Milk Somatic Cell Count Research Articles

Effects of increasing dietary zinc sulfate fed to gestating ewes: II. Milk somatic cell count, microbial populations, and fatty acid composition

The objective of the research was to evaluate the effects of increasing dietary Zn sulfate concentration for primiparous gestating ewes on subsequent milk SCC, intramammary microbial identifications, and fatty acid composition. Commercial white-face (WF; n = 27) and black-face (BF; n = 24) ewes (age ≈18 mo; BW = 87.48 ± 8.37 kg) were sorted into breed-type groups and within groups ranked by BW, and then, they were randomly divided into 3 dietary supplement treatment groups: CON (n = 13; 40 mg/kg Zn; ≈1 × NASEM recommendations), Zn500 (n = 21; 500 mg/kg Zn; ≈4 × NASEM recommendations), and Zn1000 (n = 17; 1,000 mg/kg Zn; ≈7 × NASEM recommendations). Treatments were administered in Zn-fortified pelleted alfalfa (0.45 kg/ewe per day) and fed from 87.5 ± 8.9 d of gestation until parturition. Milk traits collected at parturition (d 1 of lactation), ≈30 d of lactation, and lamb weaning (≈90 d of lactation) were assessed as repeated measures with fixed effects of treatment, breed type, and litter size. The treatment × breed type interaction affected ewe logSCC ( P = 0.01), and within Zn500, BF had greater logSCC than WF ewes (5.90 ± 0.08 vs. 5.46 ± 0.08; P < 0.01). However, breed types did not differ between CON and Zn1000 treatments ( P ≥ 0.92). Ewe logSCC was greatest ( P < 0.01) at weaning (6.03 ± 0.06), intermediate at parturition (5.72 ± 0.06; d 1), and least at d 30 of lactation (5.21 ± 0.06). Intramammary infections were common in milk samples collected at parturition (77%) and weaning (47%) based on culture-based microbial identifications. The most frequently identified species included Bacillus spp. and Staphylococcus spp. Black-face ewes had greater concentrations of C16:1 (1.78 mg/100 vs. 1.39 mg/100 mg of fatty acid per 100 mg of total fatty acids), C17:1 (0.86 mg/100 vs. 0.76 mg/100 mg of fatty acid per 100 mg of total fatty acids), and C20:4 (0.28 mg/100 vs. 0.24 mg/100 mg of fatty acid per 100 mg of total fatty acids; P ≤ 0.04) than WF ewes. Including Zn in diets beyond NASEM recommendations from mid to late gestation had no effect on ewe milk SCC, microbial pathogens identified, or fatty acid composition. However, findings indicated there may be important breed differences in dietary Zn utilization and requirements affecting intramammary inflammation.

A Low-Starch and High-Fiber Diet Intervention Impacts the Microbial Community of Raw Bovine Milk

A more sustainable dairy cow diet was designed that minimizes use of feed components digestible by monogastric animals by increasing the quantity of forages. This study determined if feeding lactating cows the more sustainable, low-starch and high-fiber (LSHF) diet was associated with changes in raw milk microbiota composition and somatic cell count (SCC). In a crossover design, 76 lactating Holstein cows were assigned to an LSHF diet or a high-starch and low-fiber (HSLF) diet, similar to common dairy cow diets in the United States, for 10 wk then placed on the opposite diet for 10 wk. The LSHF diet contained greater quantities of forages, beet pulp, and corn distillers' grain, but contained less canola meal and no high-moisture corn compared with the HSLF diet. Raw milk samples were collected from each cow 4-5 d before intervention and 5 wk into each diet treatment. Within 4 d, additional milk samples were collected for measurement of SCC using Fossmatic 7. The microbial community was determined by sequencing the 16S rRNA gene V4-V5 region and analyzing sequences with QIIME2. After quality filtering, 53 cows remained. Raw milk microbial communities differed by diet and time. Taxa associated with fiber consumption, such as Lachnospiraceae, Lactobacillus, Bacteroides, and Methanobrevibacter, were enriched with the LSHF diet. Meanwhile, taxa associated with mastitis, such as Pseudomonas, Stenotrophomonas, and Enterobacteriaceae, were enriched with the HSLF diet. Relatedly, an interaction of diet and time was found to impact SCC. In raw milk, consumption of an LSHF diet compared with an HSLF diet was associated with changes in abundance of microbes previously associated with fiber consumption, udder health, and milk spoilage. Further research is needed to determine if an LSHF diet indeed leads to lower rates of mastitis and milk spoilage, which could benefit the dairy industry.

