Holstein Calves Research Articles

Estimation of genetic parameters of Holstein calf survival.

Calf survival is not only an animal welfare issue but also helps to avoid huge losses in economic and genetic material due to calf mortality. Therefore, improving calf survival is essential in dairy breeding. The objective of this study was to explore the factors affecting the survival of Holstein calves in the Ningxia Region and to estimate the genetic parameters of calves using linear models and threshold models. Descriptive statistics were made for 43,847 Holstein calves born from 2018 to 2022 in Ningxia. The number of calves that died at 2-30 d was the highest, the survival rate was the lowest at 451-750 d, followed by 61-180 d and 2-30 d. Studies on the survival rates of calves born in different months have found that calves born in April have the lowest survival rates and calves born in October and December have higher survival rates. Calves born in autumn, third parity, and singleton calves are more likely to survive. The heritability of calf survival traits ranged from 0.002 ~ 0.136. Thus survival is a low heritability trait. Genetic correlation between different survival stages ranged from 0.3991 (2-30 d to 451-750 d) to 0.9985 (361-450 d to 451-750 d), the phenotypic correlation ranged from 0.1476 (2-30 d to 451-750 d) to 0.9582 (361-450 d to 451-750 d). The low genetic correlation between early and late survival suggests that survival in early and late stages may be influenced by different genetic factors. This study is helpful to understand the survival status of Holstein calves and provide a theoretical basis for improving the survival rate of calves.

Characterization and comparison of growth curves in slick and wild type-haired Puerto Rican Holstein calves and heifers

The ideal weight gain for Holstein heifers in the United States is between 0.73 and 0.86 kg/d. However, heat stress may limit growth, whereas a slick-haired coat confers superior thermoregulation. This study compared and evaluated (GLIMMIX and REG Procedures-SAS) body weight, hip height, shoulder to pin bone distance, thoracic perimeter, withers height, and barrel growth curves of nine slick vs. nine wild type-haired Holstein calves, weekly [one to eight weeks of age (1 to 8 WOA)] and monthly [three to 33 months of age (3 to 33 MOA)]. From 1 to 8 WOA, no hair coat type x age interactions (P≥0.1834) or hair coat type effects (P≥0.4778) were observed. During this period all variables evaluated increased linearly (R2≥0.34; P<0.0001). From 3 to 33 MOA, only body weight (P=0.0312) and barrel circumference (P=0.0038) presented a hair coat type x age interaction. No hair coat type effects (P≥0.5398) were observed. During this period, all dimensions demarcated by bones behaved quadratically (R2≥0.87; P<0.0001), while body weight remained linear (R2≥0.94; P<0.0001). From 1 to 8 WOA, gains of 0.48 and 0.48 kg/d were observed in slick and wild type-haired calves. Respective gains of 0.61 and 0.62 kg/d were noted in heifers 3 to 33 MOA. No growth-related differences were observed between hair coat types. Limited gains were observed in both groups.

Reactivity Induced by Inactivated Infectious Bovine Rhinotracheitis Vaccination and Its Related Factors in Holstein Calves Following A Modified Live Vaccine Schedule

Reactivity Induced by Inactivated Infectious Bovine Rhinotracheitis Vaccination and Its Related Factors in Holstein Calves Following A Modified Live Vaccine Schedule

Influence of metabolizable protein and methionine supplementation on growth-performance of Holstein steer calves during the initial 112-d feedlot growing phase.

