Transition Cows Research Articles

Effect of diets enriched in n-6 or n-3 fatty acids on dry matter intake, energy balance, oxidative stress, and milk fat profile of transition cows

The objective of this study was to determine the effect of dietary supplementation of n-3 polyunsaturated fatty acids (PUFA) and n-6 PUFA on dry matter intake (DMI), energy balance, oxidative stress, and performance of transition cows. Forty-five multiparous Holstein dairy cows with similar parity, body weight (BW), body condition score (BCS), and milk yield were used in a completely randomized design during a 56-d experimental period including 28 d prepartum and 28 d postpartum. At 240 d of pregnancy, cows were randomly assigned to one of the 3 isoenergetic and isoprotein dietary treatments, including a control ration containing 1% hydrogenated fatty acid (CON), a ration with 8% extruded soybean (HN6, high n-6 PUFA source), and a ration with 3.5% extruded flaxseed (HN3; high n-3 PUFA source). The HN6 and HN3 diets had an n-6/n-3 ratio of 3.05:1 and 0.64:1 in prepartum cows and 8.16:1 and 1.59:1 in postpartum cows, respectively. During the prepartum period (3, 2, and 1 wk before calving), DMI, DMI per unit of BW, total net energy intake, and net energy balance were higher in the HN3 than in the CON and NH6 groups. During the postpartum period (2, 3, and 4 wk after calving), cows fed HN3 and HN6 diets both showed increasing DMI, DMI as a percentage of BW, and total net energy intake compared with those fed the CON diet. The BW of calves in the HN3 group was 12.91% higher than those in the CON group. Yield and nutrient composition of colostrum (first milking after calving) were not affected by HN6 or HN3 but milk yield from 1 to 4 wk of milking was significantly improved compared with CON. During the transition period, BW, BCS, and BCS changes were not affected. Cows fed the HN6 diet had a higher plasma NEFA concentration compared with the CON cows during the prepartum period. Feeding HN3 reduced the proportion of de novo fatty acids and increased the proportion of preformed long-chain fatty acids in regular milk. In addition, the n-3 PUFA-enriched diet reduced the n-6/n-3 PUFA ratio in milk. In conclusion, increasing the n-3 fatty acids concentration in the diet increased both DMI during the transition period and milk production after calving, and supplementing n-3 fatty acids was more effective in mitigating the net energy balance after calving.

Methane Reduction Potential of Hydroponic Fodders and Combination of Hydroponic Fodder Bajra with Anionic Salts in Increasing Serum Calcium Level of Transition Cows

Background: The study reported in this research is to assess the methane reduction potential of hydroponic fodders and its novel combination with anionic salts on the serum calcium level in transition cows, the period cows are prone to metabolic disorders. Methods: A growth trial of hydroponic fodders to assess the biomass yield and an in vitro gas production study was conducted to assess the methane production on inclusion of different hydroponic fodders with that of conventionally cultivated fodders along with paddy straw and concentrate feed. A feeding trial was also conducted in 16 transition cows (farm and field conditions) to assess the serum calcium level through feeding anionic salts viz., calcium sulphide and magnesium chloride along with hydroponic fodder bajra. Result: Significantly (P less than 0.05) lowest methane production was observed in paddy straw, hydroponic fodder bajra, concentrate feed group compared to other treatment groups. Anionic salts supplementation for three weeks prior to calving resulted in significant (P less than 0.05) increase in the serum calcium levels. In post supplementation, average increase in serum calcium level is 0.93 mg/dl, an increase by 10.80 per cent. Further, feeding cost of anionic salts (Calcium sulphide and magnesium chloride) for three weeks (21 days) is only INR 55.65/-.

Rumination Assessment: A Managemental Tool for Dairy Cattle

Rumination is the process of regurgitation, re-mastication, salivation and swallowing of ingesta. Cows ruminate for approximately 504±93 min/day and a decrease in rumination time is typically important sign that something is affecting ruminal function and cow well-being. Rumination activity mainly occurs at night and during resting periods in the afternoon. Rumination can be detected by the several methods viz. visual observation, video recording, nose band pressure signal, accelerometer ear-tags and neck collar. The time that an animal spends ruminating is influenced by species, breed, physical & chemical characteristics of the diet, health condition, feed intake and production level. More roughage diet with long fibre increases the rumination time. Diets containing higher neutral detergent fibre (%) resulted in increase in rumination time per kilogram of roughage ingested. Rumination time decrease with increasing temperature humidity index. Rumination time significantly influence the milk yield and milk composition and reproduction performance. Rumination time could be used to monitor dairy cattle during calving, oestrous, and heat stress, as well as to detect diseases, heat stress, transition cow disorders and subclinical ketosis in dairy cows.