Milk Quality and Safety in a One Health Perspective: Results of a Prevalence Study on Dairy Herds in Lombardy (Italy).

Mastitis is one of the major diseases of dairy cows that affects milk quality and quantity and increases the potential risk for the presence of antimicrobial residues (AR) in milk, which could lead to the development of antimicrobial resistance (AMR) among human pathogens. Even if the presence of AR in milk and milk products is low in many countries, the threat is not negligible and cannot be ignored. These problems may be investigated by applying a One Health approach, and this prevalence study aimed to estimate the risks for human health related to milk production applied to dairy herds in Lombardy. Three hundred thirty-one bulk tank milk samples were randomly collected and analyzed by CombiFoss 7 and MilkoScan 7 (milk quality, bacteria, and somatic cell count), an HPLC system coupled to a Q-Exactive Orbitrap (AR), and qPCR (contagious pathogens). The data were analyzed by a generalized linear model. The results showed a relatively high prevalence of contagious pathogens (S. aureus 28.1%; Str. agalactiae 7.3%; M. bovis 3%), which primarily affect milk nutritional components decreasing mainly milk fat content (range 1%–2.5%), but did not show them to be associated to an increase of the risk of antimicrobial residues. These latter ones were recovered only in 7/331 samples at concentrations far below official MLRs. The results support currently active surveillance programs’ efficacy in reducing AR risks, which may be further improved by prioritizing them based on geographical area characteristics.

Impact of Endemic Besnoitiosis on the Performance of a Dairy Cattle Herd.

Simple SummaryBovine besnoitiosis, caused by the Apicomplexa parasite Besnoitia besnoiti, has been emerging in Europe as a disease of economic concern to the cattle industry. It is a chronic and debilitating disease mostly reported in beef cattle. However, in Europe, bovine besnoitiosis is increasingly common in dairy cattle; therefore, there is a need to assess the impact of this disease on milk production. To study the effect of B. besnoiti infection on dairy production and reproduction, a serological screening was performed on a dairy herd in an endemic area. The results showed that the herd was endemically infected, with high seroprevalence and low clinical prevalence, and the time on herd represented a risk factor to acquire the infection. Seropositive animals and cows with chronic skin lesions revealed higher milk somatic cell counts, and no negative impact on reproductive performance was found.This study aimed to assess the effect of Besnoitia besnoiti infection on the reproductive and productive performance of a dairy cattle herd. A serological screening was performed by indirect fluorescent antibody test (IFAT) on every animal aged over one year (n = 262). Subsequently, 211 animals were clinically examined, with 96 of those being screened for detection of sclerocysts. The overall seroprevalence was 62.9% (CI95%: 56.1–69.5%). On clinical examination, 7.6% (16/211) of the animals presented chronic skin lesions, and 47.9% (46/96) had sclerocysts. Multivariate logistic regression showed that the time on herd represented a risk factor, and the odds of acquiring the infection increased 1.683× per additional year on herd, ranging from less than a year to 8 years. Seropositivity and the presence of sclerocysts revealed an association with a higher milk somatic cell count, which may have a considerable economic impact on dairy production. Regarding reproductive indicators, no negative impact could be associated with clinical besnoitiosis or positive serological results. In conclusion, our study highlights the need to thoroughly evaluate the economic impact of this emerging disease in dairy herd production to help with decision making at both herd and regional levels, particularly in endemic areas.

