Effects of receiving and growing diets on compensatory gains of stressed calves

Three hundred seventy-seven male stocker calves were used to study the effects of three receiving diets, two growing-finishing diets and two levels of shipping shrink on compensatory gains during the post-receiving feeding period. Calves received on a 75% concentrate diet gained 19 kg more during the first 42 d than those received on hay plus .91 kg daily of protein supplement (P less than .01). Calves received on hay plus protein supplement gained 11 kg more than the calves received on hay alone during the same period (P less than .01). When calves were fed an 85% concentrate diet throughout finishing, there was no difference in the rate of compensatory gain made by calves fed hay alone or hay plus protein supplement. Neither of the latter two groups completely compensated for the slow rates of gain made during receiving. When calves were fed a 50% concentrate growing diet from the end of the receiving period to a body weight of 272 kg then finished on an 85% concentrate diet, those received on hay alone lacked only 1 kg of compensating fully for the low gains of the receiving period. However, this procedure had no effect on the compensatory gains of those received on hay plus protein supplement. High-shrink calves received on hay alone or hay plus protein never compensated fully for the low gains made in the receiving period. However, with low-shrink calves, those received on hay alone fully compensated for the low gains of the receiving period and those received on hay plus protein lacked only 2 kg of making full compensation.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effect of supplemental chromium on antibody responses of newly arrived feeder calves to vaccines and ovalbumin.

Two trials were conducted to investigate the effects of supplemental chromium (Cr) from organic sources (Cr chelate and high Cr yeast) on antibody responses of newly arrived feeder calves following vaccination with infectious bovine rhinotracheitis (IBR), para-influenza-3 (PI3), bovine respiratory syncytial virus (BRSV), bovine viral diarrhea (BVD) and Pasteurella haemolytica and ovalbumin (OVA). Using cross bred steer calves purchased at sales in Ontario, vaccines and OVA were given on d 0 and 21 after arrival in the feedlot. Immune responses of calves were measured as serum specific antibody titres against all antigens on d 0 and 28 or d 35. The anti-OVA antibody responses (trial 2) were further investigated by measuring antibody concentrations of calves weekly until d 55 after arrival in the feedlot. Supplemental Cr (0.14 ppm) from an amino acid-chelated source had no effect on antibody responses to IBR, P13 and BRSV, but enhanced (P < 0.05) antibody titres of calves in response to the BVD vaccine on d 28 or d 35. Supplemental Cr from Cr yeast had no effect on antibody titres of calves to any vaccines. Chromium from both sources (trial 1 and 2) had no effect on antibody responses of calves following vaccination with P. haemolytica. However, supplemental Cr (0.75 ppm) from Cr yeast enhanced (P < 0.05) serum antibody responses of calves to OVA during the primary response (d 14) and secondary response (d 35) following immunization. These data confirmed our previous finding that supplemental Cr can enhance humoral immune response of market-transit stressed calves, but its enhancement on vaccine efficacy was antigen-dependent and variable.     

The influence of supplemental chromium and vaccines on the acute phase response of newly arrived feeder calves.

The acute phase response as indicated by serum haptoglobin and total haemolytic complement activity (CH50) was measured in 72 cross-bred steer calves purchased at sales in Ontario. During the 28 day (d) trial, 18 steers were randomly assigned to each of the following groups: 1) control; 2) vaccinated (Infectious Bovine Rhinotracheitis, Parainfluenza-3, Bovine Viral Diarrhea, Bovine Respiratory Synctial Virus vaccine plus Pasteurella haemolytica vaccine); 3) supplemental chelated Cr (0.14 mg/kg); and 4) Cr plus vaccines. Haptoglobin concentrations were low at arrival, increased (P < 0.05) on day 7, and returned to near initial levels (P > 0.05) by day 14. Supplemental Cr reduced (P < 0.05) haptoglobin on day 7 when morbidity was highest. Following antibiotic treatment for respiratory disease haptoglobin was lower (P < 0.05) than during morbidity; however, during morbidity, haptoglobin concentrations were not greater in sick calves (P > 0.05) than in healthy calves. Complement activity was lowest on day 7 (P < 0.05) and peaked on day 14 (P < 0.05). Complement activity tended to be lower on day 7 for vaccine, Cr, and Cr+ vaccine groups; however, the difference from controls was not significant (P > 0.10). Complement activity did not increase on day 14 (P > 0.05) with Cr supplementation as in other treatments. Morbid calves had lower (P < 0.05) CH50 activity than healthy calves on day 14. Following antibiotic treatment, the Cr-supplemented group had higher (P < 0.05) CH50 than during morbidity. In general, chromium supplementation reduced the acute phase response in newly arrived feeder calves.     

