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PubMed1997

Effect of unilateral once or twice daily milking of cows on milk yield and udder characteristics in early and late lactation.

Twelve multiparous British Friesian cows in early (40 +/- 23 d in milk; n = 6) or late (216 +/- 17 d in milk; n = 6) lactation were used to study the effects of milking frequency on yield, udder volume and milk storage within the udder. After a 2 week control period of twice daily milking, diagonally opposed udder halves within a cow were milked once or twice daily for 3 weeks. Milk yield was 28-38% lower from the halves that were milked once daily than from halves that were milked twice daily. The loss of milk yield, expressed as a decrease in the relative milk yield quotient (an index that accounts for pretreatment differences), was greater for cows in early than in late lactation (0.59 v. 0.68). Empty udder-half volume was not decreased by once daily milking, suggesting that no cell loss occurred. Instead, once daily milking reduced the secretion efficiency (units of milk per unit of empty udder-half volume) by 46 and 27% respectively in early and late lactation; thus, at least part of the loss was due to reduced metabolic activity of the mammary epithelium. There were positive correlations between the relative milk yield quotient and the proportion (r = 0.804) or volume (r = 0.644) of cisternal milk in the glands that were milked once daily. These results confirm that, during extended milking intervals, milk loss was smallest for cows that stored a larger proportion of milk in the gland cistern.

Animals↗

PubMed1998

Effect of decreased milking frequency of cows in late lactation on milk somatic cell count, polymorphonuclear leucocyte numbers, composition and proteolytic activity.

The effects of reducing the frequency of milking of cows in late lactation on milk somatic cell count (SCC), polymorphonuclear leucocyte (PMN) content, chemical composition and proteolytic activity were investigated. Intermittent milking is frequently practised by Irish farmers in late lactation, and the objective of this study was to determine whether this procedure could be linked to altered quality of milk. Seventeen Holstein Friesian cows in late lactation (> 215 d in milk) were assigned to two treatment groups, and were either milked twice a day until drying-off (control group) or milked intermittently as the yield fell (test group). Milk composition and enzymic characteristics were measured on two occasions. At the first sampling, day 7, test cows were on once daily milking and at the second, day 15, the test cows were being milked every second day. Milk yields were significantly lower in test than control animals and decreased between days 7 and 15 in both groups. Milk SCC and PMN levels were increased on reducing milking frequency and, at day 15, the increase was not linked to decreased milk yield. Milk lactose levels were significantly decreased and pH, alpha-lactalbumin levels, plasmin activity and plasminogen activity significantly increased by reducing milking frequency. In conclusion, reduced frequency of milking in late lactation leads to the production of milk that is abnormal in character and this may be linked to reduced quality of dairy products manufactured from such milk.

Animals↗

PubMed2000

Allergenicity of mare's milk in children with cow's milk allergy.

BACKGROUND: Cow's milk allergy is a common disease of infancy and early childhood. If the baby is not breast-fed, a substitute for cow's milk formula is necessary. OBJECTIVE: The aim of this study was to investigate, in vitro and in vivo, the allergenicity of mare's milk in a population of selected children with severe IgE-mediated cow's milk allergy. METHODS: Twenty-five children (17 male and 8 female) aged 19 to 72 months (median age 34 months) with IgE-mediated cow's milk allergy were selected for this study. All the children underwent skin prick tests with cow's milk and mare's milk and double-blind placebo-controlled oral food challenge (DBPCOFC) with fresh cow's milk, fresh mare's milk, and, as placebo, a soy formula (Isomil, Abbott, Campoverde, Italy). We performed immunoblotting of cow's and mare's milk developed with IgE from allergic children. RESULTS: All the children showed strong positive skin test responses to cow's milk (4+); 2 children had positive skin test responses to mare's milk (2+). All children had positive DBPCOFCs to cow's milk; one child had a positive DBPCOFC to mare's milk. No children reacted to the placebo (Isomil). In the cow's milk, some proteins are able to strongly react with human IgE; when the sera are tested with mare's milk, the bands corresponding to the same proteins are recognized by a lower percentage of sera. CONCLUSION: These data suggest that mare's milk can be regarded as a good substitute of cow's milk in most children with severe IgE-mediated cow's milk allergy. It would be prudent, however, to confirm its tolerability by a supervised titrated oral challenge test.

