Control Calves Research Articles

Effects of intra-articular inoculation with Mycoplasma bovis on immunological responses in calf joints

Mycoplasma arthritis that caused by Mycoplasma bovis exhibit severe lameness. This disease is difficult to cure with antibiotics, but the detailed pathological mechanisms have not been fully clarified. In this study, we examined the effects of intra-articular inoculation with M. bovis on immunological responses in calf joints. We inoculated three calves each with M. bovis or phosphate buffer saline (control) into the right stifle joint and dissected them at 15 days postinoculation. Mycoplasma bovis–inoculated calves exhibited swelling of the stifle joint, increases in synovial fluid, fibrin deposition, and cartilage thinning. Intracellular M. bovis was detected in synovial tissues analyzed by immunohistochemistry and transmission electron microscopy. Messenger RNA expressions of interleukin (IL)-1β, IL-6, IL-8, IL-12p40, and IL-17A in synovial fluid cells and synovial tissues from M. bovis–inoculated calves were significantly higher than those from control calves. Protein levels of these cytokines in synovial fluid from M. bovis–inoculated calves were markedly higher than those from control calves. Our study clarified that inoculation with M. bovis into the stifle joint induced the production of inflammatory cytokines by synovial fluid cells and synovial tissues, causing a severe inflammatory response in joints. Additionally, M. bovis could invade cells in synovial tissues, which may have aided it in evading antibiotics and host immune surveillance.

A Field Study Evaluating Humoral Immunity in Calves Vaccinated with Multivalent Bovine Respiratory Pathogen Vaccines

Abstract Bovine Respiratory Syncytial Virus (BRSV), Bovine Parainfluenza 3 (BPI3) and Mannheimia haemolytica (Mh) are major respiratory pathogens in the bovine respiratory disease complex. It is important to optimize passive and active immunity to these pathogens early in life to reduce clinical and subclinical productivity losses. The administration of inactivated, adjuvanted and multivalent vaccines, such as Bovilis® Bovipast RSP (Bovipast), and Bovalto® Respi 3 (Bovalto) to calves, may enhance cellular and humoral immunity against BRSV, BPI3 and Mh. A field trial evaluated the immune responses to these three agents in the first year of life in 12 Bovipast and 13 Bovalto vaccinated calves, and 5 negative control calves. Calves were vaccinated starting at 2 weeks of age and revaccinated 4 weeks later (primo vaccination). A booster vaccination was given at approximately 10 months of age. Serum samples were taken at time intervals up to 6 months after primo vaccination and up to 1 month after the booster vaccination. BRSV serum titres were evaluated using a serum neutralisation assay (SN), and BRSV, BPI3 and Mh titres were evaluated using a commercial enzyme linked immunosorbent assay (ELISA) test. Serum antibodies after primo and booster vaccinations in the individual calves were evaluated by calculating the areas under the curve (AUC) of the Log2 transformed BRSV SN titres and the optic density measures of the ELISA tests for BRSV, BPI3 and Mh. Multivariate general linear models were used to evaluate the influence of the vaccination on the AUC of the serum measures within 6 months after the primo vaccination. Similarly, models evaluated the AUC of the serum measures after the booster vaccination. The Bovipast vaccinated calves had significantly higher SN and ELISA titres AUC following the primo vaccination and booster vaccinations compared to the negative control calves and the Bovalto vaccinated calves. The Bovalto vaccinated calves did not have a significantly different BRSV SN and ELISA titres AUC response after the primo or booster vaccinations compared to the negative control calves. The serum antibody responses to BPI3 and Mh in the vaccinated calves were less pronounced than the Bovipast BRSV antibody response. Bovipast and Boval- to vaccinated calves mounted a significantly higher AUC ELISA OD for both BPI3 and Mh and the highest AUC was measured in the Bovipast vaccinated calves. This study indicated that early vaccinations of calves with multivalent adjuvanted inactivated BRD vaccines, such as Bovilis® Bovipast RSP can elicit a humoral response with a cellular-mediated memory effect as indicated by the booster vaccination.

Holstein Friesian dairy cattle edited for diluted coat color as a potential adaptation to climate change

BackgroundHigh-producing Holstein Friesian dairy cattle have a characteristic black and white coat, often with large proportions of black. Compared to a light coat color, black absorbs more solar radiation which is a contributing factor to heat stress in cattle. To better adapt dairy cattle to rapidly warming climates, we aimed to lighten their coat color by genome editing.ResultsUsing gRNA/Cas9-mediated editing, we introduced a three bp deletion in the pre-melanosomal protein 17 gene (PMEL) proposed as causative variant for the semi-dominant color dilution phenotype observed in Galloway and Highland cattle. Calves generated from cells with homozygous edits revealed a strong color dilution effect. Instead of the characteristic black and white markings of control calves generated from unedited cells, the edited calves displayed a novel grey and white coat pattern.ConclusionThis, for the first time, verified the causative nature of the PMEL mutation for diluting the black coat color in cattle. Although only one of the calves was healthy at birth and later succumbed to a naval infection, the study showed the feasibility of generating such edited animals with the possibility to dissect the effects of the introgressed edit and other interfering allelic variants that might exist in individual cattle and accurately determine the impact of only the three bp change.