Increasing the prepartum dose of rumen-protected choline: Effects on milk production and metabolism in high-producing Holstein dairy cows

Peripartum rumen-protected choline (RPC) supplementation is beneficial for cow health and production, yet the optimal dose is unknown. In vivo and in vitro supplementation of choline modulates hepatic lipid, glucose, and methyl donor metabolism. The objective of this experiment was to determine the effects of increasing the dose of prepartum RPC supplementation on milk production and blood biomarkers. Pregnant multiparous Holstein cows (n = 116) were randomly assigned to one of 4 prepartum choline treatments that were fed from -21 d relative to calving (DRTC) until calving. From calving until +21 DRTC, cows were fed diets targeting 0 g/d choline ion (control, CTL) or the recommended dose (15 g/d choline ion; RD) of the same RPC product that they were fed prepartum. The resulting treatments targeted: (1) 0 g/d pre- and postpartum [0.0 ± 0.000 choline ion, percent of dry matter (%DM); CTL]; (2) 15 g/d pre- and postpartum of choline ion from an established product (prepartum: 0.10 ± 0.004 choline ion, %DM; postpartum: 0.05 ± 0.004 choline ion, %DM; ReaShure, Balchem Corp.; RPC1RD▸RD); (3) 15 g/d pre- and postpartum of choline ion from a concentrated RPC prototype (prepartum: 0.09 ± 0.004 choline ion, %DM; postpartum: 0.05 ± 0.003 choline ion, %DM; RPC2, Balchem Corp.; RPC2RD▸RD); or (4) 22 g/d prepartum and 15 g/d postpartum from RPC2 [prepartum: 0.13 ± 0.005 choline ion, %DM; postpartum: 0.05 ± 0.003 choline ion, %DM; high prepartum dose (HD), RPC2HD▸RD]. Treatments were mixed into a total mixed ration, and cows had ad libitum access via a roughage intake control system (Hokofarm Group). From calving to +21 DRTC, all cows were fed a common base diet and treatments were mixed into the total mixed ration (supplementation period, SP). Thereafter, all cows were fed a common diet (0 g/d choline ion) until +100 DRTC (postsupplementation period, postSP). Milk yield was recorded daily and composition analyzed weekly. Blood samples were obtained via tail vessel upon enrollment, approximately every other day from -7 to +21 DRTC, and at +56 and +100 DRTC. Feeding any RPC treatment reduced prepartum dry matter intake compared with CTL. During the SP, no evidence for a treatment effect on energy-corrected milk (ECM) yield was found, but during the postSP, RPC1RD▸RD and RPC2RD▸RD treatments tended to increase ECM, protein, and fat yields. During the postSP, the RPC1RD▸RD and RPC2RD▸RD treatments tended to increase, and RPC2HD▸RD increased, the de novo proportion of total milk fatty acids. During the early lactation SP, RPC2HD▸RD tended to increase plasma fatty acids and β-hydroxybutyrate concentrations, and RPC1RD▸RD and RPC2RD▸RD reduced blood urea nitrogen concentrations compared with CTL. The RPC2HD▸RD treatment reduced early lactation serum lipopolysaccharide binding protein compared with CTL. Overall, peripartum RPC supplementation at the recommended dose tended to increase ECM yield postSP, but no evidence was seen of an additional benefit on milk production with an increased prepartum dose of choline ion. The effects of RPC on metabolic and inflammatory biomarkers support the potential for RPC supplementation to affect transition cow metabolism and health and may support the production gains observed.

Perspective: Can early embryonic losses be reduced in lactating dairy cows?

Perspective: Can early embryonic losses be reduced in lactating dairy cows?

Resveratrol Promotes Gluconeogenesis by Inhibiting SESN2-mTORC2-AKT Pathway in Calf Hepatocytes

