Milk SCC Research Articles

Effects of different strategies of mineral supplementation (marine algae alone or combined with rumen boluses) in organic dairy systems.

This study was designed to evaluate the effect of marine algae supplementation alone or in combination with a regular mineral supplement (rumen boluses) to improve the mineral status in organic dairy cattle and their effect on the milk mineral composition, milk production, composition (% of fat and protein) and quality (SCC). Thirty-two Holstein Friesian lactating cows were randomly selected and assigned to the algae (A), boluses (B), algae+boluses (AB) and control group (C). For the algae groups (A, AB), a supplement composed of Sea Lettuce (80%), Japanese Wireweed (17.5%) and Furbelows (2.5%) was formulated to be given to the cows at the rate of 100g/animal per day (A1) for the length of 4weeks. In the second half of the experiment (weeks 5-8), the algae mixture was reformulated and the proportion of Furbelows was increased from 2.5% to 5.0% with a subsequent decrease of Lettuce to 77.5% (A2). In the boluses group (B), each cow received 2 boluses after calving. Blood (serum) and milk samples were collected at 2 and 4week intervals, respectively, and analysed for trace element concentrations by ICP-MS. Information related to the milk composition and SCC during a 305-day lactation for each animal were obtained from the Dairy Records Management System. The supplementation with algae, boluses or the combination of both treatments showed a statistically significant effect on the iodine (algae), selenium (boluses) and cobalt (algae+boluses) status of the animals. In milk, treatments had a statistical significant increase on iodine, and a tendency to increase selenium concentrations. The assayed algae mixture combined with another source of selenium could be an effective tool to improve the mineral status in serum and milk.

Peripartal rumen-protected methionine supplementation to higher energy diets elicits positive effects on blood neutrophil gene networks, performance and liver lipid content in dairy cows.

BackgroundMain objectives were to determine to what extent Smartamine M (SM) supplementation to a prepartal higher-energy diet could alter neutrophil (PMN) and liver tissue immunometabolic biomarkers, and whether those responses were comparable to those in cows fed a prepartal lower-energy diet (CON).ResultsTwenty-eight multiparous Holstein cows were fed CON (NEL = 1.24 Mcal/kg DM) during d −50 to d −22 relative to calving. From d −21 to calving, cows were randomly assigned to a higher-energy diet (OVE, n = 9; NEL = 1.54 Mcal/kg DM), OVE plus SM (OVE + SM, n = 10; SM = 0.07 % of DM) or remained on CON (n = 9). All cows received the same basal lactation diet (NEL = 1.75 Mcal/kg DM). Supplementation of SM (OVE + SM) continued until 30 d postpartum. Liver biopsies were harvested at d −10, 7, and 21 relative to parturition. Blood PMN isolated at −10, 3, and 21 d relative to calving was used to evaluate gene expression. As expected, OVE increased liver lipid content postpartum; however, cows fed OVE + SM or CON had lower concentrations than OVE. Compared with OVE, cows in CON and OVE + SM had greater DMI postpartum and milk production. Furthermore, cows fed OVE + SM had the greatest milk protein and fat percentage and lowest milk SCC despite having intermediate PMN phagocytic capacity. Adaptations in PMN gene expression in OVE + SM cows associated with the lower SCC were gradual increases from −10 to 21 d in genes that facilitate migration into inflammatory sites (SELL, ITGAM), enzymes essential for reducing reactive oxygen metabolites (SOD1, SOD2), and a transcription factor(s) required for controlling PMN development (RXRA). The greater expression of TLR4 on d 3, key for activation of innate immunity due to inflammation, in OVE compared with CON cows suggests a more pronounced inflammatory state. Feeding OVE + SM dampened the upregulation of TLR4, despite the fact that these cows had similar expression of the pro-inflammatory genes NFKB1 and TNF as OVE. Cows in CON had lower overall expression of these inflammation-related genes and GSR, which generates reduced glutathione, an important cellular antioxidant.ConclusionsAlthough CON cows appeared to have a less stressful transition into lactation, SM supplementation was effective in alleviating negative effects of energy-overfeeding. As such, SM was beneficial in terms of production and appeared to boost the response of PMN in a way that improved overall cow health.Electronic supplementary materialThe online version of this article (doi:10.1186/s40104-016-0077-9) contains supplementary material, which is available to authorized users.

