Waste Milk Research Articles

Evaluation of four commercial test for detection of ceftiofur in waste milk tank samples

Antimicrobial resistance is a great concern for human and animal health. Over the years increasing concern has been established over drug resistance to 3rd generation cephalosporins, including ceftiofur. Drug use in lactating animals commonly results in drug residues in the milk that in the U.S. is frequently used as a feed source for pre-weaned calves. This milk is commonly called waste milk, and also includes milk from cows with high somatic cell counts (SCC) and fresh cows. Feeding waste milk to preweaned calves has been shown to potentially result in a higher selection of cephalosporin resistant bacteria. The objective on this study was to evaluate factors affecting the specificity, specificity and predictive values of 4 commercially available tests (labeled for detecting beta-lactam drug residues in comingled milk) when testing waste milk (WM) tank samples.

Effects of feeding pasteurized waste milk to dairy calves on phenotypes and genotypes of antimicrobial resistance in fecal Escherichia coli isolates before and after weaning

The aim of this study was to evaluate the effects of feeding pasteurized waste milk (pWM) to calves on antimicrobial resistance of fecal Escherichia coli at both phenotypic and genotypic levels. Fifty-two Holstein female calves (3 ± 1.3 d of age) were fed 1 of the 2 different types of milk: milk replacer (MR) without antimicrobials or pWM with β-lactam residues until weaning at 49 d of age. Fecal swabs of all calves were obtained on d 0, 35, and 56 of the study and 3 E. coli isolates per sample were studied. Phenotypic resistance was tested by the disk diffusion method against a panel of 12 antimicrobials. A total of 13 resistance genes consisting of β-lactam, sulfonamide, tetracycline, and aminoglycoside families were examined by PCR. Feeding pWM to calves increased the presence of phenotypic resistance to ampicillin, cephalotin, ceftiofur, and florfenicol in fecal E. coli compared with MR-fed calves. However, the presence of resistance to sulfonamides, tetracyclines, and aminoglycosides was common in dairy calves independent of their milk-feeding source, suggesting other factors apart from the feeding source are involved in the emergence of antimicrobial resistance.

Use of whole-genome sequencing and evaluation of the apparent sensitivity and specificity of antemortem tuberculosis tests in the investigation of an unusual outbreak of Mycobacterium bovis infection in a Michigan dairy herd.

OBJECTIVE To describe use of whole-genome sequencing (WGS) and evaluate the apparent sensitivity and specificity of antemortem tuberculosis tests during investigation of an unusual outbreak of Mycobacterium bovis infection in a Michigan dairy herd. DESIGN Bovine tuberculosis (bTB) outbreak investigation. ANIMALS Cattle, cats, dog, and wildlife. PROCEDURES All cattle in the index dairy herd were screened for bTB with the caudal fold test (CFT), and cattle ≥ 6 months old were also screened with a γ-interferon (γIFN) assay. The index herd was depopulated along with all barn cats and a dog that were fed unpasteurized milk from the herd. Select isolates from M bovis-infected animals from the index herd and other bTB-affected herds underwent WGS. Wildlife around all affected premises was examined for bTB. RESULTS No evidence of bTB was found in any wildlife examined. Within the index herd, 53 of 451 (11.8%) cattle and 12 of 21 (57%) cats were confirmed to be infected with M bovis. Prevalence of M bovis-infected cattle was greatest among 4- to 7-month-old calves (16/49 [33%]) followed by adult cows (36/203 [18%]). The apparent sensitivity and specificity were 86.8% and 92.7% for the CFT and 80.4% and 96.5% for the γIFN assay when results for those tests were interpreted separately and 96.1% and 91.7% when results were interpreted in parallel. Results of WGS revealed that M bovis-infected barn cats and cattle from the index herd and 6 beef operations were infected with the same strain of M bovis. Of the 6 bTB-affected beef operations identified during the investigation, 3 were linked to the index herd only by WGS results; there was no record of movement of livestock or waste milk from the index herd to those operations. CONCLUSIONS AND CLINICAL RELEVANCE Whole-genome sequencing enhanced the epidemiological investigation and should be used in all disease investigations. Performing the CFT and γIFN assay in parallel improved the antemortem ability to detect M bovis-infected animals. Contact with M bovis-infected cattle and contaminated milk were major risk factors for transmission of bTB within and between herds of this outbreak.