BackgroundThe glucose requirement of dairy cows is mainly met by increasing the rate of hepatic gluconeogenesis. However, due to negative energy balance, the liver of periparturient cows is under oxidative stress induced by lipid over-mobilization, and hepatic gluconeogenesis is reduced. Studies have demonstrated that resveratrol, which is widely known for its antioxidant properties, can alter hepatic gluconeogenesis. However, it is not clear whether resveratrol could regulate hepatic gluconeogenesis by its antioxidant properties. ObjectivesThis study aims to investigate the precise effect of resveratrol in hepatic gluconeogenesis, the role of resveratrol on hydrogen peroxide (H2O2)-induced oxidative stress in hepatocytes and the potential mechanism using primary hepatocytes. MethodsPrimary hepatocytes were isolated from 5 healthy Holstein calves (1 d old, 30 to 40 kg, fasted) and treated with different concentrations of resveratrol (0, 5, 10, 25, or 50 μM) combined with or without H2O2 (0, 100, or 200 μM) induction for 12 h. ResultsResveratrol enhanced the expression of gluconeogenic genes of calf hepatocytes in a dose-dependent manner (P < 0.05). Conversely, H2O2 suppressed the expression of gluconeogenic genes and induced oxidative stress (P < 0.05), which was improved by resveratrol in calf hepatocytes (P < 0.001). Furthermore, the mechanistic target of rapamycin complex 2 (mTORC2)-AKT pathway was found to negatively regulate gluconeogenesis. An AKT inhibitor was used to assess the role of the mTORC2-AKT pathway in the effects of resveratrol. The results showed resveratrol promoted hepatic gluconeogenesis by inhibiting the mTORC2-AKT pathway. Moreover, sestrin 2 (SESN2) upregulated the activity of mTORC2. We further found that resveratrol decreased SESN2 levels (P < 0.001). ConclusionsThis study indicated that resveratrol enhances the gluconeogenic capacity of calf hepatocytes by improving H2O2-induced oxidative stress and modulating the activity of the SESN2-mTORC2-AKT pathway, implying that resveratrol may be a promising target for ameliorating liver oxidative stress in transition cows.

"Optimizing Calcium Metabolism in Transition Cows: A Pragmatic Review"

Dairy cows undergo tremendous metabolic and endocrine changes during the transition from dry to lactating phase. Hypocalcemia is one of the most critical metabolic conditions that dairy cows experience after calving. The objective of this review article was to underline the role of calcium homeostasis in determining the periparturient dairy cow’s health and performance.

Effects of udder edema on parlor behavior in first- and second-lactation Holstein dairy cows

Udder edema (UE) is a metabolic disorder that most commonly occurs around the transition period. However, there are gaps in our knowledge about its effects on parlor behavior. The aim of this study was to examine the prevalence and effects UE has on behavior in the milking parlor during udder preparation and active milking from 2 to 9 DIM in first (FL) and second lactation (SL) Holstein dairy cattle. Each cow (n = 375) was observed once and monitored from the point of first contact during udder preparation through the first 5 min of active milking. Behavior measurements include step, kick, and kicking off the milking unit (KOU). Cows were determined to have UE when the rear udder medial suspensory ligament lost definition and was softened due to the presence of interstitial fluid. In this study, 237/247 (95.6%) FL cows and 104/128 (81.3%) SL cows presented with UE. First lactation cows with UE had a higher step rate (3.97 steps/session) when in contact during udder preparation and attachment (2.80 steps/session), and kick rate during milking (2.68 kicks/milking session) when compared with SL cows with UE (2.37 steps/session, 1.25 steps/session, 1.24 kicks/milking session). FL cows with UE had a lower step rate during milking (6.04 steps/milking session) compared with FL cows without UE (7.20 steps/milking session). FL cows with UE had a higher average KOU count (μ = 0.220 kick-offs) than SL cows with UE (μ = 0.029 kick-offs) and FL cows without UE (μ = 0.091 kick-offs). The results indicate that UE is prevalent among dairy cattle, and the disorder has effects on behaviors presented in the milking parlor. Reducing UE has the potential to decrease step and kick behavior to improve welfare of transition cows and reduce risk to dairy caretakers in the milking parlor.

Associations between days in the close-up group and milk production, transition cow diseases, reproductive performance, culling, and behavior around calving of Holstein dairy cows

The objective of experiment I was to evaluate the association between days in the close-up group (DINCU) and milk production, early lactation diseases, reproductive performance, and culling. In experiment II behavioral changes associated with DINCU were evaluated using a neck-mounted sensor (Smarttag neck, Nedap Livestock Management, Groenlo, the Netherlands). Cow-lactations of 28,813 animals from 14,155 individual cows of 2 farms in northern Germany and western Slovakia, calving between January 2015 and December 2020, were included in the study. After exclusion of cows with a gestation length <262 and >292 d and cows with >42 DINCU data from 8,794 and 19,598 nulliparous and parous cows, respectively, were available for final statistical analyses. To analyze the association between DINCU and second test-d 305-d mature-equivalent milk projection, linear mixed models were calculated. Binary data (i.e., clinical hypocalcemia, hyperketonemia, retained placenta [RP], acute puerperal metritis [APM], mastitis, left displaced abomasum [LDA], first service pregnancy risk) were analyzed using logistic regression models. To analyze the association between DINCU and culling or death during the first 300 DIM Cox proportional hazards were used. To analyze the association between DINCU and behavior 7 d before to 7 d after calving (i.e., activity, inactivity, eating, ruminating time), linear mixed models were calculated. Nulliparous cows with a short (<10 DINCU) and a long stay (>30 DINCU) in the close-up group had a lower milk production an increased risk for hyperketonemia, RP, and APM compared with nulliparous cows with DINCU between 21 to 28 d. Parous cows with a short (<10 DINCU) and a long stay (>30 DINCU) in the close-up group had a lower milk production, an increased risk for RP and mastitis, a reduced first service pregnancy risk, and an increased culling risk, compared with parous cows with DINCU between 21 to 28 d. Furthermore, the risk for clinical hypocalcemia and LDA was increased in parous cows with >30 DINCU compared with parous cows with <30 DINCU. The risk for APM was increased in parous cows with <10 DINCU compared with parous cows with >10 DINCU. In nulliparous cows no association was found between DINCU and the risk for left displaced abomasum and mastitis. In experiment II, cows with 7 and 35 DINCU had an impaired behavior around calving compared with cows with 14, 21, and 28 DINCU. During the last 7 d before parturition, these cows were more inactive and had a reduced eating and ruminating time. After calving, cows with 7 DINCU spent less time eating. In conclusion, cows with <10 DINCU and cows with >30 DINCU had a lower milk production, a higher risk to incur diseases and an impaired behavior, especially before calving.

