Newborn Calves Research Articles

Colostrum Composition, Characteristics and Management for Buffalo Calves: A Review.

In this review, the composition, characteristics, and management of dairy buffalo calves were examined and compared with bovines. The neonatal period is critical for buffalo calves and is characterized by a high mortality rate (more than 40%). The early intake of high-quality colostrum (IgG > 50 mg/mL) is the one way to improve the immune system of calves (serum IgG > 10 mg/mL after 12 h), thus increasing their chances of survival. Mainly in intensive farms, the availability of high-quality colostrum is necessary; thus, good quality colostrum is often stored to provide newborn calves which cannot be fed by their mothers. Also, the manipulation of the immunological status of animals through vaccination has been depicted since the quality of colostrum tended to be influenced by vaccination against pathogens. Buffalo breeding is constantly expanding in Italy, mainly thanks to the Mozzarella cheese production that represents the excellence of the "Made in Italy" and is exported worldwide. Indeed, high calf mortality rates directly affect the profitability of the business. For these reasons, the aim of this review was to examine specific research on buffalo colostrum that, compared with other species, are scarce. Improving the knowledge of buffalo colostrum, in terms of characteristics and management, is critical to guarantee buffalo newborns' health in order to reduce their mortality rate. Importantly, considering the knowledge on cattle valid also for buffalo is a widespread, and often erroneous, habit in several fields, including colostrum feeding. Therefore, the two species were compared in this review.

A meta-analysis of the effects of colostrum heat treatment on colostral viscosity, immunoglobulin G concentration, and the transfer of passive immunity in newborn dairy calves

Newborn ruminants depend on colostrum intake immediately after birth to obtain immunoglobulins for effective transfer of passive immunity (TPI). As colostrum may also be a vehicle of infectious agents, heat treatment of raw colostrum is a practice aimed at eliminating or reducing its pathogen load. Despite the usefulness of heat treatment in preventing the transmission of infectious colostrum-borne diseases, heat treatment of colostrum may have some side effects. A systematic review and meta-analysis were conducted to summarize the effects of colostrum heat treatment on colostral viscosity and IgG concentration, and serum IgG concentration as a proxy for TPI in newborn calves fed raw versus heat-treated colostrum. Moderators were studied to identify sources of heterogeneity. Literature databases were searched for peer-reviewed articles published between 1946 and 2022. A Master of Science thesis was also included. Five, 21, and 19 original publications were quantitatively evaluated in 3 separate meta-analyses, based on predefined selection criteria. Two-level and 3-level random-effects meta-analysis revealed a significant overall effect of heat treatment on colostral viscosity and IgG concentration, and serum IgG concentration in newborns. Heat-treated colostrum had significantly higher viscosity (21.0 cP, 95% CI: 3.8 to 38.2) and lower IgG concentration (-7.4 g/L, 95% CI: -11.1 to -3.7) compared with raw colostrum. Overall, newborn calves fed heat-treated colostrum had higher serum IgG concentrations (2.8 g/L, 95% CI: 1.4 to 4.0) 24-48 h after birth than those fed with raw colostrum. Particularly, this positive effect on the serum IgG concentrations was seen when colostrum was heat-treated at ≤60°C (2.9 g/L, 95% CI: 0.9 to 4.2) and when the standard low-temperature low-time (LTLT) method was used for heat treatment (2.6 g/L, 95% CI: 0.1 to 5.1). Colostrum treated at >60-63.5°C tended to have higher viscosity (275.6 cP, 95% CI: -37.9 to 589.3) and had lower IgG concentration (-21.7 g/L, 95% CI: -27.3 to -16.1). Calves fed colostrum treated at this temperature range had significantly lower serum IgG (-4.2 g/L, 95% CI: -7.9 to -0.4) compared with those fed raw colostrum. Heat treatment of colostrum at 72-76°C was not associated with a significant increase in colostral viscosity (6.3 cP, 95% CI: -324.3 to 336.9) nor a reduction in IgG colostral concentration (-13.1 g/L, 95% CI: -26.5 to 0.2), but calves fed colostrum treated at this temperature range had a significant reduction in serum IgG (-11.3 g/L, 95% CI: -17.1 to -5.4). Feeding newborn calves with colostrum heat-treated at ≤60°C by the standard LTLT method, particularly within 2 h after birth, resulted in increased serum IgG concentration at 24-48 h of age. Importantly, delaying feeding of heat-treated colostrum to newborns beyond 2 h of age resulted in no significant difference in IgG serum levels compared with feeding raw colostrum, highlighting the importance of early administration of heat-treated colostrum to favor TPI. On-farm colostrum heat treating should achieve an equilibrium between pathogen elimination and the preservation of colostral immunoglobulins while minimizing undesired increases in viscosity. The beneficial effects of colostrum heat treatment on TPI can be negligible if colostrum feeding is not performed within 2 h after birth.

