Automated milking systems (AMS) are increasingly adopted for dairy cow production, promoting individualized cow management dependent on factors like lactation stage, age, and productivity. The study objective was to investigate the effects of early lactation milking frequency on cows milked via AMS. Multiparous Holstein cows blocked by parity and due date were randomly assigned to treatments (n = 8 per treatment): three (3X) or six (6X) milkings per day (MPD). The experimental phase (EXP) was defined as 4 to 29 days in milk (DIM). The AMS settings were programed so 3X cows were limited to three MPD while 6X cows were allowed six MPD. Afterwards was the carry over phase (CO) ranging from 30 to 90 DIM; all cows were allowed up to six MPD. Measurements by the AMS included bodyweight, milk yield (MY), and pellet intake. Weekly composite milk samples were analyzed for macronutrient composition and fatty acid (FA) profile. Coccygeal blood was sampled at 3, 8 ± 1, and 13 ± 1 DIM; concentrations of blood plasma analytes were quantified. Greater MPD was achieved for 6X cows versus 3X cows during EXP, but similar during the CO. Daily MY was non-separable during the EXP while 6X cows in their third or greater lactation group (3 + LG) had greater MY than 3X cows of the same LG during the CO. Milk fat content and 4% fat-corrected MY were both greater for 6X, 3 + LG cows during the EXP compared to 3X, 3 + LG cows. Milk FA methyl esters (FAME) proportions were different between MPD groups, with 6X, 3 + LG cows having the lowest short, even-chain FA from de novo or post-absorptive origin. Differences in analytes indicated that 6X, 3 + LG cows experienced metabolic stress and incorporated greater FA from adipose tissue. Greater early lactation MPD in AMS may shift cow nutrient partitioning to support greater production in 3+ parity cows.

Periparturient dairy cattle undergo physiological adaptations to support fetal growth and colostrum synthesis in late gestation and milk production in early lactation. To support energy and protein demands dairy cattle mobilize body tissue reserves. The objective of this study was to determine the effects of prepartum skeletal muscle reserves and supplementation of branched-chain volatile fatty acids (BCVFA) on body composition measurements, metabolic markers related to health, protein, and energy status, and subsequent milk yield in multiparous dairy cows. Skeletal muscle reserves were assessed by 3 ultrasounds of the longissimus dorsi muscle depth (LDD) measured 42 d before expected calving (BEC), and cows (n = 48) were assigned to either high muscle (HM; > 4.6 cm) or low muscle (LM; ≤ 4.6 cm) groups. Cows were then randomly assigned to either control (CON) of soyhull pellets (80 g/d) or BCVFA treatment which contained isobutyrate (40 g/d), isovalerate (20 g/d), and 2-methylbutyrate (20 g/d) calcium salt products. Treatments were top dressed from 42 BEC until parturition, resulting in 4 combinations of muscle groups and treatments: HM-CON (n = 13), HM-BCVFA (n = 13), LM-CON (n = 11), and LM-BCVFA (n = 11). Measurements of the LDD, BW, and BCS were taken on the following days relative to calving -42, -35, -21, -7, 0, 7, 14, 21, 28. Weekly blood samples were taken to measure glucose, BHB, and insulin concentrations, and 5 of the blood sample time points were utilized to determine 3-methylhistidine and creatinine blood concentrations. Milk yield was recorded daily for the first 28 d of lactation, and samples were taken from both milkings once a wk for the first 4 wk to determine components. The statistical model included the fixed effects of treatment, group, time, their interactions, and the random effect of cow nested within group and treatment. Prepartum muscle mobilization varied between muscle groups, as LM cows accreted muscle prepartum, and HM cows mobilized muscle. The HM cows had higher milk fat, protein, lactose, and energy corrected milk yields. The BCVFA supplementation tended to increase blood glucose concentrations both prepartum and postpartum and decreased milk urea nitrogen concentrations. Higher prepartum skeletal muscle reserves improve productivity of early lactation cows likely due to differences in muscle mobilization, and BCVFA supplementation improves glucose dynamics during the transition period, which may improve the metabolic health of the periparturient dairy cow.