Evaluation of phytochemicals from Thymus serpyllum as potential drug candidates to manage oxidative stress in transition dairy cows

Dairy cows undergo immense stress and experience autoimmune reactions during the transition period, majorly due to the generation of ROS in the body. So, pharmacological approaches are needed to manage oxidative stress in the transition cows. Recently, the use of phytochemicals as feed additives in cows’ nutrition has gained interest in managing various disease conditions. In the current study, we have evaluated the potential effects of phytochemicals derived from methanolic extract of Thymus serpyllum against oxidative stress and autoimmunity via inhibition of bovine nuclear factor kappa B (NF-κB). The free radical scavenging activity of Thymus serpyllum seed and leaf extracts was 71.8 and 75.6%, respectively at 100 µg/mL concentration. Similarly, both extracts displayed radicals reducing power and inhibition of lipid-peroxidation maximally at 100 µg/mL. A total of 52 bioactive compounds were identified when the plant extract was characterized by the GC-MS analysis, and five (Thymol, Luteolin 7-o-glucuronide, Rosmarinic acid, Apigenin 6,8-di-c-glucoside, Kaempferol) had binding free energy values of −11.6433, −10.002, −8.2615, −7.1714, −6.4870, respectively, in complexes with bovine NF-κB. Through computational analysis, the screened compounds showed good pharmacokinetic parameters, including non-toxicity, non-carcinogenic, high gastrointestinal absorption and thus can serve as potential drug candidates. MD simulation studies predicted the stability of complexes and the complex of Kaempferol was most stable based on RSMD value and MM/GBSA binding energy. The biochemical assays and computational studies indicated that Thymus serpyllum could be used as a promising feed additive in dairy cows to manage oxidative stress during the transition period. Communicated by Ramaswamy H. Sarma

Review: The Potential Role of Vitamin E Analogs as Adjunctive Antioxidant Supplements for Transition Cows

Despite routine supplementation of dairy cattle with vitamins with antioxidant functions, such as α-tocopherol, the high energy demand of the transition period creates a pro-oxidant state that can overcome antioxidant defenses and damage macromolecules. Known as oxidative stress, this condition impairs host immune defenses, predisposing cattle to disease and causing dysfunctional inflammation through a dysregulated production of lipid inflammatory mediators known as oxylipids. Non-α-tocopherol analogs of vitamin E have functions in other species that limit oxidative stress and dysfunctional inflammation but have largely remained unstudied in cattle. As non-α-tocopherol analogs of vitamin E have functions similar to α-tocopherol yet are more rapidly metabolized, they may provide further antioxidative functions with a reduced risk for adverse effects. Indeed, in vitro and in vivo evidence in cattle show a strong safety profile of most non-α-tocopherol analogs, and by several measures, non-α-tocopherol analogs present equally or more potent antioxidative activities than α-tocopherol alone. Further, vitamin E analogs are shown to compete with certain fatty acids for enzymatic metabolism, which may impact proinflammatory mediator production. Given that non-α-tocopherol analogs of vitamin E reduce the production of pro-inflammatory mediators and act as potent antioxidants, their safety and efficacy for these purposes should be further evaluated in cattle.

