Polyclonal antibody preparations from avian origin as a feed additive to beef cattle: ruminal fermentation during the step-up transition diets

Abstract

This study investigated the effects of feeding an avian-derived polyclonal antibody preparation (PAP; CAMAS, Inc.) against Streptococcus bovis, Fusobacterium necrophorum, and lipopolysaccharides (40%, 35%, and 25% of the preparation, respectively) on ruminal fermentation [pH, ammonia-N (NH₃-N), lactate, and volatile fatty acids (VFA)] of beef steers during a 21-d step-up diet adaptation. Eight ruminally cannulated Angus crossbred beef steers (658 ± 79 kg of body weight) were assigned in a crossover design to be transitioned from a diet containing ad libitum bermudagrass hay [Cynodon dactylon (L.) Pers.] plus 0.45 kg/d (as fed) of molasses with 0 (CON) or 3 g of PAP (PAP) to a high-grain diet. Transition consisted of three 7-d steps of increased inclusion of cracked corn (35%, 60%, and 82% of the diet DM for STEP1, STEP2, and STEP3, respectively). On each transition day and 7 d after STEP3 (STEP3-7d), ruminal fluid samples were obtained every 3 h for 24 h. Feeding 3 g of PAP daily increased (P < 0.01) average ruminal pH during STEP3 compared with CON steers (5.6 vs. 5.4 ± 0.05, respectively). During STEP1, NH₃-N concentration was greater (P < 0.01; 9.4 vs. 6.8 ± 0.74 mM, respectively), and time (min/d) and area (time × pH) of ruminal pH below or equal to 5.2 was lesser (P ≤ 0.03) for steers consuming PAP compared with steers assigned to CON treatment (33.4 vs. 73.3 ± 21.7 min/d and 187.4 vs. 406.3 ± 119.7 min × pH/d, respectively). Steers consuming PAP had greater acetate:propionate ratio at 0, 3, and 6 h relative to diet change compared with CON (2.42, 2.35, 2.29 vs. 1.66, 1.79, and 1.72 ± 0.17, respectively), whereas butyrate molar proportions increased (P = 0.02; 17.1 vs. 11 ± 1.58 mol/100 mol for CON and PAP, respectively) when PAP was not fed at STEP2. Total ruminal lactate concentrations were not affected by PAP feeding (P > 0.11). In conclusion, feeding 3 g/d of polyclonal antibody preparation against S. bovis, F. necrophorum, and lipopolysaccharides was effective in increasing ruminal pH, A:P ratio, and NH₃-N concentrations, possibly attenuating the risks of ruminal acidosis in steers during the step-up transition from forage to high-grain diets.

Keywords: Fusobacterium necrophorum; Streptococcus bovis; lipopolysaccharides; step-up process.

Figure 1.

Dry matter intake of Angus crossbred steers fed free-choice step-up diets that contained increased concentrations of cracked corn (35%, 60%, and 82%; STEP1 [days 14–21], STEP2 [days 21–28], and STEP3 [days–35], respectively) plus 0.45 kg of molasses that was individually fed containing or not 3 g of polyclonal antibody preparations against Streptococcus bovis, Fusobacterium necrophorum, and lipopolysaccharides (40%, 35%, and 25% of the preparation, respectively). Effect of step-up diet on DMI (P < 0.01; SEM = 1.53) but not treatment × step (P = 0.68) or treatment (P = 0.95) were detected. Within STEP, means without a common superscript (a–c) differ (P ≤ 0.05).

Figure 2.

Ruminal pH within the first 24-h post-diet transition of Angus crossbred steers fed free-choice step-up diets that contained increased concentrations of cracked corn (35%, 60%, and 82%; STEP1 [d 14–21], STEP2 [d 21–28], and STEP3 [d 28–35], respectively) plus 0.45 kg of molasses that was individually fed containing or not 3 g of polyclonal antibody preparations against S. bovis, F. necrophorum, and lipopolysaccharides (40%, 35%, and 25% of the preparation, respectively). Effect of hour posttransition on ruminal pH [STEP1 (A); P < 0.01; SEM = 0.06; STEP2 (B); P < 0.01; SEM = 0.06; STEP3 (C); P < 0.01; SEM = 0.009; and STEP3-7d (D); P < 0.01; SEM = 0.12] but not treatment × hour (P ≥ 0.38) or treatment (P ≥ 0.50) were detected. Effects of treatment × STEP (E; P < 0.01; SEM = 0.05) were detected. Within STEP, means with an asterisk differ (P ≤ 0.05).

Figure 3.

Ruminal NH₃-N within the first 24-h post-diet transition of Angus crossbred steers fed free-choice step-up diets that contained increased concentrations of cracked corn (35%, 60%, and 82%; STEP1 [d 14–21], STEP2 [d 21–28], and STEP3 [d 28–35], respectively) plus 0.45 kg of molasses that was individually fed containing or not 3 g of polyclonal antibody preparations against S. bovis, F. necrophorum, and lipopolysaccharides (40%, 35%, and 25% of the preparation, respectively). Effect of hour post-transition on ruminal NH₃-N [STEP1 (A); P < 0.01; SEM = 1.1; STEP2 (B); P < 0.01; SEM = 0.8; STEP3 (C); P < 0.01; SEM = 0.6; and STEP3-7d (D); P < 0.001; SEM = 0.9] but not treatment × hour (P ≥ 0.90) or treatment (P ≥ 0.67) were detected. Effects of treatment × STEP (E; P = 0.05; SEM = 0.74) on overall ruminal NH₃-N were detected. Within STEP, means with an asterisk differ (P ≤ 0.05).

