Efficacy of Panax ginseng extract combined with cephalexin as a dry cow therapy.

Our objective was to evaluate the efficacy of intramammary administration, at drying-off, of a Panax ginseng extract (PGe) combined with cephalexin (Ceph) on the post-calving bacteriological cure rate of pre-existing intramammary infections (IMI) and on the occurrence of new IMI during the dry period. In addition, milk yield and somatic cell count (SCC) in the post-treatment lactation were evaluated. One hundred and eight late-lactation cows were randomly divided into two experimental groups and were treated at drying-off with Ceph alone or PGe combined with Ceph.Cure rates for IMI present at drying-off were similar for both treatments (OR = 0.95, 95% CI = 0.33-2.74). Cure rates for Staphylococcus aureus were lower (OR = 15.4, 95% CI = 1.66-142.52) in quarters treated with PGe + Ceph than in those treated with Ceph alone. Intramammary infusion of PGe + Ceph at drying-off had no effect on preventing new dry period IMI (OR = 0.75, 95% CI = 0.38-1.51), compared with infusion of Ceph alone. Milk production and SCC in the ensuing lactation were not affected by PGe + Ceph treatment. In conclusion, addition of PGe to dry cow therapy did not show any advantage over the use of dry cow therapy alone.

A potential treatment approach for subclinical mastitis in dairy cows: auriculotherapy of the auricular branch of the vagus nerve.

This research aims to test the hypothesis that neural therapy (NT) on the auricular branch of the vagus nerve (ABVN) in dairy cows diagnosed with subclinical mastitis (SCM) results in a reduction of the somatic cell count. Therapeutic options for SCM are mostly based on use of antibiotics and often lead to unsatisfactory results. An alternative therapy targeting the anti-inflammatory properties of the vagus nerve showing good efficacy, economic viability and without major side effects would be of considerable interest. Auriculotherapy (AT) was performed using three repeated infiltrations of 8.0 mg (0.4 ml) procaine hydrochloride (2%) at the location of the ear tag associated with the auricular acupuncture point (AAP) of the udder. Some 85 clinically healthy cows from nine dairy farms were sampled for evaluation of quarter somatic cell count (QSCC) on four days (d0, d2, d4 and d6). Quarters with a QSCC > 100 000 cells/ml on d0 were included in the analysis. Over the study period, a total of 784 quarters were analysed, 385 control (CON) quarters from 40 cows and 399 treated (TRE) quarters from 45 cows. Results showed that AT of the ABNV resulted in a significant reduction of the QSCC after three treatments. The effect was independent of bacteriological culture results of the quarter milk samples. The bacteriological cure rate, however, was not influenced by AT. To our knowledge this is the first report of AT reducing QSCC in dairy cows with SCM. Before AT can be regarded as an alternative therapeutic approach, further research should focus on possible long-term effects of AT on the reduction of SCC, any bacterial elimination and the neural pathways of AT in dairy cows with SCM.

Effects of postpartum oral calcium supplementation on milk yield, milk composition, and reproduction in multiparous Jersey and Jersey × Holstein crossbreed cows.

The objective of the present study was to evaluate the effects of postpartum oral calcium supplementation on milk yield, energy-corrected milk yield, milk fat concentration, milk protein concentration, and somatic cell count linear score across the first 3 monthly tests postpartum, peak milk yield, risk of pregnancy at first service, and hazard of pregnancy by 150 d in milk on 1,129 multiparous Jersey and Jersey × Holstein crossbreed cows from 2 commercial dairies. After calving, cows were systematically assigned to control (no oral calcium supplementation; n = 567) or oral calcium supplementation at 0 and 1 d in milk (oral Ca; 50 to 60 g of calcium as boluses; n = 562). Monthly test milk yield, composition, and somatic cell count information was obtained from the Dairy Herd Improvement Association. Herd records were used for reproductive data. Statistical analysis was conducted using generalized multiple linear, Poisson, and Cox's hazard regressions. Treatment effects were evaluated considering cow-level information available at parturition (parity, breed, previous lactation milk yield, previous lactation length, dry period length, gestation length, body condition, and locomotion score at calving, calving ease, and calf sex). In addition, for a subset of cows serum calcium concentration before treatment administration was evaluated (n = 756). Overall, oral calcium supplementation did not affect the evaluated productive and reproductive variables. However, effects conditional to previous lactation length and calving locomotion score were observed. Milk yield and energy-corrected milk yield across the first 3 monthly tests were 1.8 kg/d higher for supplemented cows with a previous lactation length within the fourth quartile, compared with control cows on the same quartile. Energy-corrected milk yield tended to be 1.1 kg/d lower for supplemented cows with a previous lactation length within the first quartile, compared with control counterparts. Peak milk yield tended to be 1.6 kg higher for supplemented cows with a calving locomotion score ≥2, compared with control cows with the same locomotion score. Treatment effects were not conditional to serum calcium concentration before treatment administration. Our results suggest that postpartum oral calcium supplementation effects are conditional to cow-level factors such as previous lactation length and calving locomotion score in multiparous Jersey and Jersey × Holstein crossbreed cows.

