Prepartum Intake, Postpartum Induction of Ketosis, and Periparturient Disorders Affect the Metabolic Status of Dairy Cows

Combination of milk variables and on-farm data as an improved diagnostic tool for metabolic status evaluation in dairy cattle during the transition period

Milk composition, particularly milk fatty acids, has been extensively studied as an indicator of the metabolic status of dairy cows during early lactation. In addition to milk biomarkers, on-farm sensor data also hold potential in providing insights into the metabolic health status of cows. While numerous studies have explored the collection of a wide range of sensor data from cows, the combination of milk biomarkers and on-farm sensor data remains relatively underexplored. Therefore, this study aims to identify associations between metabolic blood variables, milk variables, and various on-farm sensor data. Second, it seeks to examine the supplementary or substitutive potential of these data sources. Therefore, data from 85 lactations on metabolic status and on-farm data were collected during 3 wk before calving up to 5 wk after calving. Blood samples were taken on d 3, 6, 9, and 21 after calving for determination of β-hydroxybutyrate (BHB), nonesterified fatty acids (NEFA), glucose, insulin-like growth factor-1 (IGF-1), insulin, and fructosamine. Milk samples were taken during the first 3 wk in lactation and analyzed by mid-infrared for fat, protein, lactose, urea, milk fatty acids, and BHB. Walking activity, feed intake, and body condition score (BCS) were monitored throughout the study. Linear mixed effect models were used to study the association between blood variables and (1) milk variables (i.e., milk models); (2) on-farm data (i.e., on-farm models) consisting of activity and dry matter intake analyzed during the dry period ([D]) and lactation ([L]) and BCS only analyzed during the dry period ([D]); and (3) the combination of both. In addition, to assess whether milk variables can clarify unexplained variation from the on-farm model and vice versa, Pearson marginal residuals from the milk and on-farm models were extracted and related to the on-farm and milk variables, respectively. The milk models had higher coefficient of determination (R2) than the on-farm models, except for IGF-1 and fructosamine. The highest marginal R2 values were found for BHB, glucose, and NEFA (0.508, 0.427, and 0.303 vs. 0.468, 0.358, and 0.225 for the milk models and on-farm models, respectively). Combining milk and on-farm data particularly increased R2 values of models assessing blood BHB, glucose, and NEFA concentrations with the fixed effects of the milk and on-farm variables mutually having marginal R2 values of 0.608, 0.566, and 0.327, respectively. Milk C18:1 was confirmed as an important milk variable in all models, but particularly for blood NEFA prediction. On-farm data were considerably more capable of describing the IGF-1 concentration than milk data (marginal R2 of 0.192 vs. 0.086), mainly due to dry matter intake before calving. The BCS [D] was the most important on-farm variable in relation to blood BHB and NEFA and could explain additional variation in blood BHB concentration compared with models solely based on milk variables. This study has shown that on-farm data combined with milk data can provide additional information concerning the metabolic health status of dairy cows. On-farm data are of interest to be further studied in predictive modeling, particularly because early warning predictions using milk data are highly challenging or even missing.

Blood and liver telomere length, mitochondrial DNA copy number, and hepatic gene expression of mitochondrial dynamics in mid-lactation cows supplemented with l-carnitine under systemic inflammation

The current study was conducted to examine the effect of l-carnitine (LC) supplementation on telomere length and mitochondrial DNA copy number (mtDNAcn) per cell in mid-lactation cows challenged by lipopolysaccharide (LPS) in blood and liver. The mRNA abundance of 31 genes related to inflammation, oxidative stress, and the corresponding stress response mechanisms, the mitochondrial quality control and the protein import system, as well as the phosphatidylinositol 3-kinase/protein kinase B pathway, were assessed using microfluidics integrated fluidic circuit chips (96.96 dynamic arrays). In addition to comparing the responses in cows with or without LC, our objectives were to characterize the oxidative and inflammatory status by assessing the circulating concentration of lactoferrin (Lf), haptoglobin (Hp), fibrinogen, derivates of reactive oxygen metabolites (dROM), and arylesterase activity (AEA), and to extend the measurement of Lf and Hp to milk. Pluriparous Holstein cows were assigned to either a control group (CON, n = 26) or an LC-supplemented group (CAR; 25 g LC/cow per day; d 42 ante partum to d 126 postpartum (PP), n = 27). On d 111 PP, each cow was injected intravenously with LPS (Escherichia coli O111:B4, 0.5 µg/kg). The mRNA abundance was examined in liver biopsies of d -11 and +1 relative to LPS administration. Plasma and milk samples were frequently collected before and after the challenge. After LPS administration, circulating plasma fibrinogen and serum dROM concentrations increased, whereas AEA decreased. Moreover, serum P4 initially increased by 3 h after LPS administration and declined thereafter irrespective of grouping. The Lf concentrations increased in both groups after LPS administration, with the CAR group showing greater concentrations in serum and milk than the CON group. After LPS administration, telomere length in blood increased, whereas mtDNAcn per cell decreased; however, both remained unaffected in liver. For mitochondrial protein import genes, the hepatic mRNA abundance of the translocase of the mitochondrial inner membrane (TIM)-17B was increased in CAR cows. Moreover, TIM23 increased in both groups after LPS administration. Regarding the mRNA abundance of genes related to stress response mechanisms, 7 out of 14 genes showed group × time interactions, indicating a (local) protective effect due to the dietary LC supplementation against oxidative stress in mid-lactating dairy cows. For mtDNAcn and telomere length, the effects of the LPS-induced inflammation were more pronounced than the dietary supplementation of LC. Dietary LC supplementation affected the response to LPS primarily by altering mitochondrial dynamics. Regarding mRNA abundance of genes related to the mitochondrial protein import system, the inner mitochondrial membrane translocase (TIM complex) seemed to be more sensitive to dietary LC than the outer mitochondrial membrane translocase (TOM complex).

In-Line Registered Milk Fat-to-Protein Ratio for the Assessment of Metabolic Status in Dairy Cows

This study endeavors to ascertain alterations in the in-line registered milk fat-to-protein ratio as a potential indicator for evaluating the metabolic status of dairy cows. Over the study period, farm visits occurred biweekly on consistent days, during which milk composition (specifically fat and protein) was measured using a BROLIS HerdLine in-line milk analyzer (Brolis Sensor Technology, Vilnius, Lithuania). Clinical examinations were performed at the same time as the farm visits. Blood was drawn into anticoagulant-free evacuated tubes to measure the activities of GGT and AST and albumin concentrations. NEFA levels were assessed using a wet chemistry analyzer. Using the MediSense and FreeStyle Optium H systems, blood samples from the ear were used to measure the levels of BHBA and glucose in plasma. Daily blood samples were collected for BHBA concentration assessment. All samples were procured during the clinical evaluations. The cows were categorized into distinct groups: subclinical ketosis (SCK; n = 62), exhibiting elevated milk F/P ratios without concurrent clinical signs of other post-calving diseases; subclinical acidosis (SCA; n = 14), characterized by low F/P ratios (<1.2), severe diarrhea, and nondigestive food remnants in feces, while being free of other post-calving ailments; and a healthy group (H; n = 20), comprising cows with no clinical indications of illness and an average milk F/P ratio of 1.2. The milk fat-to-protein ratios were notably higher in SCK cows, averaging 1.66 (±0.29; p < 0.01), compared to SCA cows (0.93 ± 0.1; p < 0.01) and healthy cows (1.22). A 36% increase in milk fat-to-protein ratio was observed in SCK cows, while SCA cows displayed a 23.77% decrease. Significant differences emerged in AST activity, with SCA cows presenting a 26.66% elevation (p < 0.05) compared to healthy cows. Moreover, SCK cows exhibited a 40.38% higher NEFA concentration (p < 0.001). A positive correlation was identified between blood BHBA and NEFA levels (r = 0.321, p < 0.01), as well as a negative association between BHBA and glucose concentrations (r = -0.330, p < 0.01). Notably, AST displayed a robust positive correlation with GGT (r = 0.623, p < 0.01). In light of these findings, this study posits that milk fat-to-protein ratio comparisons could serve as a non-invasive indicator of metabolic health in cows. The connections between milk characteristics and blood biochemical markers of lipolysis and ketogenesis suggest that these markers can be used to check the metabolic status of dairy cows on a regular basis.

Ruminant Metabolic Diseases: Perturbed Homeorhesis

The 6-week period encompassing parturition, termed the transition period, is recognized as the most fragile period in the life cycle of the ruminant animal. The period accounts for the greatest risk of health events that can adversely affect animal health, lactational performance, and future reproductive success. Critical endocrine and metabolic adaptations take place in allowing the animal to change nutrient priorities from supporting pregnancy to sustaining lactation. A reductionist perspective of underlying pathogenesis provided minimal metabolic disease prevalence improvement. Recent research has recognized metabolic regulatory complexity and role for activated inflammatory response underpinning dysregulation of homeorhesis during transition.