Administration, Oral↗

PubMed2005

Yield and aging of Cheddar cheeses manufactured from milks with different milk serum protein contents.

Whey proteins in general and specifically beta-lactoglobulin, alpha-lactalbumin, and immunoglobulins have been thought to decrease proteolysis in cheeses manufactured from concentrated retentates from ultrafiltration. The proteins found in whey are called whey proteins and are called milk serum proteins (SP) when they are in milk. The experiment included 3 treatments; low milk SP (0.18%), control (0.52%), and high milk SP (0.63%), and was replicated 3 times. The standardized milk for cheese making of the low milk SP treatment contained more casein as a percentage of true protein and more calcium as a percentage of crude protein, whereas the nonprotein nitrogen and total calcium content was not different from the control and high SP treatments. The nonprotein nitrogen and total calcium content of the milks did not differ because of the process used to remove the milk SP from skim milk. The low milk SP milk contained less free fatty acids (FFA) than the control and high milk SP treatment; however, no differences in FFA content of the cheeses was detected. Approximately 40 to 45% of the FFA found in the milk before cheese making was lost into the whey during cheese making. Decreasing the milk SP content of milk by 65% and increasing the content by 21% did not significantly influence general Cheddar cheese composition. Higher fat recovery and cheese yield were detected in the low milk SP treatment cheeses. There was more proteolysis in the low milk SP cheese and this may be due to the lower concentration of undenatured beta-lactoglobulin, alpha-lactalbumin, and other high molecular weight SP retained in the cheeses made from milk with low milk SP content.

Animals↗

PubMed2000

Blood pressure responses to high-calcium skim milk and potassium-enriched high-calcium skim milk.

OBJECTIVE: This study was designed to evaluate the effect of high-calcium skim milk or potassium-enriched high-calcium skim milk on blood pressure compared with nonenriched skim milk. DESIGN: This was a randomized double-blind controlled trial. Each milk intervention lasted for 4 weeks, with a minimum of 4 weeks of wash-out between interventions. METHODS: We recruited 38 healthy people, aged over 40 years, to take part in a double-blind, randomized, controlled cross-over study. We asked them to replace their usual liquid milk with two servings per day of skim milk (control), high-calcium skim milk or potassium-enriched high-calcium skim milk. We measured office blood pressures (seated and standing) at the start and after 2 and 4 weeks of milk intervention and we measured daytime ambulatory blood pressures at the start and after 4 weeks of milk intervention. Each milk intervention was interspaced by a 4-week interval. RESULTS: Office systolic blood pressure (standing) decreased from 127 +/- 16 to 124 +/- 16 mmHg (P<0.05) after 4 weeks of skim milk and from 130 +/- 18 to 126 +/- 17 mmHg (P<0.05) after 4 weeks of high calcium skim milk. After 4 weeks of consuming the potassium-enriched high-calcium milk, systolic blood pressure decreased from 125 +/- 18 to 117 +/- 16 mmHg (P<0.001) seated, and from 130 +/- 16 to 122 +/- 15 mmHg (P<0.001) standing. There were no significant changes in office diastolic blood pressure after any milk. There was no change in ambulatory blood pressure after either skim milk or high-calcium skim milk. After 4 weeks of potassium-enriched high-calcium milk, ambulatory daytime systolic blood pressure decreased from 138 +/- 13 to 135 +/- 11 mm Hg (P<0.05) and daytime diastolic blood pressure decreased from 80 +/- 8 to 78 +/- 9 mmHg (P<0.05). CONCLUSIONS: High-calcium milk enriched with potassium has a small hypotensive effect in healthy people aged over 40 years.

Adult↗

PubMed1977

Mechanism of milk secretion: milk composition in relation to potential difference across the mammary epithelium.