The objective was to examine the effects of metabolizable protein (MP) and ruminal-protected methionine supplementation on growth performance of Holstein steer calves during the initial feedlot growing phase (112 d). One hundred eighty Holstein steer calves (122 ± 7kg) were blocked by weight and assigned to 30 pens (6 steers per pen). Five treatments were applied: 1) control, a diet based on steam-flaked corn containing urea and dry distillers grains plus solubles as supplemental N sources with no amino acid addition; 2) control diet plus blood meal supplementation; 3) diet from treatment 2, with 0.064% Smartamine M (70% methionine; Adisseo, Alpharetta, GA) supplementation; 4) diet from treatment 2 with 0.096% Smartamine M supplementation; 5) diet from treatment 2 with 0.128% Smartamine M supplementation. All diets were formulated to exceed the estimated MP requirements. The estimated metabolizable lysine, as well as methionine, was deficient in the control diet. Blood meal was added to the control diet to meet estimated lysine requirements (diet 2), the other diets had increasing concentrations of supplemental methionine. Supplemental MP enhanced (10%, P < 0.02) interim and overall 112-d average daily gain (ADG). Additional effects of supplemental methionine on ADG were not appreciable (P > 0.10). Supplemental MP did not affect (P > 0.10) dry matter intake (DMI) during the first 56-d period; however, it tended to increase (P = 0.08) DMI during the subsequent 56-d period. Overall, supplemental MP or methionine had no appreciable effect (P > 0.10) on DMI. Supplemental MP improved (P < 0.01) gain efficiency and estimated dietary net energy (NE) values during the initial 56-d period (11 and 7%, respectively) and overall (7 and 4%, respectively). Supplemental MP did not affect (P > 0.10) gain efficiency during the second 56-d period, although it tended to enhance (P = 0.08) estimated dietary NE. Supplemental methionine did not appreciably affect (P > 0.10) gain efficiency or estimated dietary NE. Therefore, adding MP to cover the estimated limiting amino acid supply in diets may enhance the gain efficiency and dietary energetics of growing Holstein calves. However, amino acid addition supplementation beyond the requirements may not produce extra productive performance of steer calves.

Evidence of innate training in bovine γδ T cells following subcutaneous BCG administration.

The Bacillus Calmette Guerin (BCG) vaccine has been shown to induce non-specific protection against diseases other than tuberculosis in vaccinated individuals, attributed to the induction of trained immunity. We have previously demonstrated that BCG administration induces innate immune training in mixed peripheral blood mononuclear cells and monocytes in calves. Gamma Delta (γδ) T cells are non-conventional T cells that exhibit innate and adaptive immune system features. They are in higher proportion in the peripheral blood of cattle than humans or rodents and play an essential role in bovine immune response to pathogens. In the current study, we determined if BCG administration induced innate immune training in bovine γδ T cells. A group of 16 pre-weaned Holstein calves (2-4 d age) were enrolled in the study and randomly assigned to vaccine and control groups (n=8/group). The vaccine group received two doses of 106 colony forming units (CFU) BCG Danish strain subcutaneously, separated by 2 weeks. The control group remained unvaccinated. Gamma delta T cells were purified from peripheral blood using magnetic cell sorting three weeks after receiving the 1st BCG dose. We observed functional changes in the γδ T cells from BCG-treated calves shown by increased IL-6 and TNF-α cytokine production in response to in vitro stimulation with Escherichia coli LPS and PAM3CSK4. ATAC-Seq analysis of 78,278 regions of open chromatin (peaks) revealed that γδ T cells from BCG-treated calves had an altered epigenetic status compared to cells from the control calves. Differentially accessible peaks (DAP) found near the promoters of innate immunity-related genes like Siglec14, Irf4, Ifna2, Lrrfip1, and Tnfrsf10d were 1 to 4-fold more accessible in cells from BCG-treated calves. MOTIF enrichment analysis of the sequences within DAPs, which explores transcription factor binding motifs (TFBM) upstream of regulatory elements, revealed TFBM for Eomes and IRF-5 were among the most enriched transcription factors. GO enrichment analysis of genes proximal to the DAPs showed enrichment of pathways such as regulation of IL-2 production, T-cell receptor signaling pathway, and other immune regulatory pathways. In conclusion, our study shows that subcutaneous BCG administration in pre-weaned calves can induce innate immune memory in the form of trained immunity in γδ T cells. This memory is associated with increased chromatin accessibility of innate immune response-related genes, thereby inducing a functional trained immune response evidenced by increased IL-6 and TNF-α cytokine production.

Using the conditioned place preference paradigm to assess hunger in dairy calves: Preliminary results and methodological issues.