Suppressed lymphocyte blastogenic responses and enhanced in vitro growth of infectious bovine rhinotracheitis virus in stressed feeder calves

Hereford steers were stressed on a large-animal treadmill operating at speeds of 1.8 to 2.2 m/s. Blood samples were collected from indwelling jugular catheters before, during, and after exercise. Peripheral blood lymphocytes from stressed calves at 5 and 30 minutes after exercise had less (P less than 0.01) mitogen-induced blastogenic responses when compared to pre- or 60-minute postexercise values. Serum from stressed calves incorporated into lymphocyte cultures from nonstressed steers resulted in less (P less than 0.01) lymphocyte blastogenic responses. Infectious bovine rhinotracheitis viral growth in bovine kidney cell cultures was enhanced 4-fold when cultured with serum from stressed calves. These data indicate that acute physical exertion may cause physiologic alterations in calves that modulate cellular immunity and viral replication.     

Lead poisoning in feeder calves

A group of 90 feeder calves was accidentally exposed to lead for approximately 30 days. The source of the intoxication was determined to be contamination of feed ingredients from a railroad car. Fourteen calves died and 8 more were clinically affected. Blood samples were obtained from 24 exposed calves (16 clinically normal and 8 intoxicated), and the samples were analyzed for lead, delta-amino levulinic acid dehydrase activity, and free erythrocyte porphyrin. Blood lead values ranged from 0.44 to 1.16 parts per million. Amino levulinic acid dehydrase activity was not affected enough to be of diagnostic value, whereas free erythrocyte porphyrin was increased dramatically and consistently in lead-exposed cattle.     

Influence of yeast culture on feeder calves and lambs.

Four experiments were conducted to determine the influence of yeast culture on 1) the health and performance of feeder calves, 2) the response of calves to an infectious bovine rhinotracheitis virus (IBRV) infection, and 3) nutrient utilization in lambs fasted for 3 d. In Exp. 1, 108 feeder calves were transported from Tennessee to Texas (1,600 km) and fed receiving diets containing 0 or .75% yeast culture and .35 or .69% P in a 2 x 2 factorial arrangement of treatments. In Exp. 2, 101 calves were transported 950 kg from Austin, TX to Bushland, TX and fed receiving diets containing 0, .75, 1.125, or 1.5% yeast culture. Yeast culture did not significantly affect the health or performance of calves in either experiment, although morbid calves fed yeast culture required fewer (P less than .05) days of antibiotic therapy in Exp. 2. In Exp. 3, feeder steers were fed diets containing 0 or .75% yeast culture and challenged intranasally with IBRV. Calves fed yeast culture tended to maintain heavier weights and higher DMI during IBRV infection than did steers fed the control diet. In Exp. 4, feeder lambs were fasted for 3 d and refed diets containing 0, .75, 1.125, or 1.5% yeast culture during a N and mineral balance trial. Lambs fed yeast culture had greater (P less than .08) N balance and tended to have greater Zn and Fe balance than control lambs. Results of these studies are interpreted to suggest that supplementation of morbid calves with yeast culture can have beneficial effects (fewer sick days, higher feed intakes) and that these effects may be mediated by improved N, Zn, and Fe metabolism.     