To boost the immune function around parturition, recombinant bovine granulocyte colony-stimulating factor (rbG-CSF) has been used to increase the number of neutrophils. Therefore, the aim of this study was to quantify the effect of rbG-CSF administration on the incidence of postpartum pathologies, reproductive performance, and milk production during the first three months of lactation. A total of 199 Holstein cows from one herd were included and were randomly allocated into two groups: Control (n = 103) and rbG-CSF (n = 96). Cows in the rbG-CSF group received 2 doses of a rbG-CSF injectable formulation, one 7 days before the expected date of calving and the other within 24 h after calving. For 6 weeks following calving, animals were examined weekly to assess the presence of postpartum pathologies. Milk production, protein and fat content, and somatic cell count were determined monthly by the regional dairy herd improvement association. Data about the reproductive performance were collected from on-farm software. To analyse the effect of treatment on the incidence of postpartum pathologies, Pearson\'s χ2 test and multivariable logistic regressions were performed. The effect on reproductive performance was analysed using Cox proportional hazard regression analysis for days open, binary logistic regression for first service conception rate and Oneway ANOVA test for the number of artificial inseminations. The effects of treatment on milk yield and milk composition were checked using GLM repeated measures analysis. No statistically significant differences were observed between treatment groups for any of the parameters evaluated. Only parity had a significant effect on days open and milk production (p < 0.05). In conclusion, in the present study no evidence was found that rbG-CSF could have an effect on the reproductive and productive parameters evaluated.

BACKGROUND: It is proven that B vitamins through promote a wide range of metabolic pathways in animals as cofactors improve animal performance.
OBJECTIVE: This study was conducted to investigate the impacts of maternal B complex vitamin injection on performance and plasma parameters in goats and their offspring, as well as the faeces status of newborn kids.
METHODS: In this research, the pregnant goats (3 years old) were randomly divided into two groups: the control group (without B complex vitamin injection) and the B complex vitamin group (5 mL B complex vitamin injection per animal). The animals were injected with 5 mL B complex vitamin twice during the transition period (5 weeks pre- and 5 weeks post-kidding). The goats during the transition period and kids on days 10, 20 and 30 were weighed. Feed intake by goats and consumption of milk and starter in kids were recorded daily. The dry matter digestibility by kids was tested by collecting samples of faeces and feed for 5 days in the last week. Chemical analysis was determined using the AOAC method. The kids\' faeces were prepared daily during the study. The blood samples of goats and newborn kids were taken 7 days after kidding. Then, levels of B group vitamin, as well as concentrations of liver enzymes, thyroid hormones and immunological parameters, were determined in plasma of goat and their offspring. In addition, concentrations of glucose and insulin were measured in goat plasma (Asadi et al., 2024).
RESULTS: According to results, the performances of goats and their offspring, as well as kids\' faeces status, were improved by maternal B complex vitamin injection (p < 0.0001). The levels of cobalamin, pyridoxine, thiamine, folic acid, nicotinic, pantothenic and unconjugated pteridine increased in the plasma of goats and their kids in the B complex vitamin group compared with the control group during the transition period (p < 0.0001). Injection of maternal B complex vitamin raised the plasma levels of triiodothyronine and tetraiodothyronine, immunoglobulin G and immunoglobulin M in goats and their offspring (p < 0.0001). Higher levels of glucose and lower levels of insulin were determined in the goats injected with B complex vitamin (p < 0.0001).
CONCLUSIONS: These results suggest that maternal B complex vitamin injection is required for the improvement of performance, health status and the blood plasma parameters in pregnant goats and their kids.

The aim of this work was to develop a liver tissue function index during the transition period of dairy cows managed in low-tropic conditions. In two farms, twenty crossbred and synthetic native cows during the peripartum period were selected, and blood samples were taken on days -30 and -15 prepartum, the calving day, and 7, 20, 35, 50, 65, 80 and 105 days postpartum for serum metabolic tests. On each measurement day, body condition scores (BCS) and parameters on nitrogen metabolism (total protein-TP, albumin-ALB, globulin-GLOB, urea), adipose tissue metabolism (cholesterol-COL, non-esterified fatty acids-NEFA) and two transaminases (alanine aminotransferase-ALT and aspartate aminotransferase-AST) were evaluated. Data analysis included the Spearman correlation, principal components, multiple linear regression and cluster analysis. Results showed that regarding the days after calving and BCS, a liver tissue function index can be constructed using the TP, urea, COL, ALT and NEFA. The estimated index generated three groupings, both by days after calving and BCS. In the former, the index discriminated the metabolic behavior in the prepartum, parturition and postpartum periods, while in the latter, the index discriminated between extreme (2.25, 2.50 and 4.25), slightly low (2.75 and 3.0) and slightly high (3.25 to 4) conditions. The results allow us to conclude that it is feasible to construct mathematical function indexes for liver function to monitor metabolic changes during highly demanding productive phases in dairy cows under tropical conditions.