Effect of transition cow health and estrous expression detected by an automated activity monitoring system within 60 days in milk on reproductive performance of lactating Holstein cows

The objective of this observational study was to evaluate the association of transition cow health and estrous expression, detected by an automated activity monitoring system (Smarttag Neck, Nedap Livestock Management), with reproductive performance in lactating Holstein cows. A total of 3,750 lactating Holstein cows (1,563 primiparous cows and 2,187 multiparous cows) from a commercial dairy farm in Slovakia calving from January 2020 until July 2021 were enrolled on an ongoing basis. Activity data were recorded from d 7 until d 60 postpartum. Within this observational period, cows were classified into 3 categories: (1) no estrus event (Estrus0), (2) 1 estrus event (Estrus1), or (3) 2 or more estrus events (Estrus2+). Transition cow health was assessed by farm personnel within the first 30 d in milk (DIM) using standard operating procedures. Generalized linear mixed models were used to analyze continuous and categorical data. Cox proportional hazard models were used for time to event data. The overall prevalence of anestrus was 20.8%. Multiparous cows had a greater risk for anestrus compared with primiparous cows [odds ratio (OR) = 1.4]. Cows with stillbirth (OR = 1.76), retained placenta (OR = 2.19), puerperal metritis (OR = 1.48), or subclinical ketosis (OR = 1.51) had a greater risk for anestrus. In addition, cows calving in summer (OR = 0.82), autumn (OR = 0.38), or winter (OR = 0.56) had a higher incidence of anestrus than cows calving in spring. Estrous expression from d 7 until d 60 postpartum was associated with estrous duration (DU) and estrous intensity at first artificial insemination (AI). Cows in Estrus0 had the shortest DU at first postpartum AI (9.4 ± 0.18 h) compared with cows in Estrus1 (10.5 ± 0.13 h) and Estrus2+ (11.4 ± 0.12 h). Cows in Estrus2+ had a longer DU at first postpartum AI compared with cows in Estrus1. For Estrus0, Estrus1, and Estrus2+ cows, pregnancy per AI at first service was 42.5%, 50.9%, and 55.4%, respectively. Estrous expression from d 7 until d 60 postpartum was associated with time to first AI and time to pregnancy. Compared with Estrus0 cows, Estrus1 [hazard ratio (HR) = 1.43] and Estrus2+ cows (HR = 1.62) had an increased hazard of being inseminated within 100 DIM. Compared with Estrus2+, Estrus1 cows had a reduced hazard of being inseminated within 100 DIM (HR = 0.89). Compared with Estrus0 cows, Estrus1 (HR = 1.24) and Estrus2+ cows (HR = 1.46) had an increased hazard of becoming pregnant within 200 DIM. Median DIM to pregnancy were 121, 96, and 92 for Estrus0, Estrus1, and Estrus2+ cows, respectively. In conclusion, cows with transition cow disorders (i.e., stillbirth, retained placenta, puerperal metritis, or subclinical ketosis) had a greater chance for anestrus compared with healthy cows. Cows in Estrus0 had reduced estrous expression at first AI and inferior reproductive performance compared with cows that displayed estrous activity from d 7 until d 60.

Gut microbiome is linked to functions of peripheral immune cells in transition cows during excessive lipolysis

BackgroundPostpartum dairy cows experiencing excessive lipolysis are prone to severe immunosuppression. Despite the extensive understanding of the gut microbial regulation of host immunity and metabolism, its role during excessive lipolysis in cows is largely unknown. Herein, we investigated the potential links between the gut microbiome and postpartum immunosuppression in periparturient dairy cows with excessive lipolysis using single immune cell transcriptome, 16S amplicon sequencing, metagenomics, and targeted metabolomics.ResultsThe use of single-cell RNA sequencing identified 26 clusters that were annotated to 10 different immune cell types. Enrichment of functions of these clusters revealed a downregulation of functions in immune cells isolated from a cow with excessive lipolysis compared to a cow with low/normal lipolysis. The results of metagenomic sequencing and targeted metabolome analysis together revealed that secondary bile acid (SBA) biosynthesis was significantly activated in the cows with excessive lipolysis. Moreover, the relative abundance of gut Bacteroides sp. OF04 − 15BH, Paraprevotella clara, Paraprevotella xylaniphila, and Treponema sp. JC4 was mainly associated with SBA synthesis. The use of an integrated analysis showed that the reduction of plasma glycolithocholic acid and taurolithocholic acid could contribute to the immunosuppression of monocytes (CD14+MON) during excessive lipolysis by decreasing the expression of GPBAR1.ConclusionsOur results suggest that alterations in the gut microbiota and their functions related to SBA synthesis suppressed the functions of monocytes during excessive lipolysis in transition dairy cows. Therefore, we concluded that altered microbial SBA synthesis during excessive lipolysis could lead to postpartum immunosuppression in transition cows.8-C9RL3NXjP8b3LTSGg7i4Video

Feeding reduced levels of trace minerals in proteinate form and selenium-yeast to transition cows: Performance, trace minerals, and antioxidant status, peripheral neutrophil activity, and oocyte quality