Effects of Hydrolysable Tannin Supplementation on Nutrient Intake, Milk Production and Milk Somatic Cell Count in On-farm Dairy Cows

This study examined the effects of hydrolysable tannin (HT) supplementation on nutrient intake, milk production and milk somatic cell count in on-farm dairy cows. Fifty-four Holstein Friesian crossbred cows weighing 450 to 500 kg and were subjected to an experiment for 49 days. Dairy cows were divided into 3 groups, which were 1) the control group without HT supplementation and the HT supplementation groups, which received HT products (15 g/day), 2) one contains 3.15 g/day of HT and 3) another contains 6.30 g/day of HT. Hydrolysable tannin was extracted from sweet chestnut wood (Castanea Sativa Mill.). Dairy cows received HT products on the top of concentrate (22 % CP) in the morning after milking. Total mixed ration (TMR), pangola grass (Digitaria eriantha) hay and concentrate were offered according to animal nutrient requirements. The results showed that supplementation of HT has no influence (p &gt; 0.05) on the nutrient intake, milk yield and milk composition when compared to the control group. In addition, the increased levels of HT caused quadratic increases in fat:protein at pre-treatment and treatment periods (p &lt; 0.05; p = 0.06, respectively), while differential somatic cell count (DSCC) at treatment and post-treatment periods showed a quadratic decrease (p &lt; 0.05; p &lt; 0.05, respectively), with supplementation of HT product containing 6.30 g HT/day (p &lt; 0.05) being the lowest. Therefore, it can be concluded that supplementation with HT product does not affect nutrient intake, milk yield, however, it could reduce DSCC and probably improve udder health in on-farm dairy cows.&#x0D; HIGHLIGHTS&#x0D; &#x0D; A quantitative performance comparison of Radio over Free Space Optical links&#x0D; WDM increases the capacity while the MIMO links help to maintain the transmission range&#x0D; A combination of WDM and MIMO RoFSO links is identified to be the best&#x0D;

Animal performance and stress at weaning when dairy cows suckle their calves for short versus long daily durations

Calves in most dairy farms are separated from their dams either immediately or within a few hours after birth, prompting increasing concern of the society for reasons of animal welfare. The aim of this study was to identify systems to maintain cow-calf contact (CCC) that balance the benefits for calf growth and health against the negative impacts on sellable milk and stress at weaning. We tested reuniting cows and calves for 20 min before (Before-group) or 2.5 h after (After-group) morning milking (in Trial 1) or for a 9 h period between the morning and evening milkings (Half-day-group, in Trial 2). In Control-groups, calves were separated from their dam at birth and fed with artificial nipple with tank milk provided daily at 13% (Trial 1) and 14% (Trial 2) of their BW. In both trials, each practice was applied on a group of 14 dam–calf pairs (7 Holstein [Ho] and 7 Montbéliarde [Mo]). All calves were weaned at a BW of at least 100 kg. In Trial 1, the After-group was prematurely stopped when the calves were eight weeks of age as calf growth became limited (340 g/d) due to low milk intakes (2.97 kg/d). During the first eight weeks of lactation, milk yield at the parlour was 29%, 51% and 42% lower in After-, Before- and Half-day-cows respectively compared to Controls. From week 14 to 16 when all calves were separated from their dam, Before-cows still produced 25% less milk than Control-cows while Half-day-cows reached the milk yield of Control-cows within a week. There were no significant differences in milk somatic cell count and in frequency of health disorders (cows and calves) between suckling and Control-groups. Compared to Control-calves, calf growth until weaning was higher in the suckling calves in Trial 1 (861 vs 699 g/d) and similar in Trial 2 (943 vs 929 g/d). At weaning, Before- and Half-day-calves started to vocalise earlier and continued to vocalise longer than Controls. In conclusion, the best compromise between cow milk yield and calf growth is a long period of CCC (9 h) between the morning and evening milkings. Still abrupt weaning stresses both cows and calves even if CCC has been restricted before separation.

Formation of Blood Neutrophil Extracellular Traps Increases the Mastitis Risk of Dairy Cows During the Transition Period.

