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One hundred and eighty bulls (BW = 337 ± 10.9 kg) were blocked by BW (6 blocks) and assigned randomly to 1 of 3 treatments on d 0: (1) INJ [received 1 mL (100 mg Zn) of a Zn solution in each testis], (2) BAN (received blood-restrictive rubber band placed upon the dorsal aspect of the scrotum), or (3) BUL (bulls with testicles remaining intact) in a randomized complete block design (3 pens/block and 10 cattle/pen). A random subset of 54 animals (n = 3/pen) were fitted with accelerometers on d 0 for 28 d. The subset also had testis width and scrotal circumference determined and were bled via jugular venipuncture to assess serum haptoglobin and testosterone concentrations every 28 d until slaughter. At slaughter, INJ and BUL were castrated at chain speed to assess final testes weight and for histopathological evaluation. Data were analyzed using PROC MIXED with an alpha of 0.05, and pen served as the experimental unit for all dependent variables. Final BW was greater in INJ and BUL compared to BAN cattle (P < 0.01). Overall ADG and G:F were greater (P ≤ 0.03) in INJ and BUL than BAN; whereas, DMI was similar between treatments for the study duration (P = 0.46). Histopathological results (n = 13; INJ = 7; BUL = 6) indicated that INJ testes were degenerative and not viable while BUL testes were normal. Final serum testosterone concentrations on d 168 were similar (P = 0.14) between INJ and BUL, while after d 14, BAN were non-detectable. Serum haptoglobin concentration was greater in INJ than BUL and BAN on d 1, 3, 5, and 7 (P < 0.01). Scrotal circumference (P = 0.08) and testis width (P = 0.07) on d 168 tended to be greater in BUL compared to INJ. Motion index was greater in BUL and INJ compared to BAN cattle during the d 0 to 28 monitoring period (P ≤ 0.02). There were no differences in standing or lying time (P ≥ 0.85) or lying bouts (P = 0.35); however, step count was greater (P = 0.04) in BUL and INJ. The injection of Zn appeared to cause sterilization but did not cause complete cessation of testicular function as evidenced by testosterone concentration more similar to BUL than BAN. This resulted in increased BW and G:F compared to BAN, yet the acute phase response was markedly greater directly after injection. [ABSTRACT FROM AUTHOR]

The study objective was to determine if acute or chronic water restriction affected hematology or performance in beef calves with parenteral or intranasal vaccination. A total of 60 crossbred beef steer (n = 28) and heifer (n = 32) calves were used. On d -7, calves within sex were assigned randomly to 1 of 6 treatments arranged in a 3 x 2 factorial. Water restriction treatments (Factor A) were applied at the origin ranch via 3 different models: A1) Control, no water restriction except during transport to the feedlot (CON), A2) Acute, consisting of 48 h water restriction prior to transport to the feedlot (ACU), or A3) Chronic, consisting of alternating 24 h periods of water access and restriction, over a 7-d period prior to transport to the feedlot (CHR). Upon feedlot arrival (d 0), 2 respiratory vaccine treatments were applied (Factor B): B1) parenteral administration of a pentavalent modified-live virus (MLV) respiratory vaccine (2 mL s.c. in the neck; EX), or B2) intranasal administration of a trivalent MLV respiratory vaccine (1 mL/naris; IN). Blood was collected on d -7, -5, -3, -1, 0, 1, 3, 5, 7 and weekly thereafter through d 56 to determine complete blood count via automated hemocytometer and packed cell volume (PCV). Individual BW and rectal temperature (RT) was recorded on the same days blood sampling occurred. The PCV was greatest (P ≤ 0.01) for CHR on d -5 and -3. Similarly, hematocrit differed (P ≤ 0.01) between CON (36.4), ACU (33.5) and CHR (39.7%) on d -3. The IN group had increased total white blood cell count (P=0.009); specifically, lymphocytes (P < 0.001) and monocytes (P = 0.002) were increased for IN on d 5 and 3 and d 5, respectively. Eosinophils decreased (day effect; P < 0.01) transiently after transport to the feedlot on d -1. Rectal temperature was increased for IN on d 7 and 14 (P ≤ 0.04). The BW of ACU and CHR treatments decreased 9.5 and 9.7 kg, respectively, from d -7 to -1; however, the CON treatment gained 5.5 kg during the same time (P < 0.001). The ACU and CHR treatments had reduced ADG from d 0 to 14 compared with CON (P ≤ 0.04), regardless of vaccine treatment. Compared to IN, EX had a greater body weight (BW) change from d 42 to 56 (P = 0.01). Chronic water restriction increased PCV and hematocrit and decreased ADG during and 14-d after the restriction period; whereas, intranasal vaccination increased rectal temperature and some white blood cell differentials. [ABSTRACT FROM AUTHOR]