Dairy calves are typically fed restricted amounts of milk. Although feed restrictions are predicted to result in negative affective states, the relative aversiveness of 'hunger' remains largely unexplored in this species. Here, we investigated whether the conditioned place preference paradigm can be used to explore how calves feel when experiencing different levels of satiation. This paradigm provides insight into what animals remember from past experiences, the assumption being that individuals will prefer places associated with more pleasant or less unpleasant experiences. Sixteen Holstein calves were either fed a restricted (3L per meal totalling 6 L per day) or 'enhanced' milk allowance (ad libitum up to 6 L per meal totalling up to 12 L per day) in their home-pen. Calves were then placed in a conditioning pen for 4 h immediately after being fed their morning meal to allow them to develop an association between the pen and their state of post-prandial satiation. Calves were conditioned across four days with their satiation state alternating between days to allow them to develop an association between pen and satiation levels. On the 5th day, calves were individually allowed to roam freely between the two pens for 30 min. We expected that calves would prefer the pen where they previously experienced higher levels of satiation, but our results show no to limited effects of treatment. However, some methodological issues (colour and side bias) prevent us from drawing strong conclusions. We discuss reasons for these issues and potential solutions to avoid these in future studies.

Effects of starch content of calf starter on rumen properties and blood concentrations of metabolites and hormones in dairy calves under a high plane of milk feeding.

The objective of this study was to investigate the effects of calf starters with different starch content on rumen and blood properties in calves fed under a high plane of nutrition program. Twenty-seven Holstein calves (14 female, 13 male) were assigned to one of three starter treatment groups in a randomized block design: high-starch (41.8%) (n= 9), H; medium-starch (31.9%) (n= 9), M; low-starch (22.0%) (n= 9), L. Milk replacer on powder basis was fed up to 1.2kg/day as fed, gradually reduced from 6weeks of age; calves were weaned at 8weeks of age. Each starter (up to 3.5kg/day as fed) and chopped hay were provided ad libitum from 5days of age. Blood was collected from 4 to 13 weeks of age. Rumen fluid was collected at 6, 8, 10, and 13 weeks of age. Serum urea nitrogen concentration after weaning was the lowest in H. Plasma IGF-1 concentrations were higher in H than in L. Ruminal pH was not different, but the molar proportion of ruminal propionate was higher in H than in L throughout the study period. In summary, a high-starch starter may increase propionate production and microbial protein synthesis in the rumen, inducing higher plasma IGF-1 concentrations.

A Case Report of Hepatosplenomegaly Due to Chronic Salmonellosis in Holstein Calves

In this case report, our aim was to present the clinical, macroscopic, bacteriological, and antibiogram results of a chronic salmonellosis case in calves on a dairy farm. A total of 12 Holstein calves weaned at 75-90 days of age on a dairy farm with clinical signs were presented in the case report. The calves displayed intermittent fever, diarrhea, and pneumonia that did not respond to treatment. The most notable finding at necropsy was hepatosplenomegaly. The diagnosis of Salmonella spp. was confirmed from the samples taken from the calves, and antibiograms revealed the resistance to many antibiotics. The disease did not recur following attention to management practices and application of protective hyperimmune serum. The presented case report emphasizes that chronic Salmonella spp. infection may lead to severe losses in calves, highlighting pathological findings, antibiotic resistance, and preventive and management practices.

Immunity, rumen metagenomics, ruminal variables, and growth performance of calves fed milk with sage (Salvia officinalis) essential oil.