The current study was conducted to analyze the functions of blood neutrophils in transition cows and their association with postpartum mastitis risk as indicated by somatic cell counts (SCCs) in milk. Seventy-six healthy Holstein dairy cows were monitored from Week 4 prepartum to Week 4 postpartum. Five dairy cows with low SCCs (38 ± 6.0 × 103/mL) and five with high SCCs (3,753 ± 570.0 × 103/mL) were selected based on milk SCCs during the first three weeks of lactation. At Week 1 pre- and postpartum, serum samples were obtained from each cow to measure neutrophil extracellular trap (NET)-related variables, and blood neutrophils were collected for transcriptome analysis by RNA sequencing. The serum concentration of NETs was significantly higher (P < 0.05) in cows with high SCCs than in cows with low SCCs (36.5 ± 2.92 vs. 18.4 ± 1.73 ng/mL). The transcriptomic analysis revealed that the transcriptome differences in neutrophils between high- and low-SCC cows were mainly in cell cycle-related pathways (42.6%), including the cell cycle, DNA damage, and chromosomal conformation, at Week 1 prepartum. The hub genes of these pathways were mainly involved in both the cell cycle and NETosis. These results indicated that the formation of NETs in the blood of transition dairy cows was different between cows with low and high SCCs, which may be used as a potential indicator for the prognosis of postpartum mastitis risk and management strategies of perinatal dairy cows.

Interaction of blood calcium with luteal activity, energy metabolites and somatic cells count in post-partum dairy cows.

The aim of the research was to assess whether there was a link between serum calcium (Ca) after calving and serum progesterone, milk somatic cells count and Ca, and other blood metabolites in Achai and crossbred cows. Based on blood calcium level shortly after calving, thirty cows from both breeds were divided into a moderate group (≤10.0mg/dl of Ca) and a high group (>10.0mg/dl of Ca), with samples collected at 0, 7, 14, 21, 28 and 35days post-partum, respectively. On day 35 of the post-partum, crossbred and Achai cows with high blood Ca recorded significantly (p<.01) higher serum progesterone, glucose, triglyceride and milk Ca compared with moderate blood Ca group; however, serum cholesterol was significantly (p<.01) higher in both breeds under high blood Ca. Incidence of subclinical mastitis was significantly (p<.01) higher in crossbred and Achai cows under high blood Ca. The results showed that blood progesterone (OR=2.095), glucose (OR=1.024), triglyceride (OR=4.571), cholesterol (OR=1.111) and milk Ca (OR=1.141) resulted in a greater concentration in crossbred compared to Achai cows. A significant (p<.01) correlation was found between blood Ca and other blood metabolites (progesterone, glucose, triglyceride and cholesterol) in both breeds. In conclusion, greater serum Ca concentration after calving is associated with greater serum progesterone, glucose, triglyceride and milk Ca in crossbred cows; however, the incidence of subclinical mastitis increased.

Effect of Holstein genotype on immune response to an intramammary Escherichia coli challenge