Solids and Plant Nutrient Content, and Settling Characteristics of Milking Centre Wastewater on a Grazing Dairy

Large milking centre wastewater samples were collected from a storage pit on a grazing dairy farm in South Carolina on two different days. The samples were analysed to determine the concentrations of the following constituents: TS, VS, TKN, TAN (NH4+-N, + NH3-N), Org-N, NO3-N, total-P, total-K, Ca, Mg, S, Zn, Cu, Mn, and Na. The large amount of waste milk present on the second day (TS =7165 mg/L) resulted in significantly reduced solids and plant nutrient concentrations as compared to the sample collected on the first day (TS = 17,024 mg/L). Gravity settling and thickening experiments were performed for the two milking centre waste samples. Gravity settling was effective at removing a fraction of all of the defined constituents. The greatest mass removals were for TS, VS, Org-N, P2O5, S, Cu, and Zn. The mass removal efficiency for the soluble constituents, TAN, K2O, and Na, was a consequence of the liquid contained in the layer of settled material and not a result of a change in concentration. The data provided in this study can be used for design of primary treatment for milking centre wastewater, development of nutrient management plans, and to provide loading data for secondary treatment of the supernatant or settled solids.

Effects of feeding untreated, pasteurized and acidified waste milk and bunk tank milk on the performance, serum metabolic profiles, immunity, and intestinal development in Holstein calves

BackgroundThe present experiment was performed to assess the effects of different sources of milk on the growth performance, serum metabolism, immunity, and intestinal development of calves. Eighty-four Holstein male neonatal calves were assigned to one of the following four treatment groups: those that received bunk tank milk (BTM), untreated waste milk (UWM), pasteurized waste milk (PWM), and acidified waste milk (AWM) for 21 d.ResultsCalves in the BTM and AWM groups consumed more starter (P < 0.05) than those in the UWM group. Average daily gain in the UWM group was the highest (P < 0.05). Calves exhibited the highest (P < 0.05) serum total protein, albumin, total cholesterol, high density lipoprotein, triglycerides, growth hormone, immunoglobulin (Ig) A and IgM concentrations in the UWM group, highest malondialdehyde and tumor necrosis factor-α in the PWM group (P < 0.05), and highest glutathione peroxidase and IgG in the BTM group (P < 0.05). The jejunum and ileum of the calves in all treatments presented a slight inflammatory response. The jejunal inflammation scores were higher (P < 0.05) in the UWM and AWM groups than the BTM group; the ileal inflammation scores increased more (P < 0.05) in the AWM group than the BTM group. Jejunal immunohistochemical scores (IHS) were higher (P < 0.05) in the PWM and AWM groups than the BTM group. Compared to the other three groups, calves feeding on BTM had lower (P < 0.05) ileal IHS. Jejunal interleukin(IL)-1β, IL-8, and IL-10 mRNA expression in the UWM group was the highest (P < 0.05). Calves fed AWM increased (P < 0.05) mRNA expression of IL-8 and toll like receptor 4 (TLR-4) in the jejunum and IL-8, IL-1β, IL-6, IL-8, and IL-10 in the mesenteric lymph nodes.ConclusionsOverall, bunk tank milk is the best choice for calf raising compared to waste milk. The efficiency of feeding pasteurized and acidified waste milk are comparable, and the acidification of waste milk is an acceptable labor-saving and diarrhea-preventing feed for young calves.

CattleReview

Introduction: This edition of Cattle Review considers papers on farmer and veterinary attitudes to disease prevention and medicine prescribing respectively, as well as the antimicrobial resistance risks of feeding waste milk to calves.