An experiment was conducted to evaluate the effects of inorganic trace minerals (TM) and reduced levels of TM by using proteinate forms of Co, Zn, Mn, and Cu, and Se-yeast in diets of transition cows on performance, TM concentrations in colostrum, plasma, and liver, blood metabolites, antioxidant status, peripheral neutrophil activity, and oocyte quality. Thirty-two Holstein cows (22 multiparous and 10 primiparous cows) were enrolled in this study from 30 d before the expected calving date to 56 DIM. Cows were blocked according to body condition score, parity, and previous milk yield and randomly assigned to one of the following treatments: control (CON), with TM (Zn, Cu, Mn, and Co) supplied in form of sulfate and Se as sodium selenite to meet or exceed requirement estimates of the National Research Council; and proteinate trace minerals (PTM), with TM supplied bound with AA and peptides at 50% of CON levels and inorganic Se replaced with Se-yeast at 100% of CON level. Treatments were supplied until 56 DIM. Eight cows were removed from the study because of early calving (n = 3) or health issues (n = 5); thus, data of 24 cows (16 multiparous and 8 primiparous cows) were used in the statistical analysis. No differences between treatments were detected on nutrient intake or digestibility. Total excretion of purine derivatives was decreased when feeding PTM during the prepartum period. Feeding reduced levels of TM in proteinate form resulted in greater yield of milk (27.7 and 30.9 kg/d for CON and PTM, respectively) and protein (0.890 and 0.976 kg/d) between wk 5 and 8 of lactation. No treatment differences were detected for feed efficiency, milk somatic cell count, and milk urea nitrogen. Cows fed PTM had lower milk fat concentration during the 56 d of evaluation (4.08 and 3.74% for CON and PTM, respectively). Selenium concentration was greater in colostrum of cows fed PTM compared with CON (48.5 and 71.3 µg/L for CON and PTM, respectively), whereas Zn, Cu, and Mn concentrations were not different. Cows fed PTM showed lower liver Cu concentration compared with CON (51.4 and 73.8, respectively). Plasma concentrations of Mn and Zn were lower, but plasma Se concentration tended to be higher with PTM treatment. Feeding PTM resulted in greater blood concentrations of urea-N (16.6 and 18.2 mg/dL for CON and PTM, respectively) and β-hydroxybutyrate (0.739 and 0.940 mmol/L). Counts of lymphocytes were higher with PTM but counts of monocytes were lower in complete blood cell count. No differences were observed in serum concentrations of superoxide dismutase and glutathione peroxidase. No differences were detected in phagocytosis and oxidative burst potential of neutrophils after incubation with bacteria. Cows fed PTM had fewer viable oocytes per ovum pick-up in comparison with CON (8.00 and 11.6). Feeding PTM to transition cows may sustain performance without altering neutrophil activity despite some alterations in blood TM concentrations. More studies should be performed to evaluate production and fertility measurements when reducing TM dietary levels by using proteinate forms and Se-yeast with larger number of animals.

Dietary Supplementation of Chestnut Tannins in Prepartum Dairy Cows Improves Antioxidant Defense Mechanisms Interacting with Thyroid Status.

Cows in the peripartal period undergo changes in thyroid hormones and are susceptible to lipomobilization and/or oxidative stress. The addition of chestnut tannins as polyphenolic compounds in the diet may improve feed efficiency and prevent oxidative stress-related health disorders in transition cows. However, the relationship between chestnut tannin supplementation and thyroid function, which plays an important role in metabolic regulation, has not been investigated in dairy cows. This study was conducted to investigate the effects of chestnut tannin supplementation during the close-up period on thyroid status and to evaluate the interaction between thyroid hormones and oxidative stress biomarkers in prepartum dairy cows. Forty multiparous Holstein cows were fed either a diet containing chestnut tannins (CNTs, n = 20, 1.96 g chestnut tannins/kg feed, dry matter) or a non-supplemented diet (CON, n = 20) during the last 25 ± 2 days of gestation. Blood samples were collected on the first day of study (before chestnut tannin supplementation) and d 5 before parturition to measure hormonal and oxidative stress indices. Serum concentrations of T3 (p = 0.04) and T4 (p = 0.05) were higher in CNT cows than in the CON group on day 5 before parturition. Thyroid status of CNT cows was associated with higher serum total antioxidant capacity (T-AOC, p < 0.01), activities of superoxide dismutase (SOD, p = 0.03) and glutathione peroxidase (GPx, p = 0.01), and reduced glutathione concentration (GSH, p = 0.05). Serum thiobarbituric acid reactive substances (TBARS) were lower (p = 0.04) which was associated with lower aspartate aminotransferase (AST, p = 0.02), and lactate dehydrogenase (LDH, p = 0.01) activities in the CNT than in the CON group. Estradiol and progesterone did not differ between CNT and CON cows. Chestnut tannin supplementation improves antioxidant protection, prevents oxidation-reduction processes, reduces the degree of liver cell membrane damage, and protects thyroid tissue from damage, allowing higher T3 and T4 synthesis. Considering the importance of the thyroid hormone status before parturition, mechanisms of thyroid hormone regulation in CNT-supplemented dairy cows require more detailed investigations.

