tract DM, OM, or CP digestibility. There were no differences ( = 0.36) in serum NEFA among treatments on SUP; however, on NSUP, steers fed DGA (209.5 ± 12.7 m) had greater ( < 0.01) NEFA compared with other treatments (84.4 ± 12.7, 88.0 ± 12.7, and 77.7 ± 12.7 m for CON, DG7, and DG2, respectively). The DGA feeding strategy influenced DMI and ruminal kinetics and circulating NEFA without impacting total tract digestibility.

Eighty-one prepubertal beef heifers were used to evaluate effects of used controlled internal drug release (CIDR) insert heating methods on concentrations of progesterone after CIDR insert reinsertion. Heifers were stratified by weight and birth date and then assigned to receive a new CIDR insert (New; n = 10) or 1 of 8 used (7 d prior use) CIDR insert treatments: 1) no processing (Used; n = 10), 2) autoclaved (Autoclaved; n = 8), 3) processed in dishwasher (Dishwasher; n = 8), 4) processed in microwave for 30 s (Microwave; n = 10), 5) processed in toaster oven (Oven; n = 9), 6) processed in clothes dryer (Dryer; n = 10), 7) processed in boiling water (Boiled; n = 8), or 8) stored outdoors for 60 d (Outside; n = 8). Used CIDR inserts were processed at 121°C for 30 min for autoclaved and oven treatments, at 121°C for boiled treatment, and for 30 min for dryer and dishwasher treatments. Blood samples were collected on d -10, immediately before CIDR insert insertion (d 0), 3 h after CIDR insert insertion (3 h), daily while CIDR insert was in place (d 1 to 11), and 24 h after CIDR insert removal (d 12) for analysis of concentrations of progesterone. Subjective color scores (1 = bright white to 5 = completely stained yellow/red) were assigned to each CIDR insert after d 11. A treatment × time interaction (P< 0.0001) was present for concentrations of progesterone. Concentrations of progesterone were similar (P > 0.10) for heifers receiving a used CIDR insert compared with heifers receiving CIDR inserts processed in a dishwasher, microwave, oven, dryer, or boiling water (collectively reported as "Processed"). However, heifers receiving autoclaved CIDR inserts had greater (P < 0.05) concentrations of progesterone from h 3 to d 3 but similar (P > 0.10) concentrations of progesterone from d 4 to d 11 compared with heifers receiving used or processed CIDR inserts. From d 1 to 11 heifers receiving outside CIDR inserts had decreased (P < 0.05) concentrations of progesterone compared with all other treatments. Heifers receiving autoclaved CIDR inserts had greater (P < 0.05) concentrations of progesterone compared with all other treatments at 3 h and 1 d, whereas heifers receiving new CIDR inserts had greater (P < 0.05) concentrations of progesterone from d 6 to 11 compared with all other treatments. Outside CIDR inserts were more discolored (P < 0.001) compared with all other treatments. Processing used CIDR inserts with a dishwasher, microwave, oven, clothes dryer, boiling water, or full environmental exposure did not result in a pattern of concentrations of progesterone similar to that of autoclaved or new CIDR inserts.

Two experiments were conducted to determine the effect of calf removal (CR) on pregnancy rate (PR) and calf performance in suckled beef cows. Cows in both experiments were synchronized with the 7-d CO-Synch + CIDR protocol [i.e., 100-µg injection of GnRH at controlled internal drug release (CIDR) device insertion (d -7) with 25-mg injection of PGF2α at CIDR removal (d 0), followed by injection of GnRH and timed AI (TAI) on d 3]. Cows were blocked by location (6 locations), stratified by days postpartum (DPP) and parity, and assigned to 1 of 2 treatments in Exp. 1: 1) control (Control; n = 156); 2) calves were separated from their dams between d 0 and 3 (CR72; n = 168); and 1 of 4 treatments in Exp. 2: 1) Control (n = 103); 2) CR72 (n = 104); 3) calves were separated from their dams between d 0 and 2 (CR48A; n = 95); and 4) similar to CR48A but CR between d 1 and 3 (CR48B; n = 53). Transrectal ultrasonography of ovarian structures was performed on d 0, 1, 2, 3, 4, and 10 (in a subset of cows) to determine pregnancy status on d 33. Blood samples were collected on d -14, -7, 0, 3, and 10 (in a subset of cows) to determine concentrations of progesterone (P4) and estradiol (E2). Calves were blocked by age as young (25 to 59 d), medium (60 to 79 d), and old (≥80 d), and were weighed on d 0, 3, 33, and 63. Overall PR did not differ among treatments and averaged 50%. Follicle growth rate from d 0 to 3 tended (P = 0.06) to be greater for CR72 (0.42 ± 0.15 mm/d) compared with Control (0.02 ± 0.15 mm/d). Young (-3.9 ± 0.3%) and old (-3.1 ± 0.4%) calves lost a greater (P < 0.001) percent of BW (PBW) during CR than medium-age (-1.6 ± 0.3%) calves exposed to CR72. In Exp. 2, PR were similar among all 3 locations (49%; P = 0.15). Young (-4.8 ± 0.6%) and medium (-3.0 ± 0.5%) calves lost greater (P < 0.01) percent body weight (PBW) during CR than old (-1.4 ± 0.6%) calves within the CR72 treatment. Calves exposed to CR48 (-2.2 ± 0.6%, -1.1 ± 0.6%, and -2.4 ± 0.6% PBW change for young, medium, and old, respectively) lost more BW than calves in the Control group (-3.7 ± 0.4%, -1.7 ± 0.5%, and -2.1 ± 0.5% PBW change for young, medium, and old, respectively). Subsequent calf weights on d 33 and 63 were greater (P < 0.05) in Controls than cows exposed to CR48 or CR72 treatments. We conclude that CR stimulated follicle growth but failed to enhance PR to TAI. However, CR had a negative impact on subsequent calf performance, which differed, depending on the duration and age of the calf when exposed to CR.