Milk SCC Research Articles

PSXI-30 Economic impact of pre-training on dairy cattle automatic milking system acclimation

Abstract Pre-training in automatic milking systems (AMS) has the potential to increase milk production and milk quality. In a recent study, cows that experienced pre-training (TRT; i.e. intentional training access with an AMS prior to first AMS milking) had greater milk yield and fat percentages compared with no pre-training (38.4 vs. 37.6 ± 0.2 kg/d; 4.75 vs. 4.38 ± 0.06%; P < 0.01, and < 0.01 respectively). Similarly, cows without pre-training had greater somatic cell count (SCC; 298,860 vs. 188,220 ± 10,700 cells/mL; P < 0.001). The time required for pre-training could be a limiting factor (40 ± 10 h/wk), and the economic implications of labor versus long-term benefits must be examined. To that end, a stochastic simulation tool was developed to consider the increased costs of labor and the potential benefits of improved milk yield, milk fat percentage, and decreased somatic cell count. The GRKS distribution with minimum, mean, and maximum values was used to model increases in milk yield (0, 1.4, 1.8 kg), fat percentage (0, 3.5%, 4.5%), and labor cost ($0.0011, $0.0016, $0.0020 per h) and decreases in SCC (0, 120, 130 x 103 cells/mL) per hundredweight of milk produced. Baseline values for milk production ranged from 14.7 to 59.2 kg/cow/d in 4.4 kg increments with fat percentage of 3.5% and SCC of 312,000 cells/mL. The model assumed a minimum increase across milk yield, fat, and SCC of 0 (no change). The Simetar add-on in Microsoft Excel simulated 500 iterations across three herd size scenarios (60, 120, and 480 cows) and calculated the marginal return on investment across a 90-d period for all milk production ranges. Regardless of starting milk production level, pre-training had a positive economic impact across all levels (30 to 50 h) and herd sizes (Table 1). Financial impact per cow per d with input of 30, 40, and 50 h ranged from $0.58 to $0.73, $0.56 to $0.71, and $0.54 to $0.70. The majority of simulations returned a positive marginal impact for pre-training. If pre-training resulted in a loss, it ranged from $242 to $1,937, $323 to $2,585, $405 to $3,246, across 30, 40, and 50 hours, respectively. Based on these results, the investment in pre-training time was consistently beneficial for simulated herds.

Social interactions of dairy cows and their association with milk yield and somatic cell count

The social environment experienced by livestock can have implications for their health, welfare, and subsequently, their productivity. Changes in the dairy industry have led to larger herd sizes and altered management of cows, which has impacted their social environment. Studies have shown that mixing of animals can lead to social instability of groups and expansion of herds can lead to high stocking densities resulting in social stress and negative effects on production. Yet few studies have assessed the putative impact of positive cow-cow interactions, such as proximity to preferred herd mates and engaging in grooming, on milk production and udder health. To address this, we used cattle proximity as a proxy for affiliative interactions between cows in three dairy herds in south-west England over one week study periods. We created proximity networks of dairy cows and measured cow-cow associations according to milk yield, somatic cell count (SCC; an indicator of mastitis), parity (number of lactations in the cow’s lifetime), and lactation stage (grouped by days in milk for current lactation). We then assessed associations between social factors and production and health measures (milk yield and SCC). In all three herds, cows interacted more with cows in the same parity, suggesting early social bonding may be evident later in life and that grouping animals in terms of parity might encourage affiliative interactions. Cows did not associate according to milk yield, SCC, or lactation stage. There was no significant association between milk production or SCC and the total time spent in social contact with other cows, the mean time spent with the four closest herd mates, or the number of closest herd mates of the same parity. We suggest that further research on positive social environments for dairy cattle is warranted in the interests of improving welfare and enabling a more robust assessment of the putative effects on production and health parameters

Mastitis has a cumulative and lasting effect on milk yield and lactose content in dairy cows