Relationships between Milk and Blood Biochemical Parameters and Metabolic Status in Dairy Cows during Lactation

This study aimed to determine blood and milk metabolic parameters and their correlations for the purpose of evaluating metabolic status in dairy cows. Blood and milk samples were collected from 100 Holstein dairy cows during morning milking. The cows were allocated to four groups according to the production period, including cows in early (n = 18), full (n = 26), mid (n = 25) and late (n = 31) lactation. The value of non-esterified fatty acids (NEFA), β-hydroxybutyrate (BHB), glucose, triglycerides (TG), total cholesterol (TChol), total protein (TP), albumin, globulin, urea, total bilirubin (TBil), aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), gamma-glutamyl transferase (GGT), and lactate dexydrogenase (LDH) in the blood were determined. The following milk parameters were measured: fat, protein, lactose, urea, AST, ALT, ALP, GGT, LDH and BHB. Blood serum NEFA, BHB, TBil, AST, ALT, ALP and LDH were higher in early lactation cows, whereas glucose, TP, globulin and urea levels were significantly lower in early lactation cows. Milk fat and lactose levels were lower in early lactation cows, whereas milk protein and the activities of AST, ALT, ALP and LDH in milk were highly greater in early lactation cows. Milk fat was positively correlated with glucose, TP and TG, and negatively correlated with BHB, NEFA, TBil, ALT, LDH and ALP levels in the blood. Enzyme activities in milk were positively correlated with those in blood and with blood NEFA, BHB and TBil levels, and negatively correlated with blood glucose, TChol and TG. A significant positive correlation existed between blood and milk BHB values. Many correlations showed the same slope during all lactation periods. In conclusion, similar changes in blood and milk metabolite concentration during lactation and milk to blood correlations confirm that milk has great potential in predicting of blood metabolites and metabolic status of cows.

Diurnal variation of milk fatty acids in early-lactation Holstein cows with and without hyperketonemia

Estimates of milk constituents by Fourier-transform mid-infrared (FTIR) analysis have been shown to be a useful tool in monitoring energy deficit in early-lactation dairy cows. Our objectives were to describe the diurnal variation in milk fatty acids (FAs) and estimate the association of hyperketonemia with concentrations and diurnal patterns of FTIR estimates of milk FA. Blood samples were collected via jugular catheters bihourly for 5 d from multiparous Holstein cows (n = 28) enrolled between 3 and 9 days in milk. Milk samples were collected thrice daily at 0600, 1400, and 2200 h for d 2, 3, and 4 of the study period. Cows were retrospectively classified as hyperketonemic (HYK; n = 13) or non-HYK (n = 15) based on blood beta-hydroxybutyrate (bBHB) concentrations analyzed during the study period. Cows were classified as HYK if bBHB was ≥ 1.2 mmol/l for ≥ 50% (22/44) of bihourly timepoints; cows were classified as non-HYK if bBHB was ≥ 1.2 mmol/l for < 50% of bihourly timepoints. The HYK cows had bBHB ≥ 1.2 mmol/l for 31.4 ± 6.8 timepoints while the non-HYK cows had bBHB ≥ 1.2 mmol/l for 8.0 ± 3.9 timepoints. We used generalized linear mixed models to analyze concentrations of milk FA over time and differences between HYK groups. The relative percentage of de novo, mixed, and preformed FAs all followed diurnal patterns, however only the yield of preformed FA diurnally cycled, reaching a nadir at 0600 h and peaking at 1400 h. The yield per milking of preformed FA was also greater in the HYK cows than in the non-HYK cows. Oleic acid in milk followed a similar diurnal pattern to the yield of preformed FA, likely driving the cyclical nature of preformed FA. Finally, stearic acid was greater in HYK cows. Our results suggest that FTIR estimates of milk FA offer the potential to provide insight on the energy status of early-lactation cows, and when interested in understanding the absolute concentrations and yields of milk FA, diurnal variation should be considered.

The Occurrence of a Negative Energy Balance in Holstein-Friesian and Simmental Cows and Its Association with the Time of Resumption of Reproductive Activity

Intensive lactation (lactogenesis) in cows is conducive to a negative energy balance (NEB), so the search for traits associated with the physiological capacity to cope with its consequences is a current area of research. This is especially important because NEB overlaps with the resumption of the reproductive cycle, which determines the profitability of herds. This study analysed the relationship between NEB and the time of resumption of reproductive activity in cows with varying genetic potential (Simmental and Holstein-Friesian), fed a similar diet (TMR). The aim of the study was to analyse the dependencies between NEB markers and changes in progesterone levels between 25 and 31 days postpartum. A strong positive correlation was shown between daily milk production (DMP) and loss of body condition (LBCS; 0.772; p ≤ 0.05). These parameters were associated with the levels of NEB biomarkers. Higher values of NEB indicators (LBCS, C16:0, C18:1, NEFA, and BHBA) were usually noted during periods with higher DMP (II and III). The trends observed were confirmed by positive correlation coefficients (r), which ranged from 0.324 to 0.810 (p ≤ 0.05). The reverse trend was noted for glucose and leptin, which decreased as productivity increased, as confirmed by r values from -0.368 to -0.530 (p ≤ 0.05). In both breeds, the glucose and leptin levels decreased as DMP increased. Higher values for NEB indicators were shown to be negatively correlated with progesterone levels (r from -0.300 to -0.712; p ≤ 0.05), and a lower progesterone level was associated with a longer calving-to-first-service interval and calving-to-conception interval. The rate of postpartum triglyceride release depends on daily milk production, and therefore the adaptability of the liver should be considered an important element of mitigation of the consequences of NEB. This may have practical applications by extending productive life, which is often shortened due to deteriorating reproductive performance.

Study of the Fatty Acid Profile of Milk in Different Sheep Breeds: Evaluation by Multivariate Factorial Analysis

Simple Summary

The quality of milk is strongly influenced by its lipid profile. The increase in fats with nutraceutical properties at the expense of those negative for human health, has always been a goal to improve the functional properties of milk. To achieve this goal, it is essential to know the metabolism of the mammary gland and the relationship between the various lipid components. Much is known about bovine milk, while the aspect relating to the sheep species has not been developed. The present work aims to investigate the relationships between the various fatty acids in sheep’s milk through a multivariate approach, which can highlight the mammary role of lipid synthesis.

Abstract

A multivariate analysis was used to investigate the fatty acid (FA) profile in three different Italian sheep breeds: Comisana, Massese, and Sarda. A sample of 852 animals was considered: 118 Massese, 303 Comisana, 431 Sarda. Sarda sheep were divided into two groups, based on their breeding origin (298 and 133 reared in Sardinia and Tuscany, respectively). Sarda sheep, bred both in Sardinia and in Tuscany, were considered in different groups, both because in these two regions most of the sheep of this breed are reared, and because they differ in geographical characteristics and in the farming system. The individual milk FA composition of dairy ewes was analyzed with multivariate factor analysis. The extracted factors were representative of the following eight groups of fatty acids or functions: factor 1 (odd branched fatty acids and long-chain fatty acids), factor 2 (sn3_position), factor 3 (alternative biohydrogenation), factor 4 (SCD_1), factor 5 (SCD_2), factor 6 (SCD_3), factor 7 (fat secretion) and factor 8 (omega-3). A factor analysis suggested the presence of different metabolic pathways for de novo short- and medium-chain fatty acids and Δ9-desaturase products. The ANOVA of factor scores highlighted the significant effects of the breed. The results of the present study showed that breed is an important factor in defining the fatty acid profile of milk, combined with the effect of the diet. Breeds reared in the same farming system (Comisana, Massese and Sarda reared in Tuscany) showed significant differences for all the factors extracted. At the same time, we found differences between the Sarda sheep reared in Sardinia and Tuscany, two different regions of Italy.

A proposed structural approach to improve cow-claw health on Dutch dairy farms

Despite extensive research leading to an improved understanding of the risk factors and pathogenesis of infectious and non-infectious disorders, claw health has not structurally improved in recent decades. Several studies have shown that claw disorders harm milk production, fertility and longevity of the dairy cows and job satisfaction of the farmer. This is enough reason to structurally improve claw health on dairy farms. The focus should be on a rapid curative intervention when lameness occurs and above all the prevention of claw problems. Most claw disorder diagnoses are nowadays made during regular claw trimming by the professional trimmer or the dairy farmer. Registration of the detected disorders during claw trimming is not always done consistently, so the estimated prevalence (number of cows with a claw disorder) is in most cases an underestimation of the real prevalence. The quality of these records often makes it difficult for consultants to formulate appropriate claw health advice. To be able to give good advice on claw health, insight into the prevalence of the various hoof disorders on a farm is a key condition. However, good quality advice alone is not a guarantee for an improved claw health situation on a farm. Research has shown that in addition to high quality substantiated advice, the communication style between the consultant and the dairy farmer is essential for the interpretation and motivation of the dairy farmer to implement the advice. In this paper a 7-point plan is presented as a guidance for herd advisors who want to support dairy farmers to improve claw health.