Effects of extended transition milk feeding on blood metabolites of female Holstein dairy calves at 3 weeks of age: a liquid chromatography with tandem mass spectrometry-based metabolomics approach

Transition milk (TRM) is a rich source of bioactive components that promotes intestinal development and growth, and reduces the susceptibility to diarrhoea in calves. The objective of this study was to characterise the effects of replacing pasteurised waste milk (none-saleable milk containing antibiotic and/or drug residues) with pasteurised TRM for 3 wk on blood metabolites of dairy calves at 21 d of age. A total of 84 healthy newborn female Holstein calves was blocked by birth order and assigned randomly to four treatment groups with partial replacement of pasteurised waste milk by TRM (second milking after parturition) at 0 (0 L/day TRM + 6 L/day milk), 0.5 (0.5 L/day TRM + 5.5 L/day milk), 1 (1 L/day TRM + 5 L/day milk), or 2 L (2 L/day TRM + 4 L/day milk) for a 21-day period. Serum metabolome was determined by liquid chromatography with tandem mass spectrometry-based metabolomics analysis on a subset of 26 randomly selected individuals from calves fed pasteurised waste milk (CON, 6 L/d milk; n = 13) or TRM (2 L/d TRM + 4 L/d milk; n = 13) at 21 d of age. The identified metabolites (194 out of 265) were categorised according to chemical class and the number of metabolites per class in the serum, amongst which glycerophospholipids 16% (n = 43), fatty acyls 7% (n = 19), organic acids 7% (n = 18), organic heterocyclic compounds 5% (n = 13), benzenoids 5% (n = 12), sphingolipids 5% (n = 12), organic oxygen compounds 4% (n = 11), and nucleic acids 3% (n = 9), were the predominant types. Significant differences in metabolites were determined by the volcano plot. Applying the volcano plot, only two metabolites (ceramide and phosphatidylserine) were significantly different between CON and TRM. Overall, our results suggested that prolonged TRM feeding for 3 wk had little effect on the serum metabolome of the dairy calves. We speculate that the potential effects of feeding TRM for 3 wk compared with waste milk were spatially limited to affect the composition of the local gut microbial community and the growth or function of the intestinal epithelium, not allowing detection of the likely effects in the serum through a metabolomic approach.

68 Characterization of Bovine Extracellular Vesicles Isolated from Colostrum

Abstract Bovine colostrum is composed of a variety of biologically active compounds including microRNAs (miRNA), which are found within extracellular vesicles (EVs). Newborn calves are agammaglobulinemic. Hence, the ability of the bovine neonate to fight off pathogens is therefore almost entirely dependent upon colostrum ingestion. Extracellular vesicle-derived miRNAs may have a crucial role in the regulation of the immune response. Thus, we aimed to characterize the EVs morphology from bovine colostrum using stimulated emission depletion (STED) super resolution microscopy. Bovine colostrum samples (approx. 3-4 h after parturition) were collected from primiparous Holstein dairy cows (n = 10) at a commercial dairy farm. Colostrum samples (15 mL) were subjected to a series of centrifugation steps to achieve defatted supernatant and to label EV pellets with EV specific markers. The EV pellets were resuspended in 100µL of 1 x PBS for EV staining methods or resuspended in 1 mL of trizol reagent for further miRNA isolation. The EVs suspensions were incubated with a primary polyclonal antibody anti-CD63 and with a secondary antibody (Alexa Fluor 594) for approximately 90 minutes each. Labeled EV-antibody complex were analyzed using confocal and STED microscopy. Based on the confocal and super resolution STED imaging capability obtained from the EVs-derived from bovine colostrum (Figure 1), labeled EVs with anti-CD63 and the enhanced resolution of STED over conventional confocal imaging, allowed to image the EVs at their actual size (30-200 nm). Further in-depth view on EV morphology, marker proteins expressed on the membrane, and size will contribute to our understanding of EVs-derived from colostrum and their functions. This will be crucial in studies to evaluate EVs uptake by intestinal cells for the correct identification of compartments involved in subcellular trafficking.