Supplementation with beta-1,3-glucan improves productivity, immunity and antioxidative status in transition Holstein cows.

Dairy cows undergo dramatic physiological changes during the transition from late pregnancy to early lactation, which make them vulnerable to metabolic stress and immune dysfunction. The objective of this study was to evaluate the effects of a commercial beta-1,3-glucan product (Aleta™, containing 50% beta-1,3-glucan) on productivity, immunity and antioxidative status in transition cows. Fifty-four multiparous Holstein cows received a control diet or a diet supplemented with 5 or 10 g of beta-1,3-glucan per cow per day from 21 days before expected calving to 21 days after parturition. Blood samples were collected at day -21, 1, and 21 relative to calving. Colostrum and milk were collected at day 1 and 21 after calving, respectively. Data showed that supplementation with beta-1,3-glucan had no effect on milk composition, but increased milk production. Beta-1,3-glucan treatment also improved the milk quality, as shown by reduced milk somatic cell count and increased immunoglobulin levels in colostrum. Notably, beta-1,3-glucan markedly reduced serum levels of pro-inflammatory cytokines and C-reactive protein, while elevated serum immunoglobulin levels, indicating its immunity enhancement in transition cows. Moreover, beta-1,3-glucan addition reduced the serum malondialdehyde level and enhanced the activities of serum superoxide dismutase and catalase, which enhanced the antioxidative capacity in transition cows. In summary, supplementation with beta-1,3-glucan improves productivity, immunity and antioxidative status in transition dairy cows.

Evaluation of bovine milk extracellular vesicles for the delivery of locked nucleic acid antisense oligonucleotides.

The natural capacity of extracellular vesicles (EVs) to transport their payload to recipient cells has raised big interest to repurpose EVs as delivery vehicles for xenobiotics. In the present study, bovine milk-derived EVs (BMEVs) were investigated for their potential to shuttle locked nucleic acid-modified antisense oligonucleotides (LNA ASOs) into the systemic circulation after oral administration. To this end, a broad array of analytical methods including proteomics and lipidomics were used to thoroughly characterize BMEVs. We found that additional purification by density gradients efficiently reduced levels of non-EV associated proteins. The potential of BMEVs to functionally transfer LNA ASOs was tested using advanced in vitro systems (i.e. hPSC-derived neurons and primary human cells). A slight increase in cellular LNA ASO internalization and target gene reduction was observed when LNA ASOs were delivered using BMEVs. When dosed orally in mice, only a small fraction (about 1% of total administered dose) of LNA ASOs was recovered in the peripheral tissues liver and kidney, however, no significant reduction in target gene expression (i.e. functional knockdown) was observed.

Heat treatment of bovine colostrum: I. Effects on bacterial and somatic cell counts, immunoglobulin, insulin, and IGF-I concentrations, as well as the colostrum proteome.

The objective of this study was to investigate the effects of heat treatment on colostral low-abundant proteins, IgG and IgA, insulin, and insulin-like growth factor I (IGF-I), as well as bacteria and somatic cells. First-milking colostrum samples >8 L and Brix % > 22.0 were harvested from 11 Holstein cows on a commercial dairy in New York State and split into 2 aliquots using single-use colostrum bags. One aliquot of each pair was cooled on ice immediately after harvest (raw, R; n = 11), and the other was heat-treated for 60 min at 60°C (heat, H; n = 11). All samples were analyzed for IgG and IgA via radial immunodiffusion assay and insulin and IGF-I concentrations by radioimmunoassay. Total bacterial counts and somatic cell counts (SCC) were determined using standard plate culture techniques and flow cytometry, respectively. Samples from a subset of 5 pairs (n = 10) were further analyzed by nano liquid chromatography-tandem mass spectroscopy, after ultracentrifugation at 100,000 × g for 60 min at 4°C to enrich the low-abundant protein whey fraction. Data were analyzed using either paired t-test or Wilcoxon signed-rank test or using an online software package to analyze proteomics data. Outcomes of proteomics analysis were fold change ≥1.5 between pairs, and paired t-tests with false discovery rate-adjusted P-value < 0.05. The median reduction of IgA concentrations was 8.5% (range: 0-38.0%) due to heat treatment, whereas IgG concentrations did not change due to treatment. Insulin concentrations decreased by a median of 22% (7-45%), and IGF-I decreased by 10% (0-18%) in H samples. Heat treatment was associated with a median reduction of SCC of 36% (0-90%) in paired samples, as well as a median reduction in total bacterial count of 93% (45-100%) in H versus R samples. Proteomics analysis identified a total of 328 unique proteins that were present in all 10 samples. Nine of the 25 proteins that decreased by at least 1.5-fold in H compared with R were identified as complement proteins. We conclude that heat treatment of colostrum is associated with a reduction in the concentration of bacterial counts and SCC, IgA, insulin, and IGF-I. In addition, proteomics analysis of colostral whey identified several complement components and other proteins that decreased in abundance due to heat treatment. Although IgG concentrations were unaffected and a reduction in bacterial counts was achieved, the change in several immunologically active proteins and growth factors may have biologically important effects on the developing immune system of the neonate fed heat-treated colostrum.