Milk lactose content (LC) physiologically decreases with parity order in dairy cows, but also after udder health inflammation(s) and/or in presence of elevated milk SCC in subclinical cases. Therefore, the progressive decrease in milk LC observed along cows' productive life can be attributed to a combination of factors that altogether impair the epithelial integrity, resulting in weaker tight junctions, e.g., physiological aging of epithelium, mechanical epithelial stress due to milking, and experienced clinical or subclinical mastitis. Mastitis is known to affect the udder synthesis ability too, so our intention through this study was to evaluate if there is a cumulative and lasting effect of mammary gland inflammation(s) on milk yield (MY) and LC. For this purpose, we used diagnoses of clinical mastitis and milk data of Austrian Fleckvieh cows to evaluate the effect of cumulative mastitis events on LC and MY. Only mastitis diagnoses recorded by trained veterinarians were used. Finally, we investigated if cumulative mastitis is a heritable trait and whether it is genetically correlated with either LC or MY. Estimates were obtained using univariate and bivariate linear animal models. A significant reduction in LC and MY was observed in cows that suffered from mastitis compared with those that did not experience udder inflammation. The h2 of cumulative mastitis is promising and much greater (0.09) than the h2 of the binary event itself (≤0.03). The genetic correlations between cumulative mastitis with LC and MY were negative, suggesting that cows with a great genetic merit for MY and LC are expected to be more resistant to repeated inflammations and less recidivist. When we used number of lifetime SCC peaks (≥200,000 or 400,000 cells/mL) to calculate cumulative inflammation events, h2 was even higher (up to 0.38), implying that also subclinical mastitis has a relevant negative impact on both LC and MY. Finally, the present study demonstrated how repeated mastitis events can permanently affect the mammary gland epithelial integrity and synthesis ability, and that the number of cumulative mastitis is a promising phenotype to be used in selection index in combination with other indicator traits toward more resistant and resilient mammary glands.

Feeding nanoparticles of copper oxide coated with lysine with or without added antagonists affects the copper status but not the performance of Holstein dairy cows

The apparent absorption of copper (Cu) in ruminants is low, with between 0.01 and 0.07 g/g absorbed from sources such as copper oxide (CuO) under typical feeding conditions, resulting in high levels of excretion. Improving the bioavailability of Cu could reduce the supplemental amount required to maintain Cu status and reduce excretion, particularly in the presence of dietary antagonists such as sulfur (S) and molybdenum (Mo). The objective of our study was to determine the Cu status of cows when fed nanoparticle CuO coated with Lys compared with conventional CuO when fed without or in combination with antagonists to Cu absorption (S and Mo) in the diet of dairy cows. Fifty-six multiparous Holstein-Friesian cows that were 48 d ± 17.2 (mean ± SD) postcalving and yielding 41 ± 6.4 kg of milk per day were used in a 2 × 2 factorial design. The 4 treatment groups were: CuO (O-), CuO with added antagonists (O+), nano CuO with a lysine coating (N-), and nano CuO with a Lys coating with added antagonists (N+), fed for 16 wk. We formulated the diets to contain ∼17 mg of Cu/kg DM, and diets with antagonists contained an additional 1 g of S/kg DM and 6 mg of Mo/kg DM, with Lys added to O- and O+ to provide the same daily supply as N- and N+. Blood samples were collected at wk 0, 2, 4, 6, 10, and 16, and liver biopsy samples at wk 0 and 16. We found no effect of dietary treatment on DMI, milk yield, live weight, or BCS, with mean values of 23.3 kg/d, 40.1 kg/d, 646 kg, and 2.68, but milk SCC was higher in cows fed conventional compared with nano CuO, or added compared with no added antagonists. We also found no effect of treatment on blood activity of gamma glutamyl transferase, superoxide dismutase, or ceruloplasmin, hematology profile, or plasma Cu and iron concentration. We found that plasma Mo concentration was increased from 0.36 µmol/L in cows fed O- or N- to 0.80 µmol/L in those receiving O+ or N+. Additional dietary antagonists also decreased the concentration of Cu in the liver of cows fed conventional CuO (C+) over the study period by 1.3 mg/kg DM per day, but in cows fed dietary antagonists and nano CuO coated with Lys (N+), liver Cu concentration was increased by 1.1 mg/kg DM per day. Our study is the first to demonstrate that reducing the particle size of CuO into the nano scale with a lysine coating improves the bioavailability of CuO in the presence of dietary antagonists in dairy cattle, and we did not observe any negative effects on performance or health.

District-wide herd sanitation and eradication of intramammary Staphylococcus aureus genotype B infection in dairy herds in Ticino, Switzerland