86 Biomarkers of Inflammation in Neonatal Calves Supplemented with Condensed Solubles from Milk Permeate

Abstract Neonatal and weaning periods are the most challenging phases for enteric infections in dairy calves. While different approaches are used to minimize calf health issues, the neonatal diet remains the core approach to enhance pre- and post-weaning animal health and performance. Previous studies have shown that bioactive compounds, including oligosaccharides present in the diet of neonatal dairy calves, enhanced their growth performance post-weaning. However, the effects of oligosaccharides supplementation during the neonatal period and the impact on the health status of the calf remain to be elucidated. Thus, we aimed to evaluate blood biomarkers of inflammation in calves supplemented with condensed solubles from milk permeate (CS) during the neonatal period (from birth to 21 d) of dairy calves. Twenty-four newborn Holstein calves (n = 12/group) housed in individual hutches were used in a randomized complete block design study. Calves were blocked by birth date and sex. At 2-days old, calves were randomly assigned into two groups (n = 6 females and 6 males per group): control with no supplement; or treatment with 50 g/d of CS. Both treatment and control groups were fed pasteurized waste milk during the preweaning period. Calves were fed 2.83 L of pasteurized waste milk 2×/d during week 1 to 5, 1×/d in week 6, and weaned at week 7. At each milk feeding during week 1 to 5, 25 g of CS was added to the pasteurized waste milk for each calf on the CS treatment. Healthy scores were recorded daily. Calf growth measurements and blood samples were collected weekly. Data were analyzed using MIXED procedures of SAS 9.4 with repeated measures. Significant differences were declared at P < 0.05. Overall, body weight, fecal and respiratory scores were similar between groups during the preweaning period. During the first 3 weeks of age, a group×sex×time interaction was observed for the enzyme myeloperoxidase (MPO) expressed by neutrophils. Female calves on the CS treatment had decreased MPO concentrations in the blood relative to the female controls at week 3. Other biomarkers of inflammation (i.e., haptoglobin) or consequent liver response (i.e., albumin, paraoxonase) did not differ between groups. Based on these parameters, there was no evidence of systemic inflammation during the first 21 days of age. However, circulating MPO is an indicative of phagocytosis by neutrophils resulting in a local or systemic inflammatory responses. The decreased MPO in CS female calves can be associated with a lesser microbial infiltration in the gut. The latter suggests that oligosaccharides from the diet stimulate the growth of commensal microbiota on the host, which serve as decoy receptors to pathogenic microorganisms (i.e., blocking microbial infiltration). Overall, these findings suggest that bioactive molecules as feed supplements such as CS can help the local immune response in neonatal dairy calves.

Synbiotic supplementation influence select antioxidants markers and immune response of Murrah buffalo calves

Newborn calves undergoes tremendous physiological stress during the early life stage, leading to gut dysbiosis and reduced performance. Synbiotics administration has been shown to play a vital role in immunomodulation by replenishing gut microbiota, thereby conserving and protecting biological membranes against oxidative damage. This study examined the effects of synbiotic supplementation on selected antioxidant markers and immune response in Murrah buffalo calves. A total of twenty-four Murrah buffalo calves aged 5–7 d were enrolled randomly into three treatment groups based on body weight (BW) in a sixty-day feeding trial. Treatments were (1) control (CON); basal diet with no supplementation; (2) SYN1; control + synbiotic formulation 1 (200 mL fermented milk prepared from Lactobacillus acidophilus NCDC15 + 8g Cichorium intybus root powder); (3) SYN2; control + synbiotic formulation 2 (200 mL fermented milk prepared from Limosilactobacillus reuteri BFE7 + 8g Cichorium intybus root powder). Supplementation of SYN1 and SYN2 to calves significantly improved (P < 0.05) the cell-mediated immune response to phytohaemagglutinin-P (CMI; delayed type of hypersensitivity response to PHA-P). At the same time, the humoral immune response to chicken RBC (HIR; antibody titre to C-RBC) was enhanced (P < 0.05) in SYN-fed calves than in CON calves. Moreover, increased superoxide dismutase and catalase activities (P < 0.05) were observed in synbiotic-fed calves compared to CON calves. However, glutathione peroxidase activity was not influenced by SYN supplementation. Overall, the research showed that synbiotic formulations improved the immune system and antioxidant capacity of Murrah buffalo calves, making them less likely to get sick or stressed out during their early lives.

