Calf Blood Research Articles

Effects of Boron Supplementation in Dairy Cow Close-Up Rations on Colostrum Quality and Certain Blood Metabolites in Calves.

In this study, we aimed to investigate the effects of different levels of boron supplementation to the diet during the close-up period and the first postpartum day on postpartum colostrum quality, immunoglobulin levels in colostrum, and certain calf blood parameters in dairy cattle (n = 21). Two experimental groups and one control (C) group were formed. Boron at 300ppm (T-300) and 600ppm (T-600) was added to the experimental rations. The daily dry matter intake (DMI), body condition score (BCS) of dairy cattle, and body weight (BW) of calves were recorded. Colostrum samples were collected during the first 2 postpartum milkings, and their components were determined. Blood samples were collected from calves at 24 and 48hours after colostrum feeding. The addition of boron to rations during the close-up dry period increased the DMI of cows and the BW of calves born to the T-600 group (p < 0.05). The addition of boron to the rations changed the total protein (TP) and nonesterified fatty acid (NEFA) values in the calf blood samples taken 48hours after birth from those of the control group (p < 0.05). The differences between the blood boron values of the experimental and control groups at 24 and 48hours after colostrum and colostrum feeding were significant (p < 0.05). At the first milking after birth, the colostrum DM value and density were highest in the T-600 group (p < 0.05). In conclusion, due to the high density value of colostrum according to the quality classification of colostrum in the first postpartum milking and the increase in calf blood IgG levels at 48 hours compared to the control group, it may be considered to add up to 600 ppm boron to the rations of cows close-up period in order to improve calf health and prevent calf losses due to colostrum quality.

PSVIII-9 Effects of growth implants and timing of vaccination on calf immunity and growth performance

Abstract This study assessed calf growth performance and blood parameters of beef calves under different growth implants and timing of vaccination protocols. Crossbreed beef calves (n = 59) were stratified by birth body weight (BW) and age (41 ± 5.2 kg of BW and 70 ± 8 d of age) and randomly assigned in a split-plot design with implant strategy as the main plot and timing of vaccination as the subplot. The main plot (treatment) consisted of 3 implant strategies: 1) Synovex C (SC; n = 20; 100 mg progesterone/10 mg estradiol benzoate, or 2) Synovex One Grower (SG; n = 19; 150 mg trenbolone acetate and 21 mg estradiol benzoate; or 3) no implant (CON; n = 20). Subplot treatments were the timing of vaccination booster against bovine respiratory disease pathogens on 1) weaning (WV; n = 29) or 2) 7-d post-weaning (PWV; n = 30). Cow-calf pairs were treated alike in a single pasture during the pre-weaning phase, receiving the same vaccine (Bovi-Shield Gold One Shot and Ultrabac 7) on d 0 (implantation day) and booster time (WV or PWV). After weaning (approximately 187 d of age), calves were allocated in a single pen receiving ad libitum hay until d 60 post-weaning. Body weight and blood were collected on d 0, weaning, d 0 and 28 relative to vaccination booster, and d 60 post-weaning. Blood was collected to determine insulin-like growth factor (IGF-1), cortisol, and leptin concentrations and to perform a complete blood cell count. WV calves had decreased cortisol concentrations on booster day and 28 d post-vaccine (P = 0.01). Regardless of implant treatment, calves tended to have decreased IGF-1 concentrations 28-d post-vaccine booster (P = 0.09). An effect of treatment (P &amp;lt; 0.01) was detected for lymphocyte counts, with CON having greater concentrations vs. SG and SC calves. A treatment × timing of vaccination (P &amp;lt; 0.01) interaction was detected for monocyte counts, where SG-PWV calves had the greatest concentrations. A treatment effect (P &amp;lt; 0.02) was observed for eosinophil percentage, where SG had reduced percentages than CON, while SC was intermediate. An effect of treatment was detected for leptin (P &amp;lt; 0.01), with SG calves having the least, CON being intermediate, and SC the greatest concentrations. From d 0 to 60 d post-weaning, SG tended to have greater ADG (P ≤ 0.07) compared with CON, while SC was intermediate. On d 28 and d 35 post-weaning, calves implanted with SG were heavier (P ≤ 0.04) than the CON but not than SC. In summary, this study demonstrates that growth implants and timing of vaccination significantly affect both physiological parameters and growth performance in beef calves. Implanting calves with Synovex One Grower resulted in improved growth performance.