Presence of Mycobacterium avium subs. paratuberculosis DNA in milk used to feed calves in Portugal.

This Technical Research communication describes results of a study aimed at detecting the presence of Map in milk fed to calves, and identifying possible risk factors for that presence. A questionnaire was performed on 37 dairy farms and waste milk samples were collected on 3 occasions separated by a minimum of 1 week. For farms not feeding waste milk, bulk tank milk samples were collected instead. A real time PCR for the detection of the IS900 sequence was performed for the detection of Map. A majority of farms (89·2%) fed waste milk, with only one pasteurising the milk before feeding it to calves. Results of the PCR showed that 51·5% of the farms that were feeding waste milk had a positive result for Map on that milk. None of the studied risk factors were significantly associated with the presence of Map in milk samples, possibly due to the small number of farms entering the study. However, the prevalence of positive samples for Map on PCR was 3·5 times higher for farms that bought in animals from a single origin and 1·9 times higher for farms that bought from multiple farms, when compared with closed farms. Having a calving area for multiple cows also increased the risk of a positive Map result by 1·5 when compared with single pens. The risk of having a positive Map result on waste milk was 1·6 times higher for farms feeding that milk to male calves and 1·4 for farms feeding to both male and female calves, when compared with farms not feeding waste milk. This study highlights paratuberculosis as one of the potential risks of feeding waste milk to calves, and the need for mitigation strategies to be in place to avoid unnecessary disease transmission.

Processed milk waste recycling via thermal pretreatment and lactic acid bacteria fermentation

Processed milk waste (MW) presents a serious problem within the dairy industries due to its high polluting load. Its chemical oxygen demand (COD) can reach values as high as 80,000mg O2L-1. This study proposes to reduce the organic load of those wastes using thermal coagulation and recover residual valuable components via fermentation. Thermal process results showed that the COD removal rates exceeded 40% when samples were treated at temperature above 60°C to reach 72% at 100°C. Clarified supernatants resulting from thermal treatment of the samples at the temperatures of 60 (MW60), 80 (MW80), and 100°C (MW100) were fermented using lactic acid bacteria strains without pH control. Lactic strains recorded important final cell yields (5-7gL-1). Growth mediums prepared using the thermally treated MW produced 73% of the bacterial biomass recorded with a conventional culture medium. At the end of fermentation, mediums were found exhausted from several valuable components. Industrial scale implementation of the proposed process for the recycling of industrial MWs is described and discussed.

Nanofibrillation of deep eutectic solvent-treated paper and board cellulose pulps

In this work, several cellulose board grades, including waste board, fluting, and waste milk container board, were pretreated with green choline chloride-urea deep eutectic solvent (DES) and nanofibrillated using a Masuko grinder. DES-treated bleached chemical birch pulp, NaOH-swollen waste board, and bleached chemical birch pulp were used as reference materials. The properties of the nanofibrils after disc grinding were compared with those obtained through microfluidization. Overall, the choline chloride-urea DES pretreatment significantly enhanced the nanofibrillation of the board pulps in both nanofibrillation methods—as compared with NaOH-treated pulps—and resulted in fine and long individual nanofibrils and some larger nanofibril bunches, as determined by field emission scanning electron microscopy and transmission electron microscopy. The nanofibril suspensions obtained from the DES pretreatment had a viscous, gel-like appearance with shear thinning behavior. The nanofibrils maintained their initial crystalline structure with a crystallinity index of 61%–47%. Improved board handsheet properties also showed that DES-treated and Masuko-ground waste board and paper nanocellulose can potentially enhance the strength of the board. Consequently, the DES chemical pretreatment appears to be a promising route to obtain cellulose nanofibrils from waste board and paper.

Evaluation of different agroindustrial waste on the effect of different carcass characteristics and physiological and biochemical parameters in broilers chicken.

