Mammary Gland Health Status Research Articles

A study on the development and the application strategy of FT-MIRS-based models for the diagnosis of subclinical mastitis and milk quality classification in buffaloes

Buffalo mastitis detection and buffalo milk quality are of great importance to the world dairy industry. Somatic cell count (SCC) can be employed to assess mammary gland health and milk quality in dairy cows, but SCC detection is costly, and the detection instrument is expensive. The purpose of this study was to develop high and low SCC identification models using Fourier-transform mid-infrared spectrum (FT-MIRS), which could be used to diagnose subclinical mastitis (SCM) in buffalo and to determine the milk quality grade at a low cost. The dataset contained 899 buffalo milk samples collected from two regions in China. Firstly, the samples were divided into positive group above the threshold (SCM or unqualified milk) and negative group below the threshold (healthy or qualified milk) with SCC = 200 × 103 cells/mL (SCM in buffalo), 400 × 103 cells/mL (EU standard for raw cow milk, ES), 500 × 103 cells/mL (Indian standard for raw buffalo milk, IS), and 750 × 103 cells/mL (US standard for raw cow milk, US) as thresholds, respectively. Then, with FT-MIRS as predictive variables, predictive models were developed using Partial Least Squares Discriminant Analysis (PLSDA), Random Forest (RF), and Gradient Boosting Machine (GBM). The main results were as follows: the AUCval of the diagnostic model of SCM in buffalo using SCM criteria as a threshold was 0.84 (PLSDA). The AUCval values of the three buffalo milk quality classification models with ES, IS, and US as thresholds were 0.76 (PLSDA), 0.78 (GBM), and 0.84 (PLSDA), respectively. The predictive models established in this paper had a weak predictive ability for positive samples, and the “stepwise discriminant analysis” was recommended to improve the model application effect: The models were applied to classify samples as positive and negative, and then the samples with higher predictive probability were selected. Finally, the remaining samples were further differentiated using the reference methods of SCC detection. To conclude, FT-MIRS has the potential to predict buffalo mammary gland health status and buffalo milk quality grade, reduce the cost of SCC detection, and improve work efficiency, which will lay the foundation for rapid buffalo milk quality classification by raw milk regulatory authorities and rapid diagnosis of SCM in buffalo by farms.

Assessment of the prevalence of Subclinical Mastitis through two on-farm tests in dual-purpose livestock system of Colombian Orinoquia

ABSTRACT The assessment of the prevalence of Subclinical Mastitis (SCM) in dairy farms is essential to evaluate the health status of mammary gland. The aim of the study was to assess the prevalence of SCM in dual-purpose livestock systems in Arauca, Colombia, through the analysis the values found on-farm diagnostic California Mastitis Test (CMT) and Electric Conductivity (EC) test. Milk samples were taken from the individual mammary quarters of 481 cows. The cow level prevalence, per affected individual mammary quarters prevalence and the mammary quarter level prevalence were determined according to the values obtained for each test using two methods of analysis. An ANOVA was performed to determine the difference between prevalences. Cohen’s kappa coefficient was used for intertest agreement, and an analysis of sensitivity and specificity. The cow level prevalence was similar between the tests (CMT = 31.4%; EC = 29.7%). The quarter-level prevalence was lower with EC (11.4% vs 14.3%) (p < 0.05). The agreement test between CMT (0) and EC ranged between 0.20 and 0.25. Despite the low agreement found between the tests, they can be useful in determining the health status of the mammary gland in the dual-purpose livestock systems of the Colombian Orinoquia.

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.

Estimation of genetic parameters for subclinical mastitis using a threshold model in first parity dairy cows under pasture-based systems of Los Ríos Region in Chile

Somatic cell count (SCC) is an indirect measurement to estimate mammary gland health status. This trait provides information regarding the severity of the mammary tissue inflammation in each quarter. Milk samples coming from the farm milk storage vat containing 100,000 to 200,000 cell/mL are considered suspicious, while SCC over 200,000 cell/mL is an indication of subclinical mastitis. Chilean dairy processors penalise farmers monetarily when their bulk tank samples reach levels of 300,000 cell/ mL SCC. The objective of this study was to quantify the additive genetic component of the liability of cows to reach the 300,000 cell/mL threshold. A data set containing the highest SCC test-day record of 10,528 first lactation cows from 15 commercial dairy farms of Los Ríos Region in southern Chile was analysed. The unknown continuous underlying susceptibility of each cow to reach the 300,000 SCC threshold was modelled as a function of a contemporary group formed by the herd, year, and calving season, the regression coefficient of the unknown underlying susceptibility value of a cow on her daily milk yield (MY) and the additive animal genetic effect. Bayesian inference and Gibbs sampling were used to estimate additive and residual variances. The average daily MY and SCC were 17.84±5.25 kg and 125,327±236,297 cell/mL, respectively. The estimated heritability varied from 0.03 to 0.22 and the average was 0.10±0.03. It is concluded that the genetic variability for the susceptibility to reach the 300,000 SCC threshold could be exploited to improve resistance to subclinical mastitis.