Selective breeding of US dairy cows since the mid-1960s has contributed to remarkable gains in milk yield per cow. This increased milk yield has been associated with an increase in health issues. Since 1964, the University of Minnesota has selectively bred a Holstein herd to maintain genetically static, unselected Holsteins (UH). Comparison of these UH cows with contemporary Holsteins (CH) has demonstrated that the UH cows not only produce less milk but also have fewer health concerns than their CH herdmates. The objective of this study was to determine the effects of Holstein genotype on innate immune response in an experimental intramammary Escherichia coli challenge model. Primiparous UH (n = 5) and CH (n = 7) cows received 430 cfu of E. coli strain P4 in 1 quarter. Blood and affected quarter milk samples were collected at 0, 0.25, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 7, 9, and 11 d relative to E. coli infusion. Rectal temperatures were recorded at each milking through d 4 of the experiment. Milk bacterial counts, somatic cell count and BSA concentrations, complete blood cell counts, rectal temperature, and serum and milk whey cytokine (IL-1β and IL-6) concentrations were used as metrics to determine infection severity. Longitudinal (repeated) data were analyzed using general linear models with PROC MIXED with day of study as the repeated effect. Whole blood transcriptomes were generated by RNA sequencing. Transcripts with a false discovery rate of P < 0.05 and a delta log2 expression value greater than 0.7 or less than -0.7 were used for functional enrichment analysis. Bacterial counts were consistently greater in milk from CH than UH cows from d 0.25 through d 2.5. Milk somatic cell count increased within 6 h (d 0.25) after E. coli administration in CH and UH cows but did not differ between genotypes after d 1. Rectal body temperature peaked at d 1 in CH and UH cows but was greater in CH cows. Milk BSA, IL-1β, and IL-6 concentrations were greater in CH than UH cows after E. coli administration. Blood lymphocyte and neutrophil counts were decreased at 0.5 and 1 d in CH but not in UH cows. The number of differentially expressed transcripts at each of the postinfusion sampling times was consistently greater (4- to 90-fold) in CH than in UH cows. A key difference between the immune reaction of the 2 genotypes was that the immune response to E. coli was largely contained within the mammary gland of the UH cows but became more systemic in the CH cows. These data demonstrate that UH cows exerted more effective control of E. coli infused into the mammary gland and thus support the hypothesis that selection practices since the mid-1960s have resulted in CH cows with an immune system that is less effective in fighting intramammary infections. Identification of genetic factors associated with enhanced immune functions that differ between the UH and CH cows could contribute to efforts to reintroduce or enhance beneficial components that have been lost or reduced in the CH cows since the mid-1960s.

First test-day postcalving risk factors for clinical mastitis in southern Chile dairy farms: A retrospective cohort study

We conducted a retrospective cohort study to evaluate risk factors associated with clinical mastitis in dairy cows in southern Chile between the first milk test after calving to 200 d in milk (DIM). Data from 8,772 cows were collected from June 2017 to November 2019 on 10 dairy farms selected by convenience in southern Chile. Data were analyzed using a multivariable mixed logistic regression using a manual backward selection process with logit link function and farm as a random effect. The dependent variable was clinical mastitis between the first milking sample collected by monthly milk sampling program up to 200 DIM. Days in milk, fat, urea, parity, season, and somatic cell counts were statistically associated with clinical mastitis in the first 200 d in milk. Cows with higher than average milk yield, parity, urea, and somatic cell count were at greater odds of being diagnosed with clinical mastitis compared with their respective referents. In contrast, higher milk fat was associated with lower odds of clinical mastitis. Significant interactions between days in milk with season and parity were observed, where for every 5-d increase in DIM, the odds of clinical mastitis decreased by different proportions depending on the interaction. Identified risk factors for clinical mastitis using first monthly milk sampling data can help dairy farmers in Chile implement herd-level mastitis prevention and control measures.

Supplementation of a dried, fungal fermentation product with fibrolytic enzymatic activity in the diet of dairy cows on feeding behavior, metabolic profile, milk yield, and milk composition

• Increased milk production from high-performance cows and decreased somatic cell count Supplementation with exogenous fibrolytic enzymes in the diet of ruminants can improve the use of nutrients by animals and, consequently, improve their productive performance. The aim of this study was to evaluate the effect of supplementing a dried fungal fermentation product with residual fibrolytic enzymatic activity (MAXFIBER®, Provita Supplements, Pinneberg, Germany) on digestibility, feeding behavior, productive performance, milk quality, and various metabolic parameters of high-producing dairy cows. Thirty-six multiparous Holstein dairy cows were divided into two groups: one group with supplementation of 10 g enzyme/cow/day (GS; n = 18), top-dressed on a total mixed ration, and a control group (CG; n = 18) without supplementation. The results were analyzed using a randomized block design over a 23-day experimental period. Milk yield was evaluated daily, and milk and blood samples were collected on days 0, 14, 19, and 23 to analyze the composition and quality of the milk and blood metabolites. DMI and eating behavior were assessed daily using electronic automatic feeders. Cows that received the enzyme-supplemented diet had higher milk production (p = 0.05), lower somatic cell count (SCC) in milk (p = 0.003), and reduced milk fat (p = 0.01). The assessment of feeding behavior showed a higher frequency of access to feeders and meals per day (p = 0.001) in cows that received enzymes in their diet. Blood glucose levels tended to increase in the group with supplementation of the enzyme product (p = 0.09). However, the treatment had no effect (p > 0.05) on DMI and diet digestibility. Fibrolytic enzymes are a useful tool in dairy cow nutrition, increasing milk yield and reducing SCC in milk. Moreover, the enzymes change feeding behavior by increasing feeding frequency.