Effects of different vitamin A supplies on performance and the risk of ketosis in transition cows

This experiment investigated the effects of feeding low and high supplies of vitamin A (VA) during the transition period on plasma metabolites, prevalence of ketosis, and early milk production. In a randomized complete block design, 42 prefresh Holstein cows and 21 heifers were blocked by parity and calving date and assigned to 1 of 3 dietary treatments (n = 21 per treatment unless noted): CON, a transition diet with supplemental VA (75,000 IU/d) to meet the requirement; LVA, a transition diet with no supplemental VA; or HVA, a transition diet receiving supplemental VA (187,500 IU/d) 2.5 times greater than the requirement. Experimental periods were prepartum (-14 d prepartum), postpartum (1 to 30 d in milk), and carryover period (31 to 58 d in milk; common lactating diet with adequate VA was fed). Differences in dry matter intake in the pre- and postpartum periods and milk yield were not detected among treatment. Milk fat, protein, and lactose yields were similar among treatments and not affected by VA. Somatic cell count increased linearly with increasing VA. Body weight and body condition score decreased postpartum, but no VA effect was observed. Plasma retinol concentrations (n = 10 per treatment) decreased at d 2 postpartum and increased as lactation progressed, but the concentrations were unaffected by treatment. Plasma β-carotene (n = 10 per treatment) had a treatment by time interaction and its concentration decreased after parturition and remained low for 2 wk. Plasma fatty acids and β-hydroxybutyrate did not differ among treatments. Milk retinol concentration and yield (n = 10 per treatment) increased as VA supply increased. Segmented neutrophils (%) decreased, and lymphocytes (%) increased in blood with increasing VA supply. In conclusion, providing different supplies of VA did not affect production, mobilization of body fat, and risk of ketosis; however, excessive VA supply may have negatively affected the immune response, in part contributing to increased milk somatic cell counts during early lactation.

Zinc, Copper, and Manganese Homeostasis and Potential Trace Metal Accumulation in Dairy Cows: Longitudinal Study from Late Lactation to Subsequent Mid-Lactation

BackgroundTrace metals are supplemented in cattle to prevent nutrient deficiencies. Levels supplemented to mitigate worst-case basal supply and availability scenarios can, however, result in trace metal intakes far above the nutritional requirements of dairy cows with high feed intakes. ObjectivesWe evaluated Zn, Mn, and Cu balance in dairy cows from late lactation through the subsequent mid-lactation, a period of 24 wk characterized by large changes in dry matter intake. MethodsTwelve Holstein dairy cows were housed in a tie-stall from 10 wk before to 16 wk after parturition and fed 1 unique lactation diet when lactating and a dry cow diet otherwise. After 2 wk of adaptation to the facility and diet, Zn, Mn, and Cu balances were determined at weekly intervals, by calculating the difference between total intakes and complete fecal, urinary, and milk outputs, with the latter 3 fluxes quantified over a 48-h period. Repeated measure mixed models were used to evaluate the effects on trace mineral balances over time. ResultsThe Mn and Cu balances of cows were not significantly different from 0 mg/d between 8 wk prepartum and calving (P ≥ 0.54), when dietary intake was the lowest of the period evaluated. However, when dietary intake was highest, between wk 6 and 16 postpartum, positive Mn and Cu balances were observed (80 and 20 mg/d, respectively, P ≤ 0.05). Cows were in positive Zn balance throughout the study except during the first 3 wk after calving during which the Zn balance was negative. ConclusionsLarge adaptations occur in trace metal homeostasis in transition cows in response to changes in dietary intake. High dry matter intakes, associated with high milk production of dairy cows, combined with current Zn, Mn, and Cu supplementation practices may exceed regulatory homeostatic mechanisms resulting in potential body accumulation of Zn, Mn, and Cu.

Medium chain fatty acid supplementation improves animal metabolic and immune status during the transition period: A study on dairy cattle.

