Calf Plasma Research Articles

Metabolic profile of prepartum dairy cows and its influence on the immediate postpartum period, colostrum quality and passive immunity transference

The objective of this study was to evaluate which biochemical markers in the prepartum period of dairy cows influence the immediate postpartum period, the quality of colostrum, and the passive immunity transference in the calves. The experiment was performed on a commercial dairy farm with 52 pregnant multiparous Holstein cows. Animals that gave birth to twins or males were discarded from the experiment. On days −20 of the expected calving date and 24 hours after calving, blood collections, body condition score assessments, and animals weighing were performed. Blood samples from calves were performed 24 hours after colostrum intake. Calf plasma was used to estimate the passive immunity transfer by % brix and total plasma proteins (TPP). In the principal component analysis, it was shown that postpartum NEFA and BHBA was higher in cows with higher prepartum urinary pH and Ca lower prepartum. The cows with the highest NEFA and BHBA in pre and postpartum were the ones that had the lowest % brix in the colostrum. The % brix of the cow’s colostrum directly influenced the % brix and TPP of the calves. The NEFA in the cows prepartum negatively influenced the markers of immunity, the higher the NEFA, the lower the % brix of the cows’ colostrum, % brix of the calves, and TPP. In multivariate regression analyses it was shown that pre-calving NEFA was the marker that most influenced post-calving cow markers and calf % brix, along with colostrum time and % brix of the colostrum (P= 0.0092; r2= 0.83). Cows with higher values NEFA in the prepartum had lower calcemic in the immediate postpartum period. Prepartum NEFA was the marker that most influenced the cows’ immediate postpartum period, being directly related to Ca serum, and also to the passive immunity transference.

The Effect of Different Forms of Solid Feed on Biochemical Parameters in Blood Plasma of Calves

Abstract The study examined how different solid feeds affected the biochemical parameters in calf plasma. The experiment involved a control group and three test groups of calves, each fed with a different starter mixture. The results showed significant differences in some biochemical parameters between the feeding groups. Calves in groups P1 and P3 had a statistically higher glucose concentration in blood plasma compared to group C. Calves from group P3 had a higher concentration of urea in blood plasma than calves from group C. Calves in groups P1 and P3 also had higher concentrations of total protein and globulin in blood plasma compared to group C. The concentration of inorganic phosphate in the blood plasma of calves from group P3 was significantly higher than that of group C. Female calves in the experimental groups showed a lower concentration of NEFA at three months of age compared to the control group. It was concluded that feeding calves with a starter mixture containing whey and easily digestible protein had a positive effect on the nutritional status and energy balance of the calves.

Effect of Dietary Eicosapentaenoic and Docosahexaenoic Fatty Acid Supplementation during the Last Month of Gestation on Fatty Acid Metabolism and Oxidative Status in Charolais Cows and Calves.

Fatty acids (FAs) are of utmost importance in the peripartal period for the development of the central nervous and immune systems of the newborn. The transport of polyunsaturated fatty acids (PUFAs) through the placenta is considered to be minimal in ruminants. Nevertheless, the cow's FAs are the main source of FAs for the calf during gestation. This research aimed to investigate the influence of low-dose eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) supplementation during late gestation on the FA metabolism of cows and their calves. A total of 20 Charolais cows during the last month of their gestation were included in the feeding trial and were divided into a control group (CON) and an experimental group (EPA + DHA). The latter received a supplement in the amount of 100 g/day (9.1 and 7.8 g/cow/day of EPA and DHA, respectively). Supplementation of low-dose EPA and DHA alters colostrum and milk fatty acid composition through the elevation of n-3 long-chain polyunsaturated fatty acids (LC-PUFAs) without affecting milk fat and protein concentrations and oxidative status. Plasma composition in cows was significantly altered, while the same effect was not detected in calf plasma. No significant change in mRNA expression was detected for the genes fatty acid synthase (FASN) and acetyl-CoA carboxylase alpha (ACACA).