Effect of milking behavior on circulatory hormones and milk production in lactating Murrah buffaloes

The effect of milking temperament on plasma hormones, metabolites, milk yield and composition in lactating Murrah buffaloes was studied. Animals were selected from the institute herd and grouped as docile and nervous buffaloes, based on temperament score before and during milking. Blood sampling times were; before milking (-20 min.), after concentrate intake, after teat massage, during milking and 20 min. post- milking. Plasma prolactin (PRL), growth hormone (GH) and cortisol (CORT) concentrations were measured by enzyme-immunoassay procedures. Milk yields of individual buffaloes were recorded and milk composition (fat, protein, lactose, SNF, SCC) determined. Milk yield was significantly lower (P<0.05) in nervous buffaloes in comparison to docile buffaloes. Mean fat, protein, lactose and SNF varied non-significantly between the groups. Milk SCC and plasma NEFA concentration was more (P<0.05) in nervous buffaloes than in docile buffaloes. Milking temperament significantly influenced plasma PRL (P<0.01) and CORT release (P<0.05) but GH was unaffected. Concentrate feeding prior to milking induced release of plasma PRL and CORT without affecting GH and oxytocin levels. Teat stimulus further enhanced release of PRL, oxytocin and CORT hormone in both the groups. Plasma PRL, cortisol, oxytocin and GH varied significantly (P<0.01) before, during and after milking (P<0.01). Basal PRL, GH and CORT were attained 20 minutes after the completion of milking in both the groups. The results show that the behavior of buffaloes at milking influenced release of galactopoietic hormones (PRL, CORT, GH and oxytocin), milk yield and SCC, while milk fat, protein, lactose and SNF remain unaffected.

Pattern characterization of genes involved in non-specific immune response in Staphylococcus aureus isolates from intramammary infections

Staphylococcus aureus isolated from mammary gland are characterized by different genetic patterns. Ninety four isolates from 33 dairy herds were analyzed by the means of a microarray to investigate S. aureus virulence patterns and the distribution of genes believed to be involved in immune evasion. None of the 94 isolates considered were MRSA. However, 50% of the isolates belonged to complexes related to MRSA and to human diseases, while only about 25% of them can be considered as exclusively of bovine origin. The distribution of clonal complexes and the different gene patterns observed confirmed the presence of an influence of geographical localization.The assessment of the influence of genes related to immune evasion on quarter milk cell count showed as four of them showed to be significantly associated to an increase quarter milk SCC. These genes could be potential target for developing new vaccines against S. aureus.

Association of bedding types with management practices and indicators of milk quality on larger Wisconsin dairy farms

The objective of this study was to identify associations of bedding type and selected management practices with bulk milk quality and productivity of larger Wisconsin dairy farms. Dairy herds (n=325) producing ≥11,340kg of milk daily were surveyed during a single farm visit. Monthly bulk milk SCC and total bacteria counts were obtained from milk buyers for 255 farms for a 2-yr period. Of farms with the same type of bedding in all pens during the study period, most used inorganic bedding (IB), followed by organic nonmanure bedding (OB) and manure products (MB). Almost all bulk milk total bacterial counts were <10,000 cfu/mL and total bacterial count was not associated with bedding type. Bulk milk somatic cell score (BMSCS) was least for farms using IB, varied seasonally, and was greatest in the summer. The BMSCS was reduced when new bedding was added to stalls at intervals greater than 1wk and when teats were dried before attaching the milking unit. The BMSCS for farms using OB was reduced when bedding in the backs of stalls was removed and replaced regularly and when fewer cows with nonfunctioning mammary quarters were present. The BMSCS for farms using MB was reduced when the proportion of cows with milk discarded was less. The rolling herd average (RHA) of herds using IB was 761 and 1,153kg greater than the RHA of herds using OB and MB, respectively. The RHA was 353kg greater on farms where farmers understood subclinical mastitis and 965kg greater on farms milking 3 times daily. Each 1% increase of cows with nonfunctioning mammary quarters was associated with a decrease of 57kg of RHA. The BMSCS, proportions of cows with milk discarded and proportion of cows with nonfunctioning mammary quarters were least for herds using IB and were associated with increased productivity. Large Wisconsin dairy farms that used inorganic bedding had greater productivity and better milk quality compared with herds using other bedding types.