Use of somatic cell count as an indicator of colostrum quality.

The impact of cow mammary gland diseases on the quality of colostrum is not conclusively defined; research results are conflicting. However, it is widely believed that mastitis lowers the level of immunoglobulins and the quality of the colostrum produced. Therefore, the aim of this study was to determine the influence of somatic cell counts (SCC) on the colostrum immunostimulating and chemical components. The experiment was conducted on an experimental organic dairy farm in which a herd of approximately 250 cows was kept in a freestall housing system, with the average performance exceeding 6,000 kg of milk per lactation. Colostrum and milk samples were taken individually from each cow seven times during the experiment: from the first to second day after calving-twice per day, and from the third to fifth day after calving-once per day. Therefore, after preliminary analyses, the cows were divided into two groups based on the cytological quality of their colostrum at the first collection: 1. SCC ≤400,000 cells/ml (good quality colostrum; GCC- 18 cows), 2. SCC ≥ 400,000 cells/ml (low quality colostrum; LCC- 22 cows). The study found almost double the concentration of immunoglobulins and essential fatty acids in first milking colostrum in the GCC group than in colostrum from the LCC group. In addition, an increase in the concentration of lysozyme in first milking colostrum was associated with a decrease in the concentration of immunoglobulins. In addition, the increase in the level of lysozyme was associated with a decrease in the concentration of immunoglobulins. In conclusion, the SCC of first milking colostrum can be used as an indicator of colostrum quality.

Skin surface temperature of the mammary gland, measured by infrared thermography, in primiparous Girolando cows fed diets containing different lipid sources.

This research communication describes the influence of diet, mammary quarter position and milking process on the temperature of teats and udder of cows fed diets containing different lipid sources. Five primiparous cows were fed diets containing cottonseed, sunflower seed, soybeans or soybean oil as a source of lipids and a reference diet without the inclusion of lipid sources in a 5 × 5 Latin Square design. Milk yield was determined in the last five days of each period. Milk samples were collected for SCC analysis on the last two days of each experimental period. The images of the mammary gland were obtained using an infrared camera and were analyzed with appropriate computer software. Milk yield was 14.8% higher for cows fed soybeans as a source of lipids. Diets and somatic cell counts did not influence the temperature of teats and udder. The milking process reduced the temperature of teats and udder by 0.79°C. Rear teats and rear quarters had higher surface temperatures than front teats and fore quarters. Changes in temperature of teats and mammary quarters occurred as a function of the milking process and quarter position. However, the diet and the SCC did not influence the temperature of teats and mammary quarters in this experiment.

Randomized controlled trial investigating the effect of 2 selective dry-cow therapy protocols on udder health and performance in the subsequent lactation.