The present study demonstrates successful herd sanitation and eradication of contagious mastitis caused by Staphylococcus aureus genotype B (S. aureus GTB) in an entire Swiss district (Ticino) including 3,364 dairy cows from 168 farms. Herd sanitation included testing of all cows using a highly GTB specific and sensitive qPCR assay, implementation of related on-farm measures, appropriate antibiotic therapy of GTB-positive cows and culling of therapy-resistant animals, respectively. A treatment index was used as an objective criterion to select GTB-positive cows eligible for culling and replacement payment. 62 herds (37%) were initially GTB-positive with a cow prevalence between 10% and 100% and were submitted to sanitation. Twenty mo after the start of the campaign, all these herds were free from S. aureus GTB, whereby 73% of them were sanitized during the first 7 mo. At the cow level, a total of 343 animals were infected. 50 of them were immediately culled and financially compensated based on their treatment index value. The remaining 293 cows were intramammarily treated with antibiotics either during lactation using the combination of cephalexin-kanamycin or penicillin-gentamicin or at dry-off using cloxacillin. Out of these cows, 275 (93.9%) were treated successfully meaning that their milk was twice GTB-negative by qPCR after therapy. For lactational treatment, control samples were taken ≥10 and ≥20 d after treatment, for dry off treatment ≥14 and ≥24 d after parturition. Neither lactation number nor SCC before treatment of the cow nor the type of therapy were associated with therapeutic cure. Using data of 30 GTB-positive and 71 GTB-negative herds (1855 observations), the impact of GTB sanitation on bulk tank milk SCC (BTSCC) was evaluated applying a linear mixed statistical model. In the year before sanitation, BTSCC was always higher in GTB positive than in GTB negative herds. After the start of the campaign, BTSCC declined rapidly in the herds under GTB sanitation and achieved values that no longer differed statistically from those of GTB-free herds after only 2 mo, remaining very similar for the rest of the campaign. The farmers were very satisfied with the outcome of the campaign as all GTB positive herds could be sanitized rapidly, sanitation was sustainable, and milk quality increased.

Comparisons of recycled manure solids and wood shavings/sawdust as bedding material—Implications for animal welfare, herd health, milk quality, and bedding costs in Swedish dairy herds

Increasing shortages and costs of common bedding materials have led dairy farmers in Sweden to consider using recycled manure solids (RMS), which are readily available and low cost, as an alternative bedding material. The main risks are effects on udder health and milk quality, but RMS could also affect animal welfare and claw health. The advantages and disadvantages of using RMS bedding have not been fully investigated, and findings in other countries cannot be directly applied to Swedish conditions and climate. This observational cross-sectional study investigated the use of RMS as bedding, regarding associations with certain aspects of animal welfare, herd health, milk quality, and bedding costs in Swedish dairy herds. Thirty-four dairy farms using RMS or wood shavings/sawdust (each n = 17) were compared. Each farm was visited 2 times during the housing period from 2020 to 2021, once from October to December and once from March to May. Dairy barns were observed, animal welfare was assessed, and freestall dimensions were measured. Farm owners were interviewed about housing system characteristics, herd performance, and herd management. Data on milk production and herd health were obtained from the Swedish official milk recording scheme for the indoor period from October to March. The prevalence of claw disorders and abnormal claw conformation were collected from the national claw health database for the period from October to May. On each farm visit, composite samples of unused bedding outside the barn and used bedding material from the freestalls, respectively, were taken for total bacterial count and DM analysis. Samples of bulk tank milk for determination of total bacterial count were taken in connection to the visits. In addition, samples of unused and used bedding material and manure from alleys for analysis of 3 Treponema species associated with digital dermatitis (DD) were gathered and analyzed. Total bacterial count was significantly higher in unused (8.50 log10 cfu/g) and used RMS bedding (9.75 log10 cfu/g) than in wood shavings/sawdust (used 4.74; unused 8.63 log10 cfu/g), but there were no significant differences in bulk milk total bacterial count (median 4.07 vs. 3.89 log10 cfu/mL) or SCC (median 243,800 vs. 229,200 cells/mL). The aspects of animal welfare assessed did not differ significantly between the 2 bedding systems, whereas the prevalence of total claw disorders (25.9% vs. 38.0% of trimmed cows), dermatitis (6.9% vs. 16.2% of trimmed cows) and sole ulcers (2.0% vs. 4.0% of trimmed cows) were significantly lower in the RMS herds. Treponema spp. were not detected in unused RMS material, but all RMS herds had presence of DD recorded at foot trimming. An economic assessment based on the interview results and price level from winter 2021 revealed that the costs of RMS bedding varied with amount of RMS produced. Thus, RMS is a potential alternative bedding material for dairy cows in Sweden and can be a profitable option for large dairy herds. However, the high level of total bacteria in the material requires attention to bedding and milking routines as well as regular monitoring of herd health.

Effects of feeding an inoculated corn silage with or without a direct-fed microbial on dry matter intake, milk production, and nutrient digestibility of high-producing lactating Holstein cows.