The study aimed to determine the effect of sage (Salvia officinalis) essential oil (EO) to the drinking milk until the weaning stage of Holstein calves on the growth performance, body measurements, ruminal fermentation, rumen metagenomic profile, proinflammatory cytokines [interleukin-6 (IL-6), tumor necrosis factor (TNF-α), and IL-1β], immune globulins (IgG, IgM, and IgE), and acute phase proteins (serum amyloid-A, SAA). In the study, 24 Holstein calves were divided into three groups as 0 μL (SAG0; control group), 100 μL (SAG100), or 200 μL (SAG200) of sage EO to the milk per calf per day. The addition of sage EO to the milk linearly increased the live weight, feed intake, and daily body weight gain (P < 0.05). The addition of sage EO to the milk in calves linearly increased serum IgG titter dose dependently (P < 0.05), but serum IgM and IgE titters did not change (P > 0.05). The concentrations of serum TNF-α, IL-1β, and IL-6 in the weaned calves linearly decreased by the sage aromatic oil addition to the milk (P < 0.05). The serum SAA concentrations of calves did not differ among the control and treatment groups (P > 0.05). Probiotic Bifidobacterium and Acidaminococcus genusin calf rumen fluid canincrease bysage EO addition to milk. The relative abundance of genus Prevotella, Prevotellaceae_NK3B31_group, and Prevotella_9 increase with sage EO. The ruminal ammonia-nitrogen (NH3-N) concentration and total short chain fatty acid (T-SCFA) molarity decreased by sage EO addition to the drinking milk (P < 0.05). Themolarities of iso butyric (IBA) and iso valeric acids (IVA) in rumen fluid of the weaned calves linearly reduced by the increasing sage EO dose to the milk (P < 0.05). The butyric acid (BA) and iso caproic acid (ICA) molarities in rumen fluid did not change by the sage EO addition (P > 0.05). Consequently, it has been observed that sage EO addition to the milk of calves positively affected the immune system variables and performance parameters.Sage EO additionof calves before weaning may support the immune system in the eventual immunosuppression at the weaning stage.

The Effect of Feeding a Total Mixed Ration with an ad libitum or Restricted Pelleted Starter on Growth Performance, Rumination Behavior, Blood Metabolites, and Rumen Fermentation in Weaning Holstein Dairy Calves.

The aim of the current study was to evaluate the effect of the starter restriction and of the ad libitum TMR (total mixed ration) inclusion on intake, growth performance, rumination time (RT), and health condition of Holstein dairy calves during weaning. We randomly assigned thirty female Holstein calves (with an average weight of 38.5 ± 1.96 kg at birth) to one of three treatments. From 21 days of age, the calves were fed one of three treatments as follows: a control diet (CTR) with an ad libitum calf starter but without TMR; Treatment 1 diet (TRT1) with both an ad libitum calf starter and ad libitum TMR; Treatment 2 diet (TRT2) with ad libitum TMR and a restricted amount of a calf starter (50% of the intake recorder in the control group day by day). Calves in the TRT2 group, between 56 and 63 days of age, had a lower body weight (80.1; 79.5; 75.6 kg for the CTR, TRT1, and TRT2 groups, respectively) compared with CTR and TRT1 calves. This outcome is ascribed to the average daily gain (0.759; 0.913; 0.508 kg/day for the CTR, TRT1, and TRT2 groups, respectively), resulting also in TRT2 being lower than CTR or TRT1 calves. The inclusion of ad libitum TMR increased the rumination time, especially after weaning (15.28 min/h, 18.38 min/h, and 18.95 min/h for the CTR, TRT1, and TRT2 groups, respectively). Concerning the rumen metabolism and inflammometabolic response, overall, no differences were observed between the three dietary treatments. In conclusion, the results indicated that a TMR could partially replace a calf starter in weaning dairy calves, since neither growth performance nor health status were impaired. In addition, providing TMR (with or without concentrate restriction) led to a better rumen development and likely a better rumen fermentation efficiency in post-weaning.

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.

Effects of pre-weaning supplementation with fennel seed powder in two terms on growth performance, health status, and blood metabolites of Holstein dairy calves