Effects of prepartum dietary protein level and feed intake on postpartum lactation performance and feeding behavior of multiparous Holstein dairy cows

An experiment was conducted to determine the effects of low and high metabolizable protein (MP) diets when fed for ad libitum and controlled intake during the prepartum period on postpartum lactation performance and feeding behavior of dairy cows. Thirty-six multiparous Holstein cows were blocked by parity, expected calving date, and previous lactation milk yield at -21 d relative to expected calving and were randomly assigned to 1 of 4 close-up period dietary treatments providing low MP (LMP) or high MP (HMP) diets with controlled intake (CNI) or ad libitum intake (ALI). The concentrations of MP were 65 and 90 g/kg dry matter for LMP and HMP diets, respectively, whereas intake was controlled to supply 100 and 160% of the NRC (2001) energy requirements for CNI and ALI groups, respectively. The concentration of net energy for lactation (NE_L) in the treatment diets was 1.50 Mcal/kg. All cows were fed a similar lactation diet after calving (1.50 Mcal/kg of NE_L and 83.3 g/kg of MP). The HMP diet increased dry matter intake during the first 3 wk and tended to increase dry matter intake over the 9 wk of lactation. Meal size and eating rate increased in the ALI cows during the prepartum period. Meal frequency increased with the HMP diet during the postpartum period. Milk yield increased by 15.2% with the HMP diet over the 9 wk of lactation. The HMP diet increased energy-corrected milk (ECM) yield in CNI versus ALI cows, whereas the LMP diet increased ECM yield in ALI versus CNI cows over the 9 wk of lactation. The increase in ECM yield of LMP-ALI versus LMP-CNI cows was supported by greater body condition loss and serum β-hydroxybutyrate over the 9 wk of lactation. Taken together, these data indicate that prepartum controlled intake of a high protein diet can provide the benefits of both strategies.

Effects of pre- and postpartum dietary starch content on productivity, plasma energy metabolites, and serum inflammation indicators of dairy cows

The objective of this study was to evaluate the effects of the starch content of pre- and postpartum diets on productivity, plasma energy metabolites, and serum markers of inflammation of dairy cows during the calving transition period. Eighty-eight primiparous and multiparous cows were randomly assigned to pre- and postpartum dietary treatments balanced for parity and pretrial body condition score at d 28 ± 3 before expected calving date. Cows were fed either a control [Control; 14.0% starch, dry matter (DM) basis] or high-starch (High; 26.1% starch, DM basis) prepartum diet commencing 28 ± 3 d before expected calving date. Following calving, cows were fed either a high-fiber (HF; 33.8% neutral detergent fiber, 25.1% starch, DM basis) or high-starch (HS; 27.2% neutral detergent fiber, 32.8% starch, DM basis) postpartum diet for the first 20 ± 2 d following calving. Cows fed the High prepartum diet had greater DM intake (12.4 vs. 10.2 kg/d), plasma concentrations of insulin (1.72 vs. 14.2 ng/mL), glucose (68.1 vs. 65.0 mg/dL), and glucagon-like peptide-2 (0.41 vs. 0.32 ng/mL) before parturition, but increased plasma free fatty acid concentration (452 vs. 363 µEq/L) and milk fat yield (1.64 vs. 1.48 kg/d) after parturition. Cows fed the HS postpartum diet had lower plasma free fatty acid (372 vs. 442 µEq/L) and serum haptoglobin (0.46 vs. 0.70 mg/mL) concentrations over a 3-wk period after calving. In addition, there was a tendency for interaction between prepartum and postpartum diets for milk yield, where feeding the HS postpartum diet increased milk yield compared with the HF diet for cows fed the Control prepartum diet (40.8 vs. 37.9 kg/d) but not for cows fed the High prepartum diet. These results suggest that management efforts to minimize the change in diet fermentability during the calving transition by feeding the High prepartum diet, the HF postpartum diet, or both did not increase productivity of dairy cows but increased fat mobilization after calving. Our findings also suggest that feeding high-starch postpartum diets can decrease fat mobilization and serum indicators of systemic inflammation and increase milk production even with the transition from a low-starch prepartum diet.

One-carbon, carnitine, and glutathione metabolism-related biomarkers in peripartal Holstein cows are altered by prepartal body condition

We investigated how prepartal body condition score (BCS) alters key hepatic enzymes associated with 1-carbon, carnitine, and glutathione metabolism and the related biomarkers in liver tissue and plasma of periparturient dairy cows. Twenty-six multiparous Holstein dairy cows were retrospectively selected according to BCS at 4 wk prepartum and divided into high (HighBCS, BCS ≥ 3.50) and normal (NormBCS, BCS ≤ 3.25) BCS groups (n = 13 each). Blood plasma samples were obtained at -30, -10, 7, 15, and 30 d relative to calving. Liver tissue biopsies were performed at -15, 7, and 30 d relative to calving, and samples were used to assess protein abundance via Western blot assay. Cows in the HighBCS group lost ∼1 unit of BCS between -4 and 4 wk around calving, while NormBCS cows lost ∼0.5 unit in the same period. Prepartal dry matter intake (DMI, kg/d) did not differ between groups. Compared with NormBCS cows, HighBCS cows had higher postpartal DMI and milk yield (+5.34 kg/d). In addition, greater overall plasma concentrations of fatty acids and activity of the neutrophil-enriched enzyme myeloperoxidase were observed in HighBCS compared with NormBCS cows. Despite similar reactive oxygen metabolite concentrations in both groups at 30 d, HighBCS cows had lower overall concentrations of β-carotene and tocopherol, explaining the lower (BCS × Time) antioxidant capacity (ferric reducing ability of plasma). The HighBCS cows also had greater liver malondialdehyde concentrations and superoxide dismutase activity at 30 d. Overall, compared with NormBCS cows, HighBCS cows had lower hepatic protein abundance of the 1-carbon metabolism enzymes cystathionine-β-synthase, betaine-homocysteine methyltransferase, and methionine adenosyltransferase 1 A (MAT1A), as well as the glutathione metabolism-related enzymes glutathione S-transferase α 4 and glutathione peroxidase 3 (GPX3). A lower protein abundance of glutathione S-transferase mu 1 (GSTM1) at -15 and 7 d was also observed. Regardless of BCS, cows had increased abundance of GSTM1 and GPX3 between -15 and 7 d around calving. A marked decrease of gamma-butyrobetaine dioxygenase 1 from -10 to 7 d in HighBCS compared with NormBCS cows suggested a decrease in de novo carnitine synthesis that was partly explained by the lower abundance of MAT1A. Overall, data suggest biologic links between BCS before calving, milk yield, immune response, and hepatic reactions encompassing 1-carbon metabolism, carnitine, and antioxidant synthesis.

Genomic prediction for latent variables related to milk fatty acid composition in Holstein, Simmental and Brown Swiss dairy cattle breeds

Genomic selection (GS) reports on milk fatty acid (FA) profiles have been published quite recently and are still few despite this trait represents the most important aspect of milk nutritional and sensory quality. Reasons for this can be found in the high costs of phenotype recording but also in issues related to its nature of complex trait constituted by multiple genetically correlated variables with low heritabilities. One possible strategy to deal with such constraint is represented by the use of dimension reduction methods. We analysed 40 individual FAs from Italian Brown Swiss, Holstein and Simmental milk through multivariate factor analysis (MFA) to study the genetics of milk FA-related latent variables (factors) and assess their potential use in breeding. A total of nine factors were obtained, and their genetic parameters were inferred under a Bayesian framework using two statistical approaches: the classical pedigree best linear unbiased prediction (ABLUP) and the single-step genomic BLUP (ssGBLUP). The resulting factorial solutions were able to represent groups of FAs with common origin and function and can be considered concise pathway-level phenotypes. The heritability (h² ) values showed relevant variations across different factors in each breed (0.03 ≤ h²  ≤ 0.38). The accuracies of breeding values predicted were low to high, ranging from 0.13 to 0.72 and from 0.18 to 0.74 considering the pedigree and the genomic model, respectively. The gain in accuracy in genetic prediction due to the addition of genomic information was ~30% and ~5% in validation and training groups respectively, confirming the contribution of genomic information in yielding more accurate predictions compared to the traditional ABLUP methodology. Our results suggest that MFA in combination with GS can be a valuable tool in dairy cattle breeding and deserves to be further investigated for use in future breeding programs to improve cow's milk FA-related traits.