This study evaluated the effects of inoculating corn silage and/or feeding a direct-fed microbial (PRO) on performance and nutrient digestibility of lactating dairy cows. At harvesting, corn silage was treated either with water (culated or not [CON]) or Lactococcus lactis and Lentilactobacillus buchneri (INC; SiloSolve FC) at 1.5 × 105 cfu/g of corn silage. Ten mini silos and one farm-scale silo bunker per treatment were prepared for the laboratory and the lactating dairy cow trial, respectively. Five mini silos per treatment were opened on days 2 or 90 post-ensiling for pH measurement, as well as chemical analysis and aerobic stability, respectively. The farm-scale silo bunkers were opened 77 d post-ensiling for the beginning of the lactating cow trial. Eighty lactating Holstein cows were assigned in a 2 × 2 factorial design to: (1) CON silage without PRO (CON-CON; n = 20), (2) CON silage with PRO at 14g/head/d (CON-PRO; n = 20), (3) INC silage without PRO (INC-CON; n = 20), and (4) INC silage with PRO at 14g/head/d (INC-PRO; n = 20). Concurrently with the feeding trial, eight cows per treatment were chosen for nutrient digestibility. The pH of the corn silage was not affected by the silage inoculant (P ≥ 0.29), but INC yielded greater concentration of acetic acid and longer aerobic stability (P < 0.01). Dairy cows fed INC had a lower mean total dry matter intake (DMI), milk protein content, and somatic cell counts vs. CON (P ≤ 0.02). On the other hand, milk and fat- and protein-corrected milk (FPCM) production efficiency, milk urea-N, DM, crude protein, and starch digestibility were greater for INC-fed cows (P ≤ 0.03). Feeding direct-fed microbials (DFM) improved mean body weight, milk yield, and FPCM, as well as milk protein and lactose yield (P ≤ 0.05), but reduced milk fat and protein content (P = 0.02). A silage inoculant × DFM interaction was observed for milk production efficiency, milk protein and lactose content, and somatic cell count (P ≤ 0.05). Dairy cows fed INC-CON had a greater milk production efficiency and milk lactose content (P ≤ 0.04), but INC-PRO had lower milk protein content and SCC (P ≤ 0.03). In summary, inoculating L. lactis and L. buchneri increased acetic acid content and aerobic stability of corn silage, reduced DMI, but improved milk production efficiency and nutrient digestibility of lactating Holstein dairy cows. On the other hand, feeding PRO improved milk, protein, and lactose yield. Additionally, combining the feeding of an inoculated corn silage with PRO reduced milk somatic cell count.

Quality of raw cow’s milk intended for processing and retail sale from Eastern Poland

The study assessed the quality of raw cow’s milk intended for processing and retail sale (n = 595 samples and n = 19 production batches, respectively) and the relationship between the number of somatic cell and the fat and protein contents. All milk samples were tested for total bacteria count, somatic cell count, antibiotic residues, and fat and protein contents. Additionally, raw drinking milk samples were tested for counts of Enterobacteriaceae, Escherichia coli, coagulase-positive staphylococci, enterococci, and the presence of Listeria monocytogenes and Salmonella spp. In raw milk samples, TBC, SCC, and fat and protein contents ranged from 4.9 × 103 to 2.3 × 105 CFU mL–1, from 9.9 to 407.8 thou. mL–1, from 3.2% to 5.9% and from 3.0% to 4.8%, respectively, while TBC, SCC, and fat and protein contents in raw drinking milk samples ranged from 1.8 × 106 to 3.3 × 106 CFU mL–1, from 454 to 696.9 thou. mL–1, from 1.67% to 2.88% and from 3.11% to 3.41%, respectively. The mean counts of Enterobacteriaceae, E. coli, coagulase-positive staphylococci, enterococci in raw drinking milk were 4.0 × 105 CFU mL–1, 1.4 × 102 CFU mL–1, 2.4 × 104 CFU mL–1, and 2.2 × 105 CFU mL–1, respectively. L. monocytogenes, Salmonella spp., and antibiotic residues were not detected in any of the samples tested. The study showed that 95% of the raw milk samples were of satisfactory quality, while 100% of the raw drinking milk samples were of unsatisfactory quality in relation to the regulatory thresholds. Additionally, raw drinking milk samples were a vehicle of potentially pathogenic bacteria. The somatic cell count did not affect the fat and protein content in the analysed milk.

Dose effect of Actisaf Sc 47 yeast probiotic (Saccharomyces cerevisiae) supplementation on production, reproduction, and negative energy balance in early lactation dairy cows.