The study objective was to determine if acute or chronic water restriction affected hematology or performance in beef calves with parenteral or intranasal vaccination. A total of 60 crossbred beef steer (n = 28) and heifer (n = 32) calves were used. On d -7, calves within sex were assigned randomly to 1 of 6 treatments arranged in a 3 × 2 factorial. Water restriction treatments (Factor A) were applied at the origin ranch via 3 different models: A1) Control, no water restriction except during transport to the feedlot (CON), A2) Acute, consisting of 48 h water restriction prior to transport to the feedlot (ACU), or A3) Chronic, consisting of alternating 24 h periods of water access and restriction, over a 7-d period prior to transport to the feedlot (CHR). Upon feedlot arrival (d 0), 2 respiratory vaccine treatments were applied (Factor B): B1) parenteral administration of a pentavalent modified-live virus (MLV) respiratory vaccine (2 mL s.c. in the neck; EX), or B2) intranasal administration of a trivalent MLV respiratory vaccine (1 mL/naris; IN). Blood was collected on d -7, -5, -3, -1, 0 , 1, 3, 5, 7 and weekly thereafter through d 56 to determine complete blood count via automated hemocytometer and packed cell volume (PCV). Individual BW and rectal temperature (RT) was recorded on the same days blood sampling occurred. The PCV was greatest (P ≤ 0.01) for CHR on d -5 and -3. Similarly, hematocrit differed (P ≤ 0.01) between CON (36.4), ACU (33.5) and CHR (39.7%) on d -3. The IN group had increased total white blood cell count (P=0.009); specifically, lymphocytes (P < 0.001) and monocytes (P = 0.002) were increased for IN on d 5 and 3 and d 5, respectively. Eosinophils decreased (day effect; P < 0.01) transiently after transport to the feedlot on d -1. Rectal temperature was increased for IN on d 7 and 14 (P ≤ 0.04). The BW of ACU and CHR treatments decreased 9.5 and 9.7 kg, respectively, from d -7 to -1; however, the CON treatment gained 5.5 kg during the same time (P < 0.001). The ACU and CHR treatments had reduced ADG from d 0 to 14 compared with CON (P ≤ 0.04), regardless of vaccine treatment. Compared to IN, EX had a greater body weight (BW) change from d 42 to 56 (P = 0.01). Chronic water restriction increased PCV and hematocrit and decreased ADG during and 14-d after the restriction period; whereas, intranasal vaccination increased rectal temperature and some white blood cell differentials. [ABSTRACT FROM AUTHOR]

The study objective was to determine if acute or chronic water restriction affected haptoglobin (Hp) and serum and mucosal antibody concentration in beef calves after parenteral or intranasal vaccination. A total of 60 crossbred beef steer (n = 28) and heifer (n = 32) calves were used. Animals were previously unvaccinated and confirmed seronegative for antibodies against infectious bovine rhinotracheitis virus (IBRV), bovine viral diarrhea virus (BVDV), and parainfluenza- 3 virus (PI3V) from sera collected at weaning (d -28; 183 days of age). On d -7, calves within sex were assigned randomly to 1 of 6 treatments arranged in a 3 x 2 factorial. Water restriction treatments (Factor A) were applied at the origin ranch via 3 different models: A1) Control, no water restriction except during transport to the feedlot (CON), A2) Acute, consisting of 48 h water restriction prior to transport to the feedlot (ACU), or A3) Chronic, consisting of alternating 24 h periods of water access and restriction, over a 7-d period prior to transport to the feedlot (CHR). Upon feedlot arrival (d 0), 2 respiratory vaccine treatments were applied (Factor B): B1) parenteral administration of a pentavalent modified-live virus (MLV) respiratory vaccine (2 mL s.c. in the neck; EX), or B2) intranasal administration of a trivalent MLV respiratory vaccine (1 mL/naris; IN). Sera was collected weekly from