Nuclear magnetic resonance spectroscopy to investigate the association between milk metabolites and udder quarter health status in dairy cows

Nuclear magnetic resonance spectroscopy was applied to investigate the association between milk metabolome and udder quarter health status in dairy cows. Mammary gland health status was defined by combining information provided by traditional somatic cell count (SCC) and differential SCC (DSCC), which expresses the percentage of neutrophils and lymphocytes over total SCC. Quarter milk samples were collected in triplicate (d 1 to 3) from 10 Simmental cows, 5 defined as cases and 5 defined as controls according to SCC levels at d 0. A total of 120 samples were collected and analyzed for bacteriology, milk composition, SCC, DSCC, and milk metabolome. Bacteriological analysis revealed the presence of mostly coagulase-negative staphylococci in quarter milk samples of cows defined as cases. Nuclear magnetic resonance spectra of all quarter samples were first analyzed using the unsupervised multivariate approach principal component analysis, which revealed a specific metabolomic fingerprint of each cow. Then, the supervised cross-validated orthogonal projections to latent structures discriminant analysis unquestionably showed that each cow could be very well identified according to its milk metabolomic fingerprint (accuracy = 95.8%). The comparison of 12 different models, built on bucketed 1-dimensional NOESY spectra (noesygppr1d, Bruker BioSpin) using different SCC and DSCC thresholds, corroborated the assumption of improved udder health status classification ability by joining information provided by both SCC and DSCC. Univariate analysis performed on the 34 quantitated metabolites revealed lower levels of riboflavin, galactose, galactose-1-phosphate, dimethylsulfone, carnitine, hippurate, orotate, lecithin, succinate, glucose, and lactose, and greater levels of lactate, phenylalanine, choline, acetate, O-acetylcarnitine, 2-oxoglutarate, and valine, in milk samples with high somatic cells. In the 5 cases, results of the udder quarter with the highest SCC compared with its symmetrical relative were in line with quarter-level findings. Our study suggests that increased SCC is associated with changes in milk metabolite fingerprint and highlights the potential use of different metabolites as novel indicators of udder health status and milk quality.

Short communication: Locus-specific interrelations between gene expression and DNA methylation patterns in bovine mammary gland infected by coagulase-positive and coagulase-negative staphylococci

Pathogens are able to alter the cell cycle program and immune response of the host by changing the transcription and epigenetics of genes responsible for cell cycle control and inflammation. In this regard, we evaluated interrelations between DNA methylation and expression of autophagy, apoptosis, and lipid metabolism-related genes in a sample set of mammary gland secretory tissue sections derived from bovine mammary glands infected with coagulase-negative and coagulase-positive staphylococci. We assessed relative transcript abundance and DNA bisulfite sequencing in loci of the ATG5, IGF1R, TERT, and DGAT1 genes. Lack of DNA methylation in ATG5 and DGAT1 loci might be associated with maintenance of ATG5 and DGAT1 expression regardless of the health status of bovine mammary gland. Complete methylation of intragenic CpG regions in the IGF1R locus was apparently not related to the presence of its transcript in the investigated udder parenchyma samples. Detected hypermethylation of the TERT upstream element was associated with a small amount of TERT mRNA in bovine mammary gland, regardless of the presence, or absence, of the pathogen. A significant decrease in TERT gene expression in tissue sections of mammary gland free of bacteria and in those infected with coagulase-positive staphylococci was observed in parenchyma samples infected with coagulase-negative staphylococci. Two possible explanations are the direct involvement of the TERT gene in the etiology of bovine mastitis or the increase of TERT mRNA due to activation of the MAPK signaling pathway in response to release of exotoxins by coagulase-negative bacteria in the bovine mammary gland.