Oxidative stress, NF-κB signaling, NLRP3 inflammasome, and caspase apoptotic pathways are activated in mammary gland of ketotic Holstein cows

Ketosis is a serious metabolic disorder characterized by systemic and hepatic oxidative stress, inflammation, and apoptosis, as well as reduced milk yield. Because of the paucity of data on mammary responses during ketosis, the aim of this study was to evaluate alterations in oxidative stress, NF-κB signaling, NLRP3 inflammasome, and caspase apoptotic pathways in mammary gland of dairy cows with ketosis. Blood, mammary gland tissue, and milk samples were collected from healthy cows [Control, blood concentration of β-hydroxybutyrate (BHB) <0.6 mM, n = 10] and cows with subclinical ketosis (SCK, blood concentration of BHB >1.2 mM and <3 mM, n = 10) or clinical ketosis (CK, blood concentration of BHB >3 mM, n = 10) at median 8 d in milk (range = 6-12). Compared with Control, serum concentration of glucose was lower (3.91 vs. 2.86 or 2.12 mM) in cows with SCK or CK, whereas concentrations of fatty acids (0.25 vs. 0.57 or 1.09 mM) and BHB (0.42 vs. 1.81 or 3.85 mM) were greater. Compared with Control, the percentage of milk fat was greater in cows with SCK or CK. In contrast, the percentage of milk protein was lower in cows with SCK or CK. We detected no differences in milk lactose content across groups. Compared with Control, activities of glutathione peroxidase, superoxide dismutase, and catalase were lower in mammary gland tissue of cows with SCK or CK. In contrast, concentrations of hydrogen peroxide and malondialdehyde were greater in cows with SCK or CK. Compared with Control, mRNA abundances of TNFA, IL6, and IL1B were greater in mammary tissues of cows with SCK or CK. In addition, activity of IKKβ and the ratio of phosphorylated inhibitor of κBα to IκBα, and of phosphorylated NF-κB p65 to NF-κB p65, were also greater in mammary tissues of cows with SCK or CK. Subclinical or clinical ketosis also led to greater activity of caspase 1 and protein abundance of caspase 1, NLRP3, Bax, caspase 3, and caspase 9. In contrast, abundance of the antiapoptotic protein was lower in SCK or CK cows. The data indicate that the mammary gland of SKC or CK cows undergoes severe oxidative stress, inflammation, and cell death.

Traditional Chinese herbal medicine complex supplementation improves reproductive performance, serum biochemical parameters, and anti-oxidative capacity in periparturient dairy cows

This study was conducted to investigate the effects of a traditional Chinese herbal medicine complex (TCHMC) on the productive performance of periparturient dairy cows. Eighteen non-lactating pregnant Holstein dairy cows with similar body conditions with 1 to 2 parity were randomly divided into three groups (n = 6), receiving a basal diet with 0 (CON group), 200 (T-200 group), and 300 (T-300 group) g TCHMC per day from 14 to 9 days prepartum. The results demonstrated that TCHMC treatments decreased the days of gestation, calving to first service, and calving to first visible estrus. Compared with CON at specific time points, TCHMC treatments increased the concentrations of follicle-stimulating hormone (FSH), luteinizing hormone (LH), and estradiol (E₂), whereas progesterone (P₄) and E₂ concentrations decreased. Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), and creatine kinase (CK) concentrations were downregulated, whereas that of globulin (GLB) and immunoglobulin G (IgG) were upregulated by TCHMC treatments around the time of calving. Compared with CON and T-200 treatments, the T-300 treatment increased the serum concentrations of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), catalase (CAT) and total antioxidant capacity (T-AOC) and decreased the malondialdehyde (MDA) concentration from 7 d prepartum to 21 d postpartum when. In addition, although TCHMC treatment had no effect on average birth weight, heart rate, respiratory rate, and body temperature of calves, the T-300 treatment increased serum albumin (ALB) and IgG concentrations in calves from 3 to 14 days postpartum. The addition of TCHMC used in the present study could serve as a potential effective strategy to improve the health and productive performance of periparturient dairy cows, and the optimal dose should be set at 300 g per day.

Molecular networks of insulin signaling and amino acid metabolism in subcutaneous adipose tissue are altered by body condition in periparturient Holstein cows

Peripartal cows mobilize not only body fat but also body protein to satisfy their energy requirements. The objective of this study was to determine the effect of prepartum BCS on blood biomarkers related to energy and nitrogen metabolism, and mRNA and protein abundance associated with AA metabolism and insulin signaling in subcutaneous adipose tissue (SAT) in peripartal cows. Twenty-two multiparous Holstein cows were retrospectively classified into a high BCS (HBCS; n = 11, BCS ≥ 3.5) or normal BCS (NBCS; n = 11, BCS ≤ 3.17) group at d 28 before expected parturition. Cows were fed the same diet as a total mixed ration before parturition and were fed the same lactation diet postpartum. Blood samples collected at -10, 7, 15, and 30 d relative to parturition were used for analyses of biomarkers associated with energy and nitrogen metabolism. Biopsies of SAT harvested at -15, 7, and 30 d relative to parturition were used for mRNA (real time-PCR) and protein abundance (Western blotting) assays. Data were subjected to ANOVA using the MIXED procedure of SAS (v. 9.4; SAS Institute Inc., Cary, NC), with P ≤ 0.05 being the threshold for significance. Cows in HBCS had greater overall plasma nonesterified fatty acid concentrations, due to marked increases at 7 and 15 d postpartum. This response was similar (BCS × Day effect) to protein abundance of phosphorylated (p) protein kinase B (p-AKT), the insulin-induced glucose transporter (SLC2A4), and the sodium-coupled neutral AA transporter (SLC38A1). Abundance of these proteins was lower at -15 d compared with NBCS cows, and either increased (SLC2A4, SLC38A1) or did not change (p-AKT) at 7 d postpartum in HBCS. Unlike protein abundance, however, overall mRNA abundances of the high-affinity cationic (SLC7A1), proton-coupled (SLC36A1), and sodium-coupled amino acid transporters (SLC38A2) were greater in HBCS than NBCS cows, due to upregulation in the postpartum phase. Those responses were similar to protein abundance of p-mTOR, which increased (BCS × Day effect) at 7 d in HBCS compared with NBCS cows. mRNA abundance of argininosuccinate lyase (ASL) and arginase 1 (ARG1) also was greater overall in HBCS cows. Together, these responses suggested impaired insulin signaling, coupled with greater postpartum AA transport rate and urea cycle activity in SAT of HBCS cows. An in vitro study using adipocyte and macrophage cocultures stimulated with various concentrations of fatty acids could provide some insights into the role of immune cells in modulating adipose tissue immunometabolic status, including insulin resistance and AA metabolism.

The Role of Innate Immune Response and Microbiome in Resilience of Dairy Cattle to Disease: The Mastitis Model

Animal health is affected by many factors such as metabolic stress, the immune system, and epidemiological features that interconnect. The immune system has evolved along with the phylogenetic evolution as a highly refined sensing and response system, poised to react against diverse infectious and non-infectious stressors for better survival and adaptation. It is now known that high genetic merit for milk yield is correlated with a defective control of the inflammatory response, underlying the occurrence of several production diseases. This is evident in the mastitis model where high-yielding dairy cows show high disease prevalence of the mammary gland with reduced effectiveness of the innate immune system and poor control over the inflammatory response to microbial agents. There is growing evidence of epigenetic effects on innate immunity genes underlying the response to common microbial agents. The aforementioned agents, along with other non-infectious stressors, can give rise to abnormal activation of the innate immune system, underlying serious disease conditions, and affecting milk yield. Furthermore, the microbiome also plays a role in shaping immune functions and disease resistance as a whole. Accordingly, proper modulation of the microbiome can be pivotal to successful disease control strategies. These strategies can benefit from a fundamental re-appraisal of native cattle breeds as models of disease resistance based on successful coping of both infectious and non-infectious stressors.

Multivariate factor analysis of milk fatty acid composition in relation to the somatic cell count of single udder quarters

The present study investigated whether the fatty acid composition of milk changes in relation to an increase in the milk somatic cell count (SCC) of separate udder quarters. We investigated the potential of multivariate factor analysis to extract metabolic evidence from data on the quantity and quality of milk of quarters characterized by different SCC levels. We collected data from individual milk samples taken from single quarters of 49 Italian Holstein cows from the same dairy farm. Factor analysis was carried out on 64 individual fatty acids. In line with a previous study on multivariate factor analysis, a variable was considered to be associated with a specific factor if the absolute value of its correlation with the factor was ≥0.60. Seven factors were extracted that explained the following groups of fatty acids or functions: de novo synthesis, energy balance, uptake of dietary fatty acids, biohydrogenation, short-chain fatty acids, very long chain fatty acids, and odd- and branched-chain fatty acids. An ANOVA of factor scores highlighted the significant effects of the SCC level on de novo fatty acids and biohydrogenation. The de novo fatty acid factor decreased significantly with a high level of SCC, from just 10,000 cells/mL, whereas the biohydrogenation factor showed a significantly higher level in quarters with SCC levels greater than 400,000 cells/mL. This statistical approach enabled us to reduce the number of variables to a few latent factors with biological significance and to represent groups of fatty acids with a common origin and function. Multivariate factor analysis could therefore be key to studying the influence of SCC on the lipid metabolism of single quarters. This approach also demonstrated the metabolic differences between quarters of the same animal showing a different level of SCC.