Aim:This study was conducted to evaluate the physiological and biochemical effect in chickens of the Ross breed of a food enriched with agroindustrial waste.Materials and Methods:The food is one of the main components of the total cost for the production of chickens. Rations should be formulated to provide the correct balance of energy, protein, amino acids, minerals, vitamins and essential fatty acids, to allow optimal growth and performance. This study was intended to evaluate a natural feed for chicken, made from corn, yucca meal, eggshells, orange peel, soybean meal, salt and garlic, enriched with agroindustrial waste (molasses, milk whey and ferment of coffee). The weight gain was evaluated in broilers using a diet enriched with different agroindustrial wastes, with respect to a control food of the same composition but not containing residue. To develop the experiment 120 male Ross 308 chicks were used, these were evaluated for 6 weeks. Physicochemical test for the food and the agroindustrial waste were performed; moisture was determined; organic carbon, organic material and the ash, to characterize the agroindustrial wastes, the reducing sugars content using a spectrophotometer at 540 nm and proteins through the Kjeldahl method was evaluated. During the experiment, the weight gain of chickens and feed conversion was evaluated; the end of the experiment the weight of eviscerated channel relative weight breast, thighs, pancreas, and abdominal fat was determined, besides including blood chemistries as determination of cholesterol, triglycerides, and glucose. Finally, the microbiological analyzes to detect the presence of Escherichia coli in the cecum was determinate. Data were analyzed by InfoStat statistical program using the generalized linear model procedure. The statistical comparison was made by Tukey test at the 95% probability level.Results:After the evaluation, fed chickens with the treatments food + milk whey (FMW) and food + ferment of coffee (FFC) demonstrated increased from 1949 to 1892 g, respectively, to the 42 days of evaluation, showing the best treatment for weight gain. However, the FFC treatment showed the best feed conversion reaching values of 1.79 related to levels of blood glucose (249 mg/dl). Even so the eviscerated channel yields were higher for the treatment FFC reaching 1810.1 g unlike the treatment FMW which it reached a weight of 1718.2 g with increased formation of abdominal fat (7.4 g) unlike other treatments. From the results, it is concluded that food enriched with coffee ferment allows an increase in weight, better feed conversion in addition to high production of lean meat.Conclusion:It was shown that the best treatment was the food enriched with the ferment of coffee, due to increased intake and weight gain at the end of 42 days of the experiment.

Thawing Human Milk for Hospitalized Infants: Use of a Laboratory Bead Bath May Be an Effective Method for Large Quantities

Human milk for hospitalized infants in the neonatal intensive care unit (NICU) is often stored frozen and must be thawed before use. Frozen milk must be properly thawed, ensuring that no ice crystals remain, while minimizing overheating, to reduce risk of microbial growth and prevent nutrient loss. 1 Robbins S.T. Meyers R. Infant Feedings: Guidelines for Preparation of Human Milk and Formula in Health Care Facilities. 2nd ed. American Dietetic Association, Chicago, IL2011 Google Scholar , 2 Jones F. Best Practice for Expressing, Storing and Handling Human Milk in Hospitals, Homes, and Child Care Settings. 3rd ed. Human Milk Banking Association of North America, Fort Worth, TX2011 Google Scholar Although frozen milk may be thawed in the refrigerator over 8 to 12 hours, such a process may not be as effective for thawing large volumes for multiple patients or may result in human milk waste if orders change frequently. Therefore, some facilities may require a more rapid thawing method. 1 Robbins S.T. Meyers R. Infant Feedings: Guidelines for Preparation of Human Milk and Formula in Health Care Facilities. 2nd ed. American Dietetic Association, Chicago, IL2011 Google Scholar Such methods include holding the bottle under lukewarm running water or placing it in a container of warm water with the water level below the lid to prevent contamination. 1 Robbins S.T. Meyers R. Infant Feedings: Guidelines for Preparation of Human Milk and Formula in Health Care Facilities. 2nd ed. American Dietetic Association, Chicago, IL2011 Google Scholar However, research has shown that hospital tap water is one potential source of pathogenic organisms in the patient care environment and can cause nosocomial infections. 3 Cervia J.S. Ortolano G.A. Canonica F.P. Hospital tap water: A reservoir of risk for health care-associated infection. Infect Dis Clin Pract. 2008; 16: 349-353 Crossref Scopus (24) Google Scholar , 4 Anaissie E.J. Penzak S.R. Dignani M.C. The hospital water supply as a source of nosocomial infections: A plea for action. Arch Intern Med. 2002; 162: 1483-1492 Crossref PubMed Scopus (297) Google Scholar Commercial bottle warmers that use tap water also have been reportedly linked with Pseudomonas aeruginosa infections in one NICU. 5 Molina-Cabrillana J. Artiles-Campelo F. Dorta-Hung E. et al. Outbreak of Pseudomonas aeruginosa infections in a neonatal care unit associated with feeding bottles heaters. Am J Infect Cont. 2013; 41: e7-e9 Abstract Full Text Full Text PDF PubMed Scopus (7) Google Scholar Such data have consequently led some experts to recommend that hospitalized patients at high risk for infection avoid all exposure to hospital tap water. 4 Anaissie E.J. Penzak S.R. Dignani M.C. The hospital water supply as a source of nosocomial infections: A plea for action. Arch Intern Med. 2002; 162: 1483-1492 Crossref PubMed Scopus (297) Google Scholar