Comparison of functional indices of hemostasis of cows and calves obtained taking into account body temperature

This paper shows the results of the study of the effect of temperature on the coagulation processes in the hemostasis of cows and calves. Purpose of the work: comparison of the results of the study of the indicators of the coagulation system of blood of cows and calves of the black-and-brown breed, obtained with the use of medical and veterinary coagulometer, taking into account the age of the animal and its body temperature. The study was conducted in the Vologda region of Russia. The following coagulogram parameters were analyzed: thrombin time, prothrombin time, activated partial thromboplastin time, fibrinogen count. It was found that at physiological temperature on a veterinary coagulometer in the plasma of cows there is a reliable increase in thrombin time by 2.2 times, decrease in prothrombin time by 32.5%, increase in activated partial thromboplastin time by 11.2%, increase in the amount of fibrinogen by 315.4%; in calf plasma - decrease of thrombin time by 7.8%, increase of prothrombin time by 6.2%, increase of activated partial thromboplastin time by 20.9%, increase of fibrinogen amount by 347.6% in comparison with the results obtained during standard incubation at 37°C. The correlation between hemostasis indicators and temperature factor in cows was noticeable (thrombin time, fibrinogen), in calves negative moderate for thromboplastin time, moderate for activated partial thromboplastin time and noticeable for prothrombin time and fibrinogen. The study of coagulation processes in cows and calves using a medical coagulometer led to the results that differ significantly from the reactions occurring in the organism at physiological body temperature. Taking into account the results of the study, it is possible to consider a veterinary coagulometer with the possibility of setting the necessary temperature as a device quite suitable for adequate assessment of hemostasiological parameters in cattle.

SDS-page of magnetic isolated fraction from plasma of buffalo calves after depletion of high abundance proteins

SDS-page of magnetic isolated fraction from plasma of buffalo calves after depletion of high abundance proteins

Evaluation of an immunochromatographic point-of-care test for the detection of failure of transfer of passive immunity in calves

BackgroundAs calves are born without circulating immunoglobulin G (IgG) they depend on transfer of passive immunity via colostrum within the first hours of life. If calves are not sufficiently supplied with high qualitative colostrum they suffer from Failure of Transfer of Passive Immunity (FTPI). The objectives of this study were to evaluate a calf-side point-of-care test to detect calves with FTPI and to evaluate the cut-offs for a positive test result. Two hundred fifty calves from 11 dairy farms (born between September 2021 and September 2022) were included, whereof 23 were excluded due to incomplete data. Twelve to 16 h post partum the farmers carried out a point-of-care test (FASTest® IgG bovine, Megacor, Austria) using a whole blood sample. Between the 3rd and the 6th day of age, all calves were physically examined and blood samples were collected to carry out further point-of-care tests using whole blood supernatant and plasma and for measuring the Brix values in serum and plasma. Brix values in serum were used as reference for the evaluation of the point-of-care test between the 3rd and the 6th day of age, as radial immunodiffusion assays could not be conducted simultaneously.ResultsBrix values were not normally distributed (median at 8.6% and 9.3% in serum and plasma). In this study, the cut-off values for the point-of-care tests using whole blood supernatant and plasma were at 8.3% Brix in serum. FASTest® IgG bovine shows high sensitivities of 90% and 84% and specificities of 70% and 72% for whole blood supernatant and plasma.ConclusionsOf the 227 investigated calves, 39.7% showed Brix values of < 8.4% (cut-off for FTPI) which indicates an urgent need to improve colostrum management. The results of the study suggest that the FASTest® IgG bovine is a suitable on-farm method to assess FTPI in whole blood supernatant and plasma of calves between the 3rd and the 6th day of age. However, the results also show that FASTest® IgG bovine is not adequate to test for FTPI using whole blood at 12 to 16 h post partum.

Effects of copper, zinc, and manganese source and inclusion during late gestation on beef cow-calf performance, mineral transfer, and metabolism.