Impact of global climate change on livestock health: Bangladesh perspective

The global carbon emission rate, due to energy-driven consumption of fossil fuels and anthropogenic activities, is higher at any point in mankind history, disrupting the global carbon cycle and contributing to a major cause of warming of the planet with air and ocean temperatures, which is rising dangerously over the past century. Climate change presents challenges both direct and indirect for livestock production and health. With more frequent extreme weather events including increased temperatures, livestock health is greatly affected by resulting heat stress, metabolic disorder, oxidative stress, and immune suppression, resulting in an increased propensity for disease incidence and death. The indirect health effects relate to the multiplication and distribution of parasites, reproduction, virulence, and transmission of infectious pathogens and/or their vectors. Managing the growing crossbreeding livestock industry in Bangladesh is also at the coalface for the emerging impacts of climate change, with unknown consequences for the incidence of emerging and re-emerging diseases. Bangladesh is now one of the most vulnerable nations to global climate change. The livestock sector is considered as a major part of food security for Bangladesh, alongside agriculture, and with one of the world’s largest growing economies, the impacts are exaggerated with this disaster. There has been no direct study conducted on the impact of climate change on livestock health and the diseases in Bangladesh. This review looks to explore the linkage between climate change and livestock health and provide some guidelines to combat the impact on livestock from the Bangladesh perspective.

Symposium review: Nutrition strategies for improved health, production, and fertility during the transition period

Dairy cow nutritional programs are a major determinant of the profitability of dairy farms. Despite this, the sustainability of the dairy enterprise is beyond just cow nutrition. For almost 50 yr, the NC-2042 project (Management Systems to Improve the Economic and Environmental Sustainability of Dairy Enterprises) has been addressing most of these components as individual research units and in integrated ways. This review has the objective to report the body of research developed by members of the group in connection with the existing literature on dietary formulation and feeding management during the dry period, peripartal period, and early postpartum (fresh) period. Peak disease incidence (shortly after parturition) corresponds with the time of greatest negative energy balance (NEB), the peak in blood concentrations of nonesterified fatty acids, and the greatest acceleration of milk yield. Decreased fertility in the face of increasing milk production may be attributable to greater severity of postpartal NEB resulting from inadequate transition management or increased rates of disease. The depth and duration of NEB is highly related to dry matter intake. Periparturient diseases can result from adverse ruminal conditions caused by excessive grain in the precalving or fresh cow diet, perhaps aggravated by overcrowding, heat stress, or other stressors. Others have also implicated inflammatory responses in alterations of metabolism, occurrence of health problems, and impaired reproduction. Providing controlled-energy and negative dietary cation-anion difference diets prepartum may improve dairy cow performance during the transition period. A major area of concern in the fresh cow period is a sudden increase in dietary energy density leading to subacute ruminal acidosis, which can decrease dry matter intake and digestibility of nutrients. Adequate physical form of the diet, derived from either forage neutral detergent fiber content or a mixing strategy of different ingredients in a total mixed ration, must be present to stimulate ruminal activity and chewing behavior. In conclusion, formulation and delivery of appropriate diets that limit total energy intake to requirements but also provide proper intakes of all other nutrients (including the most limiting amino acids Met and Lys) before calving can help lessen the extent of NEB after calving. Effects of such diets on indicators of metabolic health are generally positive, suggesting the potential to lessen effects of periparturient disease on fertility.

Prepartum dietary energy intake alters adipose tissue transcriptome profiles during the periparturient period in Holstein dairy cows

Background

The aim of the study was to investigate the effect of energy overfeeding during the dry period on adipose tissue transcriptome profiles during the periparturient period in dairy cows.

Methods

Fourteen primiparous Holstein cows from a larger cohort receiving a higher-energy diet (1.62 Mcal of net energy for lactation/kg of dry matter; 15% crude protein) for ad libitum intake to supply 150% (OVR) or 100% (CTR) of energy requirements from dry off until parturition were used. After calving, all cows received the same lactation diet. Subcutaneous adipose tissue (SAT) biopsies were collected at - 14, 1, and 14 d from parturition (d) and used for transcriptome profiling using a bovine oligonucleotide microarray. Data mining of differentially expressed genes (DEG) between treatments and due to sampling time was performed using the Dynamic Impact Approach (DIA) and Ingenuity Pathway Analysis (IPA).

Results

There was a strong effect of over-feeding energy on DEG with 2434 (False discovery rate-corrected P < 0.05) between OVR and CTR at - 14 d, and only 340 and 538 at 1 and 14 d. The most-impacted and activated pathways in the Kyoto Encyclopedia of Genes and Genomes (KEGG) database that were highlighted by DIA analysis at - 14 d in OVR vs. CTR included 9 associated with carbohydrate metabolism, with 'Pyruvate metabolism', 'Glycolysis/gluconeogenesis', and 'Pentose phosphate pathway' among the most-activated. Not surprisingly, OVR led to marked activation of lipid metabolism (e.g. 'Fatty acid biosynthesis' and 'Glycerolipid metabolism'). Unexpected metabolic pathways that were activated at - 14 d in OVR included several related to metabolism of amino acids (e.g. branched chain) and of cofactors and vitamins (thiamin). Among endocrine and immune system pathways, at - 14 d OVR led to marked activation of 'PPAR signalling' and 'Antigen processing and presentation'. Among key pathways affected over time in OVR, a number were related to translation (e.g. mTOR signaling), endocrine/immune signaling (CXCR4 and IGF1), and lipid metabolism (oxidative phosphorylation) with greater activation in OVR vs. CTR specifically at - 14 d. Although statistical differences for several pathways in OVR vs. CTR nearly disappeared at 1 and 14 vs. - 14 d, despite the well-known catabolic state of adipose depots after calving, the bioinformatics analyses suggested important roles for a number of signaling mechanisms at - 14 vs. 14 than 1 vs. -14 d. This was particularly evident in cows fed to meet predicted energy requirements during the dry period (CTR).

Conclusions

Data underscored a strong activation by overfeeding energy of anabolic processes in the SAT exclusively prepartum. The study confirmed that higher-energy diets prepartum drive a transcriptional cascade of events orchestrated in part by the activation of PPARγ that regulate preadipocyte differentiation and lipid storage in SAT. Novel aspects of SAT biology to energy overfeeding or change in physiologic state also were uncovered, including the role of amino acid metabolism, mTOR signaling, and the immune system.

Moisture content of high-straw dry cow diets affects intake, health, and performance of transition dairy cows

The objective of this study was to determine the effect of adding water to a high-straw dry cow diet on feeding behavior, health, and performance of dairy cows. Holstein cows (n = 40) entering their second or greater lactation were enrolled at dry off (∼45 d before expected calving) and assigned to 1 of 2 dietary treatments, consisting of a high-straw dry cow total mixed ration [TMR; 36% wheat straw, 41% corn silage, 23% pellet, on a dry matter (DM) basis, formulated for 11.6% crude protein, 1.35 Mcal/kg net energy for lactation] with (1) no water (CON; n = 20; DM = 53.4%) or (2) water added to decrease the DM by ∼10 percentage points (wet diet, WD; n = 20; DM = 45.4%). Upon calving, all cows were fed the same lactating TMR (45.2% DM, 14.9% crude protein, 1.68 Mcal/kg net energy for lactation) and followed for 28 d. Dry matter intake, feeding behavior, and rumination activity were recorded automatically. Fresh TMR and orts samples were collected 2×/wk to determine differences in sorting. A particle separator was used to separate feed samples into 4 fractions: long (>19 mm), medium (<19, >8 mm), short (<8, >4 mm), and fine (<4 mm) particles. Feed sorting was calculated as actual intake of each particle fraction expressed as a % of predicted intake. Cows fed WD had greater DM intake during the dry period than cows fed CON (CON = 13.4 ± 0.24, WD = 14.2 ± 0.24 kg/d), but rumination did not differ (CON = 522.2 ± 8.48, WD = 518.5 ± 8.69 min/d) between treatments. Cows fed WD tended to consume their feed faster (CON = 0.08 ± 0.001, WD = 0.09 ± 0.001 kg of DM/min) compared with CON cows. Regardless of treatment, cows sorted against the longest ration particles, with cows fed CON sorting more against these (CON = 81.1 ± 2.51%, WD = 94.9 ± 2.58%). Cows fed CON tended to sort more in favor of the medium particles than those fed WD (CON = 105.0 ± 0.36%, WD = 104.2 ± 0.37%). Postcalving DM intake and feeding behavior were not affected by dry diet treatment. Cows fed WD experienced a less rapid daily decline in rumen pH during the first 7 d after calving compared with those fed the CON diet. The results suggest that increasing the moisture content of high-straw dry cow diets, by adding water, may improve intake and reduce sorting against the longest ration particles, which may help promote consistency in targeted nutrients consumed during the dry period and greater rumen health in early lactation.