Effects of machine milking on udder health in dairy ewes

• Milking machine settings that increase vacuum fluctuations under the teat must be avoided to reduce the intramammary infection risk. • Although a high milk pipeline causes higher vacuum fluctuations at teat level, no relation with bulk milk SCC have been found. • Milking machine settings that increase teat thickness would reduce the local defence mechanisms and should be avoided. • Post-milking teat disinfection, milking animals with intramammary infections last, and avoiding over-milking for longer than 2 min can affect mammary gland health status by reducing the incidence risk of mastitis. The aim of this article is to review factors associated with machine milking that would increase mastitis incidence risk and the effects of milking machine, milking management and routine in sheep. Machine milking settings that increase vacuum fluctuations under the teat or teat thickness and help to disseminate infectious agents would increase the risk of intramammary infection. Vacuum fluctuations are caused by a low effective reserve, low air and milk line diameters, low milk tube diameters, sudden air leakages caused by high milking cluster weight, teatcup slippage, excessive liner mouthpiece diameter or inadequate machine stripping. The milk line height (low vs mid line) has no relation with SCC if the rest of the settings are adequate, although higher vacuum fluctuations have been recorded in high line. The settings that increase teat thickness include an excessively high vacuum level, lack of effective massage on the teat (high pulsation ratio), liners too soft, hard, narrow or old, and overmilking for longer than 2 min. Regarding milking management, the reduction of milking frequency to 1 milking per day has an effect on yield and SCC due to a concentration effect, and some milking practices such as post-milking teat disinfection or milking animals with intramammary infections last, despite the drawbacks in overall farm management (identification and separation of infected animals), can lower the risk of mastitis incidence.

Mammary Gland Health and Identification of β-defensin Gene of Holstein-Friesian Cows

β-Defensin in bovine had known as an antimicrobial peptide group with a broad-spectrum activity. The defensin peptide found abundant in neutrophils and epithelial cells including in the mammary gland. The objectives of this research are to identify the β-defensin gene and mammary gland health status. Blood and milk samples were obtained from various lactated cows located from several farms in Bogor. The research consisted of two main activities including collecting blood and milk then laboratory examinations which carried out through amplifying genomic DNA fragments of β-defensin using polymerase chain reaction (PCR) method and milk analysis through somatic cell count. Therefore, based on these results, the β-defensin are found and identified in all samples with a low or high number of somatic cell. Hence, the genetic diversity of β-defensin gene need to be calculated to be used as genetic marker prior to select dairy cattle with increased resistance to infection of the mammary gland method. Other defensin genes need to be hold to assisted breeding programmes in accordance with mammary gland health.

Milk electrical conductivity in Manchega ewes: Variation throughout milking and relation with mammary gland health status

The aim of this work was to study the effect of milking fraction and mammary gland health status on the electrical conductivity (EC) of milk from Manchega ewes, considering also the lactation number. To this end, we also studied the relationship of EC with milk macrocomposition, and the relation existing between EC and somatic cell count (SCC). Finally, the use of EC thresholds as a mastitis detection method (sensitivity, specificity, positive (PPV) and negative predictive value (NPV)) was assessed in each of the three fractions: first streams (F1), machine milk (F2) and stripping milk (F3). Milking fraction, mammary gland health status and lactation number had a significant effect on EC and SCC. In the case of EC, the milking fraction caused a more pronounced effect than health status of the glands or number of lactation (F = 19.95, 15.88 and 6.55, respectively; P &amp;lt; 0.5). In SCC, the gland health status caused the most pronounced effect followed by milking fraction and lactation number (F = 112.02, 6.89, and 5.28, respectively; P &amp;lt; 0.05). Changes in the milk composition, especially fat and lactose contents, explained the EC variation to a great extent. For the same EC threshold, specificity and sensitivity varied slightly depending on the milking fraction. NPV above 80% was obtained in the three milking fractions and at all EC thresholds tested, but PPV was only higher than 20% as of the threshold of 4.5, 4.4, and 4.2 mS/cm in F1, F2 and F3, respectively. From the results obtained, we concluded that the algorithm design for mastitis detection in sheep should include those factors affecting the composition and which therefore cause variations in EC, such as milking fraction, individual differences, lactation stage or lactation number.