To determine effects of Cu, Zn, and Mn source and inclusion during late gestation, multiparous beef cows [n = 48; 649 ± 80 kg body weight (BW); 5.3 ± 0.5 body condition score (BCS)] were individually-fed hay and supplement to meet or exceed all nutrient recommendations except Cu, Zn, and Mn. From 91.2 ± 6.2 d pre-calving to 11.0 ± 3.2 d post-calving, cows received: no additional Cu, Zn, or Mn (control, CON), sulfate-based Cu, Zn, and Mn (inorganic, ITM) or metal methionine hydroxy analogue chelates (MMHAC) of Cu, Zn, and Mn at 133% recommendations, or a combination of inorganic and chelated Cu, Zn, and Mn (reduce and replace, RR) to meet 100% of recommendations. Data were analyzed with treatment and breeding group (and calf sex if P < 0.25 for offspring measures) as fixed effects, animal as experimental unit, and sampling time as a repeated effect for serum, plasma, and milk measures over time. Post-calving cow liver Cu was greater (P ≤ 0.07) in MMHAC compared with all other treatments. Calves born to RR had greater (P ≤ 0.05) liver Cu than ITM and CON, and MMHAC had greater (P = 0.06) liver Cu than CON. Liver Mn was less (P ≤ 0.08) for RR calves than all other treatments. Calf plasma Zn was maintained (P ≥ 0.15) from 0 to 48 h of age in ITM and MMHAC but decreased (P ≤ 0.03) in CON and RR. Gestational cow BW, BCS, and metabolites were not affected (P ≥ 0.13) by treatment, but gestational serum thiobarbituric acid reactive substances (TBARS) were greater (P = 0.01) for CON than MMHAC. Treatment did not affect (P ≥ 0.13) calf birth size, vigor, placental size and minerals, or transfer of passive immunity. Neonatal calf serum Ca was greater (P ≤ 0.05) for MMHAC than all other treatments; other calf serum chemistry and plasma cortisol were not affected (P ≥ 0.12). Pre-suckling colostrum yield, and lactose concentration and content, were greater (P ≤ 0.06) for MMHAC compared with ITM and RR. Colostral triglyceride and protein concentrations were greater (P ≤ 0.08) for RR than MMHAC and CON. Cow lactational BW and BCS, milk yield and composition, and pre-weaning calf BW and metabolism were not affected (P ≥ 0.13) by treatment. Lactational serum TBARS were greater (P = 0.04) for RR than CON at day 35 and greater (P ≤ 0.09) for MMHAC at day 60 than all other treatments. Source and inclusion of Cu, Zn, and Mn altered maternal and neonatal calf mineral status, but calf size and vigor at birth, passive transfer, and pre-weaning growth were not affected in this study.

O45 Relationship between plasma and saliva urea nitrogen in New Zealand red deer calves (Cervus elaphus)

O45 Relationship between plasma and saliva urea nitrogen in New Zealand red deer calves (Cervus elaphus)

Lipid composition of blood plasma and epithelium of the jejunal mucosa in calves with dyspepsia and its correction

Enteropathology in newborn ruminants significantly affects the functional formation of the digestive tract, which induces complications in other organs and systems, reducing the resistance and productivity in recovered animals. It is also characterized by metabolic disorders, particularly lipids, which adversely affects the regenerative processes at the cellular level. The material for the study was 2-day-old calves, from which 3 groups of 6 animals each were formed. 1st group – control was made up of clinically healthy animals, 2nd group – calves with toxic dyspepsia which received traditional treatment and 3rd group – calves which were additionally orally administered a liposomal form of a 1% solution of BAD "FLP-MD". The lipid composition of blood plasma and the epithelium of the mucous membrane of the jejunum of calves was studied by the method of thin-layer chromatography on standard Silufol plates. The lipidogram of blood plasma in 30-day-old calves recovered from dyspepsia under traditional treatment regimen was characterized by dyslipidemia, which was manifested by an increase in total lipid content by 10.0% amid hypercholesterolemia and hypertriacylglycerolemia and a decrease in free fatty acids by 24.6% and phospholipids by 11.8%. Also, phosphatidylcholine and sphingomyelin content decreasesd in the blood plasma. In epithelium of the jejunal mucosa, total lipid content decreased due to total cholesterol, triacylglycerols, and phospholipids. The restoration of total lipid content and individual fractions was found in blood plasma of calves that received additionally phospholipid-containing bio-additive "FLP-MD". Among the individual phospholipids phosphatidylcholine, phosphatidylethanolamine and phosphatidylserine prevailed. In these calves, most of the lipid components in the epithelium of the jejunal mucosa were stabilized. In the future, we plan to investigate the content of total lipids in the blood and mucous membrane of the small intestine of calves.