Influence of dairy by-product waste milk on the microbiomes of different gastrointestinal tract components in pre-weaned dairy calves

The community structure of colonised bacteria in the gastrointestinal tracts (GITs) of pre-weaned calves is affected by extrinsic factors, such as the genetics and diet of the calves; however, the dietary impact is not fully understood and warrants further research. Our study revealed that a total of 6, 5, 2 and 10 bacterial genera showed biologically significant differences in the GITs of pre-weaned calves fed four waste-milk diets: acidified waste milk, pasteurised waste milk, untreated bulk milk, and untreated waste milk, respectively. Specifically, generic biomarkers were observed in the rumen (e.g., Bifidobacterium, Parabacteroides, Fibrobacter, Clostridium, etc.), caecum (e.g., Faecalibacterium, Oxalobacter, Odoribacter, etc.) and colon (e.g., Megamonas, Comamonas, Stenotrophomonas, etc.) but not in the faeces. In addition, the predicted metabolic pathways showed that the expression of genes related to metabolic diseases was increased in the calves fed untreated waste milk, which indicated that untreated waste milk is not a suitable liquid diet for pre-weaned calves. This is the first study to demonstrate how different types of waste milk fed to pre-weaned calves affect the community structure of colonised bacteria, and the results may provide insights for the intentional adjustment of diets and gastrointestinal bacterial communities.

The effect of milk-feeding method and hay provision on the development of feeding behavior and non-nutritive oral behavior of dairy calves

We investigated the interactive effects of common feeding management factors on the development of feeding and non-nutritive oral behaviors in preweaned calves through the weaning transition. Calves were randomly assigned to 1 of 3 treatments that differed by milk-feeding method (teat or bucket) and ad libitum access to chopped timothy hay: control, milk provided by bucket and no access to hay (CON; n = 10); milk provided by bucket and access to hay (H; n = 10); milk provided via a teat and access to hay (TH; n = 10). Calves had ad libitum access to concentrate and water, and were fed 6 L/d of pasteurized waste milk, divided into 2 meals. All calves were weaned by removing the second milk meal for 9 ± 2 d, beginning at 36 d of age. Daily concentrate and hay intake were recorded, and calves were weighed weekly to measure growth. We recorded the behavior of all calves using 2 s time-lapse video during time periods that encompassed milk meals, from 6000 h to 1000 h and 1600 h to 2000 h, on 2 consecutive focal days in wk 2 and 4. We continuously monitored lying time and activity using electronic data loggers. During the preweaning period, hay selection by H and TH calves was subject to a treatment × week interaction, with TH calves increasing hay intake to a greater extent over time. Similarly, we observed a tendency for a treatment × week interaction for hay dry matter intake. Before weaning, concentrate intake was subject to a treatment × week interaction, increasing to a greater extent over time for H and TH calves, but was greater overall for CON calves. As predicted, milk-feeding method and hay provision influenced the proportion of time devoted to feeding and non-nutritive behaviors. The CON calves spent the greatest amount of time performing non-nutritive sucking directed at the pen, TH calves the least, and H calves intermediate amounts. Considering the time TH calves sucked on their teat when milk was not present in addition to the time they spent sucking on pen fixtures, the total amount of time spent performing sucking behavior was similar between treatments. Although intake was similar across the weaning transition, CON calves had greater average daily gain than H calves, and TH calves were intermediate. Providing access to hay and milk via a teat during the milk-feeding stage decreased non-nutritive oral behaviors and influenced feeding behavior.