The objective of this study was to compare culture- and algorithm-guided selective dry-cow therapy (SDCT) programs with blanket dry-cow therapy (BDCT) in a multi-site, randomized, natural exposure clinical trial for the following cow-level outcomes: clinical mastitis, removal from the herd, and Dairy Herd Improvement Association (DHIA) test-day milk yield and SCC measures during the first 120 d in milk (DIM). Two days before planned dry-off, cows in each of 7 herds were randomly allocated to BDCT, culture-guided SDCT (cult-SDCT), or algorithm-guided SDCT (alg-SDCT). At dry-off, BDCT cows received an intramammary antibiotic (500 mg of ceftiofur hydrochloride) in all 4 quarters. Antibiotic treatments were selectively allocated to quarters of cult-SDCT cows by only treating quarters from which aseptically collected milk samples tested positive on a rapid culture system after 30 to 40 h of incubation. For alg-SDCT cows, antibiotic treatments were selectively allocated at the cow level, with all quarters receiving antibiotic treatment if the cow met at least one of the following criteria: (1) any DHIA test with a somatic cell count >200,000 cells/mL during the current lactation, and (2) ≥2 clinical mastitis cases during the current lactation. All quarters of all cows were treated with an internal teat sealant. Clinical mastitis and removal from the herd events (i.e., culling or death) and DHIA test-day data from dry-off to 120 DIM were extracted from herd records. Hazard ratios (HR) for the effect of treatment group on clinical mastitis and removal from the herd during 1 to 120 DIM were determined using Cox proportional hazards regression. The effects of treatment group on test-day loge-transformed SCC and milk yield were determined using linear mixed models. Final models indicated that either SDCT program was unlikely to increase clinical mastitis risk (HRcult-SDCT/BDCT = 0.82, 95% CI: 0.58, 1.15; HRalg-SDCT/BDCT = 0.83, 95% CI: 0.63, 1.09) or test-day logeSCC (cult-SDCT minus BDCT = 0.05, 95% CI: -0.09, 0.18; alg-SDCT minus BDCT = 0.07, 95% CI: -0.07, 0.21). Risk of removal from the herd and test-day milk yield were similar between treatment groups. Findings from this study indicate that culture- or algorithm-guided SDCT can be used at dry-off without negatively affecting cow health and performance in early lactation.

Identification and comparison of exosomal microRNAs in the milk and colostrum of two different cow breeds.

Bovine milk and colostrum provide essential nutrients and immunologically active factors that are beneficial to a newborn calf. Milk-and-colostrum-derived exosomes are known as the most important for cellular communication. Exosomes also contain non-coding RNA, such as microRNA. However, there is limited information about exosomal miRNA derived from the milk and colostrum of Holstein and DAK cattle. This study aimed to identify and characterize the exosomal microRNA in the milk and colostrum of Holstein and Dogu Anadolu Kirmizisi (DAK) cows. For this purpose, total RNA isolation was carried out on the milk and colostrum samples that were collected from the Holstein and DAK cattle breeds. The RNA samples were subjected to RNA sequencing and the microRNAs were determined. Lastly, gene ontology analysis was performed for target genes. A total of 795 miRNAs that were expressed differently were identified. A total of 545 of these were known miRNAs and 260 were found to be novel miRNAs. In the functional enrichment analysis, the miRNAs expressed in Holstein milk were mostly associated with milk synthesis, and those in colostrum were mostly involved in the immunity pathways. It was also observed that the miRNAs expressed in DAK milk regulated milk fat and protein metabolism, and there were miRNAs that regulated immune pathways in the colostrum. In addition to this, many novel miRNAs were defined in DAK colostrum. When the target genes of exosomal miRNA in Holstein and DAK milk and colostrum were compared, it was suggested that the DAK breed had genes that were mostly associated with the immune system. As a result, the data obtained from this study will provide beneficial contributions to potential miRNA biomarker studies for milk yield and mastitis.

A multicomponent herbal feed additive improves somatic cell counts in dairy cows - a two stage, multicentre, placebo-controlled long-term on-farm trial.

In contrast to natural and historical diets of wild and domesticated ruminants, the diversity of plant species is limited in diets of modern dairy cows. Are "production diseases" linked to this? We conducted a trial to test the effects of a multicomponent herbal feed additive (HFA) on health, performance and fertility traits. A dose-finding study (DF) with 62 cows on 11 commercial farms compared a low (50 g) and a high (100 g) dose of HFA (HFA-50, HFA-100) with a placebo (PL). In a subsequent field trial (FT) with 280 cows on 30 commercial farms, HFA-100 was compared to PL. Cows were randomly assigned to HFA and PL groups and received HFA or PL individually daily from 14 days pre- to 300 days post-calving. Data were analysed with mixed effects models. No differences between HFA and PL were found regarding performance, body condition score and overall culling rates. A tendency towards lower milk urea for HFA-100 compared to PL (p = .06) was found in DF. HFA significantly reduced elevated milk acetone observations (≥10 mg/L) in the first 10 lactation weeks (HFA-100: 4%; HFA-50: 4%; PL: 12%) in DF. HFA-50 significantly reduced lameness incidence (HFA-100: 11%; HFA-50: 2%; PL: 14%) in DF. Calving intervals were 15 days shorter in HFA compared to PL in both trials, which could be confirmed by tendency (p = .07) in FT. In both trials, the proportion of test days with elevated somatic cell score (≥3.0) was significantly lower in HFA compared to PL (DF: HFA-100: 40%, HFA-50: 45% and PL: 55%; FT: HFA-100: 38% and PL: 55%) which is also reflected by tendency (p = .08) in lower culling rates due to udder diseases in FT. HFA showed no negative impact on any of the measured parameters. The effects of HFA indicate a potential of phytochemically rich and diverse feed additives for dairy cows' nutrition and physiology.