Sheep Infection Trials with 'Phase-Locked' Vpma Expression Variants of Mycoplasma agalactiae-Towards Elucidating the Role of a Multigene Family Encoding Variable Surface Lipoproteins in Infection and Disease.

The significance of large multigene families causing high-frequency surface variations in mycoplasmas is not well-understood. Previously, VpmaY and VpmaU clonal variants of the Vpma family of lipoproteins of M. agalactiae were compared via experimental sheep infections using the two corresponding ‘Phase-Locked Mutants’. However, nothing is known about the infectivity of the remaining four Vpma expression variants VpmaX, VpmaW, VpmaZ and VpmaV as they were never evaluated in vivo. Here, in vivo infection and disease progression of all six Vpma expressers constituting the Vpma family of type strain PG2 were compared using the corresponding xer1-disrupted PLMs expressing single well-characterized Vpmas. Each of the six PLMs were separately evaluated using the intramammary sheep infection model along with the control phase-variable wildtype strain PG2. Thorough bacteriological, pathological and clinical examinations were performed, including assessment of milk quality, quantity and somatic cell counts. Altogether, the results indicated that the inability to vary the Vpma expression phase does not hamper the initiation of infection leading to mastitis for all six PLMs, except for PLMU, which showed a defect in host colonization and multiplication for the first 24 h p.i. and pathological/bacteriological analysis indicated a higher potential for systemic spread for PLMV and PLMX. This is the first study in which all isogenic expression variants of a large mycoplasma multigene family are tested in the natural host.

EVALUATION OF TWO DIFFERENT METHODS TO ESTIMATE THE SOMATIC CELL COUNT OF BOVINE MILK

EVALUATION OF TWO DIFFERENT METHODS TO ESTIMATE THE SOMATIC CELL COUNT OF BOVINE MILK

Quantifying current and future raw milk losses due to bovine mastitis on European dairy farms under climate change scenarios

Bovine mastitis is an infectious disease that causes udder inflammation and is responsible for raw milk losses across European dairy farms. It is associated with reduced cow milk yield and contributes to elevated Somatic Cell Count (SCC) in raw milk. Staphylococcus aureus is one of the most prevalent mastitis pathogens that cause subclinical and clinical mastitis and can be present as a coloniser bacterium in cows. Climate change and geographical variability may influence the prevalence of this pathogen. Thus, this research aimed to predict the raw milk losses in three major dairy-producing regions across Europe (i.e. Mediterranean, Atlantic and Continental) under climate change scenarios. An exposure assessment model and a stepwise probabilistic model were developed to predict potential cow milk yield reduction, S. aureus and SCC concentrations in the bulk tank milk at dairy farms. Baseline (i.e. present) and future climate change scenarios were defined, and the resultant concentrations of SCC and S. aureus were compared to the actual European regulatory limits. Across the three regions, raw milk losses ranged from 1.06% to 2.15% in the baseline. However, they increased up to 3.21% in the climate change scenarios when no on-farm improvements were considered. Regarding geographical variation, the highest potential milk losses were reported for the Mediterranean and the lowest for the Continental region. Concerning the fulfilment of the regulatory limits, the mean of S. aureus and SCC levels in milk did not exceed them either in any region or scenario. Nevertheless, when looking at percentiles, the 10th percentile remained above the limits of S. aureus in Atlantic and Mediterranean, but not in the Continental region. The findings provide a snapshot of climate change impacts on raw milk losses due to mastitis. They will allow farmers to detect weaknesses and prepare them to develop adaptation plans to climate change.