The effect of heat treatment on colostral and newborn calf redox status and oxylipid biomarkers

Newborn calves experience altered redox balance upon transition to extrauterine life. In addition to its nutritional value, colostrum is rich in bioactive factors, including pro- and antioxidants. The objective was to investigate differences in pro- and antioxidants as well as oxidative markers in raw and heat-treated (HT) colostrum and in the blood of calves fed either raw or HT colostrum. Eleven colostrum samples (≥8 L) of Holstein cows were each divided into a raw or HT (60°C, 60 min) portion. Both treatments were stored for <24 h at 4°C and tube-fed in a randomized-paired design at 8.5% of body weight to 22 newborn female Holstein calves within 1 h after birth. Colostrum samples were obtained before feeding, and calf blood samples were taken immediately before feeding (0 h) and at 4, 8, and 24 h after feeding. All samples were analyzed for reactive oxygen and nitrogen species (RONS) and antioxidant potential (AOP), from which the oxidant status index (OSi) was calculated. In 0-, 4-, and 8-h plasma samples, targeted fatty acids (FA) were analyzed using liquid chromatography-mass spectrometry, and oxylipids and isoprostanes (IsoP) using liquid chromatography-tandem mass spectrometry. Results for RONS, AOP, and OSi were analyzed by mixed-effects ANOVA or mixed-effects repeated-measures ANOVA, for colostrum and calf blood samples, respectively, whereas FA, oxylipid, and IsoP were analyzed using false discovery rate-adjusted analysis of paired data. Compared with control, HT colostrum showed lower RONS [least squares means (LSM) 189, 95% confidence interval (95% CI): 159-219 vs. 262, 95% CI: 232-292) relative fluorescence units] and OSi (7.2, 95% CI: 6.0-8.3 vs. 10.0, 95% CI: 8.9-11.1), but AOP remained unchanged (26.7, 95% CI: 24.4-29.0 vs. 26.4, 95% CI: 24.1-28.7 Trolox equivalents/µL). Changes in colostrum oxidative markers due to heat treatment were minor. No changes in RONS, AOP, OSi, or oxidative markers were detected in calf plasma. In both groups of calves, plasma RONS activity declined considerably at all postfeeding time points compared with precolostral values, and AOP reached its maximum 8 to 24 h after feeding. Generally, oxylipid and IsoP plasma abundance reached nadirs at 8 h post-colostrum in both groups. Overall, effects due to heat treatment on redox balance of colostrum and newborn calves and on oxidative biomarkers were minimal. In this study, heat treatment of colostrum reduced RONS activity but did not lead to detectable changes in calf oxidative status overall. This indicates that there were only minor changes in colostral bioactive components that could alter newborn redox balance and markers of oxidative damage.

ИЗУЧЕНИЕ ЭФФЕКТИВНОСТИ ИСПОЛЬЗОВАНИЯ В РАЦИОНАХ ТЕЛЯТ СУХОЙ ПЛАЗМЫ КРОВИ

The article describes the effectiveness of preventive use of dry blood plasma in calves' diets, ways to increase total protein, contributing to increased resistance. When plasma was used in the calves' diet, it was noted that the animals were mobile, active, appetite was expressed, a low percentage of morbidity was established (3-4%), weight gain was better (by 10-15%), mortality was not observed. In the control group, no special changes were observed from the moment of the experiment, some animals were sedentary, there was a decrease in appetite, the percentage of morbidity (8-12%).

High frequency of delayed milk delivery to neonates in tropical beef herds.