This study investigated the effects of fennel seed powder (FSP) supplementation in liquid feed on growth performance, health, and blood parameters of preweaning dairy calves. In a 2 × 2 factorial design, 56 one-day-old female Holstein calves (n = 14/treatment) received liquid diet [colostrum (4.5 kg/d for the first 2 d), waste milk (6 kg/d from d 3 to 43, 5 kg/d from d 44 to 45, 4 kg/d from d 46 to 47, 3 kg/d from d 48 to 49)] supplemented with either of 3 or 6 g FSP (FSP3 or FSP6) in two terms (T: 25 or 50 d). Biometric and health traits were recorded daily, and blood metabolites were analyzed at d 25 and 50. The experiment was conducted under mild heat stress. The FSP6 group showed significant increase in starter dry matter intake (g/d and % of BW), starter crude protein (g/d), starter ether extract (g/d), starter ME (Mcal/d), total dry matter intake (g/d and % of BW), and total crude protein intake (g/d) during the last ten days of the experiment. The FSP6 group also had a significantly higher average daily gain (g/d), overall body weight (d 1–51), final weight (d 51), and total hip width compared with the FSP3 group. Feed conversion was higher in the FSP6–25 T or − 50 T groups than in the FSP3–25 T (but not −50 T) group. Calves receiving 3 g of FSP had a higher likelihood of experiencing elevated rectal temperature [≥ 39.4 ºC, odds ratio (OR) = 1.583 and confidence interval (CI) = 1.25 to 2.00], poor general appearance [(1 = normal and alert; 2 = ears drooped; 3 = head and ears drooped, dull eyes, slightly lethargic; 4 = head and ears drooped, dull eyes, lethargic; and 5 = severely lethargic); ≥ 2, OR = 1.47 and CI = 1.14 to 1.91)], and diarrhea [(1 = normal; 2 = soft to loose; 3 = loose to watery; 4 = watery, mucous, slightly bloody; and 5 = watery, mucous, and bloody); ≥ 3 (OR = 1.36 and CI = 1.04 to 1.76)] compared to those in the FSP6 group. Conversely, calves in the FSP6 group had fewer days of increased rectal temperature (4.75 vs. 7.11 d), poor general appearance (3.93 vs. 5.75 d), and diarrhea (3.85 vs. 5.11 d) than those in the FSP3 group. In addition, serum levels of alanine transferase (15.90 vs. 16.98 U/L for FSP6 vs. FSP3) and malondialdehyde (1.24 vs. 1.43 nmol/mL for FSP6 vs. FSP3) were significantly lower in the FSP6 group than in the FSP3 group. In addition, longer feeding of FSP was more effective than shorter feeding in lowering both traits. A triglyceride-lowering effect was observed in the FSP3 group compared with the FSP6 group (27.45 vs. 30.90 mg/dL). Overall, supplementation of liquid feed with 6 g FSP for 25 or 50 d improved growth performance in dairy calves.

Effect of organic mineral supplementation in reducing oxidative stress in Holstein calves during short-term heat stress and recovery conditions

BackgroundThis study investigated the effects of inorganic and organic minerals on physiological responses, oxidative stress reduction, and rumen microbiota in Holstein bull calves (123.81 ± 9.76 kg; 5 months old) during short-term heat stress (HS) and recovery periods. Eight Holstein calves were randomly assigned to four treatment groups: no mineral supplementation (Con), inorganic minerals (IM), organic minerals (OM), and high-concentration organic minerals (HOM) and two thermal environments (HS and recovery) using 4 × 2 factorial arrangement in a crossover design of four periods of 35 d. Calves were maintained in a temperature-controlled barn. The experimental period consisted of 14 d of HS, 14 d of recovery condititon, and a 7-d washing period.ResultsBody temperature and respiration rate were higher in HS than in the recovery conditions (P < 0.05). Selenium concentration in serum was high in the HOM-supplemented calves in both HS (90.38 μg/dL) and recovery periods (102.00 μg/dL) (P < 0.05). During the HS period, the serum cortisol was 20.26 ng/mL in the HOM group, which was 5.60 ng/mL lower than in the control group (P < 0.05). The total antioxidant status was the highest in the OM group (2.71 mmol Trolox equivalent/L), followed by the HOM group during HS, whereas it was highest in the HOM group (2.58 mmol Trolox equivalent/L) during the recovery period (P < 0.05). Plasma malondialdehyde and HSP70 levels were decreased by HOM supplementation during the HS and recovery periods, whereas SOD and GPX levels were not significantly affected (P > 0.05). The principal coordinate analysis represented that the overall rumen microbiota was not influenced by mineral supplementation; however, temperature-induced microbial structure shifts were indicated (PERMANOVA: P < 0.05). At the phylum level, Firmicutes and Actinobacteria decreased, whereas Fibrobacteres, Spirochaetes, and Tenericutes increased (P < 0.05), under HS conditions. The genus Treponema increased under HS conditions, while Christensenella was higher in recovery conditions (P < 0.05).ConclusionHOM supplementation during HS reduced cortisol concentrations and increased total antioxidant status in Holstein bull calves, suggesting that high organic mineral supplementation may alleviate the adverse effects of HS.