Prediction of metabolic status of dairy cows in early lactation with on-farm cow data and machine learning algorithms

Metabolic status of dairy cows in early lactation can be evaluated using the concentrations of plasma β-hydroxybutyrate (BHB), free fatty acids (FFA), glucose, insulin, and insulin-like growth factor 1 (IGF-1). These plasma metabolites and metabolic hormones, however, are difficult to measure on farm. Instead, easily obtained on-farm cow data, such as milk production traits, have the potential to predict metabolic status. Here we aimed (1) to investigate whether metabolic status of individual cows in early lactation could be clustered based on their plasma values and (2) to evaluate machine learning algorithms to predict metabolic status using on-farm cow data. Through lactation wk 1 to 7, plasma metabolites and metabolic hormones of 334 cows were measured weekly and used to cluster each cow into 1 of 3 clusters per week. The cluster with the greatest plasma BHB and FFA and the lowest plasma glucose, insulin, and IGF-1 was defined as poor metabolic status; the cluster with the lowest plasma BHB and FFA and the greatest plasma glucose, insulin, and IGF-1 was defined as good metabolic status; and the intermediate cluster was defined as average metabolic status. Most dairy cows were classified as having average or good metabolic status, and a limited number of cows had poor metabolic status (10-50 cows per lactation week). On-farm cow data, including dry period length, parity, milk production traits, and body weight, were used to predict good or average metabolic status with 8 machine learning algorithms. Random Forest (error rate ranging from 12.4 to 22.6%) and Support Vector Machine (SVM; error rate ranging from 12.4 to 20.9%) were the top 2 best-performing algorithms to predict metabolic status using on-farm cow data. Random Forest had a higher sensitivity (range: 67.8-82.9% during wk 1 to 7) and negative predictive value (range: 89.5-93.8%) but lower specificity (range: 76.7-88.5%) and positive predictive value (range: 58.1-78.4%) than SVM. In Random Forest, milk yield, fat yield, protein percentage, and lactose yield had important roles in prediction, but their rank of importance differed across lactation weeks. In conclusion, dairy cows could be clustered for metabolic status based on plasma metabolites and metabolic hormones. Moreover, on-farm cow data can predict cows in good or average metabolic status, with Random Forest and SVM performing best of all algorithms.

Early lactation performance in Holstein heifers first calving at 36 months and managed for high or low weight gain during mid- and late gestation

The effect of weight gain during mid- and late gestation in dairy heifers on performance at the start of first lactation was studied. In this experiment, 47 Holstein heifers with first calving at 36 months of age were used. The plane of nutrition aimed to have a high (900 g/d, H; n = 23) and low (500, L; n = 24) average daily gain (ADG) from the 4th month of gestation until 3 weeks before the expected day of calving, achieved by ad libitum intake of high quality pasture (H) or controlled intake of a total mixed ration (L). Body weight (BW), body condition score (BCS), milking, and reproductive performances were recorded. Concentrations of plasma non-esterified fatty acids (NEFA), glucose, beta-hydroxybutyric acid (BHBA), and urea were characterised at weeks 2, 4, 6 and 8 of lactation. Milk fatty acid composition was determined at weeks 3 and 6. A total of 39 heifers successfully calved and completed first lactation. During feeding treatment the required ADG were achieved. BW and BCS were higher in H heifers at calving compared to L heifers: 707 vs. 640 kg, and 3.91 vs. 3.01 respectively. H heifers lost more weight, BCS and had lower feed intake during the beginning of first lactation (-0.8 kg DM/d/heifer over the first 4 weeks of lactation). Per day of lactation, H heifers produced significantly more milk (29.2 vs. 26.2 kg), fat (1.27 vs. 1.07 kg) and protein (0.84 vs. 0.477 kg) from 0 to 8 weeks of lactation. Concentrations of NEFA, glucose and BHBA were higher in H heifers compared to L heifers, but urea concentration was not affected. Concentration of preformed fatty acids in the milk (C16 and more) was higher. As a result, the calculated daily net energy balance during the first 8 weeks of lactation was -1.53 and -5.95 MJ for L and H heifers, respectively.

Protein and gene expression of relevant enzymes and nuclear receptor of hepatic lipid metabolism in grazing dairy cattle during the transition period

We aimed to study the protein and gene expression of some hepatic enzymes of lipid metabolism along with plasma biomarkers in grazing dairy cattle during the transition period. Blood and liver biopsies from a group of eight multiparous cows were sampled at -28, -14, +4, +14, +28 and +56 days relative to parturition. Peak concentrations of NEFA and beta-hydroxybutyric acid with high triacylglycerol content in the liver were recorded on day 4 postpartum. Consistent with blood biomarkers, the gene expression of carnitine palmitoyltransferase 1A (CPT1A) and acyl-CoA oxidase 1 (ACOX1) increased, whereas that of diacylglycerol O-acyltransferase 1 (DGAT1) decreased. Nevertheless, CPT1A protein expression did not change during all the period evaluated and ACOX1 protein expression increased on day 56 postpartum. In addition, the protein expression of peroxisome proliferator-activated receptor alpha (PPAR-alpha) increased on day 28 postpartum. On the other hand, DGAT1 protein expression decreased on day 14 postpartum. As expected, the expression of genes associated with fatty acid oxidation increased on the first days postpartum but, notably, protein expression was highest after transition. Since most infectious diseases and metabolic disorders in dairy cattle occur particularly on the first days postpartum, it is not so clear whether an increase in the oxidation capacity of the liver at that time could help to prevent disease and improve dairy production. The valuable results about protein expression of enzymes involved in liver lipid metabolism could help to better characterize the metabolism of dairy cattle during the transition period.

Inter-individual variation in adaptive capacity at onset of lactation: Linking metabolic phenotype with mitochondrial DNA haplotype in Holstein dairy cows

Modern-day dairy cows express great variation in metabolic capacity to adapt to the onset of lactation. Although breeding programs increased the breeding value for longevity and robustness in the sires, a respective phenotype in female offspring has not been improving as predicted. Fundamental energy generating pathways such as mitochondrial fatty acid oxidation might have a crucial role for robustness and metabolic efficiency in dairy cows. Therefore, mitochondrial enzyme expression was examined in liver samples of one set of animals before and after calving. Furthermore, the mitochondrial DNA sequence was determined for each individual of a second set of animals using liver samples. Results from the first trial indicate that the expression and extent of phosphorylation of acetyl-CoA carboxylase (ACC) is the major key step for modulating fatty acid flux into the mitochondria at early onset of lactation in Holstein dairy cows. In the second trial, mitochondrial DNA sequencing and identification of mutation patterns yielded three major haplotypes. Haplotype H2 was closely associated with liver fat content, plasma glycerol and acyl-carnitine concentrations. The mitochondrial DNA haplotype, which is a feature of the maternal lines, might be related to the inter-individual variation in metabolic capacity of Holstein dairy cows.

Expression profiles of immunity and reproductive genes during transition period in Holstein cattle

The transition period is a critical time for dairy cows as the animal is subjected to the physiological stress accompanying parturition. Immunosuppression and health status were examined during this period in 80 Holstein cows. Blood samples were taken from each cow 3, 2 and 1 week before and after calving, and at calving (0 day). RNA was extracted and subjected to real-time PCR to determine mRNA levels for the immune-related genes TLR 2, 4, 6, 7 and β-defensin 5 in addition to the reproduction-related genes prolactin and IGF-I. Results showed significant up-regulation of pro-inflammatory-selected genes, TLR 4, 6 7 and β-defensin 5 at the third-week post-calving; however, earlier periods had lower expression of such genes. In contrast, the immunosuppression biomarker TLR2 gene was up-regulated at calving and 1 week after parturition and then down-regulated again at second and third week. Prolactin and IGF-I genes expression levels were significantly and gradually increased mainly post-partum. This research highlights that the expression patterns of TLRs, BNBD5, PRL and IGF-I could be biomarkers to follow up immune and reproductive status of dairy cow at peri-parturient period to predict the most susceptible risk time for disease incidence and to build up management protocol.

Ethyl-cellulose rumen-protected methionine alleviates inflammation and oxidative stress and improves neutrophil function during the periparturient period and early lactation in Holstein dairy cows

The periparturient period is the most critical phase in the productive cycle of dairy cows and is characterized by impairment of the immune system. Our objective was to evaluate the effect of feeding ethyl-cellulose rumen-protected methionine (RPM) starting at d -28 from expected parturition through 60 d in milk on biomarkers of inflammation, oxidative stress, and liver function as well as leukocyte function. Sixty multiparous Holstein cows were used in a block design and assigned to either a control or the control plus ethyl-cellulose RPM (Mepron, Evonik Nutrition & Care GmbH). Mepron was supplied from -28 to 60 d in milk at a rate of 0.09% and 0.10% dry matter during the prepartum and postpartum period. That rate ensured that the ratio of Lys to Met in the metabolizable protein was close to 2.8:1. Blood samples from 15 clinically healthy cows per treatment were collected at d -30, -14, 1, 7, 21, 30, and 60 and analyzed for biomarkers of liver function, inflammation, and oxidative stress. Neutrophil and monocyte function in whole blood was measured in vitro at -14, 1, 7, 21, and 30 d in milk. The statistical model included the random effect of block and fixed effect of treatment, time, and its interaction. Compared with control, ethyl-cellulose RPM increased plasma cholesterol and paraoxonase after parturition. Among the inflammation biomarkers measured, ethyl-cellulose RPM led to greater albumin (negative acute-phase protein) and lower haptoglobin than control cows. Although concentration of IL-1β was not affected by treatments, greater IL-6 concentration was detected in response to ethyl-cellulose RPM. Cows supplemented with ethyl-cellulose RPM had greater plasma concentration of ferric-reducing antioxidant power, β-carotene, tocopherol, and total and reduced glutathione, whereas reactive oxygen metabolites were lower compared with control cows. Compared with control, ethyl-cellulose RPM enhanced neutrophil phagocytosis and oxidative burst. Overall, the results indicate that ethyl-cellulose RPM supply to obtain a Lys-to-Met ratio of 2.8:1 in the metabolizable protein during the periparturient period and early lactation is an effective approach to help mitigate oxidative stress and inflammation as well as enhance liver and neutrophil function in dairy cows.