The effect of intramammary infection in early lactation with non-aureus staphylococci in general and Staphylococcus chromogenes specifically on quarter milk somatic cell count and quarter milk yield.

This longitudinal study aimed to evaluate the impact of subclinical intramammary infection (IMI) with non-aureus staphylococcal (NAS) species in the first 18 d in milk (DIM) on the quarter milk somatic cell count (qSCC) and quarter milk yield (qMY) during the first 4 mo of lactation in Holstein Friesian heifers. Quarter milk samples were collected from 82 heifers from 1 to 4 DIM until 130 DIM on a biweekly (14 d) basis for determination of the qSCC; qMY data were available through the automatic milking systems. The quarter samples collected on the first (1-4 DIM) and second (15-18 DIM) sampling days were used for bacteriological culturing to determine the IMI status. In this study, 324 quarters from 82 heifers were enrolled, of which 68 were NAS-infected at the first sampling day. Only 16 (23.5%) of these quarters were still NAS-infected at the second sampling day, demonstrating the high spontaneous cure rate of these infections shortly after calving; 9 of these 16 cases were infected with the same NAS species. Interestingly, none of the NAS-infected quarters at the first sampling day acquired a new infection with a major pathogen at the second sampling day, whereas 2.3% of the noninfected quarters did. All 102 isolates phenotypically identified as NAS were further identified to the species level. Staphylococcus chromogenes was the most prevalent species on the first (29.4% of all NAS) and second (52.9%) sampling days. Quarters infected with Staph. chromogenes at the first sampling day had a significantly higher qSCC in later lactation than noninfected quarters, whereas this was not true for quarters infected with all other NAS species (i.e., as a group of species). The average daily qMY in the first 4 mo of lactation did not differ between noninfected quarters and quarters infected with Staph. chromogenes or all other NAS species at the first sampling day. Persistently NAS species-infected quarters in the first 18 DIM (i.e., infected with the same NAS species on the first and second sampling days) had the highest qSCC later in lactation, followed by quarters with a new NAS IMI (i.e., noninfected at the first sampling day and infected with NAS at the second sampling day). The qSCC from transiently NAS species-infected quarters (i.e., not infected with the same NAS species at the second sampling day) was not significantly higher in later lactation compared with that in noninfected quarters. The IMI status of quarters in the first 18 DIM, combining culture results at 1 to 4 and 15 to 18 DIM (new, persistent, and transient IMI), was not significantly associated with daily qMY in the first 4 mo after calving. In general, NAS should be considered minor pathogens with no adverse effect on daily qMY in quarters of heifers infected in the first 18 DIM and with a high spontaneous cure rate. Staphylococcus chromogenes was the most prevalent species, causing an increase in qSCC comparable to the level of quarters infected with a major pathogen; Staph. chromogenes caused most infections that persisted through at least the first 18 DIM.

Evaluation of PRRSv specific, maternally derived and induced immune response in Ingelvac PRRSFLEX EU vaccinated piglets in the presence of maternally transferred immunity.

In this study, we analyzed PRRS virus (PRRSv) specific lymphocyte function in piglets vaccinated with Ingelvac PRRSFLEX EU® at two and three weeks of age in the presence of homologous maternal immunity. Complete analysis of maternal immunity to PRRSv was evaluated postpartum, as well as passive transfer of antibodies and T cells to the piglet through colostrum intake and before and after challenge with a heterologous PRRSv at ten weeks of age. Maternal-derived antibodies were detected in piglets but declined quickly after weaning. However, vaccinated animals restored PRRSv-specific antibody levels by anamnestic response to vaccination. Cell analysis in colostrum and milk revealed presence of PRRSv-specific immune cells at suckling with higher concentrations found in colostrum than in milk. In addition, colostrum and milk contained PRRSv-specific IgA and IgG that may contribute to protection of newborn piglets. Despite the presence of PRRSv-specific Peripheral Blood Mononuclear cells (PBMCs) in colostrum and milk, no PRRSv-specific cells could be detected from blood of the piglets at one or two weeks of life. Nevertheless, cellular immunity was detectable in pre-challenged piglets up to 7 weeks after vaccination while the non-vaccinated control group showed no interferon (IFN) γ response to PRRSv stimulation. After challenge, all piglets developed a PRRSv-specific IFNγ-response, which was more robust at significantly higher levels in vaccinated animals compared to the primary response to PRRSv in non-vaccinated animals. Cytokine analysis in the lung lumen showed a reduction of pro-inflammatory responses to PRRSv challenge in vaccinated animals, especially reduced interferon (IFN) α levels. In conclusion, vaccination of maternally positive piglets at 2 and 3 weeks of age with Ingelvac PRRSFLEX EU induced a humoral and cellular immune response to PRRSv and provided protection against virulent, heterologous PRRSv challenge.