Beef-calf mortality rates across tropical and subtropical Australia are high, with sub-optimal nutrition in pregnant cows being the primary risk. The nutritional deficiencies associated with calf mortality are the same as those associated with reduced milk yields. Although the highest mortality risk occurs during neonatal life, the role of inadequate milk delivery to beef neonates is not well established. This study investigated the frequency of low milk delivery in tropically adapted neonatal calves and the time for their dams to initiate full lactation in five management groups of Brahman and Droughtmaster calving cows in the dry tropics of northern Queensland, Australia. Change in calf weight in the days following birth was the primary measure of milk uptake. Plasma globulin concentration was used to indicate colostrum uptake. Across management groups, data were available on 250 calves for regression analysis of average daily gain vs. globulin and on 78 for plotting calf growth profiles. Calves had one of two growth profiles, either with immediate high growth from birth (day one) or with high growth delayed until day three. The frequency of delayed growth calves (with inadequate milk intake to gain at least 0.5kg by day three after birth) was on average 30% across management groups, with management groups ranging 25%-50%. The frequency of calves growing ≤0.2kg/day to day three was 15%-37%, depending on management group. The frequency of calves growing ≤0.2kg/day to day five was 7%-20%, depending on management group. Calf globulin explained only 25% of the variation in calf average daily gain. Our study shows that a third of tropically adapted calves may experience a three-day delay to initiation of full lactation by their dams. Although study conditions were relatively benign, any additional risks with milk delivery, such as those that occur widely in tropical and subtropical northern Australia, would place such calves at risk of dehydration and mortality. Calf plasma globulin should not be used as a standalone measure of adequacy of neonatal milk delivery, especially when comparing across herds. This study demonstrates a fundamental problem of high frequency in northern Australia. The underlying risks for delayed milk delivery should be considered in the quest for practical solutions to reduce tropically adapted beef-calf mortalities.

Energy restriction and housing of pregnant beef heifers in mud decreases body weight and conceptus free live weight.

Average temperatures in the Midwest, USA are predicted to increase 2–9°C by the end of the century; resulting in muddy pastures for spring calving beef heifers as they enter late gestation. The objective of this study was to evaluate the effects of muddy conditions on heifer body weight (BW), body condition score (BCS), conceptus free live weight (CFLW), and fetal growth when heifers were energy restricted during late gestation. Eighteen Angus heifers (n = 9/treatment) were paired based on initial BW. One heifer from each BW pair was randomly allocated to either the mud (MUD) or control (CON) treatment on day 196 of gestation. Pens in the CON treatment were bedded with wood chips, while pens in the MUD treatment were filled with mud (average depth of 19.5 ± 7.9 cm). Heifers were housed individually and fed the same diet that consisted of a limit-fed total mixed ration from day 196 to 266 of gestation that was formulated to meet 66% of the net energy for maintenance, growth, and gestation requirements. Requirements and the amount of the diet offered were adjusted weekly, and heifers were weighed and sampled for blood metabolites weekly. Data were analyzed as a randomized complete block design with repeated measurements. There was a treatment × day of gestation interaction, such that heifers had similar BW, BCS, and CFLW on day 196 of gestation. By day 266 of gestation; however, heifers in the MUD treatment weighed 43.5 kg less (P < 0.01) and were 1.8 BCS units less (P < 0.01) than heifers in the CON treatment. This is further supported by the treatment × day effects we observed for back fat (BF) and rump fat (RF) thickness, such that the MUD heifers had less BF (P = 0.02) and RF (P < 0.01) by day 266 of gestation. There was a marginally significant difference for gestation length (P = 0.06), such that heifers in the MUD treatment calved approximately 3.1 days before the heifers in the CON treatment. Though heifers in the MUD treatment decreased their BW and CFLW during the treatment period, we did not observe a difference in calf birth weight (P = 0.34), calf plasma IgG concentration (P = 0.37), or calf weaning weight (P = 0.63). Despite heifers in the MUD treatment having greater BW, CFLW, and BCS losses compared with the heifers in the CON treatment, the heifers in the MUD treatment seemed to prioritize fetal growth, as they mobilized their body tissues to meet the energetic demands of pregnancy.