Feeding fennel (Foeniculum vulgare) seed as a potential appetite stimulant for Holstein dairy calves: Effects on growth performance and health

This experiment was conducted to determine the effect of increasing dietary doses of fennel seed powder (FSP) on growth performance and health status in calves. Holstein calves (n = 48; 3 d of age; 36.3 ± 1.06 kg BW; mean ± SE) were allocated randomly to diets containing 0 (FSP0), 1.5 (FSP1.5), or 3 g/d (FSP3) FSP in milk (morning feeding; during the first month) and then in the starter feed (top-dressed; from d 31 until weaning on d 71). The calves remained in the trial until d 81. Weight gain and final BW were greater in FSP-supplemented calves compared with control calves. Heart girth and hip width gained more in FSP-supplemented calves compared with control calves. Body weight gain and frame growth were not affected by calf sex. The calves receiving FSP had a lower chance of having elevated rectal temperature (≥39.4°C) and a lower probability of suffering from diarrhea or pneumonia. The chance of having diarrhea, but not pneumonia, was greater in female calves. The chance of medication occurrence for diarrhea and pneumonia was not affected by FSP and calf sex. The FSP3 calves had shorter days with elevated rectal temperature (≥39.4°C) compared with the FSP1.5 (1.2 d; SEM = 0.10) and FSP0 (2.9 d; SEM = 0.10) calves. Days with diarrhea but not its frequency and medication days was shorter (4 d; SEM = 0.10) in the FSP-supplemented calves. Control calves experienced more days with pneumonia compared with calves fed FSP1.5 (3.1 d; SEM = 0.08) and FSP3 (5.4 d; SEM = 0.08). Calves fed FSP3 experienced shorter days (2.3 d; SEM = 0.08) with pneumonia compared with calves fed FSP1.5. Feeding FSP tended to decrease (1.6 d; SEM = 0.10) medication days for pneumonia compared with control group. The duration (2.2 d; SEM = 0.10) and medication days (1.3 d; SEM = 0.15) for diarrhea were higher in female calves compared with the male calves. Compared with the control calves, feeding 3 g/d of FSP may be more beneficial in improving the weight gain and skeletal growth (heart girth and hip width) and in reducing the susceptibility to and duration of diarrhea and pneumonia in dairy calves.

Feeding Saccharomyces cerevisiae fermentation products lessens the severity of a viral-bacterial coinfection in preweaned calves.

We have previously reported that supplementation with Saccharomyces cerevisiae fermentation products (SCFP) ameliorates clinical signs and lung pathology following experimental bovine respiratory syncytial virus (BRSV) infection in preweaned dairy calves. The objectives of this study were to determine the effect of SCFP supplementation on the metabolic and endocrine responses, and disease outcome of a viral–bacterial coinfection in preweaned calves. Twenty-seven, 1- to 2-d-old Holstein-Angus cross calves were enrolled in the study; one SCFP calf was removed from the trial during the pre-challenge phase due to complications from nephritis. Calves were assigned to two treatment groups: control or SCFP-treated, base milk replacer with 1 g/d SCFP (Smartcare, soluble formula) and calf starter top dressed with 5 g/d SCFP (NutriTek, insoluble formula). Calves were infected with BRSV on day 21, followed 6 d later by intratracheal inoculation with Pasteurella multocida (PM). Calves were euthanized on day 10 post-viral infection. Calves receiving SCFP had reduced thoracic ultrasonography scores on day 7 post-viral infection (P = 0.03) and a tendency toward reduced scores on day 10 post-viral infection (P = 0.09). Calves receiving SCFP also had less severe lung pathology scores at necropsy (P = 0.06). No differences between treatments were observed in lung viral loads (P = 0.48) or bacterial lung recovery (P = 0.34); however, there was a distinction in the lung location for PM recovery, with PM isolated more frequently from the cranial lobes in SCFP-treated calves, but more frequently from the caudal lobes of control calves. Calves treated with SCFP tended (P = 0.07) to have higher serum IL-6 concentrations following the coinfection. Calves treated with SCFP had lower concentrations of serum nonesterified fatty acids and beta-hydroxybutyric acid compared with controls following experimental challenge (P = 0.03 and P = 0.08, respectively), suggesting metabolic changes favoring growth and development. There were no differences between groups in gene expression of insulin receptor, insulin-like growth factor 1 (IGF-1), IGF-1 receptor (IGF-1R), growth hormone receptor, or haptoglobin in the liver. Results from this study suggest that supplementing with SCFP may moderate the impact of a respiratory viral–bacterial coinfection on preweaned calves through metabolic and immune modifications.