Lunar Cycle, Climate, and Onset of Parturition in Domestic Dromedary Camels: Implications of Species-Specific Metabolic Economy and Social Ecology.

Given energy costs for gestating and caring for male offspring are higher than those of female newborns, external environmental conditions might be regarded as likely to affect the timing of delivery processes differentially depending on the sex of the newborn calf to be delivered. The aim of the present paper is to evaluate the association between environmental stressors such as the moon phase and weather-related factors and the onset of labor in female dromedaries. A binary logistic regression model was developed to find the most parsimonious set of variables that are most effective in predicting the probability for a gravid female dromedary to give birth to a male or a female calf, assuming that higher gestational costs and longer labor times are ascribed to the production of a male offspring. Although the differences in the quantitative distribution of spontaneous onset of labor across lunar phases and the mean climate per onset event along the whole study period were deemed nonsignificant (p > 0.05), a non-negligible prediction effect of a new moon, mean wind speed and maximum wind gust was present. At slightly brighter nights and lower mean wind speeds, a calf is more likely to be male. This microevolutionary response to the external environment may have been driven by physiological and behavioral adaptation of metabolic economy and social ecology to give birth to cooperative groups with the best possible reduction of thermoregulatory demands. Model performance indexes then highlighted the heterothermic character of camels to greatly minimize the impact of the external environment. The overall results will also enrich the general knowledge of the interplay between homeostasis and arid and semi-arid environments.

Infectious Rotavirus and Coronavirus of Calves

Recently, some progress has been made in the study of bacterial and viral infectious diseases of calves. However, as effective systems and methods are put in place to control these diseases, other new emerging diseases will also become important. Among diseases of the neonatal period in calves, diarrhea, which causes significant economic damage, is one of the main problems in cattle breeding. Calves diarrhea is divided into two groups: infectious and non-infectious. Diarrhea of infectious origin is mainly caused by Escherichia coli, Salmonella sp., Campylobacter sp., Clostridium perfringens type C, Rotavirus, Coronavirus, Parvovirus, Astrovirus, Calicivirus, Breda virus, Cryptosporidium, Coccidia, Giardia and Neoascaris vitulorum. During field studies, it was found that 75-95% of infectious diarrhea in calves is caused by enterotoxic Escherichia coli, rotaviruses, coronaviruses, cryptosporidium, including 27-36% rotaviruses, 20-26% coronaviruses. These diseases are often registered in livestock farms of the republic of Azerbaijan and cause the death of newborn calves.

Sodium butyrate supplementation impacts the gastrointestinal bacteria of dairy calves before weaning.

The objective of this study was to systematically investigate how sodium butyrate (SB) affects the gastrointestinal bacteria in newborn calves at different stages before weaning. Forty female newborn Holstein calves (4-day-old, 40 ± 5kg of body weight) were randomly divided into four groups; each group was supplemented with four SB doses: 0, 15, 30, and 45g/day (ten replicates) in SB0, SB15, SB30, and SB45 groups, respectively. SB was fed with milk replacer from day 4 to day 60. Rumen fluid and feces were collected on days 2, 14, 28, 42, and 60 for 16S rRNA high-throughput sequencing. Data were analyzed in a complete randomized design and analyzed on the online platform of Majorbio Cloud Platform. The results showed that SB significantly increased the α-diversity in feces, especially Shannon and Chao indices in SB45 and SB30 at day 60 more than in SB15 (P < 0.05). Additionally, SB significantly enhanced Firmicutes growth from day 2 to 28 and also increased Bacteroides abundance from day 28 to 42 in rumen and feces (P < 0.05). SB also significantly inhibited Proteobacteria abundance in rumen and feces during the study period (P < 0.05). SB also promoted some potential beneficial bacterial abundance, including Prevotella, Lachnospiraceae, Clostridium, Ruminococcus, and Muribaculaceae (P < 0.05). Additionally, Escherichia-Shigella abundance at SB0 was significantly lower than in the other groups (P < 0.05). In conclusion, this study firstly reported a dynamic curve showing of the SB effects on bacteria in calves before weaning. This study provides valuable evidence for the development of the gastrointestinal tract of the calves in the early stage of the life. SB supplementation improved the gastrointestinal health by regulating the bacterial populations. KEY POINTS: • The gastrointestinal tract of calves has been improved after the SB supplementation. • Microbes were the vital influential factor in the development of calves. • Intervention before weaning is an effective strategy for calf health.