Nutrition and management of stressed beef calves. An update

In an earlier report in the Veterinary Clinics: Large Animal Practice, the author discussed some basic principles upon which receiving programs for stressed calves should be based. Additional information has been developed in some of the areas covered in that report and in certain other areas. It is the purpose of this article to discuss some of this new information, after a brief review of the basics.     

Combinations of rendered protein meals for growing calves.

Complementary responses between rendered protein meals were investigated in this study. In a preliminary trial using 12 mature wethers in two replications, there was no difference (P greater than .20) in N digestibility between meat and bone meal (MBM; 96.7%), feather meal (FTH; 89.8%), and soybean meal (SBM; 98.7%). In a 112-d growth trial, individually fed calves (n = 120; 230 kg) received graded levels of FTH, MBM, 50:50 MBM-FTH (CP basis), or SBM with or without tryptophan (Trp) supplementation. Additions of Trp increased plasma Trp levels (P less than .05) but failed to improve efficiency of protein utilization (P greater than .35). Pooled results showed that this efficiency was greater (P less than .05) for FTH (1.47) than for MBM (1.04), FTH:MBM (.80), or SBM (.66). A trial was conducted to determine whether Trp addition reduces growth response to FTH:MBM (50:50) combinations. Calves (n = 230; 285 kg) were blocked by sex and weight into six replications and received FTH:MBM supplying 35% of the supplemental CP fed alone or with a high or low level of Trp supplement. Negative (urea only) and positive controls were included. Calves receiving FTH:MBM combinations gained faster (P less than .10) and were more efficient (P less than .10) than urea-supplemented calves. Performance was not altered by Trp addition. Calves (n = 120; 230 kg) were individually fed in two replications (43 or 48% CP MBM in Replications 1 and 2, respectively) of a growth trial to determine whether there was a complementary response between blood meal (BM) and MBM.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effect of transport on feeder calves

One hundred fifty feeder steers (mean body weight, 195 kg) were assigned to 1 of 3 transport groups and were deprived of feed and water (fasted) for 24 hours. Additionally, calves were transported on a commercial livestock trailer for 0 (control-fasted only), 12 (short haul), or 24 (long haul) hours. Blood samples were obtained from the jugular vein before calves were loaded on the transport vehicle and immediately after calves of the long-haul group returned to the research feedlot. Complete blood counts were performed and 32 mineral, enzyme, and biochemical constituents were measured. Calf morbidity, mortality, and average daily weight gain were evaluated during the next 56 days. Duration of transport did not affect average daily gain; however, calves of the short-haul group had significantly (P less than 0.05) higher morbidity and mortality than did those of the control and long-haul groups. In all groups, results of differential leukocyte counts were indicative of stress response. Significant (P less than 0.05) linear contrasts were observed between duration of transport and erythrocyte, leukocyte, segmented neutrophil, lymphocyte, and eosinophil counts and results of serum enzyme (alanine transaminase, hydroxybutyrate dehydrogenase, total lactate dehydrogenase [LD], and LD-1, LD-3, and LD-4 isoenzymes), iron, urea nitrogen, beta-globulin, glucose, and urea nitrogen-to-creatinine ratio determinations. Significant (P less than 0.05) quadratic contrasts were observed between duration of transport and serum unsaturated iron binding capacity, total iron binding capacity, and LD-5 percentage. Calf source had a significant (P less than 0.05) effect on almost all variables tested.(ABSTRACT TRUNCATED AT 250 WORDS)     

Parasite control in calves and growing heifers.

Parasite control in calves and growing heifers results in animals that grow faster and remain healthier. Control programs revolve around reducing the parasites (infective stages) in the environment. In confinement, sanitation removes or reduces the number of infective stages (oocysts, cysts, and infective larvae) and the infection rate. On pasture one must resort to pasture management and parasite removal. The mites and lice are generally controlled by reducing or removing the populations on the animals, preventing the spread. Environmental control and manure management impact the fly populations.     