60 The Effect of Neomycin Inclusion in Milk Replacer on Gut Health and Development in Preweaned Male Holstein Calves

Abstract Neomycin is commonly used in calf milk replacers (MR) to prevent diarrhea, however, antimicrobial exposure in early life may have consequences to gut development. The objective of this study was to investigate the effects of neomycin inclusion in MR on calf gut health and development. Thirty-six calves were randomly assigned to one of three treatments: control (CON), non-medicated (MR, n = 12), short-term antimicrobial exposure (ST: 20 mg/kg BW neomycin mixed in MR from d 1–14, n = 12), or long-term antimicrobial exposure (LT: 20 mg/kg BW neomycin in MR from d 1–28, n = 12). Fecal samples were collected weekly to measure total bacteria, and gut permeability was measured in week 2 and 4 by comparing serum recovery of orally dosed lactulose and D-mannitol markers. Calves were dissected at week 5 to collect intestinal tissues, which were used to analyze histology, gene expression and total bacteria abundance. Digesta samples were collected to analyze for total bacteria abundance and volatile fatty acid (VFA) concentrations. No treatment effects were found in the amounts of total bacteria in fecal, digesta, or tissue samples. Marker recovery in serum was higher at week 2 compared to week 4 (P < 0.01), suggesting that calves in early life have higher gut permeability. Histomorphological measures were similar, except for villi length in the distal jejunum, which was longest in ST calves (P = 0.05). Tight-junction, mucus, and inflammatory-associated gene expression was similar overall, although the expression of Tight junction protein-1 in the distal jejunum was lowest in CON calves (P = 0.04). Distal jejunum acetic acid, propionic acid, and total VFA tended to be highest in LT calves (P = 0.09; P = 0.06; P = 0.07, respectively). Although this study found few consequences of neomycin to gut health, the lack of benefits supports the argument that antimicrobials should be used prudently.

268 Growth Performance of Weaned Angus Bulls Housed in a Compost-bedded Pack Barn

Abstract Compost-bedded pack barns (CBP) are commonly utilized in dairy cattle operations across the United States. Their popularity is the result of improved animal welfare and reduced costs. The crossover of CBP into the beef cattle industry is new and the benefits and downfalls are not yet explored. Through a grant from NRCS, a CBP was built at the Morehead State University Derrickson Agricultural Complex in 2019–2020. In fall of 2020, the pack was established by mixing manure and sawdust shavings to start the aerobic composting process. The objective of our study was to determine the performance of growing bulls utilizing a CBP compared to a fully outdoor pasture housing system and measure the pack development. Growth data from 2 consecutive years of growing bulls were utilized, with calves born in 2019 being used as a control (CON) group and calves born in 2020 being used as the CBP group. Adjusted weaning and yearling weights reported to the American Angus Association were utilized to measure growth performance. Heifers born in both years were also evaluated as an outside standardization mechanism to eliminate genetic bias. Temperature measurements, surface and internal, were collected 3 times weekly to measure pack establishment. Weaning weights for CON and CBP bulls were similar (P = 0.45), though interestingly the corresponding heifer calves weaned with CBP bulls were heavier (P < 0.01) than those weaned with the CON bulls. Bulls housed in the CBP were significantly heavier (P < 0.01) as yearlings compared to the CON bulls (496 kg vs. 425 kg, respectively). Temperature differed (P < 0.02) between day, side of the barn, and measurement location. Our results suggest that utilizing a compost bedded pack barn during the winter growing phase may be beneficial to the producer by increasing growth potential of weaned calves.

PSXV-22 Effect of inclusion of dried citrus pulp in the receiving supplement for newly received stocker cattle

Abstract Citrus pulp is a source of flavonoids which have been found to have antioxidant properties. Thus, the objective of this experiment was to investigate the effects of feeding dried citrus pulp on performance of newly received calves. Crossbred beef heifers (n = 254, initial body weight = 248 ± 5.9 kg) were obtained on 3 dates (block, 8 pens/block). Treatments were: 1) a corn and distillers’ grains based receiving supplement (control) or 2) a receiving supplement that contained 20% dried citrus pulp (replacing a portion of the corn). Upon arrival from regional livestock markets, cattle had access to hay and water and rested overnight then were processed the next day in which they received an identification tag, were vaccinated with a clostridial and a 5-way modified live bovine respiratory viral, dewormed, weighed, branded, and ear notched for detection of persistent infection with bovine viral diarrhea virus. Each truckload was assigned randomly to pens resulting in 8 pens with 9 to 12 heifers/pen. Pens were assigned randomly to 1 of the 2 treatments. Cattle were offered bermudagrass hay and water for ad libitum intake and were offered up to 1.8 kg/day of their appropriate receiving supplement. Overall average daily gain for the 42-day receiving period was increased (P < 0.01) for calves fed the supplement that included dried citrus pulp (1.01 kg/day) compared to the calves fed the control supplement (0.90 kg/day). However, the percentage of calves treated for clinical bovine respiratory disease was increased (P < 0.05) for calves fed the citrus pulp containing supplement (14% morbidity) compared to control calves (7% morbidity). The supplementation of dried citrus pulp to calves improved growth performance, but did not reduce the incidence of clinical bovine respiratory disease during the receiving period; however, clinical morbidity was low for both treatments.