Substance P concentrations in the blood plasma and serum of adult cattle and calves during different painful procedures and conditions – a systematic review

BackgroundPain in cattle is a major welfare problem, as cattle mask their pain. Subjective and objective parameters to assess pain in cattle have been described. Among the objective parameters to evaluate pain in cattle is substance P (SP). SP is a neurotransmitter, which is involved in the processing of noxious information to the brain; it seems to be a more objective indicator for nociception than cortisol, which has long been used as a biomarker for pain and stress in cattle. The objective of this systematic review was to assess the existing literature about SP during painful procedures, conditions, and diseases in cattle in form of a systematic review.ResultsFollowing the PRISMA statement, 36 out of 236 studies were included in this systematic review. Study design, grouping, age and weight of animals, processing of blood samples for the assessment of SP, and results were heterogenous. The largest number of studies originated from the United States of America and Canada and were published in 2018. A higher number of studies were done on calves (69.4%, n = 25) compared with adult cattle (30.6%, n = 11). Most studies were done to assess SP concentrations after administration of analgesics prior to husbandry procedures in calves.ConclusionsThere is a manageable number of studies assessing SP concentrations during painful procedures, conditions, and diseases in cattle. SP seems to be a suitable biomarker for nociception in cattle, but results of research work are heterogenous, and SP concentrations of calves and adult cattle differ throughout studies. Basic research work is missing and is needed to assess factors others than nociception which might influence the SP concentrations in the blood plasma.

Can diarrhea affect the pharmacokinetics of racecadotril in neonatal calves?

This study was aimed to determine the pharmacokinetics of antisecretory-acting racecadotril, used in the treatment of diarrhea in humans and dogs, following oral administration in both neonatal calves with healthy and neonatal calves with infectious diarrhea. The study was carried out on a total of 24 Holstein calves (2-20 days), of which 6 were healthy and 18 were infectious diarrhea. Calves with infectious diarrhea were divided into 3 groups according to the infectious agent (Escherichia coli, Cryptosporidium parvum, and rotavirus/coronavirus). Racecadotril was administered orally at 2.5mg/kg dose to calves. The plasma concentrations of racecadotril and its main active metabolite (thiorphan) were determined using HPLC-UV. The pharmacokinetic parameters were analyzed using the non-compartmental method. In healthy calves, the t1/2ʎz , Cmax , Tmax, and AUC0-12 of racecadotril were determined 4.70 h, 377 ng/ml, 0.75 h, and 1674 h× ng/ml, respectively. In the plasma of calves with infectious diarrhea, racecadotril and thiorphan were only detected at the sampling time from 0.25 to 1.5h. As in calves with infectious diarrhea, thiorphan in plasma was only detected in healthy calves from 0.25 to 1.5h. Racecadotril showed a large distribution volume, rapid elimination, and low metabolism to thiorphan in healthy calves.

Validation of serum paraoxonase/arylesterase 1 (PON1) as a protein marker of illicit dexamethasone treatment in veal calves

The illicit use of dexamethasone and other glucocorticoids for cattle fattening in livestock production has been widely described; evidence for illegal treatments can be obtained by direct or indirect detection. In our previous study, we applied two-dimensional electrophoresis (2DE) to identify plasma protein markers of dexamethasone administration in veal calves. Comparison of 2DE maps obtained from blood samples before and after treatment showed the disappearance of two protein spots identified as serum paraoxonase/arylesterase 1 precursor (PON1). In the present study, we validated PON1 as a marker by analysing a larger number of samples treated with dexamethasone for illicit use. Analysis of samples from experimental treatment with other glucocorticoids, androgens and oestrogens confirmed that their influence on PON1 could be excluded. The specificity of the PON1 protein marker was verified on expected negative field samples to exclude interfering factors. However, there is poor statistical evidence to support a significant association between the outcome of PON1 and the considered variables. The results on field samples were compared with histological examination of the thymus as a biomarker of corticosteroid treatment monitored in the Italian histological plan for the control of growth promoters in animals. Two suspect cases were identified from two Piedmont farms where other animals had tested positive at histological examination. In conclusion, the absence of PON1 in the plasma of veal calves can indirectly reveal illicit dexamethasone treatment in individual animals and so identify suspect farms for further investigation. It is effective in a period ranging from 3 to about 10 days from illicit treatment, covering a time span that goes beyond the limits of official chemical controls and preceding histological controls on the thymus of slaughtered animals. PON1 detection in plasma can be coupled with other tests to identify illegal dexamethasone use on veal calf farms.