The transition period is the stage of the high incidence of metabolic and infectious diseases in dairy cows. Improving transition dairy cows' health is crucial for the industry. This study aimed to determine the effects of dietary supplementation medium-chain fatty acids (MCFAs) on immune function, metabolic status, performance of transition dairy cows. Twenty multiparous Holstein cows randomly assigned to two treatments at 35 d before calving. 1) CON (fed the basal 2) MCFA treatment (basal diet was supplemented at an additional 20 g MCFAs mixture every day) until 70 d after calving. The results showed that the serum amyloid A myeloperoxidase concentrations in the blood of cows in MCFA treatment significantly decreased during the early lactation (from 1 d to 28 d after calving) 0.03, 0.04, respectively) compared with the CON, while the tumor necrosis factor concentration was significantly decreased at 56 d after calving (P = 0.02). In addition, the concentration of insulin in the pre-calving (from 21 d before calving to calving) blood of cows in MCFA treatment was significantly decreased (P = 0.04), and concentration of triglyceride also showed a downward trend at 28 d after calving 0.07). Meanwhile, MCFAs supplementation significantly decreased the concentrations of lithocholic acid, hyodeoxycholic acid, and hyocholic acid in the blood at 1 d calving (P = 0.02, < 0.01, < 0.01, respectively), and the level of hyocholic acid taurocholic acid concentrations (P < 0.01, = 0.01, respectively) decreased dramatically at 14 d after calving. However, compared with the CON, the pre-calving dry matter intake and the early lactation milk yield in MCFA treatment were significantly decreased (P = 0.05, 0.02, respectively). In conclusion, MCFAs supplementation transition diet could improve the immune function and metabolic status of dairy cows, and the health of transition cows might be beneficial from the endocrine status.

Yeast Culture Supplementation Effects on Systemic and Polymorphonuclear Leukocytes' mRNA Biomarkers of Inflammation and Liver Function in Peripartal Dairy Cows.

This study evaluated the effects of feeding a commercial yeast culture on blood biomarkers and polymorphonuclear leukocyte (PMNL) gene expression in dairy cows during the transition period until 50 d postpartum. Forty Holstein dairy cows were used in a randomized complete block design from -30 to 50 d. At -30 d, cows were assigned to a basal diet plus 114 g/d of top-dressed ground corn (control; n = 20) or 100 g/d of ground corn and 14 g/d of a yeast culture product (YC; n = 20). Blood samples were collected at various time points from -30 to 30 DIM to evaluate blood biomarkers and PMNL gene expression related to inflammation, liver function, and immune response. Liver function biomarkers, gamma-glutamyl transferase (GGT) and albumin were greater and lower, respectively, in YC cows in comparison to control. However, these biomarkers remained within physiological levels, indicating an active inflammatory process. Genes in PMNL expression related to inflammation (NFKB1, TNFA, TRAF6), anti-inflammation (IL10), and cell membrane receptors (SELL) were upregulated in the YC group in comparison to control. These results suggest that YC could stimulate a more active inflammatory response with signs of a resolution of inflammation in transition cows.

Effects of Saccharomyces cerevisiae boulardii (CNCM I-1079) on feed intake, blood parameters, and production during early lactation.

The periparturient period is a metabolically demanding time for dairy animals because of increased nutrient requirements for milk yield. The objective of this study was to investigate the effect of feeding Saccharomyces cerevisiae boulardii (CNCM I-1079), a commercial active dry yeast (ADY), in dairy cows on productive and metabolic measures during the periparturient period. Primiparous (n = 33) and multiparous (n = 35) cows were fed a close-up total mixed ration (TMR) before calving and a lactation TMR postpartum. Three weeks before expected calving time, animals were blocked by parity and body weight and then randomly assigned to either control group (control; n = 34) or treatment (ADY; n = 34). All animals were housed in a tie-stall barn with individual feed bunks; the ADY animals received supplementary Saccharomyces cerevisiae boulardii (CNCM I-1079), top dressed daily at a predicted dosage of 1.0 × 1010 cfu (12.5 g) per head. Blood samples were collected weekly along with milk yield and milk composition data; feed intake data were collected daily. Serum samples were analyzed for glucose, nonesterified fatty acid, β-hydroxybutyrate, haptoglobin (Hp), and the cytokines tumor necrosis factor-α, IL-6, and IL-18. Colostrum samples collected within the first 6 to 10 h were analyzed for somatic cell score and IgG, IgA, and IgM concentrations. Data were analyzed using PROC GLIMMIX in SAS with time as a repeated measure; model included time, parity, treatment, and their interactions. The ADY groups had greater milk yield (39.0 ± 2.4 vs. 36.7 ± 2.3 kg/d) and tended to produce more energy-corrected milk with better feed efficiency. There was no difference in plasma glucose, serum nonesterified fatty acid, serum β-hydroxybutyrate, Hp, IL-6, or IL-18 due to ADY treatment. The tumor necrosis factor-α increased in ADY-supplemented animals (1.17 ± 0.69 vs. 4.96 ± 7.7 ng/mL), though week, parity, and their interactions had no effect. Serum amyloid A tended to increase in ADY-supplemented animals when compared to control animals and was additionally affected by week and parity; there were no significant interactions. No difference in colostrum IgG, IgA, and IgM was observed between treatments. Supplementing transition cow TMR with ADY (CNCM I-1079) improved milk production and tended to improve efficiency in early lactation; markers of inflammation were also influenced by ADY treatment, though the immunological effect was inconsistent.