Concentrates of two subsets of extracellular vesicles from cow's milk modulate symptoms and inflammation in experimental colitis.

Extracellular vesicles (EVs) are involved in cell-to-cell communication and modulation of numerous physiological and pathological processes. EVs are found in large quantities in milk and contain several inflammation- and immunity-modulating proteins and microRNAs, through which they exert beneficial effects in several inflammatory disease models. Here, we investigated the effects of two EV subsets, concentrated from commercial cow's milk, on a murine model of colitis induced with dextran sodium sulfate (DSS). P35K EVs, isolated by ultracentrifugation at 35,000 g, and P100K EVs, isolated at 100,000 g, were previously characterized and administered by gavage to healthy and DSS-treated mice. P35K EVs and, to a lesser extent, P100K EVs improved several outcomes associated to DSS-induced colitis, modulated the gut microbiota, restored intestinal impermeability and replenished mucin secretion. Also, P35K EVs modulated innate immunity, while P100K EVs decreased inflammation through the downregulation of colitis-associated microRNAs, especially miR-125b, associated with a higher expression of the NFκB inhibitor TNFAIP3 (A20). These results suggest that different milk EV subsets may improve colitis outcomes through different, and possibly complementary, mechanisms. Further unveiling of these mechanisms might offer new opportunities for improving the life of patients with colitis and be of importance for milk processing, infant milk formulation and general public health.

Exogenous ß-mannanase supplementation improved immunological and metabolic responses in lactating dairy cows.

Exogenous enzymes have been used to improve nutrient utilization in several species of livestock, particularly swine and poultry. In addition, improved immunological and metabolic traits have been reported in nonruminants. The objective of this study was to determine the effects of ß-mannanase supplementation on milk yield and composition, and immunological and metabolic responses in lactating Holstein dairy cows. Two weeks after calving, 20 Holstein cows (10 multiparous and 10 primiparous) were blocked by parity and assigned to 1 of 2 diets for 182 d. All cows were housed in the same environment and fed the same basal diet. The basal diet of the treatment group was supplemented with ß-mannanase (CTCBio Inc., Seoul, South Korea) at 0.1% of concentrate dry matter. No differences were detected between the control and enzyme supplement groups in milk yield parameters or milk composition. Supplementation of ß-mannanase enzyme reduced blood haptoglobin levels in supplemented multiparous cows compared with controls. Furthermore, nonesterified fatty acid concentration levels tended to be lower in cows fed ß-mannanase, regardless of parity. Neither immunoglobulin G nor milk somatic cell count was affected by ß-mannanase supplementation, regardless of parity. The number of insemination services tended to be lower in cows fed diets supplemented with ß-mannanase. Results from this study suggest that supplementation of ß-mannanase exogenous enzyme could help to reduce instances of systemic inflammation and decrease fat mobilization in lactating Holstein cows. Multiparous cows are considered susceptible to acute infections and inflammation; thus, the enzyme had a greater effect in multiparous cows.

The impact of organic vs. inorganic selenium on dairy goat productivity and expression of selected genes in milk somatic cells.