363 Effects of supplementation of vitamin B complex on the performance of beef calves during a 42-d preconditioning program

Abstract The objective of this study was to evaluate the effects of supplementation of vitamin B complex on post-weaning performance of beef calves. The study was conducted during fall of 2023 at Eastern Oregon Agriculture Research Center (EOARC; Burns, OR). At weaning (d 0), 63 calves [Angus × Hereford; body weight (BW) = 252 ± 3.6 kg] were randomly assigned to 1 of 3 treatments: 1) Control, 2) VitB1, or 3) VitB2. Calves assigned to Control treatment served as a negative control and were not supplemented with vitamin B complex. Calves assigned to treatment VitB1 were supplemented at 1g/calf daily, while calves assigned to VitB2 treatment were supplemented at 2g/calf daily of vitamin B complex during the 42 d of preconditioning. Upon weaning processing, calves were allocated to 21 pens (3 calves/pen) and treatments were allocated to each pen (7 pens/treatment). Vitamin B complex [Vivalto, pantothenic acid (B5; 40,000 mg/kg), pyridoxine (B6; 20,000 mg/kg), folic acid (B9; 3,200 mg/kg), biotin (B7; 3,200,000 mcg/kg), cobalamin (B12; 320,000 mcg/kg); Selko USA, Indianapolis, IN] supplementation was offered at pen level beginning on d 1 and until the end of the preconditioning phase (d 42). Vitamin B complex was offered to calves assigned to vitamin B complex treatment mixed with 1.3 kg of dried distiller’s grains. Additionally, calves had free access to chopped alfalfa-grass hay mix and whole corn. Pen intake was recorded daily. On d 0, BW and blood samples were collected from all calves. Additional blood and BW were collected on d 1, 3, 7, 14, 21, 42 post-weaning. Body weights were used to calculate calf average daily gain (ADG) and blood samples were assayed for acute phase proteins (ceruloplasmin and haptoglobin). Additional blood samples will be analyzed for cortisol and vitamin B concentrations. Variables were analyzed considering pen as the experimental unit and pen(treatment) as a random effect. Blood variables were evaluated as repeated measures and effects of treatment, day, and treatment the interactions were analyzed with the MIXED procedure of SAS (SAS Inst. Inc., Cary, NC). Significance was set at P ≤ 0.05. No treatment effects (P = 0.98) were observed for final BW (283, 283, and 284 kg respectively for Control, Vit1, and Vit2) or for ADG (P = 0.53; 0.735, 0.795, and 0.747 kg/d respectively for Control, Vit1, and Vit2). Similarly, no treatment effects were observed for the acute phase proteins analyzed, ceruloplasmin (P = 0.66; 27, 30, and 33 µg/dL respectively for Control, Vit1, and Vit2) and haptoglobin (P = 0.41; 0.55, 0.62, and 0.59 mg/mL, respectively for Control, Vit1, and Vit2). Supplementation of vitamin B complex to beef calves post-weaning does not seem to affect calf performance, regardless of the level of supplementation.

24 Maternal supplementation with different sources of trace minerals to beef cattle and its effects on postweaning responses of the offspring

Abstract The goal of this trial was to evaluate the effects of different sources of trace minerals on fetal programing and their impact on cow reproductive and postweaning offspring performance until slaughter. Seventy-two non-lactating, pregnant Angus cows [initial body weight (BW) = 637 ± 13 kg; body condition score (BCS) = 5.5 ± 0.07; and age = 6.1 ± 0.57; exposed to artificial insemination (AI) = 54 and bull = 18] were ranked by BW and BCS and assigned to receive a supplement containing: 1) Cu, Mn, and Zn from sulfate source (INR; n = 24), 2) Cu, Mn, and Zn from organic source (ORG; n = 24), or 3) Cu, Mn, and Zn from hydroxychloride source (HXD; n = 24). From d 0 to calving, cows remained on the same pasture and were fed individually three times a week. After calving, pairs were assigned to the general herd management, including inorganic mineral supplementation. Calves were weaned at 6 mo of age and were managed as a single group on a backgrounding period for 85 d. Calf blood samples were collected on d -15, 0, 4, 8, 15, 20, and 28 relative to weaning to evaluate stress-related markers. After this period, calves were fed to finish in a commercial feedyard. Cattle were then harvested, and carcass data were recorded. Though not the focus of this trial, there was a numerical improvement (P = 0.22) in overall subsequent pregnancy rate for the HDX (92.1%) compared with the ING (74.3%) and ORG (75.2%) cows. Also, the HDX had a tendency (P = 0.07) for improvement in liver Cu status compared with the other treatments. At weaning, no treatment differences were detected (P ≥ 0.88) in calf weaning BW and average daily gain from weaning to feedyard receiving. There were no differences (P ≥ 0.22) in the blood stress-related enzymes and metabolites. However, there was a tendency for a decrease in plasma haptoglobin at day 15 post-weaning (P = 0.07) for the calves from HDX supplemented cows relative to other treatments (Figure 1). Which might indicate potential amelioration of inflammation for the calves from cows supplemented with HDX trace minerals during pregnancy. Feedyard growth performance were similar (P ≥ 0.35) across treatments for the offspring (Table 1). No treatment effects were detected (P ≥ 0.17) for carcass traits between treatments (Table 2). Overall, different sources of trace minerals supplemented to late gestating beef cows yield similar effects on offspring performance from weaning and background period until slaughter, whereas a potential amelioration of inflammation was observed in calves born to HDX cows.