Therapeutic effect of polysaccharide fraction of Atractylodis macrocephalae Koidz. in bovine subclinical mastitis

BackgroundMastitis is considered the most significant and persistent disease in dairy cows, bringing about large economic losses. Subclinical mastitis brings about major cost implications, for it is difficult to detect due to absence of any visible indications and can persist in the mammary tissue throughout lactation. Immunomodulators have been widely used to reduce intramammary infections by modulating bovine mammary gland. Atractylodis macrocephalae Koidz. polysaccharides (RAMP), extracted from herbal medicine, has been used widely especially for its immunomodulatory function for many years. The objective of this study was to estimate an oil emulsified Atractylodis macrocephalae Koidz. polysaccharides (RAMP-O) as a potential therapeutic agent to treat subclinical mastitis by subcutaneous injection of RAMP-O in the area of supramammary lymph node in lactating cows via analysis of SCC, IMIs and NAGase.ResultsInjection of RAMP-O in the area of supramammary lymph node significantly reduced milk SCC and NAGase activity compared with control. The quarters with bacterial infection were also progressively reduced in RAMP-O treated cows and only 9 quarters were found to have bacterial infection, while no obvious change was found in the control group.ConclusionsSubcutaneous injection of RAMP-O in the area of supramammary lymph node had therapeutic value in the treatment of bovine subclinical mastitis by reducing SCC, NAGase and IMIs in milk. Considering both the therapeutic effect and the cost of RAMP-O, 32 mg per dose was found most suitable to reduce milk SCC and NAGase. Therefore, RAMP-O deserves further study for its use in treatment of bovine mastitis.

Different chronological patterns of appearance of blood derived milk components during mastitis indicate different mechanisms of transfer from blood into milk.

This study aimed to describe chronological patterns of changes of various candidate blood components in milk during the acute phase of a mammary immune response in detail. Eight dairy cows were challenged with Escherichia coli lipopolysaccharide in one udder quarter. Milk from challenged and control quarters and blood samples were taken before, and 1 and 2 h after challenge and then every 15 min until 5 h after challenge. The SCC, serum albumin, immunoglobulin (Ig)G1, IgG2, lactate dehydrogenase (LDH), and L-lactate in milk and blood, and α-lactalbumin in blood were analysed. All selected parameters in milk increased in challenged quarters but did not increase in control quarters. Milk IgG1, IgG2, serum albumin, and LDH were already significantly increased at 2 h after challenge whereas a significant increase of SCC was detectable at 2.75 h and L-lactate was increased at 2.25 h after challenge. In blood L-lactate was increased at 3.75 h after challenge, however, other factors in blood did not change significantly within the 5 h of experiment. In conclusion, the increase of blood components in milk during inflammation follows two different patterns: There is a rapid increase for IgG1, IgG2, or LDH, before the increase of SCC, and their concentrations reach a plateau within 3 h. On the other hand, SCC and L-lactate show a slower but consistent increase not reaching a plateau within 5 h after LPS challenge. L-lactate increases to higher concentrations in milk than in blood. This clearly shows that the increase of blood components follows different patterns and is therefore a controlled and compound-specific process and not exclusively an unspecific type of leakage.