The study evaluated the dose effect of dietary supplementation with yeast probiotic Saccharomyces cerevisiae (CNCM I-4407, 1010 CFU/g, Actisaf Sc 47; Phileo by Lesaffre, France) on production, energy metabolism, and reproduction in lactating dairy cows. About 117 multiparous Holstein cows from 3 to 60 d in milk held in a barn with an automatic milking system were enrolled in a randomized complete block design and blocked according to calving day, parity, and previous milk yield. The cows were assigned to a basal diet (15% CP, 22% starch) plus either 5g (Y5 group, n = 39), 10g (Y10 group, n = 39), or 0g (CON, n = 39) of yeast probiotic, presented on top of concentrate fed in the robot. Milk yield and body weight were recorded daily, milk composition, and somatic cell count (SSC) every 2wk, and body condition score (BCS) was estimated at days -14, 14, and 40 post-calving. Data were analyzed using a linear mixed model. The Y10 group showed an increased average daily yield of energy-corrected milk (ECM) over CON (+3.5kg, P < 0.05) and Y5 (+0.8kg). There were no significant differences between the groups in milk fat, milk protein, milk SCC linear score, milk urea, blood beta-hydroxy-butyric acid levels, and BCS. Body weight loss from 3 to 90 d in milk was numerically lower (13.8kg) in Y5 than in CON (25.3kg), and the success rate from the first insemination was the highest in YP5 and YP10 groups (39%) than in Control (26%). The yeast probiotic supplementation to early lactation high-producing dairy cows showed a clear effect of the high dose (10g) on ECM milk production, although the lower dose (5g) showed only numerical ECM production increase, both doses displayed better use of energy from the diet than the control and suggest a better resource efficiency.

Multi-criteria decision analysis for supporting the selection of subclinical mastitis screening tests to use in large- and small-scale dairy farms in Türkiye.

The production of high-quality and safe milk is closely associated with the udder health of dairy cows. While there are many mastitis diagnostic tests/methods available, choosing the most appropriate diagnostic test for a sustainable udder health control program could be a challenge. This study was aimed at selecting tests for the screening of subclinical mastitis on small- and large-scale dairy farms in Türkiye, using multi-criteria decision-making methods. An integrated approach employing the analytical hierarchy process (AHP) and technique for order preference by similarity to ideal solution (TOPSIS) together was used to select subclinical mastitis screening tests for on-farm use. While the AHP determines the weights of the evaluation criteria, the TOPSIS provides a final ranking. Nine different subclinical mastitis screening (SCM) methods (DeLaval somatic cell counter, PortaSCC test, California mastitis test (CMT), rapid culture, portable/hand-held electrical conductivity meter, infrared thermography, leukocyte esterase strip test, milk pH, UdderCheck test) were analyzed on the basis of five selection criteria (the market availability of the test, the diagnostic accuracy of the test, the cost of the test, the cow-side use of the test, and the practicality of the test). The selection criteria were determined based on literature review and stakeholder input. The weighting of the criteria with the AHP was based on the pairwise comparison of the criteria by stakeholders. The criteria were weighted from 1 to 9 according to their relative importance as follows: "1: equally important," "3: moderately important," "5: strongly important," "7: very strongly important," "9: extremely important," and "2, 4, 6, 8: intermediate values." Final ranking of SCM tests with the TOPSIS was based on the stakeholder evaluations of fulfillment of the criteria by the alternatives. The most appropriate screening test for both large- and small-scale dairy farms was determined to be the CMT. The CMT is a very useful, easy to perform, and low-cost tool for detecting subclinical mastitis. Being a major element of udder health control programs, the CMT, if regularly used on dairy farms in Türkiye, would enable the culling of chronically infected animals and the reduction of mastitis-associated economic losses. Furthermore, regular CMTs would contribute to reducing milk SCC and improving milk quality. In conclusion, multi-criteria decision-making methods not only provide a systematic approach that may assist both veterinarians and farmers in deciding on the best choice among the different tests available for the screening of subclinical mastitis but also offer potential benefits to policymakers, researchers, and other industry stakeholders.

The Relationship between Mastitis and Antimicrobial Peptide S100A7 Expression in Dairy Goats.