Feeding of waste milk to Holstein calves affects antimicrobial resistance of Escherichia coli and Pasteurella multocida isolated from fecal and nasal swabs

The use of milk containing antimicrobial residues in calf feeding programs has been shown to select for resistant fecal Escherichia coli in dairy calves. However, information is scarce about the effects of feeding calves waste milk (WM) on the prevalence of multidrug-resistant bacteria. The objective of this study was to determine the antimicrobial resistance patterns of fecal E. coli and nasal Pasteurella multocida isolates from calves fed either milk replacer (MR) or WM in 8 commercial dairy farms (4 farms per feeding program). Fecal and nasal swabs were collected from 20 ± 5 dairy calves at 42 ± 3.2 d of age, and from 10 of these at approximately 1 yr of age in each study farm to isolate the targeted bacteria. Furthermore, resistance of E. coli isolates from calf-environment and from 5 calves at birth and their dams was also evaluated in each study farm. Resistances were tested against the following antimicrobial agents: amoxicillin-clavulanic acid, ceftiofur, colistin, doxycycline (DO), enrofloxacin (ENR), erythromycin, florfenicol, imipenem, and streptomycin. A greater number of fecal E. coli resistant to ENR, florfenicol, and streptomycin and more multidrug-resistant E. coli phenotypes were isolated in feces of calves fed WM than in those fed MR. However, the prevalence of fecal-resistant E. coli was also influenced by calf age, as it increased from birth to 6 wk of age for ENR and DO and decreased from 6 wk to 1 yr of age for DO regardless of the feeding program. From nasal samples, an increase in the prevalence of colistin-resistant P. multocida was observed in calves fed WM compared with those fed MR. The resistance patterns of E. coli isolates from calves and their dams tended to differ, whereas similar resistance profiles among E. coli isolates from farm environment and calves were observed. The findings of this study suggest that feeding calves WM fosters the presence of resistant bacteria in the lower gut and respiratory tracts of dairy calves.

Nutritional, Economic, and Environmental Costs of Milk Waste in a Classroom School Breakfast Program.

To measure fluid milk waste in a US School Breakfast in the Classroom Program and estimate its nutritional, economic, and environmental effects. Fluid milk waste was directly measured on 60 elementary school classroom days in a medium-sized, urban district. The US Department of Agriculture nutrition database, district cost data, and carbon dioxide equivalent (CO2e) emissions and water footprint estimates for fluid milk were used to calculate the associated nutritional, economic, and environmental costs. Of the total milk offered to School Breakfast Program participants, 45% was wasted. A considerably smaller portion of served milk was wasted (26%). The amount of milk wasted translated into 27% of vitamin D and 41% of calcium required of School Breakfast Program meals. The economic and environmental costs amounted to an estimated $274 782 (16% of the district's total annual School Breakfast Program food expenditures), 644 893 kilograms of CO2e, and 192 260 155 liters of water over the school year in the district. These substantial effects of milk waste undermine the School Breakfast Program's capacity to ensure short- and long-term food security and federal food waste reduction targets. Interventions that reduce waste are urgently needed.