Effect of the pulsation type (alternate or simultaneous) on milk yield and health status of the mammary gland of Murciano-Granadina goats

Recent research into how the pulsation type affects goat milking concluded that alternate pulsation (AP) and simultaneous pulsation (SP) similarly affect the milking efficiency (milking duration and milking fractioning) and teat end condition after milking when both pulsations are employed in short-term experiments. However, the use of SP in high pipeline milking machines led to higher vacuum fluctuations, which, in the long term, may entail a potential risk factor for the mammary gland health status. The aim of this work was to study how AP and SP affect the milk yield, mammary gland health status, and milk composition of goats in the long term, during a complete lactation period, in a high pipeline milking machine. With this objective, 100 Murciano-Granadina goats with similar parturition dates (4 ± 1 postpartum weeks) were divided into 2 similar groups (50 goats per group) according their parity, milk yield, mammary gland health status, and milking duration (after a 15-d pre-experimental period). Throughout the experimental period (7 mo), one group was milked using SP and the other group using AP. Every month, samplings were carried out of the variables related to sanitary status of the mammary gland, milk fractioning, milking duration, average and maximum milk flows, milk composition, teat end status, vacuum fluctuations at the short milk tube during milking, and pulsation tests. Results showed that the use of SP in a high pipeline milking machine showed higher vacuum fluctuations without involving any difference in the other variables studied. We concluded that the use of AP in the milking of Murciano-Granadina goats offers little improvement of the milking performance and increases the investment required for installation and maintenance of the milking machines.

Phenotypic and genetic relationships between indicators of the mammary gland health status and milk composition, coagulation, and curd firming in dairy sheep

The present study investigated the effect of somatic cell count, lactose, and pH on sheep milk composition, coagulation properties (MCP), and curd firming (CF) parameters. Individual milk samples were collected from 1,114 Sarda ewes reared in 23 farms. Milk composition, somatic cell count, single point MCP (rennet coagulation time, RCT; curd firming time, k20; and curd firmness, a30, a45, and a60), and CF model parameters were achieved. Phenotypic traits were statistically analyzed using a mixed model to estimate the effects of the different levels of milk somatic cell score (SCS), lactose, and pH, respectively. Additive genetic, herd, and residual correlations among these 3 traits, and with milk composition, MCP and CF parameters, were inferred using a Bayesian approach. From a phenotypic point of view, higher SCS levels caused a delayed gelification of milk. Lactose concentration and pH were significant for many milk quality traits, with a very intense effect on both coagulation times and curd firming. These traits (RCT, RCT estimated using the curd firming over time equation, and k20) showed an unfavorable increase of about 20% from the highest to the lowest level of lactose. Milk samples with pH values lower than 6.56 versus higher than 6.78 were characterized by an increase of RCT (from 6.00 to 14.3 min) and k20 (from 1.65 to 2.65 min) and a decrease of all the 3 curd firmness traits. From a genetic point of view, the marginal posterior distribution of heritability estimates evidenced a large and exploitable variability for all 3 phenotypes. The mean intra-farm heritability estimates were 0.173 for SCS, 0.418 for lactose content, and 0.206 for pH. Lactose (favorably), and SCS and pH (unfavorably), at phenotypic and genetic levels, were correlated mainly with RCT and RCT estimated using the curd firming over time equation and scarcely with the other curd firming traits. The SCS, lactose, and pH were significantly correlated with each other's. In conclusion, results reported in the present study suggest that SCS, pH, and lactose affect, contemporarily and independently, milk quality and MCP. These phenotypes, easily available during milk recording schemes measured by infrared spectra prediction, could be used as potential indicators traits for improving cheese-making ability of ovine milk.

Effect of addition of dried blood plasma to feed on chemical composition of milk and health status of mink lactation mammary gland

The aim of the study was to evaluate the selected parameters of milk mulberry fed with plasma and to assess the health status of the mammary gland of animals. The studies were conducted on american mink (Neovison vison). Two groups of animals were set up: the experimental one which received 0.5% beef-pork plasma for daily dosage of feed and the control group - without plasma. It was determined the content of fat, protein, lactose, dry matter and somatic cells counts in 1 ml of milk. Diagnosis of mastitis was done three times (in 1, 2 and 3 weeks of lactation) in both groups.In the group of animals fedded by dried blood plasma, there were significant differences in fat content in milk, lactose, dry matter and somatic cell counts. Diagnosis of mastitis of mammary gland showed positive plasma effects. The obtained that data suggest that feeding by dried blood derivatives may favorably affect the animal's immune system and support the first line of defense against environmental microorganisms..