S100A7 is an inflammation-related protein and plays an essential role in host defenses, yet there is little research about the relationship between mastitis and S100A7 expression in dairy goats. Here, according to the clinical diagnosis of udders, SCC, and bacteriological culture (BC) of milk, 84 dairy goats were grouped into healthy goats (n = 25), subclinical mastitis goats (n = 36), and clinical mastitis goats (n = 23). The S100A7 concentration in subclinical mastitis goats was significantly upregulated than in healthy dairy goats (p = 0.0056) and had a limited change with clinical mastitis dairy goats (p = 0.8222). The relationship between log10 SCC and S100A7 concentration in milk was positive and R = 0.05249; the regression equation was Y = 0.1446 × X + 12.54. According to the three groups, the log10 SCC and S100A7 were analyzed using the receiver operating characteristics (ROC) curve; in subclinical mastitis goats, the area under the ROC curve (AUC) of log10 SCC was 0.9222 and p < 0.0001, and the AUC of S100A7 concentration was 0.7317 and p = 0.0022, respectively; in clinical mastitis goats, the AUC of log10 SCC was 0.9678 and p < 0.0001, and the AUC of S100A7 concentration was 0.5487 and p = 0.5634, respectively. In healthy goats, S100A7 was expressed weakly in the alveolus of the mammary gland of healthy goats while expressed densely in the collapsed alveolus of mastitis goats. Moreover, S100A7 expression increased significantly in mastitis goats than in healthy dairy goats. In this research, results showed the effects of mastitis on the S100A7 expression in the mammary gland and S100A7 concentration in milk and the limited relationship between SCC and mastitis, which provided a new insight into S100A7's role in the host defenses of dairy goats.

Effect of milk flow-rate switch-point settings on milking duration and udder health throughout lactation

The objective of this study was to quantify the effects of different milk flow-rate switch-point settings on milking duration, SCC, strip milk, teat condition and milk yield in a grass based system in a long-term experiment. Much work has already been conducted providing strong support for significant reduction in milking duration without impact on yield through increasing the flow-rate switch-point at which vacuum to the milking cluster ceases and the cluster is removed from the cow by means of a retracting cord. However, in practice many farms have not adopted this labor saving technology on the basis that it may increase milk SCC. Recent research on commercial Irish dairy herds identified the contagious mastitis causing pathogen Staph. aureus as the most prevalent pathogen detected. Staph. aureus could have a cyclical shedding pattern which would inhibit detection at certain time points. Therefore, to reliably assess the effect of milk flow-rate switch-points on SCC, a long-term study was required, consisting of multiple observations on cow level SCC. The present study filled this gap in knowledge by informing on any impact that ceasing milking at different flow-rates may have on milking duration and SCC levels, particularly with regard to spring calving grass based systems. Four treatments, consisting of milk flow-rate switch-points increasing from 0.2 kg/min to 0.8 kg/min in steps of 0.2 kg/min, were deployed for 31 weeks to cows at the Teagasc Research Centre at Moorepark, Ireland. The effect of treatment on daily milking duration was significant (P < 0.001). The milking duration for a milk flow-rate switch-point of 0.8 kg/min was 95 s (14%) shorter than for 0.2 kg/min. We did not find a significant effect of increasing the milk flow-rate switch-point from 0.2 to 0.8 kg/min on milk yield or SCC in this long-term study. We did find a significant effect of week of experiment on milk SCC, whereby the SCC of the cows on the experiment increased similarly among treatment groups as lactation progressed. A significant reduction in Dead Time (time from cluster attachment to reach a milk flow-rate of 0.2 kg/min) was also noted as the milk flow-rate switch-point increased. On average reductions in Dead Time contributed 12% to the overall reductions in Milking Duration. Similarly, reductions in Low Flow Time (time from a flow-rate of 0.2 kg/min to cluster detachment at the end of milking) contributed 26% to the overall reductions in Milking Duration. Reductions in Dead Time and Low Flow Time played a greater role in reducing PM Milking Duration rather than AM Milking Duration due to the milking interval practiced on the research farm.

Comparative studies on milk parameters and somatic cell count of Badri cattle over Sahiwal and crossbred counterparts

This study aims to provide reference values of some of milk parameters and somatic cell count of Badri cows as well their comparison with Sahiwal and crossbred counterparts. Lower milk SCC in Badri cattle reflects their resistance to mastitis. Further, the use of milk SCC as a management tool on a routine basis will help to maximize immunity and improve quality and quantity of milk as well as cattle’s comfort and welfare. In India, higher milk production was never the reason for reversing Zebu/indigenous germplasmas quality of milk has been the talk of folklore. The data generated provides only meagre baseline information on comparison studies on milk composition of Badri, Sahiwal and crossbred cattle. Additional studies are required to substantiate the results.

Comparative studies on milk parameters and somatic cell count of Badri cattle over Sahiwal and crossbred counterparts

This study aims to provide reference values of some of milk parameters and somatic cell count of Badri cows as well their comparison with Sahiwal and crossbred counterparts. Lower milk SCC in Badri cattle reflects their resistance to mastitis. Further, the use of milk SCC as a management tool on a routine basis will help to maximize immunity and improve quality and quantity of milk as well as cattle’s comfort and welfare. In India, higher milk production was never the reason for reversing Zebu/indigenous germplasmas quality of milk has been the talk of folklore. The data generated provides only meagre baseline information on comparison studies on milk composition of Badri, Sahiwal and crossbred cattle. Additional studies are required to substantiate the results.