Comparisons of plasma and fecal pharmacokinetics of danofloxacin and enrofloxacin in healthy and Mannheimia haemolytica infected calves

Danofloxacin and enrofloxacin are fluoroquinolones (FQs) used to treat and control bovine respiratory disease (BRD) complex. While low toxicity, high bactericidal activity, and availability in single and multiple dosing regimens make them preferable, the increasing incidence of FQ-resistance in foodborne pathogens and effects on gut microbiota necessitate evaluating their pharmacokinetics (PKs). The objective of this study was to determine the exposure level of gut microbiota to subcutaneously administered FQs and compare their PKs between plasma and feces in healthy and Mannheimia haemolytica infected calves. A single dose of danofloxacin (8 mg/kg), low dose (7.5 mg/kg), or high dose (12.5 mg/kg) of enrofloxacin was administered to calves. Blood and feces were collected from calves under experimental conditions over 48 h, and FQ concentrations were measured using Ultra High-Pressure Liquid Chromatography. While moderate BRD signs were exhibited in most calves in the infected cohorts, the plasma PKs were similar between healthy and sick calves. However, the fecal danofloxacin concentration was lower in the BRD group (area under concentration–time curve [AUCinf], BRD median = 2627, healthy median = 2941 h*μg/mL, adj.P = 0.005). The dose normalized plasma and fecal danofloxacin concentrations were higher than those of enrofloxacin and its metabolite ciprofloxacin. Further, FQs had several fold higher overall concentrations in feces than in plasma in both groups. In conclusion, parenterally administered FQs expose gut microbiota to high concentrations of the antibiotics.

Integrated 16S rDNA Gene Sequencing and Untargeted Metabolomics Analyses to Investigate the Gut Microbial Composition and Plasma Metabolic Phenotype in Calves With Dampness-Heat Diarrhea.

Dampness-heat diarrhea (DHD), a common syndrome in Chinese dairy farms, is mainly resulted from digestive system disorders, and accompanied with metabolic disorders in some cases. However, the underlying mechanisms in the intestinal microbiome and plasma metabolome in calves with DHD remain unclear. In order to investigate the pathogenesis of DHD in calves, multi-omics techniques including the 16S rDNA gene sequencing and metabolomics were used to analyze gut microbial compositions and plasma metabolic changes in calves. The results indicated that DHD had a significant effect on the intestinal microbial compositions in calves, which was confirmed by changes in microbial population and distribution. A total of 14 genera were changed, including Escherichia-Shigella, Bacteroides, and Fournierella, in calves with DHD (P < 0.05). Functional analysis based on the Kyoto Encyclopedia of Genes and Genomes (KEGG) annotations indicated that 11 metabolic functions (level 2) were significantly enriched in DHD cases. The untargeted metabolomics analysis showed that 440 metabolites including bilineurin, phosphatidylcholine, and glutamate were significantly different between two groups (VIP > 1 and P < 0.05), and they were related to 67 signal pathways. Eight signal pathways including alpha-linolenic acid, linoleic acid, and glycerophospholipid metabolism were significantly enriched (P < 0.05), which may be potential biomarkers of plasma in calves with DHD. Further, 107 pairs of intestinal microbiota-plasma metabolite correlations were determined, e.g., Escherichia-Shigella was significantly associated with changes of sulfamethazine, butyrylcarnitine, and 14 other metabolites, which reflected that metabolic activity was influenced by the microbiome. These microbiota-metabolite pairs might have a relationship with DHD in calves. In conclusion, the findings revealed that DHD had effect on intestinal microbial compositions and plasma metabolome in calves, and the altered metabolic pathways and microorganisms might serve as diagnostic markers and potential therapeutic targets for DHD in calves.