Evaluation of blood evacuation efficiency using 99m Tc-RBC imaging: a comparative study of exsanguination tourniquet rings and Esmarch bandages.

The objective of this study is to compare the effectiveness of the Esmarch bandage and exsanguination tourniquet rings (ETRs) in blood evacuation procedures using a controlled intra-subject design involving healthy volunteers. A total of 20 healthy adult volunteers (12 males, 8 females) were recruited from the community. Participants underwent blood evacuation procedures on both legs, using the Esmarch bandage on one leg and the ETR on the other. The order of the procedures was randomized. Blood evacuation time, overall blood evacuation rate, and calf blood evacuation rate were measured using 99m Tc-labeled red blood cell imaging. Paired t -tests were conducted to compare the effectiveness of the two methods. The ETRs demonstrated a significantly faster blood evacuation time compared to the Esmarch bandage (mean difference = -41.72 s, P < 0.0001). The overall blood evacuation rate was slightly higher for the ETRs (mean difference = 1.717%), though not statistically significant ( P = 0.3680). The calf blood evacuation rate was significantly higher for the ETRs (mean difference = 6.86%, P = 0.0225). No significant discomfort or adverse reactions were reported by any participants. ETRs are more efficient in terms of blood evacuation time and calf blood evacuation rate compared to the Esmarch bandage, without causing significant discomfort or adverse reactions. These findings suggest that ETRs could be a preferable option in clinical settings for blood evacuation procedures.

Injection of antioxidant trace minerals/vitamins into peripartum crossbred cows improves the nutritional and immunological properties of colostrum/milk and the health of their calves under heat stress conditions.

Multimineral and vitamin injections can provide better nutrient availability at the cellular level, which is essential for mitigating transition period stress and improving the wellbeing and productivity of dairy cows. The present study was conducted to assess the colostrum quality and calf health after intramuscular injection of multi-minerals (MM) and multi-vitamins (MV) to peripartum cows during winter (THI = 58 to 66) and summer (THI = 78 to 82) months. In each season, twenty-four pregnant crossbred Karan Fries cows were grouped into four, each consisting of six cows. Group I, referred to as the Control, received solely the basal diet, without any additional supplements. Groups II, III, and IV were administered additional MM (T1), MV (T2), and a combined MM and MV (T3) along with their basal diet, starting 30days before calving and continuing for 30days after calving. Blood samples were collected from the calves, while colostrum/milk samples were obtained from the cows on days 1, 3, 7, and 15 after calving. The somatic cell counts (SCC) in the milk were determined using a cell counter. Cortisol, IgG, IGF1 and total immunoglobulins (TIG) in whey and plasma from cow colostrum/milk or calf blood samples were estimated by ELISA. Cows that calved in the summer exhibited notably reduced levels (P < 0.05) of IgG, milk, and plasma IGF1, along with lower calf body weights, in comparison to those calving in the winter season. Furthermore, the summer months saw significant increases (P < 0.05) in plasma and milk cortisol levels, as well as total somatic cell counts (SCC) in both colostrum and milk samples. Maximum beneficial effect was observed in T3 group. Results indicate that injections to peripartum cows could be an important strategy for improving colostrum quality and calf health during the summer seasons.

Evaluating the Bias of Two Point-of-Care Glucometers for Calves and Ewes: Awareness for Ruminant Practitioners