Choline acts during preimplantation development of the bovine embryo to program postnatal growth and alter muscle DNA methylation.

The preimplantation period of embryonic development can be a key window for programming of postnatal development because extensive epigenetic remodeling occurs during this time. It was hypothesized that modification of one-carbon metabolism of the bovine embryo by addition of the methyl-donor choline to culture medium would change postnatal phenotype through epigenetic modification. Embryos produced in vitro were cultured with 1.8mM choline chloride or control medium. Blastocysts were transferred into females and pregnancy outcomes and postnatal phenotype of the resultant calves determined. Exposure of embryos to choline increased gestation length and calf birth weight. Calves derived from choline-treated embryos were also heavier at weaning and had increased ratio of body weight to hip height than control calves. Choline altered muscle DNA methylation of calves 4 months after birth. A total of 670 of the 8149 CpG examined were differentially methylated, with the predominant effect of choline being hypomethylation. Among the genes associated with differentially methylated CpG were ribosomal RNAs and genes in AMPK, mTOR, integrin, and BEX2 canonical pathways and cellular functions involved in growth and proliferation. Results demonstrate that provision of the methyl-donor choline to the preimplantation embryo can alter its developmental program to increase gestation length, birth weight, and weaning weight and cause postnatal changes in muscle DNA methylation including those associated with genes related to anabolic processes and cellular growth. The importance of the nutritional status of the embryo with respect to one-carbon metabolism for ensuring health and well-being after birth is emphasized by these observations.

Effect of Methane Inhibitors on Ruminal Microbiota During Early Life and Its Relationship With Ruminal Metabolism and Growth in Calves

The present study aimed to determine whether dietary supplementation with methanogen inhibitors during early life may lead to an imprint on the rumen microbial community and change the rumen function and performance of calves to 49-weeks of rearing. Twenty-four 4-day-old Friesian x Jersey cross calves were randomly assigned into a control and a treatment group. Treated calves were fed a combination of chloroform (CF) and 9,10-anthraquinone (AQ) in the solid diets during the first 12 weeks of rearing. Afterward, calves were grouped by treatments until week 14, and then managed as a single group on pasture. Solid diets and water were offered ad libitum. Methane measurements, and sample collections for rumen metabolite and microbial community composition were carried out at the end of weeks 2, 4, 6, 8, 10, 14, 24 and 49. Animal growth and dry matter intake (DMI) were regularly monitored over the duration of the experiment. Methane emissions decreased up to 90% whilst hydrogen emissions increased in treated compared to control calves, but only for up to 2 weeks after treatment cessation. The near complete methane inhibition did not affect calves’ DMI and growth. The acetate:propionate ratio decreased in treated compared to control calves during the first 14 weeks but was similar at weeks 24 and 49. The proportions of Methanobrevibacter and Methanosphaera decreased in treated compared to control calves during the first 14 weeks; however, at week 24 and 49 the archaea community was similar between groups. Bacterial proportions at the phylum level and the abundant bacterial genera were similar between treatment groups. In summary, methane inhibition increased hydrogen emissions, altered the methanogen community and changed the rumen metabolite profile without major effects on the bacterial community composition. This indicated that the main response of the bacterial community was not a change in composition but rather a change in metabolic pathways. Furthermore, once methane inhibition ceased the methanogen community, rumen metabolites and hydrogen emissions became similar between treatment groups, indicating that perhaps using the treatments tested in this study, it is not possible to imprint a low methane microbiota into the rumen in the solid feed of pre-weaned calves.

Brief Report: Case Comparison of Therapy With the Histone Deacetylase Inhibitor Vorinostat in a Neonatal Calf Model of Pulmonary Hypertension.

