Effect of varying concentrations of vitamin C on performance, blood metabolites, and carcass characteristics of steers consuming a common high-sulfur (0.55% S) diet

Abstract

The objective of this study was to examine the effects of vitamin C (VC) supplementation for an average of 102 d before harvest on finishing performance and blood metabolites of steers receiving a 40% dry distillers grains plus solubles diet (0.55% S). Yearling, Angus-cross steers (n = 140) were blocked by initial BW (432 ± 25.5 kg), stratified within blocks by intramuscular fat (3.6% ± 0.30%) determined by ultrasonography, and assigned to treatments (5 steers/pen, 7 pens/treatment). Treatments included 1) no VC control (CON), 2) 5 g VC • steer(-1) • d(-1) (5VC), 3) 10 g VC • steer(-1) • d(-1) (10VC), and 4) 20 g VC • steer(-1) • d(-1) (20VC). Jugular blood was collected from 2 steers/pen before feeding at the beginning and end of the 102-d study, and steers were harvested by block on 3 separate dates (d 91, 105, and 112). Sulfur intake linearly decreased (P = 0.01) as VC inclusion increased (59.2, 57.7, 57.0, and 54.8 ± 0.79 g S • steer(-1) • d(-1) for CON, 5 VC, 10 VC, and 20 VC, respectively). The CON cattle had greater (P < 0.01) DMI than the VC-supplemented cattle. Inclusion of VC did not influence ADG or final BW, resulting in a tendency for a linear increase (P = 0.08) in G:F as VC inclusion increased (0.150, 0.152, 0.158, and 0.160 ± 0.004 for CON, 5 VC, 10 VC, and 20 VC, respectively). Ending (2 d before harvest) plasma ascorbate showed a quadratic effect (P < 0.05) because of lesser concentrations exhibited by 5 VC cattle (1,186 µg/L) compared with the CON (1,454 µg/L), 10 VC (1,304 µg/L), and 20 VC (1,436 µg/L; SEM ± 64.8) cattle. Ending plasma insulin concentrations of CON cattle tended (P = 0.07) to be less than the VC-supplemented cattle. Plasma glucose and NEFA concentrations were not affected (P ≥ 0.23) by VC inclusion. Hot carcass weight, 12th-rib back fat, marbling, and quality grade were not affected (P ≥ 0.27) by VC inclusion. Increasing VC inclusion linearly increased (P = 0.02) rib eye area (84.9, 86.5, 88.7, and 89.1 cm(2) ± 1.17 for CON, 5 VC, 10 VC, and 20 VC, respectively), corresponding to a linear decrease (P = 0.02) in yield grade with increasing inclusions of VC. A tendency (P = 0.06) for a quadratic effect on KPH was observed, in which values generally increased from CON (2.27%) to 5 VC (2.37%) to and 10 VC (2.39%), then decreased in 20 VC (2.20%). In conclusion, VC supplementation to a high-S diet for an average of 102 d before harvest has limited effects on blood metabolites but increased rib eye area and tended to increase feed efficiency of yearling steers.

Impact of supplementing vitamin C for 56, 90, or 127 days on growth performance and carcass characteristics of steers fed a 0.31 or 0.59% sulfur diet

“…Cattle in the present study had plasma ascorbate values that exceed the normal range (2.4 to 4.7 mg/L) reported by Smith et al (2009), indicating excellent VC status of cattle in the present study. Plasma ascorbate values reported in the current study are similar to those reported by reported by Knight et al (1941) and Pogge and Hansen (2013a); however, in these studies, no decrease in plasma ascorbate was observed. The lack of a decrease in ascorbate concentration in response to treatment may be related to the age of the cattle used in the respective studies, 3-yr-old cows by Knight et al (1941) and Pogge and Hansen (2013a) compared to calf-fed steers (8 mo of age) used in the present study and by Pogge and Hansen (2013b).…”

“…Plasma ascorbate values reported in the current study are similar to those reported by reported by Knight et al (1941) and Pogge and Hansen (2013a); however, in these studies, no decrease in plasma ascorbate was observed. The lack of a decrease in ascorbate concentration in response to treatment may be related to the age of the cattle used in the respective studies, 3-yr-old cows by Knight et al (1941) and Pogge and Hansen (2013a) compared to calf-fed steers (8 mo of age) used in the present study and by Pogge and Hansen (2013b). The differing response in plasma ascorbate during the finishing period may indicate that calf-fed cattle have a greater requirement for VC compared to yearling steers.…”

“…Oohashi et al (1999) reported no difference in BF of Japanese black steers consuming 50 g VC•steer -1 •d -1 for differing time periods throughout a 15-mo finishing period (the initial 7 mo, the later 8 mo, or the entire 15 mo), but VC inclusion to the diet during the first 7 mo of finishing increased lipid accumulation in steers whereas VC supplementation during the latter 8 mo period increased LMA, which authors attributed to a potential growth promoting effect of VC. Similarly, the supplementation of VC for the entire finishing period of calf-fed steers (149 d; Pogge and Hansen, 2013b) and yearling steers (102 d; Pogge and Hansen, 2013a) consuming a HS (0.55%) diet increased marbling score and BF in calf-fed steers (Pogge and Hansen, 2013b) and LMA in yearling steers (Pogge and Hansen, 2013a). Dissimilarly, no effects of supplemental VC on marbling score or LMA were noted in the present study.…”

“…The limited effect of VC supplementation on steer performance is consistent with the results of Yano (2002), who supplemented 40 mg VC•kg BW -1 •d -1 (as a rumen-protected source) to Japanese black steers (12 to 24 mo of age) for 365 d, and Pogge and Hansen (2013b), who supplemented 10 g VC•steer -1 •d -1 (same VC source as in the present study) for 149 d to calf-fed steers (approximately 8 mo of age). Alternately, Pogge and Hansen (2013a) indicated that increasing the dose of supplemental VC (0, 5, 10, or 20 g VC•steer -1 •d -1 ; same source as the present study) to yearling steers consuming a 0.55% S diet linearly decreased DMI while tending to increase feed efficiency. Although no treatment differences were noted in feed efficiency in the present study, plasma ascorbate concentrations on d 127 were positively correlated with feed efficiency between d 91 and 127 but not during other periods of the current study.…”

“…Cattle requirements for VC are unknown, but plasma VC has been observed to decrease during the finishing period (Takahashi et al, 1999). Supplementation of VC throughout finishing can result in increased marbling score (Yano, 2001;Pogge and Hansen, 2013b) and LMA (Oohashi et al, 1999;Pogge and Hansen, 2013a). Because maximal H 2 S production occurs early in the finishing period and VC supplementation represents an extra expense to the feedlot producer, our objective was to examine differential timing of VC supplementation during the finishing period (for the first 56 or 90 d or the entire period, 127 d) on growth performance, concentrations of plasma antioxidants VC and GSH, and carcass traits of steers receiving a 0.31 or 0.59% S diet.…”