Responses of Lactation, Rumen Fermentation and Blood Biochemical Parameters with Increasing Dietary Inulin Supplementation in Mid-Lactation Dairy Cows

Effects of dietary supplementation of inulin in dairy cows were investigated in this study. Thirty-six mid-lactation Holstein dairy cows were randomly divided into six groups with six cows per group and offered a total mixed ration supplemented with 0 (control), 50, 150, 200, 250 and 350 g/d inulin per head, respectively. The animals were pre-fed for 2 weeks before rumen fluid, milk and blood samples were collected weekly for 3 weeks. With increasing inulin doses, milk yield (p &lt; 0.01) and milk fat concentration (p = 0.04) were linearly increased, while milk urea nitrogen (p &lt; 0.01) and somatic cell count (p = 0.04) were linearly decreased. Linear increases were also detected in the proportions of milk saturated fatty acids (p &lt; 0.01) and polyunsaturated fatty acids (p = 0.04); however, milk monounsaturated fatty acids were linearly decreased (p = 0.04). The ruminal concentrations of acetate, propionate and butyrate increased, while the ruminal pH and the concentration of NH3-N reduced at a decreasing rate with increasing inulin doses (p &lt; 0.01). Moreover, the concentrations of lactic acid (p = 0.03) and total volatile fatty acids (p &lt; 0.01) were linearly upregulated. There were linear increases in the serum concentrations of superoxide dismutase (p = 0.02), immunoglobin G (p &lt; 0.01), immunoglobin M (p = 0.04), interleukin-2 (p &lt; 0.01) and interleukin-10 (p = 0.04); quadratic increases in serum total protein (p &lt; 0.01) and albumin (p = 0.02) and linear decreases in serum total cholesterol (p = 0.02), triglyceride (p &lt; 0.01) and malondialdehyde (p &lt; 0.01). The results indicated that inulin increased milk production, shifted milk fatty acid profile, upregulated rumen volatile fatty acid concentration, and enhanced antioxidant and immunity function in dairy cows in a dose-dependent manner.

Relationship between polymorphism within Peptidoglycan Recognition Protein 1 gene (PGLYRP1) and somatic cell counts in milk of Holstein cows

Abstract Bovine peptidoglycan recognition protein 1 (PGLY RP1) is an important receptor that binds to murein peptidoglycans (PGN) of Grampositive and Gram-negative bacteria and is, therefore, involved in innate immunity. The SNP T&gt;C rs68268284 located in the 1st exon of the PGLYRP1 gene was identified by the PCR-RFLP method in a population of 319 Holstein cows. Somatic cell count (SC) was measured 7–10 times in each of three completed lactations to investigate whether the PGLYRP1 polymorphism is associated with SC. Using the GLM model, it was found that cows with the TT genotype showed significantly lower somatic cell counts than those with the CC genotype during the first lactation (P = 0.023). Moreover, during lactations 1–2 and 1–3, cows with the TT genotype reveal significantly lower SCC than CT heterozygotes, at P = 0.025 and P = 0.006, respectively. Computer-aided analysis showed that rs68268284 polymorphism could modify the PGLY RP1 functions because the mutated residue is located in a domain that is important for the binding of other molecules.

Epigenetic states of genes controlling immune responsiveness in bovine chronic mastitis

Abstract Mastitis is a common disease in dairy cows, causing substantial economic losses. The leading cause of elevated milk somatic cell count (SC), which is the best indicator for detecting mastitis, is the invasion of pathogens. A major pathogen responsible for bovine mastitis is Staphylococcus aureus, a member of the coagulase-positive staphylococci. Some strains of coagulase-negative staphylococci can also be a cause of clinical or subclinical mastitis. Our study used bisulfite sequencing PCR (BSP) to detect the methylation status of nine candidate genes (CCL2, HCK, F11R, CD8A, PDIA3, LGMN, HSPA1A, IL18 and NFKBIA). We investigated the mechanisms associated with overexpression of these genes, in the mammary gland secretory tissue of cows diagnosed with mastitis and infected with coagulase-positive or coagulase-negative staphylococci. The results showed no changes at the DNA methylation level between the mastitis (CoPS and CoNS) and control groups (H), except for in the HCK region, where the observed differences between the CoPS and H groups were statistically significant. The low methylation level of the CpG sequence seems not to correspond to the previously observed increased activity of these genes, suggesting that mechanisms other than DNA methylation may control mRNA expression at the analyzed loci.