(1) Background: Multiple point-of-care (POC) glucometers are in use in veterinary medicine, but few are compared to each other. This leaves the potential for clinicians to be unaware of the effect of bias when comparing results from different POC glucometers. (2) Methods: Samples from healthy calves and ewes were simultaneously compared with two POC veterinary glucometers, the Precision Xtra and the AlphaTrak2, under both the “canine” and “feline” settings. The results of each sample were statistically analyzed with linear regression and Bland–Altman analysis. (3) Results: 170 samples from healthy calves and 108 samples from healthy ewes were available for comparison. Calves: The AT2 consistently overestimated blood glucose concentrations when compared to the PX device with the calves. Correlationt with the PX was r = 0.8496 (canine setting) and r = 0.8861 (feline setting). Both the canine and feline settings demonstrated a consistent bias (41.11 and 33.64 mg/dL, respectively). Ewes: The AT2 consistently overestimated blood glucose concentrations when compared to the PX device with the ewes. Correlation with the PX was R = 0.4710 (canine setting) and R = 0.7269 (feline setting). Both the canine and feline settings demonstrated a consistent bias (21.23 and 14.54 mg/dL, respectively). (4) Clinicians should be aware of the potential for consistent bias when evaluating calf and sheep blood glucose concentrations as the AT2 device, at both settings, overestimated blood glucose compared to the previously validated PX. This reliability appears to change when the values are farther from the normal ranges, which should be considered when making clinical decisions based on data from these devices.

Study of the epithelial state of the oral mucosa in patients with recurrent aphthous stomatitis

Relevance. Recurrent aphthous stomatitis (RAS) is one of the most common diseases affecting the oral mucosa. It is characterized by the recurrent appearance of ulcers (aphthae) and a prolonged course with periodic exacerbations.Purpose. To study the condition of the oral mucosa epithelium in patients with recurrent aphthous stomatitis undergoing treatment with antiseptics and reparative agents.This study examined samples of buccal epithelium from 64 patients, who were randomly divided into two equal groups: the first group used chlorhexidine as a mouthwash (control group); the second group used octenidine + phenoxyethanol for 7 days. For pain relief, patients in both groups applied a gel containing lidocaine + chamomile extract. After 7 days, the therapy continued with reparative agents (a hydrogel-based material with sodium alginate, Derinat, and lidocaine, deproteinized calf blood extract, and sea buckthorn oil). Each group was further divided into three subgroups for this part of the therapy. The condition of the buccal epithelium was assessed three times: before treatment, on the 7th day, and on the 21st day of therapy. Buccal epithelium preparations were prepared and analyzed using standard methods.Results. The analysis of cytogenetic and karyological indicators of buccal epithelial cells in patients with CRAS revealed that, at the peak of the inflammatory process, cells with micronuclei and various forms of nuclear protrusions were more frequently observed. During therapy, there was a notable reduction in buccal epithelial cells exhibiting these pathological features.Conclusion. Before therapy, patients with RAS exhibited cytogenetic instability and various karyological anomalies in the buccal epithelial cells of the oral mucosa. These anomalies included significantly higher occurrences of micronuclei, karyopyknosis, karyolysis, nuclear vacuolization, intercellular bridges, and chromatin condensation. During the different therapy regimens for RAS, normalization of the epithelial state of the oral mucosa was observed, with the most pronounced improvements seen with the use of octenidine + phenoxyethanol in combination with a hydrogel-based material containing sodium alginate, Derinat, and lidocaine.

A pilot survey on knowledge, attitudes, and practices of smallholder dairy owners towards the importance of colostrum feeding to newborn calf in Humbo District of Wolaita Zone, Southern Ethiopia

BackgroundColostrum is the secretion produced by the mammary gland of mammals and it is passively transferred immunity that protects neonates from infectious diseases.MethodsA cross-sectional study was conducted from December 2021 to June 2022 to assess the community’s knowledge, attitude, and practice of smallholder dairy owners towards the importance of colostrum feeding to newborn calves in Humbo districts. A structured questionnaire was provided for 400 randomly selected smallholder dairy owners for face-to-face interviews.ResultsThe results showed that females (21.6%), college and university levels (20.2%), farmers (15.4%), and single individuals (17.6%) had better knowledge compared to the respective status of respondents on colostrum feeding practices. Also, there was an association between sex, occupation, marital status, and knowledge of colostrum-feeding practices. Similarly, 32.5% of respondents with an elementary background practice the separation of calves from the dam soon after birth to prevent transmission of infection. There was an association between the educational background of the respondents and the perception of the respondents regarding colostrum feeding to newborn calves. Nearly, 30% of respondents had an elementary education background waiting for their calf to get up on its own and suckle from their dam. Likewise, 26.1%, 31.5%, and 23.8% of illiterate, elementary, college, and university graduate respondents, respectively, provide calves with 10 to 12% of their birth weight as colostrum within the first 8 h of calf’s life. Besides, the majority of the respondents (27.5%) believed that colostrum was the best food for calves’ growth, and the level of circulating antibodies in the calf's blood has a direct influence on its disease resistance.ConclusionThe study revealed that smallholder dairy owners have different perceptions concerning knowledge, practice, and attitude on the importance and time of feeding colostrum to neonates during the early life of postpartum. Thus, awareness creation and training programs should be provided for smallholder dairy farmers as well as the use of colostrum feeding, and its role in the prevention of neonatal and preweaning calf mortality and morbidity.