Figure 4.

Ruminal volatile fatty acids within the first 24-h post-diet transition of Angus crossbred steers fed free-choice step-up diets that contained increased concentrations of cracked corn (35%, 60%, and 82%; STEP1 [d 14–21], STEP2 [d 21–28], and STEP3 [d 28–35], respectively) plus 0.45 kg of molasses that was individually fed containing or not 3 g of polyclonal antibody preparations against S. bovis, F. necrophorum, and lipopolysaccharides (40%, 35%, and 25% of the preparation, respectively) during the STEP1. Effect of hour post-transition on ruminal VFA [Acetate (A); P < 0.01; SEM = 0.8; Propionate (B); P < 0.01; SEM = 0.7; Butyrate (C); P < 0.01; SEM = 0.8; BCVFA (D); P < 0.001; SEM = 0.07; Total (E); P < 0.01; SEM = 5.6; and A:P (F); P < 0.001; SEM = 0.17] but not treatment × hour (P ≥ 0.45) or treatment (P ≥ 0.23) were detected.

Figure 5.

Ruminal volatile fatty acids within the first 24-h post-diet transition of Angus crossbred steers fed free-choice step-up diets that contained increased concentrations of cracked corn (35%, 60%, and 82%; STEP1 [d 14–21], STEP2 [d 21–28], and STEP3 [d 28–35], respectively) plus 0.45 kg of molasses that was individually fed containing or not 3 g of polyclonal antibody preparations against S. bovis, F. necrophorum, and lipopolysaccharides (40%, 35%, and 25% of the preparation, respectively) during the STEP2. Treatment × hour interaction observed for propionate (B; P < 0.01; SEM = 0.7) and A:P ratio (F; P < 0.01; SEM = 0.17). Effect of hour post-transition on ruminal VFA [Acetate (A); P < 0.001; SEM = 1.7; and Butyrate (C); P = 0.003; SEM = 1.9, but not for BCVFA (D; P = 0.52; SEM = 0.53) and total (E; P = 0.44; SEM = 5.6). Within hours, means with an asterisk differ (P ≤ 0.05).

Figure 6.

Ruminal volatile fatty acids within the first 24-h post-diet transition of Angus crossbred steers fed free-choice step-up diets that contained increased concentrations of cracked corn (35%, 60%, and 82%; STEP1 [d 14–21], STEP2 [d 21–28], and STEP3 [d 28–35], respectively) plus 0.45 kg of molasses that was individually fed containing or not 3 g of polyclonal antibody preparations against S. bovis, F. necrophorum, and lipopolysaccharides (40%, 35%, and 25% of the preparation, respectively) during the STEP3. Effect of hour posttransition on ruminal VFA [Acetate (A); P < 0.01; SEM = 1.71; Propionate (B); P < 0.01; SEM = 1.77; BCVFA (D); P < 0.01; SEM = 0.26; Total (E); P < 0.01; SEM = 4.7; and A:P (F); P < 0.001; SEM = 0.19] but not treatment × hour (P ≥ 0.11) or treatment (P ≥ 0.28) were detected. No effects of hour, treatment, or treatment × hour interaction was observed for butyrate (C; P ≥ 0.10).

Figure 7.

Ruminal volatile fatty acids within the first 24-h post-diet transition of Angus crossbred steers fed free-choice step-up diets that contained increased concentrations of cracked corn (35%, 60%, and 82%; STEP1 [d 14–21], STEP2 [d 21–28], and STEP3 [d 28–35], respectively) plus 0.45 kg of molasses that was individually fed containing or not 3 g of polyclonal antibody preparations against S. bovis, F. necrophorum, and lipopolysaccharides (40%, 35%, and 25% of the preparation, respectively) during the STEP3-7d. Effect of hour posttransition on ruminal VFA [Acetate (A); P < 0.01; SEM = 1.0; Propionate (B); P < 0.01; SEM = 1.6; BCVFA (D); P < 0.01; SEM = 0.31; Total (E); P < 0.01; SEM = 7.7; and A:P (F); P < 0.01; SEM = 0.10] but not treatment × hour (P ≥ 0.21) or treatment (P ≥ 0.23) were detected. No effects of hour, treatment, or treatment × hour interaction was observed for butyrate (C; P ≥ 0.14).

Figure 8.

Ruminal lactate concentrations (mmol/L) within the first 24-h post-diet transition of Angus crossbred steers fed free-choice step-up diets that contained increased concentrations of cracked corn (35%, 60%, and 82%; STEP1 [d 14–21], STEP2 [d 21–28], and STEP3 [d 28–35], respectively) plus 0.45 kg of molasses that was individually fed containing or not 3 g of polyclonal antibody preparations against S. bovis, F. necrophorum, and lipopolysaccharides (40%, 35%, and 25% of the preparation, respectively) during STEP1, STEP2, STEP3, and STEP3d-7 (A–D). Effect of hour post-transition on ruminal lactate was observed for STEP2, STEP3, and STEP3d-7 ([B]; P = 0.02; SEM = 0.384; [C]; P < 0.01; SEM = 0.06; [D]; P = 0.04; SEM = 0.220). Effect of STEP was observed for ruminal concentrations of lactate ([E]; P = 0.04; SEM = 0.151). Within hours or STEP, means without a common superscript (a–b) differ (P ≤ 0.05). No effect of hour was observed for STEP1 ([A]; P = 0.24; SEM = 0.289).