Pulmonary hypertension (PH) is an incurable condition in humans; driven by pulmonary vascular remodeling partially mediated by epigenetic mechanisms; and leading to right ventricular hypertrophy, failure, and death. We hypothesized that targeting chromatin-modifying histone deacetylases may provide benefit. In this Brief Report we describe case comparison studies using the histone deacetylase inhibitor vorinostat (suberanilohydroxamic acid, 5 mg/kg/day for the first 5 study days) in an established model of severe neonatal bovine PH induced by 14 days of environmental hypoxia. Echocardiographic, hemodynamic, and pharmacokinetic data were obtained in hypoxia-exposed (one each, vorinostat-treated vs. untreated) and normoxic vorinostat-treated control animals (n = 2). Echocardiography detected PH changes by day 4 and severe PH over 14 days of continued hypoxic exposure. RV dysfunction at day 4 was less severe in vorinostat-treated compared to untreated hypoxic calves. Cardioprotective effects were partially maintained following cessation of treatment through the duration of hypoxic exposure, accompanied by hemodynamic evidence suggestive of reduced pulmonary vascular stiffening, and modulated expression of HDAC1 protein and genes involved in RV and pulmonary vascular remodeling and pathological RV hypertrophy. Control calves did not develop PH, nor show adverse cardiac or clinical effects. These results provide novel translation of epigenetic-directed therapy to a large animal severe PH model that recapitulates important features of human disease.

Feeding milk supplemented with Ulva sp., Ascophyllum nodosum, or Saccharina latissima to preweaning dairy calves: Effects on growth, gut microbiota, gut histomorphology, and short-chain fatty acids in digesta

Emerging knowledge shows the importance of preweaning nutrition on programming the gastrointestinal microbiome and development of the gut barrier function. The aim of this study was to assess the effects of supplementing cow milk with either intact dried Ulva sp., Ascophyllum nodosum, or Saccharina latissima on growth performance and several gut health parameters of preweaning dairy calves. Forty male Holstein calves were selected based on birth weight (41 ± 4 kg) and plasma Brix percentage (≥8.7%) at d 2 of life. From d 2 to d 42 of life, the control calves (n = 10) were fed with cow milk (8 L/d) without seaweed supplementation, and the experimental calves were fed with cow milk (8 L/d) supplemented with either Ulva sp. (n = 10), A. nodosum (n = 10), or S. latissima (n = 10) at a concentration of 50 g/8 L of cow milk per day (i.e., 5% on a dry matter basis). Calves were weighed every week, and body weight gain and calf starter intake were monitored weekly. At d 42 ± 3 of life, calves were slaughtered. The organ weights and digesta pH from the reticulorumen, mid- and end small intestine, and mid-colon were recorded. A tissue sample (5 cm) collected from the mid-small intestine was analyzed for histomorphology. Digesta from the mid-small intestine and mid-colon were analyzed for lactobacilli, Escherichia coli, and Enterobacteriaceae, and short-chain fatty acid profile. Weight gain of the calves was not affected by seaweed supplementation. Proportional organ weights were not affected by seaweed supplementation except for reticulorumen weight, which was higher in calves fed Ulva sp. Both the mid-small intestinal and mid-colonic digesta populations of lactobacilli, Enterobacteriaceae, and E. coli, as well as the mid-small intestinal histomorphology in seaweed-supplemented calves were not different from control calves. However, acetic acid proportion in mid-colonic digesta was increased in calves fed Ulva sp. and A. nodosum, whereas butyric acid proportion was decreased compared with the control calves. Digesta pH in mid- and end small intestine and mid-colon were not affected, whereas ruminal pH was increased in calves fed Ulva sp. compared with the control calves. In conclusion, intact dried seaweed supplementation did not improve the growth or selected gut health parameters (i.e., histomorphology, digesta pH, bacteria, and short-chain fatty acids) in preweaning Holstein calves.

Protection against Mycoplasma bovis infection in calves following intranasal vaccination with modified-live Mannheimia haemolytica expressing Mycoplasma antigens

Novel live vaccine strains of Mannheimia haemolytica serotypes (St)1 and St6, expressing and secreting inactive yet immunogenic leukotoxin (leukotoxoid) fused to antigenic domains of Mycoplasma bovis Elongation Factor Tu (EFTu) and Heat shock protein (Hsp) 70 were constructed and tested for efficacy in cattle. Control calves were administered an intranasal mixture of M. haemolytica St1 and St6 mutants (ΔlktCAV4) expressing and secreting leukotoxoid while vaccinated calves were administered an intranasal mixture of like M. haemolytica St1 and St6 leukotoxoid mutants coupled to M. bovis antigens (EFTu-Hsp70-ΔlktCAV4). Both M. haemolytica strains were recovered from palatine tonsils up to 34 days post intranasal exposure. On day 35 all calves were exposed to bovine herpes virus-1, four days later lung challenged with virulent M. bovis, then euthanized up to 20 days post-challenge. Results showed all cattle produced systemic antibody responses against M. haemolytica. The vaccinates also produced systemic antibody responses to M. bovis antigen, and concurrent reductions in temperatures, middle ear infections, joint infection and lung lesions versus the control group. Notably, dramatically decreased lung loads of M. bovis were detected in the vaccinated cattle. These observations indicate that the attenuated M. haemolytica vaccine strains expressing Mycoplasma antigens can control M. bovis infection and disease symptoms in a controlled setting.