Prevalence of Extended Spectrum Beta Lactamase (ESBL) Producing Escherichia coli and Klebsiella pneumoniae Isolated from Raw Milk Samples in Al Jazirah State, Sudan

Milk play a major role in human sources of nutrition and remain as the most important prominent in the Sudanese diet. Escherichia coli and Klebsiella pneumoniae are humans and animals opportunistic pathogens, responsible for a wide range of infections. The aim of this study was to evaluate the quality of the commercial available milk and to detect ESBL producing E. coli and K. pneumoniae from raw milk samples of cow in Al Jazirah state, Sudan. Seventy fresh row cow milk samples were collected and examined using standard microbiological methods, ESBL detection was performed on all the isolates by Ceftazidime screening test, those shows positive results by screening method were subjected to ESBL confirmatory test using Double-Disk Synergy Test and Molecular base detection using conventional PCR. Out of the 70 collected samples, 58 (82.8%) showed positive isolating result, the highest prevalence of the isolates was K. pneumoniae 36 (62%) followed by E. coli 22 (38%). The most resistance antibiotics against isolates was Ampicillin (98%), ESBL production was detected among 17 out of the 22 isolated E. coli (29.3%) and 26 (44.8%) out of the 36 isolated K. pneumoniae. The ESBL gene encoding the ESBL isolates was CTX-M gene representing 61% fellows by SHV gene (23%) and TEM gene (16%). ESBL-producing bacteria may also be transferred via waste milk to calves, thus further spreading antibiotic resistance in the farm environment.

Quantification of whole ultra high temperature UHT milk waste as a function of packages type and design

The food waste during consumption should be decreased to assure environmental sustainability and food safety. Packages play an important role in the preservation of quality and safety of food, but their design is related with food waste. The Ultra High Temperature (UHT) milk residue remaining inside the packages after consumption is an example of this condition. The purpose of this work was to quantify and analyze the factors influencing the whole UHT milk waste, as a function of its packages. Ten different types of one liter packages were analyzed, and a descriptive study of their characteristics has been developed according to package material, type of opening, and their dimensions. A method for quantification of UHT milk waste in the analyzed packages was developed. The waste was quantified by means of gravimetric analysis and volume conversion under two conditions: WITHOUT and WITH packages stirring after their deflation. A large variation in the wasted volume of milk was observed for the different types of package under both tested conditions. The package stirring process has significantly influenced the waste decrease in five different types of package. It was observed that the package design directly influences the UHT milk waste, mainly due to folding at package bottom, corrugations in its internal wall and kind of opening of the packages. The values of wasted milk ranged from (0.43 ± 0.03) to (7.7 ± 0.4) ml and (0.51 ± 0.04) to (14.7 ± 0.4) ml for the WITH and WITHOUT stirring, respectively. Thus, the choice of packaging showing suitable design for complete emptying of the content may reduce the UHT milk waste contributing to the food safety and environmental protection.

Genetic Characterization of Lactic Acid Bacteria Isolated from Tunisian Milk Waste and their Antimicrobial Activity Against some Bacteria Implicated in Nosocomial Infections.

A total of 94 lactic acid bacteria (LAB) were isolated from Tunisian artisanal (Ricotta cheese's whey) and industrial (bactofugate) milk waste, identified and then screened for their antimicrobial activity against some bacteria implicated on nosocomial infections. Bacterial genera and species identification was performed using molecular tools. The antimicrobial activity was tested against 7 strains of Gram-negative bacteria and 4 strains of Gram-positive bacteria as well as 6 yeasts. The Crude extract was found to have a narrow antimicrobial spectrum on Gram-positive bacteria mainly Listeria monocytogenes. Among the strains which showed antibacterial activity, four were determined to be bacteriocins-producers. They were identified as Lactococcus lactis. Brain Heart Infusion (BHI) Agar was found more adapted than Man, Rogosa and Sharpe (MRS) to investigate the antimicrobial activity of L. actococcus lactis against L. isteria monocytogenes. The genetic determinants encoding the antimicrobial peptides were targeted by specific PCR. All L. lactis bacteriocin producing strains possessed the Nisine Z gene (nisZ) except for one, which contained both Nisine A and Nisine Z genes (nisA and nisZ). They have been identified as antilisterial agentS.