1. In conscious lactating goats a significant correlation was found between blood-milk potential difference (p.d.) and milk [lactose] such that in goats with a lower milk [lactose], milk was more negative with respect to blood.2. When mannose was substituted for glucose in the substrate mixture of isolated perfused goat mammary glands, milk yield and milk [lactose] fell while milk [Na] and [K] increased; in parallel experiments the blood-milk p.d. changed such that milk became more negative with respect to blood. These changes were reversed following the addition of glucose.3. When milk was made hypertonic by the addition of hyperosmotic sucrose or lactose solutions, water entered milk osmotically and milk became electrically less negative or even positive with respect to blood in goats, cows and guinea-pigs.4. No effect on p.d. was apparent following the addition of isosmotic sucrose to milk in goats.5. When milk was held in the teat of goats by a pneumatic cuff around the base of the teat, no effect on p.d. was apparent when hyperosmotic sucrose was introduced into this teat pouch.6. It is suggested that waterflow-induced potentials (the streaming potential and the transport number effect) can be induced across the mammary epithelium.7. In goats exogenous oxytocin lowered milk [lactose] and blood-milk p.d. became less negative with respect to blood.8. In non-lactating and mastitic glands of goats the blood-milk p.d. was within 0.5-2.5 mV of zero.9. The effects of oxytocin, and the low p.d. in non-lactating and mastitic glands, are compatible with the view that in such circumstances there is a paracellular pathway across the mammary epithelium which partially short-circuits the two sides.10. It is suggested that, with water being drawn osmotically into milk to dilute newly formed lactose, waterflow-induced potentials may be responsible for establishing the normal p.d. across the apical membrane of the secretary cell, thereby keeping milk [K] and [Na] lower than in intracellular fluid.

Animals↗

PubMed2005

Genetic evaluation of dairy sires for milking duration using electronically recorded milking times of their daughters.

The potential of using electronically recorded data from on-farm milking parlor and herd management software programs for genetic evaluation of dairy sires for milking duration of their daughters was assessed in the present study. Single measurements of milking duration were collected weekly from 29 herds between June 1, 2003 and April 1, 2004. These included 73,547 observations corresponding to 10,152 Holstein cows from 1551 sires. Average milking duration for a single milking in our data set was 4.5 min. Estimated heritability of milking duration was 0.17, and predicted transmitting abilities (PTA) of individual sires ranged from -0.48 min for sires with the fastest milking daughters to 0.59 min for sires with the slowest milking daughters. The correlation between PTA for milking duration and PTA for somatic cell score (SCS) was -0.15, indicating that sires whose daughters milk most quickly also tend to transmit higher SCS to their progeny. Correlations between PTA milking duration and PTA for teat placement and teat length were -0.14 and 0.20, respectively, indicating that sires that transmit wide teat placement and long teats tend to have daughters that milk slowly. Based on the results presented herein, it appears that genetic selection based on objective, electronically recorded milking times is possible. This approach would greatly improve the quality and efficiency of data collection relative to conventional evaluations of milking speed, which are based on farmer surveys. The number of herds currently equipped to routinely capture milking times is limited, but this number is increasing very rapidly. Future research should focus on refinement of data reporting and validation systems, as well as estimation of the economic value of milking duration. This trait may have an intermediate optimum, because cows that milk too slowly will disrupt parlor flow and reduce milking efficiency, but cows that milk too quickly may be at greater risk for mastitis.

Animals↗

PubMed1985

Milk lipoprotein lipase distribution in the major fractions of bovine milk.

Raw, bovine bulk tank milk and milks from selected cows were separated by ultracentrifugation into four major fractions: casein, sloughed membrane material, serum, and milk fat globule membrane. Milk lipoprotein lipase activity was measured by the pH stat method and protein determinations were made by the Lowry procedure for each of the four fractions in order to calculate specific activity (units per milligram of protein). In six farm-cooled bulk milk samples stored less than or equal to 24 h, casein had a significantly higher milk lipoprotein lipase total activity, 35.66 units/ml of milk, than all of the fractions. Serum had the next highest activity with 11.69 units/ml of milk. Fluff and milk fat globule membrane had activities of .80 and .41 units/ml of milk, respectively. The specific activity of the fluff was 3.3 milk lipoprotein lipase units/mg of protein, which was significantly higher than the casein and serum fractions in pooled milk. Milks from five cows in midlactation were assayed individually for milk lipoprotein lipase activity and protein content immediately after milking and after 12, 24, 48 and 72 h of cold (4 degrees C) storage. Fresh warm milk was characterized by the absence of fluff. Casein had the highest mean activity (29.91 units/ml), followed by serum (10.25 units/ml) and milk fat globule membrane (.26 units/ml) in the warm milk from the individual cows. Upon cooling to 4 degrees C, significant increases in enzyme activity in the fluff and milk fat globule membrane fractions were observed at 12 h.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed2004

Goat milk is less immunogenic than cow milk in a murine model of atopy.