Effect of Supplementation of Seaweed Formulations on Haematological, Blood Biochemical Parameters and Immune Response of Crossbred Calves

Background: Seaweeds are rich in complex carbohydrates, proteins and low molecular weight nitrogenous compounds, lipids, organic minerals, vitamins and pigments. The aim of the study is to evaluate the effect of supplementation of seaweed formulations on haematological, blood biochemical parameters and immune response of crossbred calves. Methods: A total of 18 male crossbred calves (130±7.56 kg live weight) were divided into 3 groups of 6 each based on complete randomized design. Calves in control (T0) was fed on standard diet, while treatment groups: T1 and T2 were supplemented with AF-KWP or AFRD-5 at the rate of 4% of concentrate mixture with 1% calcium carbonate and 1% dicalcium phosphate replacing mineral mixture and common salt offered in T0. The experiment was conducted for a period of 240 days. Blood was collected from each calf on 0, 100 and 200 days of experimental periods. Result: Concentration of Hb, PCV and RBC count was significantly higher in T1 and T2. Supplementation of seaweed increased significantly (P less than 0.001) the lymphocytes to neutrophil ratio. Serum total protein, albumin (A), globulin (G) and A:G ratio were comparable. Humoral immune response was significantly higher (P less than 0.001) in T1 and T2. Study concluded that supplementation of seaweed formulations of T1 and T2 improved erythropoiesis, alleviate stress and increased humoral immune responses in crossbred calves and recommend as replacement to mineral mixture and common salt.

Clinical and Ultrasonographic Studies in Bovine Respiratory Disease (BRD) Affected Calves

Bovine Respiratory Diseases (BRD) are one of the most common and important disease problem affecting newborn calves. The aim of this study was to use clinical respiratory score and thoracic ultrasonography as a screening method for the diagnosis of BRD in newborn calves. This study was carried out on 59 newborn calves in the Al-salhia farm for investment in Alsharqia Governorate, Egypt. These calves were divided into two groups. The first group (G1) including 16 healthy control calves and the second group (G2) including 43 newborn calves suffered from respiratory disorders. The most prominent clinical finding in BRD-affected calves was fever, nasal and ocular discharge, coughing with abnormal tracheal and lung sounds. According to the ultrasonographic examination of the lung, the lower respiratory tract disorders classified lesion into lobar pneumonia 12 calves (35.3%), lobular pneumonia 16 calves (47.1%), mixed pneumonia 3 calves (8.82%) in addition to lung abscess 3 calves (8.82%). Clinical respiratory score and thoracic ultrasound score showed a highly significant increase in BRD affected calves, meanwhile, CRS showed a non-significant change in calves suffered from upper and lower respiratory tract disorders. TUS revealed a non-significant change in calves with lobar and mixed pneumonia and in lung abscess, in addition to a significant increase in calves with lobar pneumonia when compared with lobular pneumonia. BRD affected calves had CRS ≥ five meanwhile calves with TUS ≥ two were considered sick.

Merozoites of Theileria orientalis buffeli reduce the parasitaemia of T. orientalis ikeda following tick challenge

Theileria orientalis is a tick-borne protozoal parasite causing anaemia and death in susceptible cattle. This investigation aimed to confirm whether immunisation with the “benign” buffeli genotype of T. orientalis could reduce the parasitaemia of the virulent ikeda genotype. Calves were inoculated intravenously or subcutaneously with bovine blood containing merozoites of T. orientalis buffeli and when recipients became positive by PCR, they and control calves were challenged with unfed nymphs of Haemaphysalis longicornis ticks infected as larvae with T. orientalis ikeda. All calves became positive for the challenge within 12 days after tick application. In the immunised calves, the first wave of parasitaemia with T. orientalis ikeda from 4 to 6 weeks was reduced significantly by >80 % before the parasite burden declined into the carrier state by 9 weeks. The parasitaemias in two calves which exhibited low infections with T. orientalis ikeda shortly after arrival, were also significantly reduced after tick challenge. The results confirm the previous studies on immunity to T. sergenti in Japan, and field experience with theileriosis in endemic zones where the carrier state appears to prevent clinical disease despite repeated, seasonal tick infestations with virulent genotypes of the parasite. This method offers a means to reduce the severity of the first wave of theilerial parasitaemia after tick challenge and possibly recover associated production losses.

Evaluation of the Efficacy of BCG in Protecting Against Contact Challenge With Bovine Tuberculosis in Holstein-Friesian and Zebu Crossbred Calves in Ethiopia.