Interaction of Antioxidant Trace Minerals Affecting Blood Picture Including Antioxidant Profile of Healthy Buffalo (Bubalus bubalis) Calves.

Copper (Cu) and selenium (Se) are antioxidants and essential trace elements that have mutual interaction and are reported to have beneficial effects at supranutritional levels. The experiment was executed to evaluate the individual impact of supranutritional levels of targeted elements with the effect of their interactions in buffalo calves. Twenty male Murrah buffalo calves of about 8-9months (bodyweight 112.1 ± 7.69kg) were distributed into four groups of five calves in each group and fed either a control (C) diet or supplemented with supranutritional levels of Cu (T1), Se (T2), or combination of both (T3) for 120days. Higher (P = 0.015) values of packed cell volume were observed in group T2 at day 120; otherwise, all other hematological parameters remained comparable among groups. Over the period (day 120 vs. day 0), an enhancement in the percentage of lymphocytes (P = 0.006) with a reduction in neutrophils (P = 0.028) and hemoglobin (P = 0.024) values was observed in the control group. An enhancement in the percentage of monocytes (P = 0.031), with a reduced percentage of neutrophils (P = 0.022), was reported in groups T2 and T3, respectively. Interaction of Cu and Se at supranutritional level (T3) dramatically reduced plasma Cu (P = 0.008) level against the control values, with an improvement in Se markers (i.e., plasma Se, P = 0.041 and enzyme glutathione peroxidase, P = 0.057) over the values in calves fed supplemental Se alone (T2). Additionally, Cu (T1 and T3) was forced to decline (P < 0.05) Zn level in the plasma of buffalo calves. Cu (T1, P < 0.05) and Se (T2 and T3, P ≤ 0.01) supplementation was able to improve their respective plasma levels. The interaction of two trace elements at the supranutritional level further helped in reducing the lipid peroxidation (P = 0.01) values as well. Though antioxidant vitamins and cell-mediated immunity remained unaffected, humoral immunity against antigen P. multocida was high (P = 0.005) in the group T2. The conclusion may be drawn that supranutritional Cu and Se were capable to influence certain blood parameters with an additional interaction effect due to simultaneous supplementation in buffalo calves.

Pharmacokinetics in plasma and alveolar regions of a healthy calf intramuscularly administered a single dose of orbifloxacin.

This study analyzed the pharmacokinetics of orbifloxacin (OBFX) in plasma, and its migration and retention in epithelial lining fluid (ELF) and alveolar cells within the bronchoalveolar lavage fluid (BALF). Four healthy calves received a single dose of OBFX (5.0 mg/kg) intramuscularly. Post-administration OBFX dynamics were in accordance with a non-compartment model, including the absorption phase. The maximum concentration (Cmax) of plasma OBFX was 2.2 ± 0.1 μg/ml at 2.3 ± 0.5 hr post administration and gradually decreased to 0.3 ± 0.2 μg/ml at 24 hr following administration. The Cmax of ELF OBFX was 9.3 ± 0.4 μg/ml at 3.0 ± 2.0 hr post administration and gradually decreased to 1.2 ± 0.1 μg/ml at 24 hr following administration. The Cmax of alveolar cells OBFX was 9.3 ± 2.9 μg/ml at 4.0 hr post administration and gradually decreased to 1.1 ± 0.2 μg/ml at 24 hr following administration. The half-life of OBFX in plasma, ELF, and alveolar cells were 6.9 ± 2.2, 7.0 ± 0.6, and 7.8 ± 1.6 hr, respectively. The Cmax and the area under the concentration-time curve for 0–24 hr with OBFX were significantly higher in ELF and alveolar cells than in plasma (P<0.05). These results suggest that OBFX is distributed and retained at high concentrations in ELF and alveolar cells at 24 hr following administration. Hence, a single intramuscular dose of OBFX (5.0 mg/kg) may be an effective therapeutic agent against pneumonia.