Prepartum Magnesium Butyrate Supplementation of Dairy Cows Improves Colostrum Yield, Calving Ease, Fertility, Early Lactation Performance and Neonatal Vitality.

Butyrate promotes rumen epithelium growth and function; however, the effect of prepartum butyrate supplementation on dairy cow productivity, health and their offspring has not been extensively studied. Furthermore, no studies have investigated the effect of magnesium butyrate (MgB), which is also a source of magnesium. A trial was performed to test the hypothesis that prepartum MgB supplementation (105 g/cow/day) would increase colostrum quality and improve calving, newborn calf vitality and cow health. Multiparous Holstein cows were randomly assigned to MgB supplemented (n = 107) and Control groups (n = 112). Colostrum yield and the total yield of IgG, protein and lactose were higher (p ≤ 0.05) in the supplemented group. The calving assistance rate was lower (p ≤ 0.012), and the neonatal vitality score was higher (p ≤ 0.001) in the MgB group. Improved parameters related to cow health and fertility were observed in the supplemented group. The MgB group also had higher milk yield during the first week of lactation (p ≤ 0.001), and a higher (p ≤ 0.05) body condition score from 3 to 9 weeks after calving. In conclusion, prepartum MgB supplementation provides a wide range of benefits for dairy cows, as well as their newborn calves.

Effects of replacing inorganic salts of trace minerals with organic trace minerals in the diet of prepartum cows on quality of colostrum and immunity of newborn calves

Our objectives were to evaluate the impact of supplementary trace mineral (TM) form-inorganic salts (STM; Co, Cu, Mn, Zn sulfates, and Na selenite) or organic (OTM; Co, Cu, Mn, Zn proteinates, and selenized yeast)-in the prepartum diet on quantity and quality of colostrum, passive immunity, antioxidant biomarkers, cytokine responses to lipopolysaccharide (LPS), health, and growth of newborn calves. Pregnant heifers (n = 100) and cows (n = 173) were enrolled at 45 d before calving, blocked by parity and body condition score, and allocated randomly to STM (50 heifers; 86 cows) or OTM (50 heifers; 87 cows) supplementation. Cows in both treatments were fed the same diet, except for the source of supplementary TM. Within 2 h of calving, dams and calves were separated, colostrum was harvested, the yield was measured, and a sample was saved for posterior analyses of colostrum quality. A subgroup of calves (n = 68) had a blood sample collected before colostrum feeding. After colostrum feeding, all samples and data collection were limited to 163 calves (STM = 82; OTM = 81) fed 3 L of good quality (Brix% >22) maternal colostrum via nipple bottle minutes after harvesting. Concentration of IgG in colostrum and serum was determined 24 h after colostrum feeding using radial immunodiffusion. Concentration of TM in colostrum and serum were performed by inductively coupled plasma mass spectrometry. Activity of glutathione peroxidase, ferric reducing ability of plasma, and concentration of superoxide dismutase were evaluated in plasma by colorimetric assays. Ex vivo whole blood stimulation with LPS was performed on d 7 of life to evaluate cytokine responses in a subgroup of 66 calves. Health events were recorded from birth to weaning, and body weight was recorded at birth (all calves) and on d 30 and 60 (heifers only). Continuous variables were analyzed by ANOVA and binary responses were analyzed by logistic regression. Complete replacement of STM by OTM in prepartum diet resulted in greater concentration of Se (461 vs. 543 ± 7 μg/g; ± SEM) but did not alter the concentration or total mass of other TM and IgG in colostrum. Female calves of the OTM group had greater concentration of Se in serum at birth (0.23 vs. 0.37 ± 0.05 μg/mL), were lighter in weight at birth (40.9 vs. 38.8 ± 0.6 kg) and weaning (93.2 vs. 89.7 ± 1.6 kg) than those of the STM group. Maternal treatments did not affect passive immunity or antioxidant biomarkers. On d 7, basal concentrations (log10 of concentration in pg/mL) of IFNγ (0.70 vs. 0.95 ± 0.083) and LPS-stimulated concentrations of CC chemokine ligand 2 (CCL2; 2.45 vs. 2.54 ± 0.026), CC chemokine ligand 3 (CCL3; 2.63 vs. 2.76 ± 0.038), IL-1α (2.32 vs. 2.49 ± 0.054), and IL-1β (3.62 vs. 3.86 ± 0.067) were greater in OTM than in STM. Supplementation with OTM in pregnant heifers, but not in pregnant cows, reduced the incidence of preweaning health problems in their calves (36.4 vs. 11.5%). Complete replacement of STM by OTM in the prepartum diet did not cause major changes in colostrum quality, passive immunity, and antioxidant capacity, but increased cytokine and chemokine responses to LPS on d 7 of life and benefited preweaning health of calves born to primiparous cows.