Bovine tuberculosis (bTB) is prevalent in intensive dairy farms in Ethiopia. Vaccination could be an alternative control approach given the socio-economic challenges of a test-and-slaughter control strategy. The efficacy of the BCG was evaluated on 40 Holstein-Friesian (HF) and zebu crossbred calves recruited from single intradermal cervical comparative tuberculin (SICCT) test negative herds and randomly allocated into two groups. Twenty-two calves were vaccinated within 2 weeks of age, and 18 were kept as a control. Six weeks post-vaccination, the two groups were exposed and kept mixed with known SICCT test positive cows for 1 year. Immune responses were monitored by interferon gamma (IFN-γ) release assay (IGRA), SICCT test, and antibody assay. Vaccinated calves developed strong responses to the SICCT test at the sixth week post-vaccination, but did not respond to ESAT-6/CFP-10 peptide antigen-based IGRA. During the exposure, IFN-γ response to the specific peptide cocktail [F(2.44, 92.67) = 26.96; p < 0.001] and skin reaction to the specific proteins cocktail [F(1.7, 64.3); p < 0.001] increased progressively in both groups while their antibody responses were low. The prevalence of bTB was 88.9% (95% CI: 65.3–98.6) and 63.6% (95% CI: 40.7–83.8) in the control and vaccinated calves, respectively, based on Mycobacterium bovis isolation, giving a direct protective efficacy estimate of 28.4% (95% CI: −2.7 to 50.1). The proportion of vaccinated calves with lesion was 7.0% (34/484) against 11.4% (45/396) in control calves, representing a 38% (95% CI: 5.8–59.4) reduction of lesion prevalence. Besides, the severity of pathology was significantly lower (Mann–Whitney U-test, p < 0.05) in vaccinated (median score = 2.0, IQR = 0–4.75) than in control (median score = 5, IQR = 3.0–6.25) calves. Moreover, survival from M. bovis infection in vaccinated calves was significantly (log-rank test: χ2 = 6.749, p < 0.01) higher than that of the control calves. In conclusion, the efficacy of BCG was low, but the reduced frequency and severity of lesion in vaccinated calves could suggest its potential role in containing onward transmission.

Повышение эффективности выращивания телят в послемолочный период

Aim. To establish the effect of raising young cattle on whole milk, a substitute for whole and skimmed milk powder on its productivity and physiological state in the post-dairy period. Materials and Methods. The studies were conducted on three groups of young cattle of the first phase of cultivation, 10 heads each, at the age of 115 days with an initial live weight of 125.3-127.5 kg. Animals of all groups were given the same diet. During the dairy period, the calves of the control group received milk, a second and third substitute for whole milk and a substitute for skimmed milk powder. Classical and modern zootechnical, biochemical and mathematical methods of analysis were used in research. The digital material obtained in the course of the research was processed by the method of variation statistics, taking into account the Student's criterion of reliability and using the Microsoft Excel software package. Results. Taking into account the feed consumption in the scientific and economic experience showed that the consumption of silage-haylage mixture increased by 0.5-0.6 kg in the animals of the experimental groups. 1 kg of dry matter contained 10.47-10.56 MJ of exchange energy and 0.90-0.91 feed units, 13.4% of crude protein and 22.4-23.2% of fiber. Per 1 feed unit, 95.7-96.4 g of digestible protein was accounted for. As a result of the research, it was found that the majority of the blood parameters studied by us, reflecting the general physiological state of the body, in the compared groups were within the physiological norm. In the blood of animals of the II and III experimental groups, compared with control animals, there was an increase in the number of red blood cells by 10.0 and 9.8%, hemoglobin – by 5.8 and 3.9%, glucose – by 11.0 and 9.5%. The study of the growth dynamics of experimental animals during the experimental period of scientific and economic experience showed that the increase in the live weight of young animals of the experimental group was more intense than the control ones. At the same time, the average daily increase in live weight of control calves was 796.7 g, experimental calves-870.0 and 881.7 g, or increased by 9.2 and 10.7%. The increase in the growth energy of the bulls of the experimental group allowed to obtain an additional 4.4 and 5.1 kg of live weight per head during the experiment period. Based on the conducted studies, it was found that the cost of feed per kg of growth in the II and III experimental groups was lower than the control variant by 5.8 and 7.6%, and therefore the cost of growth in the experimental groups decreased by 6.1 and 7.7% compared to the control analogues, this allowed us to get additional profit per 1 head in the experimental groups in the amount of 8.35 and 10.58 rubles for the research period. Conclusion. The use of ZTSM and ZSOM in feeding young cattle at the age of 10-115 days provided an increase in the average daily increase in the post – dairy period by 9.2 and 10.7%, while reducing the cost of feed for obtaining an increase by 5.8 and 7.6%, the cost of growth-by 6.1 and 7.7 percent.