Application of Near-Infrared Reflectance Spectroscopy for Predicting Chemical Composition of Feces in Holstein Dairy Cows and Calves.

Traditional methods for determining the chemical composition of cattle feces are uneconomical. In contrast, near-infrared reflectance spectroscopy (NIRS) has emerged as a successful technique for assessing chemical compositions. Therefore, in this study, the feasibility of NIRS in terms of predicting fecal chemical composition was explored. Cattle fecal samples were subjected to chemical analysis using conventional wet chemistry techniques and a NIRS spectrometer. The resulting fecal spectra were used to construct predictive equations to estimate the chemical composition of the feces in both cows and calves. The coefficients of determination for calibration (RSQ) were employed to evaluate the calibration of the predictive equations. Calibration results for cows (dry matter [DM], RSQ = 0.98; crude protein [CP], RSQ = 0.93; ether extract [EE], RSQ = 0.91; neutral detergent fiber [NDF], RSQ = 0.82; acid detergent fiber [ADF], RSQ = 0.89; ash, RSQ = 0.84) and calves (DM, RSQ = 0.92; CP, RSQ = 0.89; EE, RSQ = 0.77; NDF, RSQ = 0.76; ADF, RSQ = 0.92; ash, RSQ = 0.97) demonstrated that NIRS is a cost-effective and efficient alternative for assessing the chemical composition of dairy cattle feces. This provides a new method for rapidly predicting fecal chemical content in cows and calves.

Difructose Anhydride and Passive Immunity Effects on Passive Immune Transfer and Performance of Feeding Difructose Anhydride to Neonatal Calves.

The objective of this study was to assess the potential effects of supplementing difructose anyhdride III (DFAIII) during the first days of life on the absorption of immunoglobulin G (IgG) and growth performance of calves early in life fed colostrum with a high IgG concentration. Sixty-six healthy new-born Holstein calves were randomly assigned to three treatments consisting of no supplementation (control), supplementation of 12 g/d (DFA12), or 36 g/d (DFA36) of DFAIII during the first 7 d of life via colostrum and milk replacer (MR). Calves were separated from dams at birth and bottle-fed colostrum in two meals, each targeting 2.5 L within the first 18 h of birth. Colostrum had been previously collected from other dams (and preserved frozen) within the first 2 h of calving and had a Brix value ≥32%. Daily consumption of starter concentrate and MR (and colostrum on the first day) were individually monitored. Calves were body weighed using an electronic scale at birth and on a weekly basis thereafter until the end of study at 42 d of age. A sample of colostrum fed to each calf and a blood sample from the jugular vein of the calves were collected at 12 and 24 h of life to determine the IgG concentration. The mean colostrum IgG concentration fed in the current study was 110 ± 33.7 g/L (mean ± SD). No differences in animal performance were found among the treatments. Calves on all treatments consumed the same amount of colostrum with a similar concentration of IgG, and thus the amount of IgG consumed was also similar. Serum IgG concentrations were greater at 24 than at 12 h but did not differ among treatments. However, the apparent efficiency of absorption of colostral immunoglobulins was greater in DFA12 and DFA36 at 12 h of life than in control calves, with no differences observed at 24 h. Even when feeding high-quality colostrum, in terms of IgG concentration, supplementation with difructose anhydride III may pose an additional advantage in promoting the passive transfer of immunoglobulins in neonatal Holstein calves during the first 12 h of life.

Individuality of calves: Linking personality traits to feeding and activity daily patterns measured by precision livestock technology