Short communication: Species group-specific predictors at the cow and quarter level for intramammary infection with coagulase-negative staphylococci in dairy cattle throughout lactation

Coagulase-negative staphylococci (CNS) are frequently isolated from quarters with subclinical mastitis, teat apices, and the cows’ environment. Virulence, ecology, epidemiological behavior, and effect on udder health vary between different CNS species. Staphylococcus chromogenes, Staph. simulans, and Staph. xylosus are frequently present in milk and have a more substantial effect on quarter milk somatic cell count than other species. Therefore, these species are considered the “more relevant” CNS. As species-specific factors associated with CNS intramammary infection (IMI) have not yet been identified and susceptibility for IMI differs between cows and quarters, this study aimed to identify predictors for CNS IMI at the cow and quarter level (some of them changing over time) with a specific focus on the aforementioned more relevant CNS. Precise data were available from a longitudinal study (3,052 observations from 344 quarters from 86 dairy cows belonging to 3 commercial dairy herds). All CNS were molecularly identified to the species level, and multivariable, multilevel logistic regression models taking into account the longitudinal nature of the data, were fit to study the likelihood of infection. Staphylococcus chromogenes, Staph. xylosus, and Staph. cohnii were the most frequently isolated species from CNS IMI in older cows, whereas Staph. chromogenes, Staph. xylosus, and Staph. simulans were the main species found in IMI in heifers. Quarters from heifers (as opposed to multiparous cows), from heifers and multiparous cows in third or fourth month in lactation (as opposed to early lactation, <60 d in milk), and with an increasing quarter milk SCC were more likely to be infected with the more relevant CNS species. Quarter milk SCC was identified as the sole statistically significant predictor for IMI with other CNS species, although the size of the effect was lower [odds ratio of 1.6 (1.4–1.9) vs. 2.1 (1.8–2.5)] than the effect for IMI with the more relevant CNS. As a strong herd effect was present, studying herd-level predictors is warranted.

THE FREQUENCY OF DISTRIBUTION OF SOMATIC CELL COUNT IN DAIRY EWE’S MILK

The objective of this study was to evaluate the situation in somatic cell counts in one selected herd throughout three-years period The was study performed in the experimental herd of the RIAP Nitra, Slovakia, between 2010 and 2013. Genotypes of purebred Tsigai (TS), Improved Valachian (IV) and Lacaune (LC) and their crossbred Tsigai× Lacaune (TS×LC) and Improved Valachian × Lacaune (IV×LC) ewes on their 1-3 lactation were investigated. SCC of milk was determined in 2632 milk samples collected from lactating dairy ewes. On the basis of SCC the dairy ewes were divided into the five groups: G1= SCC 106 cells.ml-1 to study the frequency of distribution of health problems of mammary gland in selected group of ewes throughout experimental period. In total the percentage of samples in first three groups was 78 %. The ewes of TS and IV had higher percentage of samples in G1 and lower in G5 as compared with L, TSxLC and IVxLC. In conclusion, the high percentage of ewes in a groups under 600×103 cells.ml-1 could indicate possible legislative limit for SCC related to good udder health in a future legislative.

Dairy Herd-Level Prevalence of Johne's disease and BVD in the Intermountain West of the U.S.A. and Farm Management Practices and Characteristics for Test-Positive Herds