Health-associated changes of the fecal microbiota in dairy heifer calves during the pre-weaning period.

Neonatal calf diarrhea is a multifactorial condition that occurs in early life when calves are particularly susceptible to enteric infection and dysbiosis of the gut microbiome. Good calf health is dependent on successful passive transfer of immunity from the dam through colostrum. There are limited studies on the developing gut microbiota from birth to weaning in calves. Therefore, the objective of this study was to examine the effect of immune status and diarrheal incidence on the development of the fecal microbiota in Jersey (n = 22) and Holstein (n = 29) heifer calves throughout the pre-weaning period. Calves were hand-fed a colostrum volume equivalent to 8.5% of their birthweight, from either the calf's dam (n = 28) or re-heated mixed colostrum (≤2 cows, ≤1d; n = 23) within 2 h of birth. All calves were clinically assessed using a modified Wisconsin-Madison calf health scoring system and rectal temperature at day (d) 0, d7, d21, or disease manifestation (DM) and weaning (d83). Weights were recorded at d0, d21, and d83. Calf blood samples were collected at d7 for the determination of calf serum IgG (sIgG). Fecal samples were obtained at d7, d21/DM [mean d22 (SE 0.70)], and at weaning for 16S rRNA amplicon sequencing of the fecal microbiota. Data were processed in R using DADA2; taxonomy was assigned using the SILVA database and further analyzed using Phyloseq and MaAsLin 2. Significant amplicon sequence variants (ASVs) and calf performance data underwent a Spearman rank-order correlation test. There was no effect (p > 0.05) of colostrum source or calf breed on serum total protein. An effect of calf breed (p < 0.05) was observed on sIgG concentrations such that Holstein calves had 6.49 (SE 2.99) mg/ml higher sIgG than Jersey calves. Colostrum source and calf breed had no effect (p > 0.05) on health status or the alpha diversity of the fecal microbiota. There was a relationship between health status and time interaction (p < 0.001), whereby alpha diversity increased with time; however, diarrheic calves had reduced microbial diversity at DM. No difference (p > 0.05) in beta diversity of the microbiota was detected at d7 or d83. At the genus level, 33 ASVs were associated (adj.p < 0.05) with health status over the pre-weaning period.

Serological Investigation of Bovine Enterovirus in Calves in Konya Province

Bovine enterovirus (BEV) infection is a common viral disease in cattle. Although the infection is often subclinical, it is among the possible causes of gastroenteritis. BEV infections have also been associated with respiratory and reproductive system disorders and signs of diarrhea. BEV is divided into two serotypes, enterovirus serotype E (EV-E) and enterovirus serotype F (EV-F). This study aims to determine the seroprevalence of EV-E in calves in Konya province. For this purpose, 504 BEV unvaccinated calf blood serum samples from the Selcuk University Veterinary Faculty Virology Department laboratory were used. A serum neutralization test (SNT) was used to determine EV-E seroprevalence. 342 (67.85%) samples were found to be seropositive, and 162 (32.14%) were seronegative. In addition, as the serum neutralization 50 (SN50) antibody titers of seropositive animals were examined, the titers determined as 1/10, 1/15 and 1/20. Among the results we obtained, the highest antibody titers were defined as 1/80 and 1/120; the total number of animals with these values was In conclusion, bovine enteroviruses are an infection of importance for cattle breeding. Therefore, necessary precautions must be taken to protection infection. It is thought that the results of the present study will provide important data for future studies.

Milk replacer feeding once or twice a day did not change the ruminal metabolomic profile and the microbial diversity of dairy calves from birth to weaning

In commercial dairy production systems, feeding calves once a day could be an alternative to reduce labor expenses. Several studies comparing once (OAD) versus twice (TAD) a day milk feeding systems have not evidenced differences in calf growth, rumen development, blood parameters or health scores, but impact on ruminal microbiota remains to be investigated. The objective of this study was to determine the effects of OAD or TAD on the establishment of the ruminal microbiota and its metabolic activity. Sixteen male calves (45.9 ± 5.7 kg at birth) were involved in the trial from birth to weaning (63 d). After the colostrum phase, 2 feeding programs based on a milk replacer were tested and calves were allocated to these programs on d 5. To study the establishment of the bacterial community, ruminal fluid was obtained from each calf one hour after the morning meal at 7 (d 7), 35 (d 35) and 63 (d 63) days of age. The ruminal metabolome was evaluated at a 7 d interval from d 1 to d 63. Ruminal microbiota and metabolite profiles were characterized by 16 S rRNA gene sequencing- and by H-NMR spectroscopy, respectively. Our results showed that feeding milk replacer once or twice a day did not change the ruminal microbiota and metabolites of dairy calves from birth to weaning. Microbial data showed that diversity and richness increased with age, suggesting a shift from an heterogeneous and less diverse community after birth (d 7) to a more diverse but homogeneous community at 35 and 63 d. These findings suggest that feeding milk once a day can be successfully applied to a calf feeding system without compromising microbial establishment and functions.