The impact of plane of nutrition and ambient temperature on the energy utilisation, performance, health and behaviour of newborn dairy-bred bull calves

The impact of plane of nutrition and ambient temperature on the energy utilisation, performance, health and behaviour of newborn dairy-bred bull calves

Secreted Colostrum Volume, Transition and Mature Milk Outputs After Calving in Holstein Friesian Cows

Colostrum volume after calving, transition and mature milk outputs in the time from 1^st to 10^th milkings were evaluated at 30 primiparous and 30 multiparous cows milked twice daily. Colostrum volume at the first milking after calving varied from 1.5 to 19.2 kg (mean 9.44 ±5.6 kg SD) in multiparous and from 1.2 to 9.8 kg (mean 5.65 ± 2.3 kg SD) in primiparous cows. Timing of the first milking did not negatively influence colostrum volume. Colostrum volume of the second milking decreased over all multiparous and primiparous cows because the period of time between first and second milking was shorter (10.5 hours). The hourly milk outputs increased sharply from the second to the fourth milking in multiparous and primiparous Holstein Friesian cows. Applying a linear regression model we observed a significant large positive relationship between volume of colostrum at first milking and subsequent transition and mature milk outputs from 2^nd to 10^th milkings. A low colostrum volume secreted was identified in multiparous cows, as a results of sorter dry period and in primiparous cows, probably as a result of low secretory capacity of mammary gland. Extended feeding with transition milk can be real health benefits for the newborn calf.

Maternal treatment with pegbovigrastim influences growth performance and immune-metabolic status of calves during the pre-weaning period

This study aimed to investigate the immune-metabolic status and growth performance of Simmental calves born from cows subjected to pegbovigrastim administration 7 days before calving. Eight calves born from cows subjected to pegbovigrastim administration (PEG group) and 9 calves born from untreated cows (CTR group) were used. Growth measurements and blood samples were collected from birth to 60 d of age. The PEG group had lower body weight from 28 up to 60 d of age (P < 0.01), lower heart girth (P < 0.05), lower weekly and total average daily gain values (P < 0.05) than the CTR group throughout the monitoring period. A decrease in milk replacer (MR) intake was observed in the PEG group compared with the CTR group around 20–28 d of age (P < 0.01). The PEG group had lower values of γ-glutamyl transferase (GGT) at d 1 of age (P < 0.05), Zn at 21 and 28 d of age (P < 0.05), hemoglobin, MCH and MCHC at 54 and 60 d of age (P < 0.01), and higher urea concentration at 21 and 28 d of age (P < 0.05) compared with the CTR group. Lower values of retinol (P < 0.05), tocopherol (P < 0.01), mean myeloperoxidase index (P < 0.05) and higher total reactive oxygen metabolites (P < 0.05) and myeloperoxidase (P < 0.05) were also detected in the PEG group. In light of the results gathered in the current study, it can be speculated that activation of the cow's immune system by pegbovigrastim could have influenced the immune competence, growth performance as well as the balance between oxidant and antioxidant indices of the newborn calf.

Evaluation of tributyrin supplementation in milk replacer on diarrhoea occurrence in preweaning Holstein calves