The aim of this study was to determine the effect of diet supplemented with selenized yeast (Se-yeast) on milk yield and milk composition of goats and expression of casein and mammary-gland-immune system genes in milk somatic cells (MSC). Twenty-four dairy goats in their second to fourth lactations were divided into control and experimental groups, balanced according to lactation number and breed (Polish White or Fawn Improved). Morning milk and blood samples were collected four times during lactation (on the 21st, 70th, 120th, 180th day after kidding). The control and experimental groups were fed diets with 0.7 mg inorganic Se/goat/day (sodium selenite) or 0.6 mg organic Se/goat/day (selenized yeast), respectively. Milk, fat and protein yields during lactation as well as average somatic cell count, fat, protein and lactose contents in milk were evaluated. Microelements in milk and blood serum and biochemical parameters in blood serum were determined at the beginning and the end of the experiment. The expression levels of the genes encoding αS1-casein (CSN1S1), αS2-casein (CSN1S2), κ-casein (CSN3), interleukin 8 (IL-8), serum amyloid A3 (SAA3), interleukin 1ß (IL-1ß), bactenecin 7.5 (BAC7.5), bactenecin 5 (BAC5), ß2-defensin (GBD2), hepcidin (HAMP), chemokine 4 (CCL4), tumour necrosis factor α (TNFα), toll-like receptor 2 (TLR2), cathelicidin-7 (MAP34) and cathelicidin-6 (MAP28) were determined in MSC. Milk, fat, and protein yields were higher and somatic cell count (SCC expressed as natural logarithm) was lower in the milk of goats fed organic Se. The Se concentration in milk was twice as high in the organic vs. inorganic treatment groups at the end of the experiment, while there were no differences in studied biochemical parameters between groups. The transcript levels of CSN1S2 and BAC7.5 were higher and IL-8 was lower in MSC of Se-yeast treated groups. Such results may indicate better health status of mammary glands of goats treated with organic Se as well as positive impact of selenized yeast on the goat's milk composition. Differences in the IL-1ß and IL-8 transcript levels were also noted between the stages of lactation, with the highest expression at the peak of lactation (day 70), highlighting the metabolic burden at this time. We concluded that the Se-yeast supplementation improved the productivity and health status of goats and could have significant economic impact on farmer's income.

Papaya extract upregulates the immune and antioxidants-related genes, and proteins expression in milk somatic cells of Friesian dairy cows.

Carica papaya is a perennial plant containing bioactive constituents with free radical-scavenging and immune-modulating activities. In contrast, the immune suppression is predominant in the periparturient period, where oxidative stress has a substantial impact on the mammary gland health. The aim of the experiment reported here was to determine the potential effect of C. papaya aqueous extract (CPE) on milk production traits, and expression of genes and proteins related to immune and antioxidant status in dairy milk somatic cells (MSCs). Forty Friesian dairy cows were divided equally between a control and CPE-treated groups (orally drenched 250 µg/kg bwt, once weekly a month before expected parturition and continued until 5 months post-partum). CPE did not affect milk yield or composition but upregulated the expression of ß13-defensin (DEFB13), cathelicidin 2 (CATHL2), cathelicidin antimicrobial peptide (CATHL3), hepcidin (HAMP), lysozyme (LYZ), catalase (CAT) and glutathione peroxidase (GSH-Px) in MSCs. The environmental micro-organisms did not influence the levels of the transcripts. The DEFB13, CATHL2, CATHL3, HAMP and LYZ, but not ß1-defensin (DEFB1) transcripts and proteins were constitutively expressed in MSCs obtained from pathogen-free udders. It could be concluded that CPE has immunostimulant and antioxidant activities; thereby, it could be utilized to minimize the occurrence of mastitis.

Mineral supplementation stimulates the immune system and antioxidant responses of dairy cows and reduces somatic cell counts in milk.

The aim of this study was to evaluate whether the use of subcutaneous mineral supplementation would affect metabolic parameters, immunological response, milk quality and composition of dairy cows in the postpartum period. Twelve pregnant primiparous Holstein cows, were divided into two groups: six animals supplemented with the mineral complex (magnesium, phosphorus, potassium, selenium and copper), and six animals used as controls. Milk samples were collected every two other weeks postpartum up to sixty days of lactation to analyze composition and quality. Blood samples were collected, and the levels of ketone bodies, total proteins, glucose, albumin, and globulin were measured. The catalase and superoxide enzymes, reactive oxygen species, tumor necrosis factor, and interleukins were determined. Animals supplemented with minerals showed lower levels of ketone bodies and somatic cell counts on days 30, 45 and 60 of the experiment, without changes in milk composition compared to the control group. Supplemented cows had lower levels reactive oxygen species and increased superoxide enzymes activity. Total protein, globulin and cytokine levels were higher in cows supplemented with mineral complexes. Therefore, we can conclude that subcutaneous mineral supplementation improved the immune response and minimized the oxidative stress in dairy cows during lactation.

Udder health of dairy cows fed different dietary energy levels after a short or no dry period without use of dry cow antibiotics.