Herd-level prevalence of Mycobacterium avium subsp. paratuberculosis (MAP), causative agent of Johne’s disease (JD) and Bovine Viral Diarrhea (BVD) virus were estimated on dairy farms in Utah. Duplicate milks were collected at 3-4 day intervals on 5 dates from each bulk tank on participating farms. Samples were tested at separate laboratories for BVD (real-time, RT-PCR) and for JD/MAP (ELISA and qPCR). 151/209 (72%) eligible dairy farms participated. Farms detected positive were: 58 JD (38%) and 14 BVD (9%); 5 farms had both diseases. Follow up visited farms’ (n=22) means, medians: 778,420 milking cows; 20,052 lbs, 20,311 lbs 305d milk; 175,545/ml, 178,000/ml bulk milk SCC; stalls visibly soiled in rear one-third 37%, 32%, range 5% to 90%. Seventeen of 21 (81%) farms with JD had observed adult cows becoming thin while retaining appetite, 52% had seen adult cows contract diarrhea and subsequently die. Both BVD-positive farms had observed abortions. Free stalls housed milking cows on 91% of farms; dry lots housed dry cows on 55%. Nine farms (41%) had purchased animals within the past year: 27% pregnant heifers, 18% bulls, 9% calves, 14% cows; 9% had purchased only bulls. Whenever animals were last purchased, 14 farms (64%) had performed no disease testing or segregation; 8 farms (36%) utilized at least one biosecurity practice for replacements. Most common were 9-way vaccine including BVD on arrival (27%), 14% segregated replacements for any time, 11% tested for any diseases (none for JD). Fourteen (67%) farms with JD would identify known positive cows; none would segregate positives. Most producers (57%) allowed known JDpositive cows to calve again, farms with BVD were equivocal. No producers would have a separate calving area for JD or BVD-positive cows. Six farms (27%) fed calves only individual cow colostrum and pasteurized milk. All 22 farms vaccinated against BVD.

Prevalence of bacterial genotypes and outcome of bovine clinical mastitis due to Streptococcus dysgalactiae and Streptococcus uberis.

BackgroundStreptococcus dysgalactiae and Streptococcus uberis are common causes of clinical mastitis (CM) in dairy cows. In the present study genotype variation of S. dysgalactiae and S. uberis was investigated, as well as the influence of bacterial species, or genotype within species, on the outcome of veterinary-treated CM (VTCM). Isolates of S. dysgalactiae (n = 132) and S. uberis (n = 97) were genotyped using pulsed-field gel electrophoresis. Identical banding patterns were called pulsotypes. Outcome measurements used were cow composite SCC, milk yield, additional registered VTCMs and culling rate during a four-month follow-up period.ResultsIn total, 71 S. dysgalactiae pulsotypes were identified. Nineteen of the pulsotypes were isolated from more than one herd; the remaining pulsotypes were only found once each in the material. All S. uberis isolates were of different pulsotypes. During the follow-up period, the SCC of S. dysgalactiae-cows was significantly lower than the SCC of S. uberis-cows (P <0.05). Median SCC of S. dysgalactiae-cows was 71 500 cells/ml and of S. uberis-cows 108 000 cells/ml. No other differences in outcome parameters could be identified between species or genotypes.ConclusionsIdentical S. dysgalactiae genotypes were isolated from more than one herd, suggesting some spread of this pathogen between Swedish dairy herds. The genetic variation among S. uberis isolates was substantial, and we found no evidence of spread of this pathogen between herds. The milk SCC was lower during the follow-up period if S. dysgalactiae rather than S. uberis was isolated from the case, indicating differences in treatment response between bacterial species.Electronic supplementary materialThe online version of this article (doi:10.1186/s13028-014-0080-0) contains supplementary material, which is available to authorized users.

Staphylococcus aureus intramammary infection affects milk yield and SCC of dairy cows.

Staphylococcus aureus (S. aureus) is the most prevalent infectious microorganism affecting dairy cattle worldwide, and its pathogenic characteristics facilitate its spread in dairy herds. S. aureus intramammary infections (IMI) are mainly subclinical, and associated losses can exceed average herd losses where the pathogen is not isolated. However, the extent it affects milk composition at udder and quarter levels is still unknown, and cow composite milk losses may be underestimated due to the dilution effect. The aim of this study was to investigate the effects of S. aureus subclinical mastitis on mammary quarter milk yield and composition. In order to determine the effects of the pathogen on milk yield and composition at quarter level, a pairwise comparison of infected and non-infected mammary quarters (n = 28) from two dairy herds was carried out. Quarters were individually milked, and milk production and composition were assessed. S. aureus has increased somatic cell counts at quarter level; however, no effect of S. aureus IMI on milk lactose, fat, and protein contents was observed. Fat yield from infected quarters decreased, but losses due to the infection caused by S. aureus were not associated with quarter positioning in cows.