The effects of a nonsteroidal anti-inflammatory drug on the behavioural and physiological parameters of beef cows and calves assisted at calving

Non-steroidal anti-inflammatory drugs (NSAIDs) may be administered to the cow or the calf as a pain mitigation strategy to combat the negative impacts of injury or trauma associated with a difficult calving. However, the effects of NSAIDs on beef cows’ and calves’ behaviour related to pain and cow-calf bonding after an assisted calving have not been studied. Therefore, the objective of this study was to investigate the effects of meloxicam administered to beef cows and calves after an assisted calving by measuring differences in behaviours associated with pain and cow-calf bonding, and physiological parameters associated with pain. Twenty-three cow-calf pairs assisted at calving were randomly allocated to two medication groups, meloxicam (Metacam®, 20 mg/ml, 0.5 mg/kg body weight, Boehringer Ingelheim, Ingelheim, Germany) or placebo (0.025 ml/kg). Cow blood samples for serum haptoglobin concentration and thermal images of the vulva were taken within 10 minutes after calving and 24±1 hours after calving. Calf blood samples for L‐lactate concentration and thermal images of the head were taken at birth and images repeated at 24±1 hours after birth. Blood samples for serum IgG concentration were taken at 24±1 hours after birth. After at-birth sample collection and treatment administration, the cow-calf pairs were placed in separate box stalls, and behaviours were video recorded for 24±1 hours. A human approach test and a separation test were performed after the 24±1 hour period. Descriptive statistics, multivariable linear and logistic regression models, and non-parametric tests were used to analyze the data. There were no significant differences between meloxicam and placebo groups for serum IgG concentration, haptoglobin concentration, or changes in temperature in the cows’ vulva or calves’ head. Additionally, there were no significant differences between meloxicam and placebo groups for the cows’ behaviours (i.e., time spent lying in sternal recumbency, standing, feeding, self-grooming, grooming the calf, and frequency of tail flicking, tail raising, and pressing against the box stall). Calves treated with meloxicam were more active (P=0.04) and played more (P=0.01) than placebo calves. No other behaviours (i.e., time spent lying in sternal recumbency, attempting to stand, standing, walking, being in a nursing position, investigating, and frequency of approaching the cow) were significantly different between calves treated with meloxicam or placebo. No significant difference (P=0.83) in bonding behaviours was identified for cows and calves treated with meloxicam or a placebo. The anti-inflammatory effects of meloxicam in calves after an assisted calving may improve calf welfare.

Impact of different levels of lactose and total solids of the liquid diet on calf performance, health, and blood metabolites.

This study aimed to evaluate the effect of feeding milk replacer (MR) with varying levels of lactose and the increased supply of total solids (from 750 to 960 g/d) on performance, blood metabolites, and health of Holstein male calves during the preweaning period. Forty newborn Holstein calves (10 per treatment) were blocked according to birth weight and date of birth and distributed in a randomized block design to different liquid diets: Whole milk powder (WMP) diluted to 125 g/L solids; MR with 48% lactose (48L), diluted to 125 g/L solids; MR with 53% lactose (53L), diluted to 125 g/L solids; 53L MR corrected to 160 g/L solids (16TS) by the inclusion of a solid corrector. Calves were individually housed in wood hutches, fed 6 L/d of the liquid diet, and had free water and starter concentrate access. The study lasted 56 days. Liquid diet intake was higher for calves fed 16TS than for other treatments. Calves fed 16TS presented higher protein and fat intake, followed by those fed WMP and the 48L or 53L MRs. Lactose intake was higher for 16TS-fed calves, followed by 53L, 48L, and WMP-fed calves. Starter and total dry matter intake did not differ among liquid diets. The average daily gain was higher for 16TS than 48L-fed calves, with the other treatments being intermediary. The lowest feed efficiency was observed for calves fed 48L. No effects on health were observed, as well as on selected blood metabolites, except for albumin concentration, which was higher for calves fed 16TS and WMP. Higher total solids content (160 g/L) in MR increases nutrient intake and consequently improves the performance of dairy calves. Feeding MRs with levels of lactose up to 53% of the DM had no deleterious effect on the performance or health of the calves.