Feeding fennel (Foeniculum vulgare) seed as potential appetite stimulant to newborn Holstein dairy calves: Effects on meal pattern, ingestive behavior, oro-sensorial preference, and feed sorting

This trial was performed to investigate the effects of feeding graded levels of fennel seed powder (FSP) on nutrient intake, meal and rumination patterns, chewing and sorting behaviors in newborn Holstein dairy calves. Forty-eight calves (27 males and 21 females; n = 16 per treatment group; 3 d of age; 36.3 ± 1.06 kg of BW; mean ± SE) were assigned randomly to receive incremental levels of FSP at 0.0 (FSP0), 1.5 (FSP1.5) or 3.0 g/d (FSP3) in milk (morning feeding; during the first month of study period) and then in the starter feed (as top-dressed; from d 31 until weaning). Calves were weaned on d 71 and remained in the study until d 81. Starter feed dry matter (DM) intake increased linearly with increasing amount of FSP and increased and tended to increase in FSP3 and FSP1.5 as compared with FSP0, respectively. Growth rate increased linearly with increasing amount of FSP and was greater in FSP supplemented calves than in control calves. Overall body weight but not feed conversion ratio was greater in FSP supplemented calves compared with FSP0. Oro-sensorial preferences were greater in FSP supplemented calves and it was also greater in FSP3 compared with FSP1.5. Sorting index decreased linearly with increasing amount of FSP and decreased in FSP3 compared with FSP0 for particles retained on the 2.36, 1.18, and 0.6 mm sieves and tended to decrease in FSP1.5 compared to FSP0 for particles retained on the 2.36 and 1.18 mm sieves with significant difference for particles retained on the 0.6 mm sieve. Sorting index increased linearly with increasing amount of FSP and increased and tended to increase in FSP3 and FSP1.5 compared with FSP0 for feed materials retained on the bottom pan, respectively. Irrespective of the amount of FSP fed, all calves sorted for particles retained on all studied sieves and against feed materials on the bottom pan. Starter feed DM intake from particles retained on all studied sieves (except for 4.75 mm sieve) and feed materials retained on the bottom pan increased linearly with increasing amount of FSP and increased in FSP supplemented calves compared with control calves. Calves fed FSP initiated to eat their first solid feed in a shorter timeframe after starter feed provision with no changes in first meal duration among treatment groups. Despite of linear increase in eating rate and meal size in FSP supplemented calves, meal and rumination patterns and time devoted to eating, ruminating, resting, drinking, standing, and lying were not affected by treatment; however, non-nutritive oral behaviors were linearly decreased with increasing amount of FSP and decreased and tended to decrease in FSP3 and FSP1.5 compared with FSP0, respectively. In general, feeding FSP shortened time-delay to initiate first solid feed consumption by increasing oro-sensorial preference of the feed, increased feed intake through increases in the rate of eating and thereby the meal size, decreased non-nutritive oral behaviors without affecting chewing behavior, and improved growth performance.

The genomes of precision edited cloned calves show no evidence for off-target events or increased de novo mutagenesis

BackgroundAnimal health and welfare are at the forefront of public concern and the agricultural sector is responding by prioritising the selection of welfare-relevant traits in their breeding schemes. In some cases, welfare-enhancing traits such as horn-status (i.e., polled) or diluted coat colour, which could enhance heat tolerance, may not segregate in breeds of primary interest, highlighting gene-editing tools such as the CRISPR-Cas9 technology as an approach to rapidly introduce variation into these populations. A major limitation preventing the acceptance of CRISPR-Cas9 mediated gene-editing, however, is the potential for off-target mutagenesis, which has raised concerns about the safety and ultimate applicability of this technology. Here, we present a clone-based study design that has allowed a detailed investigation of off-target and de novo mutagenesis in a cattle line bearing edits in the PMEL gene for diluted coat-colour.ResultsNo off-target events were detected from high depth whole genome sequencing performed in precursor cell-lines and resultant calves cloned from those edited and non-edited cell lines. Long molecule sequencing at the edited site and plasmid-specific PCRs did not reveal structural variations and/or plasmid integration events in edited samples. Furthermore, an in-depth analysis of de novo mutations across the edited and non-edited cloned calves revealed that the mutation frequency and spectra were unaffected by editing status. Cells in culture, however, appeared to have a distinct mutation signature where de novo mutations were predominantly C > A mutations, and in cloned calves they were predominantly T > G mutations, deviating from the expected excess of C > T mutations.ConclusionsWe found no detectable CRISPR-Cas9 associated off-target mutations in the gene-edited cells or calves derived from the gene-edited cell line. Comparison of de novo mutation in two gene-edited calves and three non-edited control calves did not reveal a higher mutation load in any one group, gene-edited or control, beyond those anticipated from spontaneous mutagenesis. Cell culture and somatic cell nuclear transfer cloning processes contributed the major source of contrast in mutational profile between samples.