Biochemical and Computational Assessment of Acute Phase Proteins in Dairy Cows Affected with Subclinical Mastitis.

Subclinical mastitis (SCM) is a predominant form of mastitis wherein major visible signs of disease are absent. The present study aimed to determine acute phase proteins (APPs) like ferritin, C-reactive protein (CRP), and microalbumin (Malb) in 135 composite milk and serum samples of healthy (n = 25) and SCM (n = 110) cows. As bovine mastitis is an inflammatory disease, the present study also aimed at finding novel anti-inflammatory compounds from natural sources by repurposing approach using computational studies. The findings of the present study revealed substantial elevation (p < 0.001) in milk SCC and an increase in ferritin, CRP, and Malb (p < 0.001) in milk and sera of the SCM group as compared to healthy animals. Receiver operating characteristics of milk SCC, milk, and serum APPs unraveled statistically substantial alteration (p < 0.001). Further, SCC was correlated with milk APPs ferritin (r = 0.26 **, p < 0.002), CRP (r = 0.19 *, p < 0.02), and Malb (r = 0.21 *, p < 0.01). Additionally, milk SCC was correlated with serum ferritin (r = 0.28 **, p < 0.001), CRP (r = 0.16, p > 0.05), and Malb (r = 0.16, p > 0.05). The findings of molecular docking revealed that Chaetoglobosin U was the most effective molecule that showed the highest binding affinity (kcal/mol) of -10.1 and -8.5 against ferritin and albumin. The present study concluded that the estimation of cow-side tests, SCC, and APPs in milk/serum is suitable to detect SCM and screening herd community. Furthermore, Chaetoglobosin U could be developed as a promising anti-inflammatory inhibitor; however, further studies are required to validate these findings.

Subklinik mastitisli manda sütünden izole edilen bakteri grupları ile somatik hücre sayıları arasındaki ilişkinin araştırılması

The aim of this study was to investigate the relationship between the bacterial groups obtained from the milk of buffaloes with subclinical mastitis and the milk SCC rate. For this purpose, this study was carried out on 60 milk samples collected from Water buffalo with subclinical mastitis and healthy. Milk samples were divided into three groups as healthy (Group 1; n=20), and with subclinical mastitis caused by Gram negative (Group 2; n=20) and by Gram positive bacteria (Group 3; n=20). SCC value was statistically lower in Group 1 compared to Group 2 and Group 3 (P0.05). In conclusion, SCC value significantly increased in milk with sub-clinical mastitis compared to healthy milk. However, there was no difference in SCC value in milk samples with mastitis caused by gram negative and gram positive bacteria.

Udder health of dairy cows with an extended voluntary waiting period from calving until the first insemination.

This study aimed to evaluate the effect of an extended voluntary waiting period (VWP) on SCC, SCC elevations and clinical mastitis incidence during the complete lactation and the first 6 weeks of the next lactation. Holstein-Friesian dairy cows (N = 154) were blocked for parity, expected milk yield, calving season and breeding value for persistency and were randomly distributed across 3 VWP (50, 125, or 200 d: VWP-50, VWP-125, VWP-200). Cows were monitored from calving until 6 weeks into the next lactation, or until culling. An elevation of SCC in milk was defined as SCC in milk ≥200 000 cells/ml after two previous weeks with SCC < 200 000 cells/ml. Over the complete lactation, extending the VWP did not affect SCC elevations and the occurrence of clinical mastitis per lactation or per cow per year. There was no clear effect of VWP length on SCC in the complete lactation, except that multiparous cows in VWP-125 had a higher SCC compared with multiparous cows in VWP-50. Dry-off antibiotic usage per cow per year was lower in VWP-200 compared with VWP-50 for multiparous cows. In the first 6 weeks of the next lactation, cows in VWP-200 had a higher SCC compared with cows in VWP-50, with no effect of VWP on the number of elevations of SCC or the occurrence of clinical mastitis. Extending the VWP may therefore be used to reduce the frequency of transition periods and the associated use of dry-cow antibiotics, with limited impact on udder health, and a similar occurrence of SCC elevations and clinical mastitis per year.