착유시스템 및 계절이 홀스타인 착유우의 유성분에 미치는 영향

This study was conducted to examine the effect of different types of milking instrument and season on milk composition (fat, protein, non-fat milk solids, milk urea nitrogen and somatic cell count) on Holstein-Friesian lactating cows. Raw milk samples were collected from 20 automatic milking system (AMS) installed dairy farms and 85 conventional milking system (CMS) installed dairy farms. Milk fat, protein, NFMS and MUN contents did not changed between AMS and CMS and different seasons. On the other hand, the average SCC in AMS was <TEX>$239{\times}10^3cells/mL$</TEX> which was lower than in CMS (<TEX>$373{\times}10^3cells/mL$</TEX>, (p<0.05). In conclusion, present results indicated that SCC in milk might be influenced by AMS. However, this area needed more study to confirm the reason of reducing SCC content from AMS.

Formation of NET, phagocytic activity, surface architecture, apoptosis and expression of toll like receptors 2 and 4 (TLR2 and TLR4) in neutrophils of mastitic cows.

Neutrophils employ both oxidative and non oxidative mechanisms to destroy pathogens. Function of neutrophils coming in milk during mammary invasion is not clearly understood in dairy animals. Therefore, the present study was designed in 36 Sahiwal cows to see the changes occurring in the neutrophil activity of cows suffering from subclinical (SCM) and clinical mastitis (CM). Cows were divided into three groups as healthy (n = 12), SCM (n = 12) and CM (n = 12) groups on the basis of CMT scoring, gross morphological changes in milk, bacteriological examination of milk and by counting milk SCC. Significantly (P < 0.05) higher milk SCC, neutrophil percent and significantly (P < 0.05) lower viability of both blood and milk neutrophils were observed in CM group of cows as compared to SCM and control group of cows. Phagocytic activity (PA) was significantly (P < 0.05) higher in milk neutrophils of SCM and CM cows as compared to control cows. Toll like receptors 2 and 4 in blood and milk neutrophils were found to be significantly (P < 0.05) higher, whereas, apoptosis in terms of altered mitochondrial transmembrane potential, Caspase 3 and 7 activities were found to be significantly (P < 0.05) lower in CM cows. Alterations in surface architecture of neutrophils in terms of formation of pseudopods was observed by scanning electron microscope (SEM) and found to be higher in CM cows. Blood neutrophils were found to be spherical as compared to milk neutrophils. Formation of neutrophil extracellular trap (NETs) were found milk neutrophils of CM cows, whereas, SCM and healthy cows did not exhibit NET formation. The study indicated a positive correlation between lower neutrophil apoptosis and higher expression of TLR2 and TLR4 with the formation of NETs and change in surface architecture. Formation of NET like structures seemed to be an effective mode of defense employed by neutrophils of cows suffering from clinical mastitis.

Relationship between somatic cell count and udder health in Damascus goats.