Effects of zinc methionine and zinc oxide on performance, blood characteristics, and antibody titer response to viral vaccination in stressed feeder calves.

Ninety steers with an average weight of 214 kg were purchased at 2 feeder calf sales and transported 70 to 100 km. On arrival at the feedlot, steers were weighed and identified, blood was withdrawn, and the steers were vaccinated against bovine herpesvirus-1 (BHV-1) and parainfluenza3 (PI3), using a modified live vaccine, and randomly assigned to treatment groups. Treatments were: control (no supplemental zinc; zinc methionine; and zinc oxide. The control diet contained 26 mg of zinc/kg diet, and zinc was added in treatments 2 and 3 to provide 25 mg of supplemental zinc/kg diet. Neutralizing antibody titers were determined on serum samples taken on days 0 and 14 as a measure of the immune response to BHV-1 and PI3 vaccination. Weight gains for the 28-day study were similar across treatments. Dry matter intake tended to be higher in steers fed supplemental zinc from either source, because steers fed zinc methionine and zinc oxide consumed 5.2 and 4.4% more feed, respectively, than controls. Antibody titers against BHV-1 tended to be higher in steers supplemented with zinc methionine on day 14. Differences between treatments were not found for PI3 titers. Mortalities did not occur and morbidity rate was low.     

The route of liquids administered to calves by esophageal feeder.

An esophageal feeder and a rubber nasoesophageal tube were used to administer fluids to calves. Radio-opaque fluids were given and their destination determined by fluoroscopy and radiography. Fluids containing glucose and xylose were also given and plasma glucose and xylose concentrations measured. In at least 93% of calves, the radio-opaque fluids entered the reticulum, indicating that the reticular groove did not close. Oral administration of sodium bicarbonate, copper sulfate and guanidine HCl did not influence groove closure in calves that received fluids through an esophageal feeder. As administration of the fluids continued, overflow to the abomasum occurred after about 400 mL had been given. When 2.0 L of glucose and electrolyte solution was given by esophageal feeder, plasma glucose levels rose significantly (p less than 0.01), showing that absorption had occurred. Plasma xylose levels rose in seven out of eight calves 30 minutes after a second 2.0 L dose (containing xylose) had been administered. Thus, even though esophageal feeders do not cause reticular groove closure, they can be used to administer fluids for enteric absorption, provided large quantities are given.     

Market stress-associated changes in serum complement activity in feeder calves.

Classical hemolytic complement (C) of calves was analyzed during a protocol designed to imitate the usual market handling of feeder calves from the southeastern United States. Serum C concentrations of the calves (n = 100 x 4 years) were evaluated on their farm of origin, on arrival at an auction market, on arrival at a feedyard, and during their first 4 weeks in the feedyard. Complement concentrations (measured in CH50 units) were typically lowest at the farm of origin and highest when the calves entered the auction market 28 to 133 days later. Serum C concentrations decreased after the calves encountered the severe stresses of being in the auction market for 7 days, 24-hour truck transport (1,932 km) to the feedyard, and the first 7 days in the feedyard. The C concentrations recovered after 21 to 28 days in the feedyard. Steers had significantly (P less than or equal to 0.05) lower C concentrations than did heifers in 3 of 4 years at the farm of origin, and in 2 of 4 years at the auction market. Morbid calves had significantly (P less than or equal to 0.05) lower C values than did healthy calves on day 7 in the feedyard in 3 of 4 years. There were significant differences in C concentrations of calves from different farms of origin in each of the 4 years. There was no significant difference in C concentrations of calves that were vaccinated vs those not vaccinated with Pasteurella haemolytica.     