Investigation of Milk Somatic Cell Counts During Early Lactation Stages in Awassi Ewes

This study aimed to investigate the change of somatic cells counts (SCC) and to determine its normal value during the early lactation period in healthy Awassi ewes. The study was conducted on a total of 75 healthy Awassi ewes. The animals were divided into three groups as those in the second week of lactation (Group 1; n= 25), those in the fourth week of lactation (Group 2; n= 25), and those in the sixth weeks of lactation (Group 3; n= 25). California Mastitis Test (CMT) negative animals were included in the study and, milk samples were collected for SCC analysis. In addition, blood samples were taken from all animals for alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase and gama glutamil transferaz analysis. SCC was significantly reduced in Group 2 compared to Group 1 (p

Effects of Dietary Natural Mycotoxins Exposure on Performance, Biochemical Parameters and Milk Small Molecule Metabolic Pathways of Lactating Cows

The presence of mycotoxins in feed has the potential to cause significant detriment to animal and human health, and even severe economic implications. Previous studies on the effects of mycotoxins mainly focused on the addition of commercially available mycotoxins into feeds in animals. In the present study, corn meal and cottonseed were kept in warm and humid conditions to allow for mycotoxins produced and then used to substitute 50% and 100% of normal corn meal and cottonseed in diets for lactating cows for 14 days. The results showed that aflatoxin M1, deoxynivalenol, aflatoxin B1, and zearalenone were primary mycotoxins in milk from cows fed the diets. Compared with the control group, feeding the diets containing mildewy corn meal and cottonseed reduced feed intake, milk yield, and milk fat, protein and lactose productions (p &gt; 0.05). No significant difference was observed in the acetate and valerate concentrations, acetate to propionate ratio, and the calculated CH4 production in rumen fluid (p &gt; 0.05), whereas, the propionate, butyrate, isovalerate concentrations were affected (p &lt; 0.05) depending on the content and type of natural mycotoxins. Serum creatinine and total glyceride concentrations were influenced with corn meal and cottonseed fully replaced with the mildewy feeds. Metabolic pathways for small molecule metabolites in milk were altered by dietary mycotoxin exposures, and the changes were mainly associated with amino acid metabolism, glucose metabolism, and energy metabolism. However, cows exposed to natural mycotoxins in the diets were still in healthy conditions and had low somatic cell count in milk.

Relationship among production traits, somatic cell score and temperature–humidity index in the Italian Mediterranean Buffalo

The temperature–humidity index (THI) has been commonly used to analyse heat stress in dairy cattle, but little is known about its effects on buffaloes. In this study, daily milk yield (MY), fat percentage (FP), protein percentage (PP) and somatic cell count (SCC) data from 808 buffalo cows plus environmental temperature and relative humidity were used to investigate the consequence of heat stress. Two mixed models were used to evaluate the impact of THI on MY, FP, PP and log transformed SCC (SCS). The effect of THI was significant for PP, FP and SCS, whereas its interaction with parity was statistically significant for PP and SCS. The relationship between PP and FP and THI was positive but of different magnitude according to the parity. When THI was below 62, an unfavourable effect was observed, especially in primiparous buffalo cows. A significant interaction between SCS and THI across parities was also observed. The effect of THI on MY across parities was not definite but overall a favourable relationship was observed. Our findings depict a susceptibility of buffaloes to low values of THI, suggesting an optimal THI range for water buffaloes between 59 and 63, although some deleterious effects were observed in primiparous buffaloes at THI values lower than 62. Additional investigations are needed to better elucidate the influence of THI on buffalo species. HIGHLIGHTS The overall effect of THI on buffalo diverges from what commonly observed in dairy cattle Cold stress affects milk and udder health in buffaloes The effect of THI on buffaloes’ performance depends on parity, with a larger susceptibility in primiparous than pluriparous buffalo cows Udder health in buffaloes, evaluated using somatic cell count, is also affected by THI