OBJECTIVES: Cow milk protein allergy occurs in 2% to 6% of infants population. Goat milk has been used as an alternative to cow milk, but there is probably some cross-reactivity between the milks. Little is known about the allergenicity of goat milk per se. The aim of this study is to compare cow and goat milk allergenicity in a mouse atopy model. METHODS: Balb/C mice were intragastrically sensitized to cow or goat milk by five doses administrated weekly. Six weeks after the first dose mice were killed, sera were collected and spleens removed for analysis. RESULTS: The number of mice with diarrhea was significantly higher in the cow milk-sensitized group than in the goat milk-sensitized group. Serum cow milk-specific immunoglobulin G1 and histamine levels were also significantly higher in cow milk-sensitized mice. Cytokine production by spleen derived T cells showed a Th2 response with high levels of interleukin-4 production and low levels of interferon-gamma in cow milk-sensitized mice. In addition, goat milk induced a lower lymphocyte sensitization as a result of a significant decrease in the specific proliferation ratio of these cells. CONCLUSION: Goat milk, when used as the first source of protein after a breast-feeding period, is less allergenic than cow milk in mice. Further studies are needed to clarify if goat milk is suitable as an alternative to cow milk in milk based formulas for infant nutrition.

Administration, Oral↗

PubMed1988

Effects of prepartum milking on milk production and health performance.

A field study using seven Holstein herds was conducted to determine effects of prepartum milking on milk production, health disorders, and reproductive performance. In each herd, 80 cows (30% first lactation cows) were assigned 1 mo prior to expected calving date to one of two treatments: postpartum or prepartum milking. The group milked prepartum was machine-milked twice daily at regular milking intervals beginning 14 d prior to date of expected calving. The group milked postpartum was milked for the first time after calving. The day prior to calving, 36, 33, and 31% of the cows milked prepartum produced less than 4.5 kg, 4.5 to 9 kg, and greater than 9 kg of milk, respectively. No relationship existed between days milked prepartum and prepartum milk yield. Lactation milk yield and persistency were not affected by prepartum milking. Prepartum milking reduced incidence of milk fever and mastitis during the 1st mo after parturition. Treatment was not a significant source of variation for reproductive performance or body condition; however, culling was higher for cows milked postpartum. Results indicate no adverse effects on cow performance due to prepartum milking nor increase in lactation milk yield.

Animals↗

PubMed1995

Bias and accuracy of single milking testing schemes to estimate daily and lactation milk yield.

This study evaluated the adequacy of an alternate a.m.-p.m. testing scheme for milk yield in comparison with the official test method based on weighing two milkings within 24 h. A total of 88,558 single test day milking weights from 15,670 Italian Friesian cows in 610 herds in the province of Milano (Italy) were collected between September 1991 and October 1992. Ratios were computed for daily milk yield to a.m. and p.m. milking weights (direct yield ratios) and ratios of a.m and p.m. milking weights to daily milk yield (inverse yield ratios). Analysis of variance indicated that the milking interval is the most important source of variation for yield ratios. Factors for estimating daily milk yield from single milking weights adjusted for milking intervals were derived through regression analysis of direct and inverse yield ratios on the length of the milking interval. Daily milk yield was estimated more precisely and accurately when adjustment factors were used than when single milking weights were doubled. The doubling of a.m. and p.m. milking weights overestimated and underestimated (5% on average) daily milk yield, respectively. For 305-d lactation yield, accuracies of these methods were comparable. In conclusion, alternate recording of a.m. and p.m. milking weights led to reliable estimates of milk yield. Effects of the alternate a.m.-p.m. testing scheme on estimates of milk components and genetic evaluations of dams of sires should be investigated.

Animals↗

PubMed2004

Effects of cleaning duration and water temperature on oxytocin release and milk removal in an automatic milking system.