Neonatal calf diarrhoea is one of the most important health challenges in cattle herds causing substantial economic losses and antimicrobial use. Due to the raising problem of antimicrobial resistance, effective alternatives are urgently required, in line with European policies. The aim of this study was to evaluate the effect of tributyrin supplementation in milk replacer on diarrhoea, performance and metabolic status in preweaning Holstein calves. Twelve newborn calves, after colostrum administration, were randomly allotted in two experimental groups for 42 days: control (CTRL) fed milk replacer, tributyrin (TRIB) fed milk replacer supplemented with 0.3% of liquid tributyrin on milk powder weight. Calves BW was recorded on a weekly basis from day 7 to day 42, and feed intake was recorded daily to calculate zootechnical performance. Faecal consistency was assessed daily through the faecal score (0–3 scale; considering diarrhoea moderate = 2 and severe = 3). Faecal samples were collected weekly from rectal ampulla for microbiological analysis by plate counting method evaluating the number of total bacteria, lactic acid bacteria and coliform bacteria. On day 0 and day 42, individual blood samples were collected from jugular vein for metabolic profile analysis. Serum samples of day 42 were also evaluated for the antioxidant barrier using a colorimetric test, while glucagon-like peptide 2 and diamine oxidase concentrations were measured through immunoenzymatic assays. Tributyrin supplementation did not influence the zootechnical performance of calves over 42 days of trial. Diarrhoea frequency was significantly lower in TRIB compared to CTRL group (27.91 and 38.37%; P < 0.01) considering the whole experimental period. In particular, the major effect was observed for moderate diarrhoea in TRIB group that showed a significantly reduced frequency compared to CTRL (P < 0.01) thus suggesting a preventive effect of tributyrin. Faecal total bacterial, lactic acid and coliform bacteria counts did not show differences between groups. Urea serum concentrations tended to be lower in TRIB compared to CTRL, indicating an efficient utilisation of dietary protein. Antioxidant barrier and glucagon-like peptide 2 were comparable between CTRL and TRIB on day 42. Diamine oxidase concentrations were significantly decreased in TRIB compared to CTRL group after 42 days of trial (P < 0.01), suggesting a higher gut epithelial integrity probably due to lower diarrhoea frequency and the nourish effect of tributyrin on enterocytes. In conclusion, tributyrin could be considered as a valuable bioactive feed additive to decrease the neonatal diarrhoea occurrence and support intestinal integrity in preweaning calves.

Confirmation of the passive transfer of maternal antibodies to calves following vaccination of pregnant cows with an inactivated Mannheimia haemolytica and Bovine herpes virus type 1 vaccine.

The objective of this study was to evaluate the passive transfer of maternal antibodies to calves following vaccination of pregnant cows with an inactivated Mannheimia haemolytica (MH) and Bovine herpes virus type 1 (IBR) vaccine (Bovilis® MH + IBR). Sixty-two pregnant cows were allocated at random to two groups; one group was retained as a negative control group (T01), while the other group (T02) was vaccinated with Bovilis® MH + IBR on two occasions during their third trimester of pregnancy. Following calving, blood samples were collected from calves for the measurement of serum antibody titres to IBR and MH, with samples collected prior to suckling (Day 0) and on days 5 (±2), 14 (±3), 28, 56, 84, 112, 140, 168, 196, 224, 252 and 280. The group mean IBR blocking percentage remained low for T01 calves (calves born to T01 cows) between days 0 and 224 (range 4.5%-15.4%), while the group mean IBR blocking percentage increased for T02 calves (calves born to T02 cows) from 14.3% on Day 0 to 94.9% on Day 5 and remained significantly higher than T01 calves up until Day 252. The group mean MH titre (Log2) for T01 calves increased after suckling to 8.9 on Day 5, before declining and remaining stable (range 5.0-6.5). The group mean MH titre for T02 calves increased after suckling to 13.6 on Day 5 and then gradually declined; however, it remained significantly higher than T01 calves between days 5 and 140. Outcomes from this study have confirmed that colostral transfer of IBR and MH antibodies to newborn calves was successful and a high level of passive immunity was acquired by calves.

The prevalence and factors contributing to the incidence of neonatal gastroenteritis in newborn calves

The results of monitoring the situation of neonatal gastroenteritis of calves are presented for four farms in the north-western districts of the Saratov region, during the period of mass calving. The incidence of neonatal gastroenteritis of calves was 11.92 - 16.36%. Factors contributing to the morbidity of newborn calves with neonatal gastroenteritis - complications of pregnancy, depending on the gestational period, subclinical ketosis (27.65%), osteodystrophy (15.71%), liver and kidney diseases (10.59%) have been established. In 30.23% of calves with NG, a large number of under-oxidized metabolic products and impaired liver and kidney function were observed. In patients with severe neonatal gastroenteritis, the following indicators were at a low level: alkaline reserve (40.8 ± 1.3 vol% CO2), glucose content (2.86± 0.12 mmol/L). In the central part of the liver, large-drop granular dystrophy is observed with the preservation of the structure of hepatocytes.