Vitamin D status of dairy cattle: Outcomes of current practices in the dairy industry.

The need for vitamin D supplementation of dairy cattle has been known for the better part of the last century and is well appreciated by dairy producers and nutritionists. Whether current recommendations and practices for supplemental vitamin D are meeting the needs of dairy cattle, however, is not well known. The vitamin D status of animals is reliably indicated by the concentration of the 25-hydroxyvitamin D [25(OH)D] metabolite in serum or plasma, with a concentration of 30ng/mL proposed as a lower threshold for sufficiency. The objective of this study was to determine the typical serum 25(OH)D concentrations of dairy cattle across various dairy operations. The serum 25(OH)D concentration of 702 samples collected from cows across various stages of lactation, housing systems, and locations in the United States was 68±22ng/mL (mean ± standard deviation), with the majority of samples between 40 and 100ng/mL. Most of the 12 herds surveyed supplemented cows with 30,000 to 50,000 IU of vitamin D3/d, and average serum 25(OH)D of cows at 100 to 300 DIM in each of those herds was near or above 70ng/mL regardless of season or housing. In contrast, average serum 25(OH)D of a herd supplementing with 20,000 IU/d was 42±15ng/mL, with 22% below 30ng/mL. Cows in early lactation (0 to 30d in milk) also had lower serum 25(OH)D than did mid- to late-lactation cows (57±17 vs. 71±20ng/mL, respectively). Serum 25(OH)D of yearling heifers receiving 11,000 to 12,000 IU of vitamin D3/d was near that of cows at 76±15ng/mL. Serum 25(OH)D concentrations of calves, on the other hand, was 15±11ng/mL at birth and remained near or below 15ng/mL through 1mo of age if they were fed pasteurized waste milk with little to no summer sun exposure. In contrast, serum 25(OH)D of calves fed milk replacer containing 6,600 and 11,000 IU of vitamin D2/kg of dry matter were 59±8 and 98±33ng/mL, respectively, at 1mo of age. Experimental data from calves similarly indicated that serum 25(OH)D achieved at approximately 1mo of age would increase 6 to 7ng/mL for every 1,000 IU of vitamin D3/kg of dry matter of milk replacer. In conclusion, vitamin D status of dairy cattle supplemented with vitamin D3 according to typical practices, about 1.5 to 2.5 times the National Research Council recommendation, is sufficient as defined by serum 25(OH)D concentrations. Newborn calves and calves fed milk without supplemental vitamin D3, however, are prone to deficiency.

Simulating the Epidemiological and Economic Impact of Paratuberculosis Control Actions in Dairy Cattle.

We describe a new mechanistic bioeconomic model for simulating the spread of Mycobacterium avium subsp. paratuberculosis (MAP) within a dairy cattle herd. The model includes age-dependent susceptibility for infection; age-dependent sensitivity for detection; environmental MAP build up in five separate areas of the farm; in utero infection; infection via colostrum and waste milk, and it allows for realistic culling (i.e., due to other diseases) by including a ranking system. We calibrated the model using a unique dataset from Denmark, including 102 random farms with no control actions against spread of MAP. Likewise, four control actions recommended in the Danish MAP control program were implemented in the model based on reported management strategies in Danish dairy herds in a MAP control scheme. We tested the model parameterization in a sensitivity analysis. We show that a test-and-cull strategy is on average the most cost-effective solution to decrease the prevalence and increase the total net revenue on a farm with low hygiene, but not more profitable than no control strategy on a farm with average hygiene. Although it is possible to eradicate MAP from the farm by implementing all four control actions from the Danish MAP control program, it was not economically attractive since the expenses for the control actions outweigh the benefits. Furthermore, the three most popular control actions against the spread of MAP on the farm were found to be costly and inefficient in lowering the prevalence when used independently.