Animal personality has established connections with animal performance, resilience, and welfare which are related to stable behavioral patterns. Precision livestock technologies introduce the opportunity to measure these behavior patterns automatically and noninvasively. Thus, the primary aim of this study was to determine if personality traits in dairy calves measured via standardized personality assessments were associated with activity measured via a commercially available accelerometer. Secondary aims of this study were to investigate if personality traits were associated with feeding behaviors measured via an automatic feeding system (AFS) and with average daily gain (ADG). We characterized personality traits of Holstein calves (n = 49) utilizing standardized personality (novel environment, novel person, novel object, and startle) tests. Behaviors from these tests were summarized and 3 factors were extracted from a principal component analysis to represent calf personality traits: fearful, active, and explorative. Factor scores were regressed against behaviors from the accelerometer and AFS and with ADG. We found that calves that were more active were associated with taking more steps in the home environment, consuming more calf starter, and with reaching the benchmark of 1 kg of starter consumed in a day at a younger age. The trait active was also associated with greater ADG throughout the study. In addition, calves that were more explorative in the personality tests were associated with less starter consumed and lower ADG specifically during the weaning period. The findings of this research contribute to the existing literature by further establishing the links between personality traits and the daily behavioral patterns and performance of young calves. This study suggests the potential for using precision technology to assess and characterize personality traits, thereby enhancing their practical applicability on farms. Future research should focus on evaluating how personality traits, as measured through standardized assessments and precision technologies, correlate with deviations in behavior observed in dairy calves during stressors.

Effect of Dietary and Age Changes on Ruminal Microbial Diversity in Holstein Calves.

Ruminal microorganisms play a crucial role in the energy supply of ruminants and animal performance. We analyzed the variations in rumen bacteria and fungi at 45 d, 75 d, and 105 d by using 16SrRNA and ITS sequencing data and investigated their correlation with rumen fermentation. According to the results, rumen microflora tended to gradually mature with age, and bacterial and fungal establishment gradually stabilized. Upon comparing the three periods, the concentration of propionic acid increased significantly (p < 0.05) after weaning, and weaning accompanied by a transition in diet remarkably decreased (p < 0.05) rumen diversity in the short term and induced a corresponding change in the rumen microbiota composition. Bacteroidota, Actinobacteriota, and Firmicutes were the core bacterial phyla for all age periods. Ruminococcus, NK4A214_group, Sharpea, Rikenellaceae_RC9_gut_group, and norank_f__Butyricicoccaceae were the markedly abundant bacterial genera in pre-weaning. After weaning, the relative abundance of Erysipelotrichaceae_ UCG-002, Eubacterium_ruminantium_group, and Solobacterium significantly increased (p < 0.05). The relative abundance of Acetitomaculum increased with age with the greatest abundance noted at 105 d (37%). The dominant fungal phyla were Ascomycota and Basidiomycota, and Aspergillus and Xeromyces were the most abundant fungal genera after weaning. Trichomonascus, Phialosimplex, and Talaromyces were enriched at 105 d. However, the low abundance of Neocallimastigomycota was not detected throughout the study, which is worthy of further investigation. In addition, correlations were observed between age-related abundances of specific genera and microbiota functions and rumen fermentation-related parameters. This study revealed that rumen microbiota and rumen fermentation capacity are correlated, which contributed to a better understanding of the effects of age and diet on rumen microbiology and fermentation in calves.

Concentrations of serum amyloid A, haptoglobin and some cytokines in calves with Cryptosporidiosis in the pre- and post-treatment stage

This study aims to determine serum amyloid A (SAA), haptoglobin (Hp), interleukin-1β (IL-1β), interleukin 6 (IL-6) and tumor necrosis factor-α (TNF-α) concentration in cases of Cryptosporidiosis that are frequently encountered in calves in veterinary medicine. Although many experimental studies have been conducted in this field, studies of naturally infected calves are quite a few. In this study, 10 neonatal Holstein calves diagnosed with Cryptosporidium were included. Stool samples were taken from calves with diarrhea using a rapid test kit (BIO-K 313 rapid test kit). Blood samples were obtained from the jugular vein pre- and post-treatment for biochemical measurements. SAA, Hp, IL-1β, IL-6 and TNF-α concentration measurements were conducted with ELISA reader using commercial kits. Calves with Cryptosporidiosis presenting with diarrhea showed a statistical difference in SAA, Hp, IL-1β, IL-6, white blood cell and hemoglobin values before and after treatment, whereas hematocrit, red blood cell and TNF-α concentrations did not show any statistical difference before and after treatment. According to these findings, to follow up the treatment process of calves with Cryptosporidiosis, it is thought that measuring the concentration of SAA, Hp, IL-1β and IL-6 will be useful for determining disease severity, selecting appropriate treatment, following treatment efficacy and determining subclinical diseases.