Management and Behavior of Livestock Guarding Dogs in a Multiuse Rural Landscape in Northern Israel

The efficacy of livestock guarding dogs (LGDs; Canis familiaris) on modern ranches in the dense multiuse landscape of rural northern Israel is controversial. Minimal time is spent by the ranchers with the herd and LGDs, and the LGDs are known to wander to nearby army bases, homesteads, villages, and other facilities. Thirteen Akbash and six mixed-breed LGDs guarding cattle in a paddock were observed through direct observations and tracking with Global Positioning System collars. Predator presence and interaction with LGDs were recorded using telemetry and trail cameras. In addition, 10 local ranchers were interviewed to assess the effects of management and LGD use on depredation. We expected Akbash LGDs to exhibit behavioral traits consistent with depredation mitigation and that differing ranch-LGD management methods would impact depredation levels. At the study ranch, depredations were at a minimum despite the presence of three wolf packs (Canis lupus) and jackals (Canis aureus) in the vicinity of the observed ranch. The Akbash LGDs spatially displaced wolves and temporally displaced jackals, but they also regularly roamed away from the paddock and returned. In addition, Akbash LGDs were more likely to follow the herd than mixed-breed LGDs; the total number of LGDs in the paddock increased with the number of newborn calves; and LGD intra-aggression increased with the number of LGDs present in the paddock. In the survey, we found little relationship between ranch management type and depredation outcomes. In particular, the use of protective enclosures by some ranches did not mitigate depredation compared with ranches without enclosures. In modern multiuse landscapes, Akbash LGDs show potential for being an important component of depredation mitigation, but their relative contribution needs to be studied further. In addition, the use of protective enclosures, which are known to have negative ecological impacts, should be reconsidered. Several improvements to LGD management are suggested.

Recombinant Hexon Protein as a New Bovine Adenovirus Type 3 Subunit Vaccine Candidate.

Bovine adenovirus (BAdV) type 3 causes respiratory and gastroenteric diseases of varying severity in cattle, particularly newborn calves. Trials have been conducted of a vaccination against the diseases caused by BAdV using both modified live-virus and inactivated-virus preparations in cattle, but no commercial BAdV-3 vaccine has yet reached the market. Therefore, there is an urgent need to develop new, safe, and effective vaccines against BAdV-3. Recombinant hexon protein (rhexon) of BAdV-3 was expressed in the E. coli system to evaluate immune response in mice and goats. Antibody responses and cytokine levels were analysed and the effects of administrations of different amounts of recombinant protein compared. Long-term antibody production was evaluated by indirect ELISA, and the total immunoglobulin G secreted by goats and mice immunised with the purified rhexon protein was determined. The immunised mice had a stronger antibody response than the control group at eight weeks post vaccination. The immunised groups also showed significantly higher (P ˂ 0.05) expression of interferon-γ, interleukin 2 (in mice), and interleukin 21 (in goats) at four weeks. Furthermore, vaccination with rhexon was able to induce long-term antibody production for at least 16 weeks in mice and goats. The rhexon protein induced immune responses, especially long-term antibody production and T helper 1 cell cytokine production in mice and goats. The immunogenic properties of this protein make it a promising subunit vaccine antigen.

Importance of Monitoring Fetal and Neonatal Vitality in Bovine Practices.

Prior to initiating any obstetrical intervention for anterior or posterior presentation, it is imperative to emphasize the need for a precise and accurate diagnosis of fetal viability and to select the most appropriate approach for assistance. In uncertain cases, diagnostic tools such as ultrasonography, pulse oximeter, or measurement of acid-base balance or lactate concentration may be employed to confirm the diagnosis. In situations of severe asphyxia, a cesarean section is preferred over traction, even if the duration of asphyxia is less than 60 s, to maximize the likelihood of the survival of the fetus. Postcalving, several vitality scores have been proposed to evaluate the vigor of the newborn calf. Originally, four different clinical signs were recommended for assessing the well-being of newborn calves. Subsequently, five or more different clinical signs were recommended to evaluate vitality. However, despite the efforts for devising a practical tool to assess newborn calf vitality; a user-friendly and highly accurate instrument that can be used on farms remains elusive. Measuring the acid-base balance or lactate concentration may increase the diagnostic accuracy. It is critical to emphasize the importance of reducing the incidence of dystocia to mitigate the occurrence of severe asphyxia. In instances where asphyxia is unavoidable, adequate treatments should be administered to minimize losses.