Effects of electrolyte supplementation on performance and physiological responses of preconditioning beef calves.

The objective of this study was to evaluate the effects of electrolyte solution supplementation on the performance and physiological responses of beef calves during a 45-d preconditioning phase. Forty Angus × Hereford steers (230.4 ± 4.8kg body weight [BW]) were sorted into 20 pens (2 steers/pen) following weaning (day 0). Treatments were randomly assigned to pens: (1) control: access to water only and (2) electrolyte: access to water and electrolyte solution supplementation (10% of total daily water intake) from days 1 to 14. Calf BW and blood samples were collected on days 0, 1, 3, 7, 14, 21, and 44 of the study. Blood samples were analyzed for sodium, potassium, albumin, haptoglobin, ceruloplasmin, and cortisol. All variables were analyzed using the MIXED procedure of SAS. Electrolyte solution consumption was estimated at 0.70kg/calf daily (SEM ± 0.21). Calves assigned to the Electrolyte treatment had greater water and total liquid intake than control (P < 0.05). No effects of treatment were observed on ADG or BW (P > 0.05). Effects of day (P < 0.004), but not treatment or treatment × day were observed for sodium, potassium, albumin, cortisol, ceruloplasmin, and haptoglobin. Electrolyte solution supplementation during the preconditioning period did not improve performance nor influenced stress-related markers, however improved liquid intake.

Comparison of nutrient supply from the dam to fetus and placental development in Holstein and Japanese black cows pregnant with similar or different fetus breeds.

A lower nutrient supply from Holstein (HOL) dams to beef fetuses than HOL fetuses has been demonstrated, but the underlying factors remain unclear. We investigated maternal, umbilical vein, and calf blood glucose and amino acid concentrations at calving, along with placental development at term, in HOL dams with similar fetuses (HOL-HOL, n = 12), F1 crosses (HOL × Japanese Black [JB]; HOL-F1, n = 4), JB fetuses (HOL-JB, n = 7), and JB dams with similar fetuses (JB-JB, n = 11). Calf birth weight, total cotyledonary weight, and surface area were greater in HOL-HOL compared to JB-JB or HOL-JB (P < 0.05), whereas those of HOL-F1 were similar. Blood amino acid concentrations in the umbilical veins and calves were similar among HOL-HOL, HOL-F1, and HOL-JB. Calf blood glucose concentrations were lower in HOL-F1 than HOL-HOL (P < 0.05), despite similar maternal blood glucose levels. HOL-JB exhibited higher maternal, umbilical vein, and calf blood glucose concentrations than JB-JB (P < 0.05). Therefore, the glucose supply to the fetus may be inhibited in HOL-F1 due to maternal-fetal breed differences. Higher maternal blood glucose concentrations in HOL-JB may result in elevated fetal glucose exposure, potentially affecting postnatal growth and metabolism.

Dairy cow parity affects relationships among nutritional parameters in the blood of dams, umbilical cords, and calves and placental development at calving.

Heifer growth and milk production in lactating cows may diminish the nutrient supply to the fetus. This study aimed to analyze the characteristics of the nutrient supply to the fetus in primiparous and multiparous cows. We investigated maternal, umbilical cord, and calf blood glucose and amino acid levels, as well as placental development in 28 primiparous (PP) and 30 multiparous (MP) Holstein cows. Although the total cotyledonary weight and surface area showed no significant differences, the MP group exhibited larger individual cotyledons (P < 0.01) and fewer medium-sized cotyledons (P < 0.05). Within the PP group, total cotyledonary weight and surface area positively correlated with blood glucose (r = 0.71-0.77; P < 0.01) and total essential amino acid (r = 0.55; P < 0.05) concentrations in the umbilical veins. However, no significant correlation was observed in the MP group. Blood glucose and amino acid concentrations in the umbilical vein, umbilical artery, and calf were significantly lower in the MP group (P < 0.05), although no difference was observed in the dams between the groups. In conclusion, the nutrient status of primiparous cows can alter fetal nutrient supply. Moreover, multiparous cows have larger individual cotyledons as an adaptive response to increased milk production during pregnancy. However, this adaptive response in multiparous cows did not completely restore nutrient supply to the fetus to the same extent as that in primiparous cows. Therefore, the nutritional management of multiparous cows during pregnancy must be reconsidered.