Effects of grain processing (cracked vs. steam-flaked) and forage sources (alfalfa hay and wheat straw) as a free-choice provision on growth performance, rumen fermentation, blood metabolites, and behavior of dairy calves

The aim of this study was to investigate the interaction between physical form of starter (PFS) and forage source (FS) with free access to forage on feed intake, growth performance, rumen fermentation, blood metabolites and behavioral traits of dairy calves. A total of 48 7-day-old Holstein calves were randomly assigned to one of four treatments in a 2 × 2 factorial arrangement, with FS [alfalfa hay (AH) and wheat straw (WS)] as free-choice supply and PFS diets (cracked vs. steam-flaked) as main effects. Feeding treatments included (1) starter diet with steam flaked corn (SFC) and free access to AH (SFC-AH), (2) starter diet with SFC and free access to WS (SFC-WS), (3) starter diet with cracked corn (CRC) and free access to AH (CRC-AH) and (4) starter diet with CRC and free access to WS (CRC-WS). The calves were weaned on day 58 and remained in the experiment until day 70. All calves had free access to water and starter feed. The results showed that there was no interaction between PFS and FS in terms of starter intake, forage intake, dry matter intake (DMI), average daily gain (ADG), body weight (BW) or feed efficiency (FE). Calves fed CRC consumed more dry matter, TMR and forage than calves fed SFC diets. Regardless of the PFS diet, weaning weight, total weight and total ADG were higher in calves fed WS, while forage intake was higher in calves fed AH. Calves fed CRC-AH had the lowest rumen pH at day 68 compared to the other groups (except SFC-WS at day 70). An interaction between PFS diets and FS affected rumen proportion of propionate on day 35, since calves, which were fed CRC-AH had the highest molar percentage of propionate than calves fed other diets (except for SF-WS). At day 65, calves fed SFC starter feed had higher plasma glucose concentrations than calves fed CRC. It was found that PFS feed and FS had an interaction effect on BUN at day 65, with calves fed CRC-AH having the highest BUN. Compared to the other groups, calves fed CRC-WS had the highest BHB at day 33 and throughout the period (days 35 and 65). An interaction between PFS diets and FS affected lying time and forage eating time, with CRC-AH calves exhibiting the longest lying time and lowest forage eating time. The time spent on NNOB tended to be longer in SFC-fed calves than in CRC-fed calves, regardless of the forage source. Compared to calves fed SFC, calves fed CRC with high levels of fine particles consumed more dry matter, TMR, and forage while spending less time on NNOB. Furthermore, feeding calves chopped WS instead of AH increased weaning weight, total weight, and total ADG, although forage intake was higher in calves fed AH. In summary, a combination of cracked corn starter with free access to wheat straw appears to provide the best growth outcomes for dairy calves.

Early pain experiences in dairy calves on pain sensitivity later in life

In humans, early painful experiences can increase pain sensitivity later in life, but little is known regarding this phenomenon in cattle. This study assessed if a painful event early in life affects later pain sensitivity in 40-d-old calves. Holstein calves (n = 26) were randomly assigned to control or treatment conditions, blocked within sex and birth weight. At 9.5 ± 1.8 d old, treatment calves had 1 horn bud disbudded using caustic paste, whereas control calves had 1 horn sham disbudded; in both cases, multimodal pain control was provided. All calves had the contralateral horn bud disbudded using a hot iron 4 wk later, again with multimodal pain control. Mechanical nociceptive responses were assessed weekly using an algometer applied adjacent to both horn buds and on the rump, beginning 3 d before the first disbudding and ending 30 d after the second disbudding. Following the second disbudding, both groups of calves showed evidence of increased sensitivity (i.e., algometer pressure declined 3.69 ± 0.60 √N to 2.13 ± 0.70 √N) on the contralateral bud, but there was no difference between the control group and the treatment groups. An interaction between treatment and time, likely driven by treatment differences, was found on the rump when tested 5 h after the second disbudding event. These responses are not consistent with the hypothesis that an early pain experience results in increased sensitivity to later painful experiences.