Methionine and Choline Supply during the Periparturient Period Alter Plasma Amino Acid and One-Carbon Metabolism Profiles to Various Extents: Potential Role in Hepatic Metabolism and Antioxidant Status

The objective of this study was to profile plasma amino acids (AA) and derivatives of their metabolism during the periparturient period in response to supplemental rumen-protected methionine (MET) or rumen-protected choline (CHOL). Forty cows were fed from −21 through 30 days around parturition in a 2 × 2 factorial design a diet containing MET or CHOL. MET supply led to greater circulating methionine and proportion of methionine in the essential AA pool, total AA, and total sulfur-containing compounds. Lysine in total AA also was greater in these cows, indicating a better overall AA profile. Sulfur-containing compounds (cystathionine, cystine, homocystine, and taurine) were greater in MET-fed cows, indicating an enriched sulfur-containing compound pool due to enhanced transsulfuration activity. Circulating essential AA and total AA concentrations were greater in cows supplied MET due to greater lysine, arginine, tryptophan, threonine, proline, asparagine, alanine, and citrulline. In contrast, CHOL supply had no effect on essential AA or total AA, and only tryptophan and cystine were greater. Plasma 3-methylhistidine concentration was lower in response to CHOL supply, suggesting less tissue protein mobilization in these cows. Overall, the data revealed that enhanced periparturient supply of MET has positive effects on plasma AA profiles and overall antioxidant status.

A comparison of serum metabolic and production profiles of dairy cows that maintained or lost body condition 15 days before calving

Body condition score (BCS) change is an indirect measure of energy balance. Energy balance before calving may affect production and health in the following lactation. It is likely that cows may experience BCS loss before calving due to negative energy balance. The objective of this study was to determine if loss of BCS 15d before calving affected milk production, BCS profile, and metabolic status during the transition period and early lactation. On d -15 to d 0 relative to calving, BCS was assessed (1=emaciated, 5=obese) for 98 Holstein-Friesian cows. The cows were divided into 2groups: those that did not lose BCS between d -15 and d 0 (maintained, BCS-M, n=55) and those that lost BCS from d -15 to d 0 (lost, BCS-L, n=43, average loss of 0.29±0.11 BCS). The fixed effects of BCS group, parity, week (day when analyzing milk production records), their interactions, and a random effect of cow were analyzed using PROC MIXED of SAS (SAS Institute Inc., Cary, NC). Before calving, BCS-L cows tended to have higher concentrations of nonesterified fatty acids than BCS-M cows (0.88 vs. 0.78mmol/L). After calving, BCS-L cows had higher nonesterified fatty acid concentrations in wk 1 (0.93 vs. 0.71mmol/L), wk 2 (0.84 vs. 0.69mmol/L), and wk 4 (0.81 vs. 0.63mmol/L) than BCS-M cows. The BCS-L cows had higher concentrations of β-hydroxybutyrate (BHB) in wk 1 (0.72 vs. 0.57mmol/L), wk 2 (0.97 vs. 0.70mmol/L), and wk 4 (0.94 vs. 0.67mmol/L) compared with BCS-M cows. We detected significant reductions in insulin concentrations in BCS-L cows from wk -1 (2.23 vs. 1.37 µIU/mL) to wk 2 (1.68 vs. 0.89 µIU/mL) and wk 4 (2.21 vs 1.59 µIU/mL) compared with BCS-M cows. Prevalence of subclinical ketosis increased in BCS-L cows in wk 3 and 4 when BHB was ≥1.4mmol/L and in wk 1, 3, and 4 when BHB was ≥1.2mmol/L. In wk 1, BCS-L cows tended to have lower levels of calcium than BCS-M cows (2.33 vs. 2.27mmol/L). We found no differences between the groups of cows for milk yield and energy-corrected milk. The BCS-L cows had lower BCS up to 75d in lactation. Overall, BCS-L cows had higher somatic cell scores with an elevated somatic cell score on d 45, d 60, and d 75. There was an overall tendency for BCS-L cows to have higher fat yield and an overall significant increase in fat percentage. Overall, BCS-L cows had lower lactose percentage, with a reduction on d 60. This work shows that BCS loss before calving may have significant consequences for metabolic status, milk composition, somatic cell score, and BCS profile in dairy cows.

Rumen-protected methionine compared with rumen-protected choline improves immunometabolic status in dairy cows during the peripartal period

The immunometabolic status of peripartal cows is altered due to changes in liver function, inflammation, and oxidative stress. Nutritional management during this physiological state can affect the biological components of immunometabolism. The objectives of this study were to measure concentrations of biomarkers in plasma, liver tissue, and milk, and also polymorphonuclear leukocyte function to assess the immunometabolic status of cows supplemented with rumen-protected methionine (Met) or choline (CHOL). Forty-eight multiparous Holstein cows were used in a randomized complete block design with 2×2 factorial arrangement of Met (Smartamine M, Adisseo NA, Alpharetta, GA) and CHOL (ReaShure, Balchem Inc., New Hampton, NY) level (with or without). Treatments (12 cows each) were control (CON), no Met or CHOL; CON and Met (SMA); CON and CHOL (REA); and CON and Met and CHOL (MIX). From -50 to -21d before expected calving, all cows received the same diet [1.40Mcal of net energy for lactation (NE_L)/kg of DM] with no Met or CHOL. From -21d to calving, cows received the same close-up diet (1.52Mcal of NE_L/kg of DM) and were assigned randomly to each treatment. From calving to 30d, cows were on the same postpartal diet (1.71Mcal of NE_L/kg of DM) and continued to receive the same treatments until 30d. The Met supplementation was adjusted daily at 0.08% DM of diet, and CHOL was supplemented at 60g/cow per day. Liver (-10, 7, 21, and 30d) and blood (-10, 4, 8, 20, and 30d) samples were harvested for biomarker analyses. Neutrophil and monocyte phagocytosis and oxidative burst were assessed at d 1, 4, 14, and 28d. The Met-supplemented cows tended to have greater plasma paraoxonase. Greater plasma albumin and IL-6 as well as a tendency for lower haptoglobin were detected in Met- but not CHOL-supplemented cows. Similarly, cows fed Met compared with CHOL had greater concentrations of total and reduced glutathione (a potent intracellular antioxidant) in liver tissue. Upon a pathogen challenge in vitro, blood polymorphonuclear leukocyte phagocytosis capacity and oxidative burst activity were greater in Met-supplemented cows. Overall, liver and blood biomarker analyses revealed favorable changes in liver function, inflammation status, and immune response in Met-supplemented cows.

Alterations in Hepatic FGF21, Co-Regulated Genes, and Upstream Metabolic Genes in Response to Nutrition, Ketosis and Inflammation in Peripartal Holstein Cows

In rodents, fibroblast growth factor 21 (FGF21) has emerged as a key metabolic regulator produced by liver. To gather preliminary data on the potential importance of FGF1, co-regulated genes, and upstream metabolic genes, we examined the hepatic mRNA expression in response to nutrition and inflammation in dairy cows. In experiment 1, induction of ketosis through feed restriction on d 5 postpartum upregulated FGF21, its co-receptor KLB, and PPARA but only elicited a numerical increase in serum FGF21 concentration. In experiment 2, cows in control (CON) or receiving 50 g/d of L-carnitine (C50) from -14 through 21 d had increased FGF21, PPARA, and NFIL3 on d 10 compared with d 2 postpartum. In contrast, compared with CON and C50, 100 g/d L-carnitine (C100) resulted in lower FGF21, KLB, ANGPTL4, and ARNTL expression on d 10. In experiment 3, cows were fed during the dry period either a higher-energy (OVE; 1.62 Mcal/kg DM) or lower-energy (CON; 1.34 Mcal/kg DM) diet and received 0 (OVE:N, CON:N) or 200 μg of LPS (OVE:Y, CON:Y) into the mammary gland at d 7 postpartum. For FGF21 mRNA expression in CON, the LPS challenge (CON:Y) prevented a decrease in expression between d 7 and 14 postpartum such that cows in CON:N had a 4-fold lower expression on d 14 compared with d 7. The inflammatory stimulus induced by LPS in CON:Y resulted in upregulation of PPARA on d 14 to a similar level as cows in OVE:N. In OVE:Y, expression of PPARA was lower than CON:N on d 7 and remained unchanged on d 14. On d 7, LPS led to a 4-fold greater serum FGF21 only in OVE but not in CON cows. In fact, OVE:Y reached the same serum FGF21 concentration as CON:N, suggesting a carryover effect of dietary energy level on signaling mechanisms within liver. Overall, results indicate that nutrition, ketosis, and inflammation during the peripartal period can alter hepatic FGF21, co-regulated genes, and upstream metabolic genes to various extents. The functional outcome of these changes merits further study, and in particular the mechanisms regulating transcription in response to changes in energy balance and feed intake.