Effects of corn grain processing method in starter ration and weaning strategy on performance, nutrient digestion, rumen fermentation, and blood metabolites of Holstein calves

This research explored how corn processing methods and weaning protocols interact and impact calf performance, digestibility, ruminal fermentation, and blood metabolites. Forty-eight 3-day-old Holstein calves (24 females and 24 males; body weight = 38.2 ± 1.56 kg) were allocated to one of the four treatment groups using a 2 × 2 factorial design. The physical form of corn grain [steam-flaked corn (SFC) or ground corn (GC)] and weaning protocol [abrupt weaning (AW) or gradual weaning (GW)] were the experimental factors and resulted in the following treatments: 1) a starter diet containing SFC + AW protocol (SFC/AW), 2) a starter diet containing SFC + GW protocol (SFC/GW), 3) a starter diet containing GC + AW protocol (GC/AW), and 4) a starter diet containing GC + GW protocol (GC/GW). The starter feeds had similar feed ingredients (50.4% corn grain, 35.1% soybean meal, plus 5% chopped wheat straw) and were different only in the physical form of corn grain (SFC vs. GC). In the AW protocol, calves were given 4 L of milk/d from days 3 to 15, then increased to 7 L/d from days 16 to 67. Weaning occurred abruptly from days 68 to 69 by decreasing milk to 3.5 L/day. In the GW protocol, calves received 4 L of milk/day from days 3 to 15, followed by 7 L/day from days 16 to 59. Weaning occurred gradually from days 60 to 69, with this reduction schedule: 6 L/d from days 60–61, 5 L/d from days 62–63, 4 L/d from days 64–65, 3 L/d from days 66–67, 2 L/d on day 68, and 1 L/d on day 69. Total starter intake (d 1 to 90) remained unaffected by the corn grain processing method, but weaning strategy and corn processing method interacted for starter feed intake, as the greatest intake was observed in calves assigned in SFC/GW treatment. Feeding a starter diet containing SFC rather than GC increased DM and NDF digestion. Calves that were fed an SFC-based starter diet grew faster than calves fed a GC-based starter diet. The average daily gain (from d 1 and 90) was greater in calves assigned to GW vs. AW protocol. Calves fed an SFC-based starter feed and assigned to AW protocol converted nutrients toward growth more efficiently throughout the experiment (d 1 to 90). Feeding a GC- vs. SFC-based starter feed resulted in greater rumen ammonia-N concentration. Ruminal pH on day 80 was greater in calves weaned gradually compared to those weaned abruptly. Calves fed GC- vs. SFC-based starter diet had higher blood urea-N and β-hydroxybutyrate concentrations on day 60. Overall, an SFC- vs. GC-based starter feed (containing 5% chopped wheat straw) promoted faster calf growth and improved nutrient utilization. Feeding an SFC-based starter diet in combination with GW protocol resulted in the greatest starter feed intake.

Anaplasma marginale transplacental transmission in a calf: clinical, anatomopathological, and molecular reports

Bovine anaplasmosis is caused by obligate intracellular rickettsia Anaplasma marginale transmitted by ticks Rhipicephalus microplus, hematophagous flies, and/or iatrogenically. Transplacental transmission is possible but sub-reported. In this context, the present work aimed to report a case of a calf that was born with anemia, jaundice, and neurological problems. A calf blood smear showed intraerythrocytic inclusion of A. marginale. Accordingly, the animal was treated with oxytetracycline but died three days after the start of treatment. The necropsy revealed conjunctival and subcutaneous jaundice, splenic congestion and distension, and an intensely yellow liver were noted. Histopathology showed moderate, multifocal hepatocellular degeneration, diffuse and marked cholestasis, and histiocytic necrotizing encephalitis. A. marginale infection was confirmed by PCR, and real-time PCR (qPCR). qPCR analysis showed that 3.3% of the erythrocytes in the calf's blood sample were parasitized. Thus, here we report a case of transplacental transmission A. marginale in a newborn calf.

Vertical transmission of Trypanosoma evansi in a dromedary camel calf that spontaneously recovered after colostrum consumption

AbstractA weak dromedary calf with signs of prematurity was born in April of 2023 to a healthy multiparous camel with a good body condition. The calf was diagnosed strongly positive to Trypanosoma evansi by haematocrit centrifugation technique (immediately after birth). The mother at that time was asymptomatic and negative by haematocrit centrifugation technique and PCR of blood. Indirect ELISA of the calf's serum before colostrum ingestion showed negligible levels of antibodies. However, 12 hours after colostrum ingestion and without any treatment, the levels of antibodies increased significantly, which coincided with negative haematocrit centrifugation technique. This indicates a possible role of colostral antibodies in neutralising the trypanosomes in the calf's blood. Examination of the placenta showed placentitis, and PCR confirmed a positive result for Trypanosoma nucleic acid. The importance of vertical transmission in maintaining the infection in a herd is discussed, as well as the role of colostrum in decreasing calf mortalities due to trypanosomosis.