d 0 to 56 for antibody titer analyses, and d -7, -5, -3, -1, 0, 1, 3, 5, 7 and 14 to determine Hp concentration. Nasal swabs were collected on d 0, 3, 7, 14, 21, 28, 35, 42, 49 and 56 to determine presence of bovine respiratory syncytial virus (BRSV)-specific mucosal antibodies. Data were analyzed using Proc Mixed with repeated measures. Overall, haptoglobin was increased on d -7, decreased before feedlot transport on d -1, and increased after arrival (day effect; P < 0.001). An A x B x day interaction (P = 0.004) existed for Hp such that CON-EX and ACU-IN were greatest on d 5 (P ≤ 0.04). The BRSV (P ≤ 0.002) and IBRV (P ≤ 0.04) antibody titer was greater for IN vs. EX from d 14 to 56 and d 21 to 35, respectively. The EX treatment had increased BRSV-specific mucosal antibodies on d 3 and 7 (P ≤ 0.03); however, these were greater for IN from d 35 to 56 (P ≤ 0.05). In this study, water restriction did not clearly alter Hp or antibody responses to parenteral or intranasal vaccination but BRSV and IBRV antibody was increased for IN vs. EX. [ABSTRACT FROM AUTHOR]

Three treatments were evaluated in feedlot heifers to determine the effects of zinc supplementation on the immune response to a combined viral-bacterial respiratory disease challenge. Thirty-two beef heifers (255 ± 15 kg) were subjected to a 30d period of Zn depletion, then randomly assigned to one of three treatment diets fed for 30d before the challenge: 1) Supplementation with 100 mg of Zn from Zn sulfate/kg of DM (Zn100), 2) Supplementation with 200 mg of Zn from Zn sulfate/kg of DM (Zn200), and 3) Supplementation with 80 mg of Zn/kg of DM from zinc methionine (ZinMet® Global Animal Products, Inc., Amarillo, TX) and 20 mg of Zn from Zn sulfate/kg of DM (ZinMet). All heifers were fitted with indwelling vaginal temperature (VT) devices and intra-nasally challenged with 1x108 PFU bovine herpesvirus-1 on d -3, and then allowed to rest in outdoor pens for 3d. On d0, each heifer was challenged intratracheally with an average dose of 2.38 x 107 CFU Mannheimia haemolytica (MH), fitted with an indwelling jugular catheter, then moved into individual stanchions in an environmentallycontrolled enclosed barn. Whole blood samples were collected at 1-h (serum) or 2-h (complete blood counts) intervals from 0 to 8h, and at 12, 24, 36, 48, 60, 72, 168 and 360h relative to MH challenge. Data were analyzed using the MIXED procedure of SAS specific for repeated measures with fixed effects of treatment, time and their interaction. There was a treatment effect (P < 0.01) for VT such that Zn200 heifers had greater VT than Zn100 and ZinMet heifers. There was a trend (P = 0.10) for a serum cortisol treatment effect with Zn100 heifers having greater cortisol than ZinMet heifers. Total leukocytes and lymphocytes were greater (P ≤ 0.008) in Zn100 heifers than Zn200 and ZinMet heifers, while monocytes were less (P = 0.05) in ZinMet heifers than Zn100 and Zn200 heifers. Concentrations of IL-6 were greater (P = 0.02) in ZinMet heifers than Zn100 and Zn200 heifers. Concentrations of IFN-γ were greater in Zn200 heifers than ZinMet heifers at 0h, and Zn100 heifers from 0 to 12h post-MH challenge (trt x time P = 0.02). Serum haptoglobin was not affected by treatment or treatment x time (P ≥ 0.36), but increased over time (P < 0.001). There was a trend (P = 0.11) for ZinMet heifers to have less severe nasal lesion scores than Zn100 heifers. The observed differential physiological responses in this study indicate that zinc source and concentration may alter the response to a bovine respiratory challenge in heifers. [ABSTRACT FROM AUTHOR]

The study objective was to determine if acute or chronic water restriction affected haptoglobin (Hp) and serum and mucosal antibody concentration in beef calves after parenteral or intranasal vaccination. A total of 60 crossbred beef steer (n = 28) and heifer (n = 32) calves were used. Animals were previously unvaccinated and confirmed seronegative for antibodies against infectious bovine rhinotracheitis virus (IBRV), bovine viral diarrhea virus (BVDV), and parainfluenza- 3 virus (PI3V) from sera collected at weaning (d -28; 183 days of age). On d -7, calves within sex were assigned randomly to 1 of 6 treatments arranged in a 3 × 2 factorial. Water restriction treatments (Factor A) were