ABSTRACTThis study aimed to investigate the relationship between SCC, milk yield and composition in Damascus goats in Egypt, as well as, to evaluate the validity of using SCC for monitoring early udder infection.A total of 204 milk samples were collected at mid lactation (June 2013) from both halves of udders of 51 Damascus goats. Milk bacteriological examination was performed using all half milk samples of morning milking, while percentage of fat (F), total protein (P), lactose (L), total solid (TS), solid not fat (SNF) and SCC were estimated in all collected samples of morning and evening milking. In the present study, 68.3% of the udder half were bacteriologically free of mastitis (healthy), while 31.7% was infected. Seven types of microorganisms were isolated from the milk of Damascus goats. Intermammary infection (IMI) was categorized as 1- healthy (68.3%), 2- infected with single major pathogen (10.9%), 3- infected with single minor pathogen (7.9%), 4- infected with double major pathogens (2.97%), 5- infected with double minor pathogens (0.99%) and 6- infected with one major pathogen plus one minor pathogen (8.9%).Milk yield was significantly higher in healthy than in infected goats, while insignificant changes were recorded on the percentage of protein, fat, lactose, total solid, solid not fat and SCC. Meanwhile, a negative insignificant correlation was detected between milk yield and SCC. Results showed that the highest milk yield was recorded in the 5th parity, while the lowest observed in the 1st parity. Moreover, percentages of protein, total solids and solids not fat were significantly higher for Damascus goats in the 2nd parity than other parities, with a parallel, but insignificant, increase in fat content. High SCC scores combine with alteration in milk composition, where protein and solid not fat percentage increased and lactose percentage decreased with the increase of SCC in milk (log SCC ranged from 6.51 to 7.25). Although, a threshold of 1,000,000 cells /ml showed the best indication for IMI, this study showed that high SCC does not always reflect mastitis probably due to the apocrine secretion in goats. Animals with elevated SCC should declare positive mastitis after successful isolation and identification of bacteria causing mastitis. Nevertheless, in case of suspected udder infection, SCC in goat' milk could be suitable as early and cost-effective screening parameter till initiate further analysis.

Escherichia coli J5: imunização de fêmeas bovinas leiteiras contra mastites causadas por Escherichia coli

Neste trabalho, revisamos os principais aspectos ligados à mastite causada por coliformes, mais especificamente a Escherichia coli, com enfoque principal nos fatores de risco associados ao animal, bem como na utilização da vacina Escherichia coli J5 na imunização de fêmeas bovinas leiteiras. Os coliformes estão amplamente distribuídos no ambiente, assumindo especial importância em sistemas de criação em que a busca pela qualidade do leite mantém a contagem de células somáticas (CCS) em níveis inferiores a 150000 células ml-1. Nesse contexto, o período seco representa um momento de extrema importância na definição da ausência ou não de um quadro de mastite, decorrente da ação de patógenos ambientais no pós-parto imediato. A terapia para vacas secas frente a infecções por germes ambientais perde eficácia, sendo necessária a associação a outros métodos, como, por exemplo, a vacinação com Escherichia coli J5. A cepa J5, por possuir um antígeno nuclear relativamente exposto, é capaz de estimular a produção de imunoglobulinas que apresentam reação cruzada com antígenos nucleares de outras bactérias, resultando em uma imunidade contra uma variedade de gêneros e cepas bacterianas. Estudos demonstram que a vacinação com Escherichia coli J5 é capaz de reduzir a ocorrência, intensidade e duração de casos clínicos de mastite por Escherichia coli, sendo também observada uma maior produção de leite nos animais vacinados. Entretanto, ainda é controverso seu papel na redução da CCS.

Development of protocols to evaluate in-line mastitis-detection systems

This paper proposes and discusses a methodology to evaluate the performance of automated mastitis-detection systems with respect to their practical value on farm. The protocols are based on 3 on-farm requirements: (1) to detect cows with clinical mastitis promptly and accurately to enable timely and appropriate treatment, (2) to identify cows with high somatic cell count to manage bulk milk SCC levels, and (3) to report the mastitis infection status of cows at the end of lactation to support decisions on individual cow dry-cow therapy. Separate protocols for each requirement are proposed and discussed, including gold standards, evaluation tests, performance indicators, and performance targets. Aspects that require further research or clarification are identified. Actual field data are used as examples. Further debate is invited, the aim being to achieve international agreement on how to evaluate and report performance of different mastitis-detection technologies. Better performance information will allow farmers to compare different mastitis-detection systems sensibly and fairly before investing. Also, the use of evaluation protocols should help technology providers to refine current, or develop new, automated mastitis-detection systems. Such developments are likely to accelerate adoption of these systems, potentially leading to improved animal health, milk quality, and labor productivity.