Relationship of mammary gland health status and other noninfectious factors with electrical conductivity of milk in Manchega ewes

Measuring the electrical conductivity (EC) of milk during milking has been extensively studied in cattle as a low-cost mastitis detection method that can be easily automated. The aim of this work was to study the effect of the health status of the glands and several noninfectious factors (lactation stage, milking session, and lactation number) that affect the use of EC measurement of milk to detect mastitis in dairy sheep livestock. Likewise, we studied the relation between EC and milk composition (macrocomposition and mineral content) and between EC and somatic cell count (SCC). Finally, we evaluated the use of EC thresholds as a mastitis detection method. To this end, we monitored the glandular milk EC throughout 2 consecutive lactations, during which 42 and 40 ewes were controlled, respectively. We carried out 7 biweekly checks, analyzing the EC, SCC, composition, and mineral content of glandular milk at morning and evening milkings. Before the morning milking, samples were aseptically collected for bacteriological analysis, and the results along with the SCC were used to classify the glands according to their sanitary status (healthy, latently infected, or infected). Lactation stage, parity, milking (morning or evening), health status, and the interactions of parity with health status, lactation stage with health status, and parity with lactation stage all had a significant effect on SCC and EC of the milk. The correlation between EC and SCC was only significant when all the data were analyzed jointly (r = 0.33) and for SCC ≥ 600.000 cells/mL (r = 0.25). The changes in milk composition, mainly in fat content, largely explained the variation in EC (R2 = 0.69). For the same EC threshold, the specificity and sensitivity varied depending on the parity or the milking, with the negative predictive value obtained being higher than the positive predictive value at all times. We concluded that developing methods of detecting mastitis in sheep by milk EC readings would require consideration of noninfectious factors that also affect the gauging of EC. One option to consider would be individualized daily monitoring of the glands, as demonstrated in other species such as cattle and goat.

Pathway-based genome-wide association analysis of milk coagulation properties, curd firmness, cheese yield, and curd nutrient recovery in dairy cattle

It is becoming common to complement genome-wide association studies (GWAS) with gene-set enrichment analysis to deepen the understanding of the biological pathways affecting quantitative traits. Our objective was to conduct a gene ontology and pathway-based analysis to identify possible biological mechanisms involved in the regulation of bovine milk technological traits: coagulation properties, curd firmness modeling, individual cheese yield (CY), and milk nutrient recovery into the curd (REC) or whey loss traits. Results from 2 previous GWAS studies using 1,011 cows genotyped for 50k single nucleotide polymorphisms were used. Overall, the phenotypes analyzed consisted of 3 traditional milk coagulation property measures [RCT: rennet coagulation time defined as the time (min) from addition of enzyme to the beginning of coagulation; k20: the interval (min) from RCT to the time at which a curd firmness of 20 mm is attained; a30: a measure of the extent of curd firmness (mm) 30 min after coagulant addition], 6 curd firmness modeling traits [RCTeq: RCT estimated through the CF equation (min); CFP: potential asymptotic curd firmness (mm); kCF: curd-firming rate constant (% × min-1); kSR: syneresis rate constant (% × min-1); CFmax: maximum curd firmness (mm); and tmax: time to CFmax (min)], 3 individual CY-related traits expressing the weight of fresh curd (%CYCURD), curd solids (%CYSOLIDS), and curd moisture (%CYWATER) as a percentage of weight of milk processed and 4 milk nutrient and energy recoveries in the curd (RECFAT, RECPROTEIN, RECSOLIDS, and RECENERGY calculated as the % ratio between the nutrient in curd and the corresponding nutrient in processed milk), milk pH, and protein percentage. Each trait was analyzed separately. In total, 13,269 annotated genes were used in the analysis. The Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway databases were queried for enrichment analyses. Overall, 21 Gene Ontology and 17 Kyoto Encyclopedia of Genes and Genomes categories were significantly associated (false discovery rate at 5%) with 7 traits (RCT, RCTeq, kCF, %CYSOLIDS, RECFAT, RECSOLIDS, and RECENERGY), with some being in common between traits. The significantly enriched categories included calcium signaling pathway, salivary secretion, metabolic pathways, carbohydrate digestion and absorption, the tight junction and the phosphatidylinositol pathways, as well as pathways related to the bovine mammary gland health status, and contained a total of 150 genes spanning all chromosomes but 9, 20, and 27. This study provided new insights into the regulation of bovine milk coagulation and cheese ability that were not captured by the GWAS.