applied at the origin ranch via 3 different models: A1) Control, no water restriction except during transport to the feedlot (CON), A2) Acute, consisting of 48 h water restriction prior to transport to the feedlot (ACU), or A3) Chronic, consisting of alternating 24 h periods of water access and restriction, over a 7-d period prior to transport to the feedlot (CHR). Upon feedlot arrival (d 0), 2 respiratory vaccine treatments were applied (Factor B): B1) parenteral administration of a pentavalent modified-live virus (MLV) respiratory vaccine (2 mL s.c. in the neck; EX), or B2) intranasal administration of a trivalent MLV respiratory vaccine (1 mL/naris; IN). Sera was collected weekly from d 0 to 56 for antibody titer analyses, and d -7, -5, -3, -1, 0, 1, 3, 5, 7 and 14 to determine Hp concentration. Nasal swabs were collected on d 0, 3, 7, 14, 21, 28, 35, 42, 49 and 56 to determine presence of bovine respiratory syncytial virus (BRSV)-specific mucosal antibodies. Data were analyzed using Proc Mixed with repeated measures. Overall, haptoglobin was increased on d -7, decreased before feedlot transport on d -1, and increased after arrival (day effect; P < 0.001). An A × B × day interaction (P = 0.004) existed for Hp such that CON-EX and ACU-IN were greatest on d 5 (P ≤ 0.04). The BRSV (P ≤ 0.002) and IBRV (P ≤ 0.04) antibody titer was greater for IN vs. EX from d 14 to 56 and d 21 to 35, respectively. The EX treatment had increased BRSV-specific mucosal antibodies on d 3 and 7 (P ≤ 0.03); however, these were greater for IN from d 35 to 56 (P ≤ 0.05). In this study, water restriction did not clearly alter Hp or antibody responses to parenteral or intranasal vaccination but BRSV and IBRV antibody was increased for IN vs. EX. [ABSTRACT FROM AUTHOR]

Three treatments were evaluated in feedlot heifers to determine the effects of zinc supplementation on the immune response to a combined viral-bacterial respiratory disease challenge. Thirty-two beef heifers (255 ± 15 kg) were subjected to a 30d period of Zn depletion, then randomly assigned to one of three treatment diets fed for 30d before the challenge: 1) Supplementation with 100 mg of Zn from Zn sulfate/kg of DM (Zn100), 2) Supplementation with 200 mg of Zn from Zn sulfate/kg of DM (Zn200), and 3) Supplementation with 80 mg of Zn/kg of DM from zinc methionine (ZinMet® Global Animal Products, Inc., Amarillo, TX) and 20 mg of Zn from Zn sulfate/kg of DM (ZinMet). All heifers were fitted with indwelling vaginal temperature (VT) devices and intra-nasally challenged with 1x108 PFU bovine herpesvirus-1 on d -3, and then allowed to rest in outdoor pens for 3d. On d0, each heifer was challenged intratracheally with an average dose of 2.38 x 107 CFU Mannheimia haemolytica (MH), fitted with an indwelling jugular catheter, then moved into individual stanchions in an environmentallycontrolled enclosed barn. Whole blood samples were collected at 1-h (serum) or 2-h (complete blood counts) intervals from 0 to 8h, and at 12, 24, 36, 48, 60, 72, 168 and 360h relative to MH challenge. Data were analyzed using the MIXED procedure of SAS specific for repeated measures with fixed effects of treatment, time and their interaction. There was a treatment effect (P < 0.01) for VT such that Zn200 heifers had greater VT than Zn100 and ZinMet heifers. There was a trend (P = 0.10) for a serum cortisol treatment effect with Zn100 heifers having greater cortisol than ZinMet heifers. Total leukocytes and lymphocytes were greater (P ≤ 0.008) in Zn100 heifers than Zn200 and ZinMet heifers, while monocytes were less (P = 0.05) in ZinMet heifers than Zn100 and Zn200 heifers. Concentrations of IL-6 were greater (P = 0.02) in ZinMet heifers than Zn100 and Zn200 heifers. Concentrations of IFN-γ were greater in Zn200 heifers than ZinMet heifers at 0h, and Zn100 heifers from 0 to 12h post-MH challenge (trt x time P = 0.02). Serum haptoglobin was not affected by treatment or treatment x time (P ≥ 0.36), but increased over time (P < 0.001). There was a trend (P = 0.11) for ZinMet heifers to have less severe nasal lesion scores than Zn100 heifers. The observed differential physiological responses in this study indicate that zinc source and concentration may alter the response to a bovine respiratory challenge in heifers. [ABSTRACT FROM AUTHOR]