Effects of dry period management on milk production, dry matter intake, and energy balance of dairy cows

Khazanehei, H., Li, S., Khafipour, E. and Plaizier, J. C. 2015. Effects of dry period management on milk production, dry matter intake, and energy balance of dairy cows. Can. J. Anim. Sci. 95: 433–444. Effects of dry-period management on milk production, feed intake, and energy balance were determined in 11 second-parity (PAR 2) and 15 third or later parity (PAR 3+) cows. Cows were paired based on expected calving date, and randomly assigned to treatments including a conventional 60-d dry period with a 39-d far-off and a 21-d close-up diet (CONV), and a short 40-d dry period with only a close-up diet (SHORT). Treatment did not affect dry matter intake (DMI) and energy balance across the 6 wk before calving and the 4 wk after calving. Across the first 16 wk of lactation, cows on the short treatment had lower milk yield compared to cows on the CONU treatment that was mostly due to the lower production in PAR 3+ cows. Also, PAR 3+ cows on the SHORT treatment had lower milk protein yields and higher somatic cell counts than the other cows. In general, PAR 2 cows on the SHORT treatment had similar DMI, fat corrected milk yields, and protein and fat yields and percentages compared to cows in both parity groups on the CONV treatment. This suggests that the SHORT treatment may be suitable for PAR 2 cows, but not for older cows.

Hormonal profile and body condition scoring in dairy cows during pre partum and post partum periods

The aim of this study was to evaluate the dynamics of selected indicators of energy, hormonal profile, body condition score (BCS) and their relationships in dairy cows of the Slovak Pied Cattle from 3 weeks before parturition to 9 weeks after. Significant differences were found in the mean values of non-esterified fatty acids (NEFA) (P < 0.001) and β-hydroxybutyrate (BHB) (P < 0.05). According to BCS results, the dry cows were overweight (4.42 ± 0.75 points). After calving the cows lost weight significantly, as the BCS was 3.25 ± 0.30 points at 9 weeks post partum (P < 0.001). The highest concentration of leptin was recorded before calving (26.80 ± 11.47 ng/ml). The concentrations of insulin and ghrelin did not change significantly (an increase in insulin concentrations from 580.8 ± 66.30 IU/ml to 625.50 ± 174.90 IU/ml and a decrease in ghrelin concentrations from 29.25 ± 4.82 pg/ml to 26.57 ± 5.35 pg/ml were found comparing 3 weeks to 1 week before parturition, respectively). Relationships between the hormones showed positive correlation between insulin and leptin (r = 0.220, P < 0.05), BCS and leptin (r = 0.360, P < 0.001), BCS and insulin (r = 0.232, P < 0.05) and negative correlation between leptin and ghrelin (r = -0.235, P < 0.05), BCS and ghrelin (r = -0.257, P < 0.05). These data provide evidence that the variations in the concentrations of leptin, ghrelin, and insulin are related to variations in the BCS. Negative correlation between leptin and ghrelin contributes to the argument that leptin negatively regulates ghrelin.

Prepartum and postpartum nutritional management to optimize fertility in high-yielding dairy cows in confined TMR systems

The 6 to 8-week period centered on parturition, known as the transition or periparturient period, is critical to welfare and profitability of individual cows. Fertility of high-producing cows is compromised by difficult transitions. Deficiencies in either nutritional or non-nutritional management increase risk for periparturient metabolic disorders and infectious diseases, which decrease subsequent fertility. A primary factor impeding fertility is the extent of negative energy balance (NEB) early postpartum, which may inhibit timing of first ovulation, return to cyclicity, and oocyte quality. In particular, pronounced NEB during the first 10 days to 2 weeks (the time of greatest occurrence of health problems) is critical for later reproductive efficiency. Avoiding over-conditioning and preventing cows from over-consuming energy relative to their requirements in late gestation result in higher dry matter intake (DMI) and less NEB after calving. A pooled statistical analysis of previous studies in our group showed that days to pregnancy are decreased (by 10 days) by controlling energy intake to near requirements of cows before calving compared with allowing cows to over-consume energy. To control energy intake, total mixed rations (TMR) must be well balanced for metabolizable protein, minerals and vitamins yet limit total DM consumed, and cows must uniformly consume the TMR without sorting. Dietary management to maintain blood calcium and rumen health around and after calving also are important. Opportunities may exist to further improve energy status in fresh cows. Recent research to manipulate the glucogenic to lipogenic balance and the essential fatty acid content of tissues are intriguing. High-producing cows that adapt successfully to lactation can have high reproductive efficiency, and nutritional management of the transition period both pre- and post-calving must facilitate that adaptation.

Effect of additional chromium supplementation on health status, metabolic responses, and performance traits in periparturient Murrah Buffaloes (Bubalus bubalis)

This study was conducted to determine the effects of inorganic chromium (Cr) on body condition, metabolic responses, lactation performance, and reproductive parameters in periparturient Murrah buffaloes. Twenty-four multiparous advanced pregnant Murrah buffaloes were randomly assigned to four treatment diets. Feeding regimen was the same in all the groups, except that the animals in the four respective groups were additionally supplemented with 0.0, 0.5, 1.0, and 1.5 mg of Cr/kg dry matter (DM) from day 60 prepartum to 150 days postpartum. Dry matter intake (DMI) and milk production were recorded every day, while body condition score (BCS) and whole blood samples were collected at days -60, -45, -30, -15, -7, -3, 0, 3, 7, 15, 30, 45, 60, 90, 120, and 150 relative to actual calving. As the days to calving advanced, DMI, plasma glucose, insulin, leptin, and Cr levels decreased (P < 0.05), and the levels were minimum on the day of calving. In contrast, the concentration of nonesterified fatty acid (NEFA) increased (P < 0.05) and was found to be highest at parturition. No change in DMI as well as BCS was observed due to dietary treatments. Supplementation of Cr improved plasma concentration of glucose, leptin, and Cr levels. However, the concentration of insulin decreased (P < 0.05) with the increased level of supplemental Cr. Milk yield (kg/day) was improved significantly (P < 0.05) in groups supplemented with 1.0 or 1.5 mg Cr/DM; however, only a small change was recorded in the group fed 0.5 mg Cr/kg DM. Fat-corrected milk and energy-corrected milk were 28.78 and 42.32 % and 28.76 and 41.68 % higher in the 1.0 and 1.5 mg Cr/DM groups, respectively. Dietary Cr supplementation during the peripartum period had beneficial effects on the reproductive performance of buffaloes. These results could be interpreted as an improvement in the body condition, metabolic response, milk yield, efficiency of milk production and nutrient utilization, and reproductive performance of peripartum Murrah buffaloes.

Energy metabolites, lipid variables and lactation performance of periparturient Murrah buffaloes (Bubalus bubalis) fed on diet supplemented with inorganic chromium

The aim of this study was to elucidate the effects of chromium (Cr) supplementation as inorganic Cr (CrCl3·6H2O) on energy balance, lipid peroxidation, and lactation performance in periparturient Murrah buffaloes. Twenty-four multiparous Murrah buffaloes according to lactation, parity, body mass, and expected calving date were divided equally. Experimental buffaloes were randomly assigned to four treatment diets: a control diet and three diets with an inorganic Cr supplementation at 0.5, 1.0, and 1.5 mg of Cr/kg dry matter (DM), respectively from 60 days before expected calving date until 60 days of lactation. Milk productions of buffaloes were recorded every day until 60 days in milk. Blood samples were collected at days -60, -45, -30,-21, -15, -7, -3, 0, 7, 15, 21, 30, 45, and 60 days relative to actual calving for determination of plasma glucose, nonesterified fatty acid (NEFA), thiobarbituric acid reactive substance (TBARS), total cholesterol, total protein, albumin, blood urea nitrogen (BUN), and minerals. Adding inorganic Cr to the diet of Murrah buffaloes increased milk yield. Percentage of fat and total solid yield increased significantly through the experiment in the Cr-supplemented group. At the day of calving, buffaloes showed a decrease in dry matter intake (DMI), plasma glucose, and zinc (Zn) and Cr concentrations. In contrast, plasma NEFA, TBARS, and copper (Cu) levels were found highest at the day of calving among all groups. Cr supplementation increased peripheral blood glucose concentration while decreased level of NEFA and TBARS was recorded in Cr-fed buffaloes. Supplemental Cr had no effect on plasma cholesterol, total protein, albumin, and BUN in periparturient period. Dietary Cr supplementation had positive effect on plasma Cr concentration, but the plasma concentration of Cu, Zn, and iron (Fe) was not affected by different dietary Cr level supplementation. The results suggest that dietary inorganic Cr supplementation improved milk yield by reducing negative energy balance and lipid peroxidation in buffaloes during periparturient period.