The transition period (TP), which extends from 3 weeks before 3 weeks post parturition, is a critical period regarding the health, productivity, and profitability of dairy animals, during which most health disorders arise, including lameness, mastitis, rumen acidosis, ketosis, hypocalcemia (HC) (milk fever), left-displaced abomasum, fatty liver, hypophosphatemia and post-parturient hemoglobinuria, subacute ruminal acidosis, RP, and metritis. Biomarkers are biological molecules distributed in blood, body fluids, or tissues that represent physiological or pathophysiological indicators of events, processes, or conditions happening within the animal\'s body. In the field of veterinary medicine, biomarkers are thought to have enormous valuable potential in the field of clinical diagnosis, therapeutical research, surgery, and obstetrical outcome. This review article aims to explore the significance of biomarkers used to predict pathological conditions and health status of cattle during the TP to facilitate the early clinical diagnosis and prompt treatment of TP-related diseases/or conditions and thus improve animal welfare and health and increase productivity.

The objectives of this study were to identify factors associated with prepartum DMI, evaluate the performance of linear models to estimate prepartum DMI using different classes of predictors, and investigate the consequences of different levels of prepartum DMI on transition metabolism and lactation performance. Individual feed intake of nulliparous (n = 100) and parous cows (n = 173) was measured by automatic feeding bins from d -35 to 98 relative to calving. Rumination and physical activities were monitored by wearable sensors. Blood metabolites were measured on d -21, -10, -3, 0, 3, 7, 10, 14, and 21. Body weight (BW) and body condition score (BCS) were assessed throughout the study. The average prepartum DMI as percentage of BW (DMIpBW) was calculated for each cow and used as dependent variable of linear models. Parity, prepartum BCS and BW, milk production in the previous lactation (M305) and at dry-off (MYDO), and length of the dry period were associated with DMIpBW and explained 41% of the variation in all cows, and 49% in parous cows. Estimations of DMIpBW were improved when data on prepartum rumination and blood metabolites were added in the predictive models. In the latter, the adjusted R-Sq increased to values between 47 and 61%, and selected models performed consistently in a 5-fold cross-validation analysis. To evaluate the implications of DMIpBW to transition metabolism and performance, cows were ranked within parity and classified into terciles as low (LFI), moderate (MFI), or high feed intake (HFI). The mean DMI was 1.44, 1.70, and 1.91 ± 0.01% of BW, respectively. No differences in BW were observed in nulliparous cows, but all 3 groups of parous cows differed (LFI = 892, MFI = 849, HFI = 798 ± 8 kg). The proportion of cows with BCS > 3.5 at enrollment differed among all groups, and averaged 67.4, 55.1, and 36.5 ± 6%, respectively. For parous cows, M305 and MYDO differed among all groups and averaged 9,808, 10,457, and 11,182 ± 233 kg, and 18.1, 23.1, and 26.2 ± 1 kg/d, respectively. After calving, DMI (LFI = 20.9, MFI = 21.9, and HFI = 22.1 ± 0.2 kg/d) and milk yield (LFI = 36.7, MFI = 38.2, and HFI = 38.3 ± 0.4 kg/d) was lower in LFI cows compared with the other 2 groups. Postpartum EBAL differed among all groups and averaged -2.79, -1.63, and -0.66 ± 0.3 Mcal/d for LFI, MFI, and HFI, respectively. During the transition period, LFI cows had higher serum concentrations of NEFA, BHB, Cl (prepartum only), and AST (postpartum only), and lower serum concentrations of cholesterol, P, GLDH, GGT (prepartum only), AST (prepartum only), urea (parous only), and SOD activity (parous only). In conclusion, a low level of prepartum DMI was associated with fatter and heavier cows, lower milk production in previous lactation, important adjustments in energy metabolism, and moderate losses in DMI and milk yield in the subsequent lactation. Moreover, the inclusion of prepartum rumination activity and target blood metabolites into predictive models improved the estimations of prepartum DMI.

Metabolic adaptations to negative energy balance, as well as lipomobilization, influence inflammatory responses, immune function, and oxidative stress in animals. This study aimed to evaluate the biochemical profile of Mediterranean buffaloes with different levels of lipomobilization from the prepartum to the postpartum period. A total of 76 Mediterranean buffaloes were enrolled, and a weekly blood sample was taken from 7 weeks before to 6 weeks after calving. The concentration of non-esterified fatty acids (NEFAs) was determined in serum and was used to categorize buffaloes into three lipomobilization groups 7 weeks before calving: mild (NEFA-I; NEFA ≤ 0.29 mEq/L; n = 18), medium (NEFA-II; 0.29 < NEFA < 0.57 mEq/L; n = 20), and severe (NEFA-III; NEFA ≥ 0.57 mEq/L; n = 38). Two-way repeated measures ANOVA was used to assess changes within and between the groups and over time. Significant differences were found in the concentration levels of NEFA, β-hydroxybutyrate, glucose, cholesterol, protein profile, oxygen radicals, antioxidants, lysozyme, complement, and minerals. These results suggest that both medium and severe lipomobilization groups are associated with metabolic alterations. In conclusion, buffaloes with higher NEFA levels (>0.29 mEq/L; NEFA-II and NEFA-III) at 7 weeks before calving should be monitored more closely to reduce the risk of metabolic diseases. Furthermore, the medium (NEFA-II) and severe (NEFA-III) lipomobilization groups could be associated with differences in the animals\' ability to manage their metabolic status. Specifically, the severe mobilization group was most associated with a greater energy deficit during both the prepartum and postpartum periods without oxidative stress. On the contrary, the medium mobilization group was associated with a less severe energy deficit but was also associated with an inflammatory status and oxidative stress during the prepartum period. These distinctions highlight the need for tailored management strategies to address varying levels of metabolic stress in dairy buffaloes.