Dietary magnesium and urolithiasis in growing calves

The effect of high levels of dietary magnesium (1.4%) alone or in combination with elevated calcium (1.8%) or phosphorus (1.6%) on growth and health of male calves was evaluated during a nine week feeding trial after weaning. Twenty calves were randomly divided into 4 feeding groups consisting of controls, high magnesium, high magnesium and calcium or high magnesium and phosphorus. Elevated dietary minerals caused decreased feed intake and growth rate. Blood urea nitrogen and serum creatinine levels were greatly elevated in calves fed high magnesium or magnesium and phosphorus and serum urea nitrogen was moderately elevated in calves fed high magnesium and calcium. These elevations suggested the occurrence of renal damage as a result of microcrystalline obstruction of renal tubules. Serum magnesium levels were three times normal in calves fed high magnesium or magnesium and phosphorus, but only twice normal in calves fed high magnesium and calcium. High dietary magnesium resulted in a significant depression in blood calcium level. This effect was somewhat overcome by additional dietary calcium Three calves fed the high magnesium diet and two calves fed the high magnesium and phosphorus diet developed urinary tract obstruction. The chemical composition of uroliths recovered from these calves was calcium apatite. Elevated dietary magnesium has been shown to be a cause of urolithiasis in growing male calves. Additional dietary calcium, but not phosphorus, appears to protect calves against urolithiasis induced by elevated dietary magnesium.     

Conglutinin and immunoconglutinin titers in stressed calves in a feedlot

OBJECTIVE: To determine whether increased conglutinin titers are evident in stressed calves that do not develop respiratory tract disease in feedlots, compared with respiratory tract disease, and to determine the increase in immunoconglutinin titers. ANIMALS: 101 mixed-breed beef calves. PROCEDURE: Calves were processed at 4 farms of origin and allowed to remain with their dams for another 100 days. Calves from each farm were brought to a centrally located order-buyer barn. In a feedlot, 101 calves were assigned to pens and observed daily for clinical signs of acute respiratory tract disease. When sick calves were detected, they were treated with antibiotics and isolated in a pen for 4 days. Conglutinin and immunoconglutinin titers were determined for all calves. RESULTS: During the 28-day study, 73 calves developed respiratory tract disease, whereas 28 calves remained healthy. Mean conglutinin titers differed significantly among calves from the 4 farms. Significant differences were not detected in conglutinin titers among calves on the basis of sex, morbidity, or vaccination status against Mannheimia haemolytica at each farm, the order-buyer barn, or the feedlot on days 8, 15, and 28 after arrival. Immunoconglutinin titers in calves differed significantly among farms and morbidity status. CONCLUSIONS AND CLINICAL RELEVANCE: Mean conglutinin titers in calves do not appear to be associated with the incidence of acute respiratory tract disease; however, increased immunoconglutinin titers appear to be associated with recovery of stressed calves from respiratory tract disease during the first 15 days after arrival in a feedlot.     

Effects of preconditioning on pre- and post-shipment performance of feeder calves

A preconditioning (PC) program that involved preweaning vaccination and preshipment weaning was evaluated utilizing 600 calves produced on four South Dakota ranches. Nonpreconditioned (NPC) controls were herd mates that were maintained with their dams during the preconditioning process. All calves were shipped from the ranch to the feedlot on the same date. In Exp. I, PC caused lower (P less than .001) preshipment gains. However, management x ranch and management x year effects indicated that response to PC was variable. Preconditioning reduced (P less than .001) transit shrink in Exp. I but caused greater (P less than .05) shrink in Exp. II. Ranch and management x ranch effects accounted for more of the variation in shrink than PC did. In the feedlot, PC calves consumed more feed initially (d 1 to 28; P less than .001) and during the entire (P less than .10) feeding period when fed to slaughter condition. During the 28-d postshipment period, calves fed higher-grain diets consumed more feed (P less than .001) and were less efficient (P less than .001) than calves fed corn silage. When fed for longer periods (greater than 28 d), higher-energy diets improved feedlot gains and feed efficiency independent of preconditioning. Health and performance responses to this preconditioning procedure were variable. Our preconditioning procedure did not improve beef production efficiency.