Reports on the effects of length of dry period (DP) on udder health of cows that were not treated with dry cow antibiotics are scarce. Additionally, the effects of a reduced dietary energy level for cows with a 0-d DP on udder health have not yet been studied. The aims of this study were (1) to compare effects of a 0-d or 30-d DP without use of dry cow antibiotics on udder health across the DP and subsequent lactation in dairy cows fed different dietary energy levels and (2) to evaluate associations between udder health and metabolic status of dairy cows. Five weeks before the expected calving date, Holstein-Friesian dairy cows (n = 115) were blocked for parity, expected calving date, and milk yield and somatic cell count (SCC) at their 2 last test days and were randomly assigned to 2 DP lengths: 0-d DP (n = 77) or 30-d DP (n = 38). Quarter milk samples were taken in wk 5 prepartum and in wk 1 and 5 postpartum. Proportion of quarters with elevated SCC (SCC ≥200,000 cells/mL) and proportion of udder pathogens in quarter milk samples did not differ between DP lengths among weeks. After calving, 102 of these cows were randomly assigned to 3 treatments: a 30-d DP with a standard energy level required for expected milk yield (30-d DP SEL; n = 36), a 0-d DP with the same energy level as cows with a 30-d DP (0-d DP SEL; n = 33), and a 0-d DP with a low energy level (0-d DP LEL, n = 33). From wk 8 of lactation onward, cows received either a glucogenic ration consisting of corn silage and grass silage or a lipogenic ration consisting of grass silage and sugar beet pulp at a standard or low energy level. During wk 1 to 7 postpartum, treatment did not affect SCC or SCC corrected for milk yield. During wk 8 to 44 of lactation, 0-d DP SEL cows had a greater SCC than 0-d DP LEL or 30-d DP SEL cows and had a greater SCC corrected for milk yield than 0-d DP LEL cows. During wk 1 to 44 of lactation, occurrence of at least 1 elevation of SCC (SCC ≥200,000 cells/mL after 2 wk of SCC <200,000 cells/mL) was not different among treatments. The 0-d DP SEL cows but not the 0-d DP LEL cows tended to have a 2.17 times greater hazard of having a case of clinical mastitis at any time in lactation than 30-d DP SEL cows. In wk 1 to 44 of lactation, lower fat- and protein- corrected milk yield and energy intake, greater energy balance, and greater plasma insulin concentration were associated with greater SCC. In conclusion, DP length did not affect udder health in the DP and in early lactation but seemed to decrease udder health for 0-d DP SEL cows in later lactation compared with 30-d DP SEL or 0-d DP LEL cows.

Added dietary sulfur and molybdenum has a greater influence on hepatic copper concentration, intake, and performance in Holstein-Friesian dairy cows offered a grass silage-rather than corn silage-based diet.

To test the hypothesis that the metabolism of Cu in dairy cows is affected by basal forage and added S and Mo, 56 dairy cows that were 35 (standard error ± 2.2) days postcalving and yielding 38.9 kg of milk/d (standard error ± 0.91) were offered 1 of 4 diets in a 2 × 2 factorial design for a 14-wk period. The 4 diets contained approximately 20 mg of Cu/kg of dry matter (DM), and had a corn silage-to-grass silage ratio of 0.75:0.25 (C) or 0.25:0.75 (G) and were either unsupplemented (-) or supplemented (+) with an additional 2 g of S/kg of DM and 6.5 mg of Mo/kg of DM. We found an interaction between forage source and added S and Mo on DM intake, with cows offered G+ having a 2.1 kg of DM lower intake than those offered G-, but no effect on the corn silage-based diets. Mean milk yield was 38.9 kg/d and we observed an interaction between basal forage and added S and Mo, with yield being decreased in cows offered G+ but increased on C+. No effect of dietary treatment on milk composition or live weight was noted, but body condition was lower in cows fed added S and Mo irrespective of forage source. We found an interaction between forage source and added S and Mo on milk somatic cell count, which was higher in cows offered G+ compared with G-, but not in cows fed the corn silage-based diets, although all values were low (mean values of 1.72, 1.50, 1.39, and 1.67 log10/mL for C-, C+, G-, and G+, respectively). Mean plasma Cu, Fe, and Mn concentrations were 13.8, 41.3, and 0.25 µmol/L, respectively, and were not affected by dietary treatment, whereas plasma Mo was 0.2 µmol/L higher in cows receiving added S and Mo. The addition of dietary S and Mo decreased liver Cu balance over the study period in cows fed either basal forage, but the decrease was considerably greater in cows receiving the grass silage-based diet. Similarly, hepatic Fe decreased more in cows receiving G than C when S and Mo were included in the diet. We concluded that added S and Mo reduces hepatic Cu reserves irrespective of basal forage source, but this decrease is considerably more pronounced in cows receiving grass silage- than corn silage-based rations and is associated with a decrease in intake and milk performance and an increase in milk somatic cell count.