Quality of refrigerated raw milk obtained by milking machine and manual

The objective of this paper to evaluate the centesimal composition, SCC and TBC, of the cooled raw milk obtained from milking manual and mechanic in Sudoeste Goiano. Samples were collected from cooled raw milk at 87 dairy farms that performed manual milking and 55 properties with mechanic milking in the period December 2010 to February 2011. Electronics Analysis were performed at the Laboratorio de Qualidade do Leite do Centro de Pesquisa em Alimentos da Escola de Veterinaria e Zootecnia da Universidade Federal de Goias. The experimental design was completely randomized with two treatments: one treatment of milk obtained by manual milking and the two treatment of milk obtained by mechanic milking. Statistical analysis was performed using the software SISVAR-UFLA, was used to test FISCHER 5% significance for the analysis of averages. In physico-chemical composition, lactose was the only component that varied according to the type of milking, and in the milk obtained by manual milking its concentration was higher than that obtained by milking machine. High TBC cooled raw milk showed poor preservation of milk production at source. The SCC of milk milked manually if framed within the ceiling set by the legislation, however mechanically milked in milk SCC was highest. These results indicate the need for care hygienical-sanitary more effective, in order to prevent the incidence of mastitis in dairy herds in the region.

Peripartum infection with Streptococcus uberis but not coagulase-negative staphylococci reduced milk production in primiparous cows

The effect of an intramammary infection (IMI) at calving on the milk yield of heifers during their first 200 d in milk (DIM) was estimated by comparing monozygotic twins, where one member had a naturally occurring IMI detected at the first milking after calving and the other twin did not. Data collected weekly over a full lactation for 29 twin pairs were used to estimate the effects of a peri-calving Streptococcus uberis IMI on milk yield and composition. Data for 19 twin pairs were used to estimate the effects of pericalving coagulase-negative staphylococci (CNS) IMI. A heifer with a Strep. uberis IMI produced 200kg (7%) less milk during the first 200 d of lactation compared with her uninfected twin, with significant differences evident throughout the 200-d period. Similar milk losses were recorded for heifers that developed CM or remained subclinical. An elevated milk SCC for infected heifers was only apparent for the first month (d 2–30), although SCC tended to remain high during the second (d 31–60) and third (d 61–90) months. Milk protein concentrations were greater in the Strep. uberis-infected twin over the 200-d period, whereas fat and lactose concentrations showed little change. An IMI caused by Strep. uberis was associated with a lower milk yield, whereas an IMI by CNS was not, despite CNS-infected twins having a higher SCC than their uninfected twin for the first 30 d of lactation.

Influence of somatic cell count and total bacterial counts of raw milk in cheese yield using small-scale methodology

The objectives of this study were to evaluate the influence of SCC and TBC of raw milk in cheese yield, using a reduced scale method, and to evaluate theoretical prediction of cheese yield. 270 samples of raw milk were split into three SCC levels (below 200,000; 200,000-750,000; above 750,000 SC/mL) and three TBC levels (below 100,000; 100,000-750,000; above 750,000 CFU/mL). Raw milk samples were submitted to compositional analysis (fat, protein, lactose, total solids and SNF content), SCC, TBC, freezing point and pH. The production of the small-scale cheese was conducted according to the method developed at Cornell University (Melilli et al., 2002). Cheese whey samples were submitted to compositional analysis (fat, total protein, true protein, lactose, total solids and SNF content) and SCC. The increase in the SCC of raw milk resulted in increased protein loss in cheese whey. High SCC (above 200,000 SC/mL) in milk samples was correlated to reduced dry matter yield. There was no effect of TBC in cheese yield in the experimental conditions used. There was a high correlation between the theoretical yield values and the yield values predicted by the small-scale method, indicating that this method is appropriate for cheese yield prediction.