Quality Analysis of Raw Cow Milk from the Cojocna Farm, UASVM Cluj Napoca in Correlation with the Feeding Technique and Mammary Gland Health Status

Quality analysis of 576 milk samples, obtained from the eight controls was performed in 2015 at the didactics UASVM farm from Cojocna. The biological material was represented by a 107 cows of Romanian spotted breed. On this population, individual and overall, were analized more aspects: productive performances and the main milk quality indicators such as fat, protein, lactose, pH, with particular reference to somatic cell counts as the main indicator of subclinical mastitis and the content of urea as the main indicator of nutritional aspects of the dairy cows. Following the official control of milk production, it was found that the milk production was on average 14.76 kg/day with a quite high values of coefficient of variability, between 31.05% and 40.47%, depending on the controls, which indicating a strong heterogeneity of this trait. The chemical characteristics of 576 samples showed considerable variations from one control to another. The amount of total fat and protein was found to be on average of 3.92% and 3.37% respectively. Regarding the content of urea and somatic cells, in all tested milk samples, the lowest value was found in the fifth control, with an average of 8.04±0.6 mg/dl and 69.20±23.3 cell/mlx103, while the highest was in the first control 19.37±0.7 mg/dl for urea, and 263.17±31.7 cell/mlx103 for the somatic cells.

Short communication: Effects of pulsation type (alternate and simultaneous) on mechanical milking of dairy goats (II)—Effect of milk pipeline height on the milking efficiency and status of teat-end in Murciano-Granadina goats

The aim of this experiment was to determine the effect of alternate and simultaneous pulsation on milking in Murciano-Granadina goats. To this end, four experiments were carried out in Latin square design at two milk pipeline heights (high line and low line) and two stages of lactation (onset and end). For each Latin square, 42 animals were selected and divided into two lots of 21 animals with similar features in terms of parity, machine milk, milking duration and mammary gland health status. Sampling was then carried out to determine the milking efficiency (milk extracted and milking time), teat- end status and variables related to vacuum level in the milking unit, comparing both pulsation types (alternate and simultaneous). Results showed that the use of alternate or simultaneous pulsation presented no relevant differences in milking efficiency or teat-end status after milking at either of the two milk pipelines heights or in the two stages of lactation studied. In low line, no differences were found in the variables related to vacuum level. However, in high line, deeper vacuum fluctuations were observed when simultaneous pulsation was applied. It was concluded that subsequent studies are needed to determine how alternate pulsation affects production and milk composition in the long-term, and whether the deeper vacuum fluctuations observed in high line when applying simultaneous pulsation might affect mammary gland health status.

Appreciation of the Mammary Gland Health Status Based on the Quality Traits of Milk Obtained from Friesian - Black Spotted Breed

One of the main objectives in dairy cows exploitation is to guarantee food security and safety of the population, a desideratum achieved through better milk quality and better control of production in all aspects imposed by the health and welfare of animals from which milk is obtained. The purpose of this sciencific paper is to highlight the status of mammary gland health in a population of Friesian-Black Spotted breed based on the main traits of milk quality, with particular reference to somatic cell counts as the main indicator of subclinical mastitis. The research was conducted in 2014 within the farm S.C. “Modern Farm” S.R.L., located in Jucu village. The individual analysis of Holstein Friesian milked cows was performed, the main indicators of milk production were analysed both quantitatively, based on production obtained daily, and especially qualitatively, based on seven controls with individual sampling from all milked cows at the date of control. Qualitative analysis of 1,391 milk samples highlighted the fact that the somatic cell count in milk obtained from cattle included in this study  recorded an average value of 390.54 ± 11.16 cells/ml x 10 3 with the variability between controls of 314.94 ± 28.93 and 482.36 ± 91.12 cells/ml x 10 3 . Regarding the fat content, the average values was 4.19%, 3.63% for protein content, a pH value of 6.56 and the values of  urea was 20.09 mg/dl. Individual analysis also revealed some cows with subclinical mastitis, which were milked separately, verified and monitored supplementarily in order to reestablish udder health and to prevent the occurrence of clinical mastitis, which can compromise the mammary gland. Â

Povezanost velicine legla s proizvodnjom mlijeka, morfologijom i zdravljem vimena istocnofrizijskih ovaca