Comparison of cow milk components between daily actual and AM-PM composite samples from 2 consecutive milkings by Dairy Herd Improvement

This study was undertaken to evaluate the level of agreement of milk fat, protein, lactose, MUN, and SCC concentrations between daily actual and AM-PM composite milk samples taken at 2 consecutive DHI milkings and to assess factors affecting their level of agreement. Milk samples from 2 consecutive milkings were collected using in-line milk meters on 4,340 Holstein cows in 100 Canadian commercial dairy herds. Three milk samples per cow were analyzed for major components: (1) evening samples; (2) morning samples; and (3) an AM-PM composite sample obtained by visually mixing equal volumes of milk from 2 consecutive milkings. Daily actual milk component concentrations were computed proportionally to milk yields. Equal 50:50 composite milk component concentrations were the average of evening and morning samples. Concordance correlation coefficients (CCC) between actual and equal 50:50 samples varied from 0.997 to 1.000. For the comparison between daily actual and AM-PM composite milk component concentrations, CCC ranged from 0.911 to 0.964. This suggested that AM-PM composite samples were not always composed of an equal 50:50 volume of milk from evening and morning milkings. A great variation of CCC was observed between herds, indicating differences in their assessment of volumes of milk to pour into vials at each milkings. Assuming that milk samples were homogeneous, AM-PM composite samples predicted daily actual milk components with great precision and accuracy. However, this was not the case in all herds. Visually assessing milk volumes to pour into vials when creating AM-PM composite milk samples was the major cause of a decrease in level of agreement when predicting daily actual milk component concentrations, which varied between herds. One recommendation might be to add indicators on DHI vials to guide in mixing an equal milk volume from 2 consecutive milkings. Because DHI records are used in decision making, it is important that predicted daily milk component concentrations are as close as possible to daily actual milk component concentrations. Producers can make an informed decision on which sampling scheme to chose according to their management objectives.

Associations between udder and skin cleanliness and somatic cell counts, yield and composition of milk of Polish Holstein-Friesian Black-and-White cows in the autumn-winter season

The aim of this study was to determine the associations between the cleanliness of the udder and skin of the hind part of body and somatic cell counts in milk as well as milk yield and its composition in Polish Holstein-Friesian Black-and-White cows in the autumn-winter season. Animals were kept in the freestall cubicle barn with access to a hardened surface outdoor run. In the roofed part the run was regularly bedded with barley straw. In the milking parlour during test milkings each animal was subjected to a visual inspection performed to evaluate the cleanliness status of the udder, the underbelly, tail base, as well as the upper part of the hind limbs and the lower part of the hind limbs. Soiling on the skin with feces in each analysed cow’s body section had a significant effect on the somatic cell counts in milk. Results of this study indicate a greater effect of the cleanliness status of the hind quarters of the udder on the SCC in milk. An increased degree of soiling on the skin in the underbelly, tail base as well as the upper and lower parts of the hind limbs significantly reduced the contents of protein, casein and dry matter in milk.

Multiple-Vessel-Based Blood Gas Profiles Analysis Revealed the Potential of Blood Oxygen in Mammary Vein as Indicator of Mammary Gland Health Risk of High-Yielding Dairy Cows.

Simple SummaryThe objective of the study was to realize the function of blood gas parameter in relation to the health of high-yielding dairy cows. The study showed that most blood gas parameters differ across the three vessels (coccygeal artery, coccygeal vein, and mammary vein). The associations of oxygen-related variables in the mammary vein are negatively correlated with the levels of malondialdehyde, lactate dehydrogenase, and plasmin in the milk. In the present study, we used blood gas profile to identify the mammary gland health condition in lactating dairy cows.The blood gas profile is a routine method in the rapid disease diagnosis of farm animals, yet its potential in evaluating mammary health status of dairy cows remains to be investigated. This study was conducted to learn the potential of the blood gas parameter regarding the mammary gland health status in lactating dairy cows. Twenty animals were divided into two groups, the H-SCC group (milk SCC > 122 k/mL) and L-SCC group (milk SCC < 73.8 k/mL), to compare blood gas profiles from different blood vessels and to identify the key parameters associated with milk somatic cell count. H-SCC cows are higher in malondialdehyde content, but lower in SOD and T-AOC activities in the milk, compared to the L-SCC group. In terms of blood gas parameters, most differ across the three vessels, including K+, CO2 pressure, O2 pressure, HCO3−, base excess in the extracellular fluid compartment, and saturation of O2. The Pearson correlation analysis showed that oxygen-related variables in the mammary vein, including oxygen concentrations, O2 pressure, and saturation of O2, are negatively correlated with levels of malondialdehyde, lactate dehydrogenase, and plasmin in the milk. Our study revealed that oxygen-related variables in the mammary vein can be a marker in suggesting mammary-gland health status in high-yielding cows.