This study aimed to evaluate the relationship between prepartum subclinical hypomagnesemia (pre-SHMg) and the occurrence of dystocia, metritis, clinical mastitis, lameness, and subclinical hypomagnesemia postpartum (post-SHMg) in pasture-based dairy cows. Also, the difference in means of prepartum magnesium (Mg) concentration by postpartum health events was evaluated. A total of 890 dairy cows from 32 commercial farms located in southern Chile were enrolled. Cows were examined twice, once between 30 and 3 days before and once between 3 and 30 days after calving. Blood samples were collected on both assessments, and cows were considered as having SHMg if serum total Mg < 0.65 mmol/L. On the postpartum visit, cows were evaluated for metritis and lameness. Information about clinical mastitis and dystocia was collected from on-farm records. Data were analyzed using multivariable mixed linear models and multivariable mixed logistic regression models. The overall prevalence of pre-SHMg was 9.9%, and its presence was associated with the occurrence of post-SHMg (odd ratio [OR] = 5.7; P < 0.0001) and metritis (OR = 3.1; P = 0.04). However, we did not detect an association between pre-SHMg and dystocia, clinical mastitis, or lameness after calving. Prepartum serum Mg concentrations were lower in cows that developed post-SHMg than those that did not (LSM ± SE = 0.75 ± 0.02 mmol/L vs. 0.83 ± 0.02 mmol/L; P < 0.0001). In conclusion, pre-SHMg was associated with a higher risk of post-SHMg and metritis in grazing dairy cows but not other postpartum health events.

A dysregulated inflammatory response contributes to the occurrence of disorders in cows during the transition period from pregnancy to lactation. However, a detailed characterization of clinically healthy cows that exhibit an enhanced inflammatory response during this critical period remains incomplete. In this experiment, a total of 99 individual transition dairy cows and 109 observations (18 cows monitored in 2 consecutive lactations), submitted to similar transition management were involved to evaluate the relationship between elevated an inflammatory response and metabolic and oxidative status, as well as transition outcomes. Blood was taken at -7, 3, 6, 9, and 21 DIM, and concentrations of metabolic parameters (glucose, β-hydroxybutyric acid, nonesterified fatty acids [NEFA], insulin, IGF-1, and fructosamine) were analyzed. Additionally, oxidative parameters (proportion of oxidized glutathione to total glutathione in red blood cells, the activity of glutathione peroxidase [GPx] and superoxide dismutase, concentrations of malondialdehyde, and oxygen radical absorbance capacity) and acute phase proteins (APP) including haptoglobin (Hp), serum amyloid A (SAA) and albumin-to-globulin ratio (A:G) were determined in the blood at 21 DIM. The 3 APP parameters were used to group clinically healthy cows into 2 categories through k-medoids clustering (i.e., a group showing an acute phase response, APR; n = 39) and a group not showing such a response (i.e., non-APR; n = 50). Diseased cases (n = 20) were handled in a separate group. Lower SAA and Hp concentrations as well as higher A:G were observed in the non-APR group, although for Hp, differences were observed from the APR group and not from the diseased group. Only 1 of the 5 oxidative parameters differed between the groups, with the non-APR group exhibiting lower GPx activity compared with the diseased group. The non-APR group showed the highest IGF-1 levels among the 3 groups and and lower NEFA concentrations compared with the diseased groups. Cows in the diseased group also showed reduced dry matter intake and milk yield compared with clinically healthy cows, regardless of their inflammatory status. Moreover, the APR group exhibited temporarily lower activity levels compared with the non-APR group. These findings highlight that cows with a lower inflammatory status after 21 DIM exhibited better metabolic health characteristics and productive performance, as well as activity levels. Nevertheless, the detrimental effects of a higher inflammatory status in the absence of clinical symptoms are still relatively limited.