The aim of this study was to determine relationship between litter size and milk yield, udder morphology, and udder health of East Friesian ewes. For that purpose a total of 80 East Friesian ewes, from 2nd to 4th lactation, with symmetrical udders, without visible (clinical) signs of mastitis were involved in this study. Until weaning at average age of 60±5 days lambs suckled their mothers exclusively. During milking period regular milking controls (on a monthly basis) were carried out (AT method) and, on these occasions, individual milk samples for chemical composition analysis were taken. Three times per lactation (1st, 3rd and 5th milking control), prior to the milking, evaluation and measuring of udder morphology traits were performed. Also, during above-mentioned test-day controls (three times per lactation) one sample of half udder milk was taken with purpose of bacterial and somatic cell counts (SCC) tests. Ewes with twin and triplet lambs had significantly (P 0.05) and depth (P>0.05). Besides that,udders of ewes with twins and triplets had higher cistern, greater teat angle and larger teat dimensions than ewes with singles, although those differences were not statistically significant. Ewes with single lamb had teats more (P<0.05) cranially oriented than ewes with twins and triplets. Significant (P<0.05) differences in somatic cell count (log10SCC) between ewes of different litter sizes were determined, regardless of the health status of mammary gland. The higher (P<0.05) prevalence of subclinical mastitis was observed in ewes with twin and triplet lambs than in ewes with singles. In 46% of mammary glands (udder halves) of sheep with twins and triplets a subclinical mastitis was established and even 65.8% of them undergone an infection of one or both halves of the udder during the milking period.

Effect of parenteral administration of selenium and vitamin E on health status of mammary gland and on selected antioxidant indexes in blood of dairy cows.

This study focuses on the effect of parenteral administration of Selenium (Se) and vitamin E on concentration of Se in plasma and the activity of glutathione peroxidase (GPx) in the blood of dairy cows during peripartal period and their effect on the reduction of clinical mastitis. From a 220 individuals Holstein herd in a two-four lactation-gestation cycle the control group (C), 1st (D1) and 2nd (D2) experimental group were selected. Every group consisted of 15 cows in the last phase of the pregnancy. All cows were fed with the diet containing 0.1 mg of Se per kg/DM. The blood samples from vena jugularis were collected approximately 21 days before calving (control sampling), 3 days, 12 days and 21 days after calving. On the day of control sampling and 12 days before calving in D1 group, cows were injected subcutaneously in the sprescapular region with preparation Selevit inj. a.u.v. at the doses of 48.4 mg/head of Se, and 550 IU/head of alpha-Tocoferol (alpha-Toc). In D2 group, cows were injected by the same preparation only on 21th day before calving with the same doses of Se and alpha-Toc. The increase in the concentration of Se in the plasma and activity GPx in blood in D1 group on the 3rd day and 12th day after calving were determined. Increase in plasmatic concentrations alpha-Toc on 3rd day after calving and reduction of occurrence of clinical mastitis (13.3%) as compared with control group were found.

Effects of overmilking and liner type and characteristics on teat tissue in small ruminants

The aim of this work was to study the effect on teat wall thickness and canal length in sheep and goats of overmilking for 2min (OM+2) and of milking with used (AL; +3000 milkings) and twisted (TL; 45°) liners in sheep and goats, as well as the effect of milking goats with liners designed for sheep (SL, shorter length and diameter than liners for goats). To this end, we performed four experiments in goats and three in sheep, in a Latin square design with two experimental periods. During the experimental period 4 controls were carried out, performing ultrasound scans before and immediately after milking to determine the teat wall thickness (TWT), teat wall area (TWA), teat end area (TEWA) and teat canal length (TCL). OM+2 caused a significant increase in TWT, TWA, TEWA and TCL in goats and in TWA, TEWA and TCL in sheep. Liner features had a strong influence on the variables studied; aged liners caused significant changes in TWT and TCL in goats and in TWT in sheep; twisted liners produced a significant effect on the increase of TWT and TCL in goats, without reaching significance level in sheep; and milking goats with sheep liners led to a significant increase in TWT, TWA, TEWA and TCL. In practice, it is therefore important to avoid overmilking and the use of worn-out liners. It is also necessary to use liners designed for the morphological features of each species, taking special care to carry out periodic liner positioning revisions to ensure the benefits of pulsation on the teat end. Finally, it would be necessary to carry out long-term experiments to study whether the increase in thickness observed in some experiments is sufficient to affect milking efficiency and mammary gland health status.