Four different methods of teat preparation during milking in an automatic milking system were studied in 2 experiments on Red Holstein/German Fleckvieh cross-breed cows. Milking routines used were milking: 1) without premilking teat preparation; 2) with one cleaning cycle (58 to 60 s) with cold (13 to 15 degrees C) water; 3) with one cleaning cycle with warm water (30 to 32 degrees C); or 4) with 2 cleaning cycles (122 s) with warm water. In experiment 1, milking characteristics were evaluated and milking routines were randomly assigned to 62 cows during 3 measuring periods of 24 h each. In experiment 2, 10 randomly selected cows were assigned to the same milking routines during 4 d and blood samples for oxytocin (OT) determination were taken during milking in addition to milk flow recording. Milk production, peak flow rate, total, and quarter milk yields showed no differences among treatments. Premilking preparation with cold water compared with warm water showed no differences in OT release, milk yield, peak flow rate, main milking time, average flow rate, or time until main milk flow. Baseline OT concentrations were consistently low. At the start of teat cup attachment without premilking teat preparation OT concentrations remained on the basal level but were elevated in all other treatments. By 30 s from the start of milking, OT concentrations were markedly increased in all treatments and were no longer different between treatments. In conclusion, the teat cleaning device used in the automatic milking system, either with warm or cold water, was suitable to induce milk ejection in cows before the start of milking.

Animals↗

PubMed1977

Iron absorption from human milk, simulated human milk, and proprietary formulas.

Studies from our laboratory have shown that iron is better absorbed from human milk than from cow milk and that human milk can provide insufficient iron for infants during their first year. We compared iron availability from human milk with that from other formulas and determined the factors responsible for its superiority. Adults were fed 100 ml of human milk, simulated human milk, simulated human milk containing added lactoferrin, two commercial formulas containing iron, 12 mg/qt, and human milk that had been boiled. The simulated human milk resembled human milk in concentration of protein, fat, carbohydrate, iron, total minerals, calcium, and phosphorus. Iron 59 was added to each feeding and iron incorporation into RBCs was determined 14 days after each feeding. Percent iron absorption was highest from human milk and lowest from the commercial formulas. The simulated human milk supported a 9.0% absorption; addition of lactoferrin reduced this to 4.7%. Net iron absorption was 0.12 mg/liter from human milk and 0.40 and 0.37 mg/liter from the iron-enriched commercial formulas. Absorption of iron from boiled human milk was the same as from the unboiled milk. This study confirms the unique ability of human milk to promote iron absorption. Simple manipulation of the protein, fat, lactose, calcium, phosphorus, or lactoferrin content of proprietary milk did not reproduce the iron absorption demonstrated with human milk.

Adult↗

PubMed1994

Continuously elevated concentrations of oxytocin during milking are necessary for complete milk removal in dairy cows.

The importance of elevated concentrations of oxytocin (OT) during the entire milking period was investigated in seven primiparous dairy cows with inherent disturbed milk ejection and in sixteen healthy cows with disturbed milk ejection induced by placing them in an operating theatre. Disturbance of milk removal in both groups has previously been demonstrated to be exclusively due to central blockage of the expected OT release in response to teat stimulation and milking. However, milk ejection can be induced by exogenous OT. OT (0.2 i.u.) was injected i.v. before milking and 49 +/- 6% of the total milk was removed. When plasma OT decreased, milk flow stopped. In response to a second and third injection of 0.2 i.u. OT, 30 +/- 4 and 7 +/- 2% of the milk were removed respectively. The remaining milk was removed with 10 i.u. OT. The lag time from injection of OT to the start of milk flow was inversely correlated with the amount of milk actually removed in response to the OT injection. If 0.2 i.u. OT was injected during intramammary pressure (IMP) recording, IMP immediately increased to its maximum value. After 2.5 +/- 0.3 min, IMP decreased to an intermediate IMP (between preinjection and maximum IMP). After two additional injections of 0.2 i.u. OT and after injection of 0.5 i.u. OT, IMP increased to a similar maximum. However, after injection of 0.5 i.u. OT, maximum IMP lasted longer (2.9 +/- 0.3 min; P < 0.05) than after injections of 0.2 i.u. If OT was continuously infused (0.15 i.u./min) during milking, milk flow lasted until the udder was completely emptied. IMP increased during OT infusion to a maximum which remained stable until infusion was stopped after 10 min. The same IMP maximum was reached after the first individual OT injection (0.2 i.u.), but when plasma OT decreased towards basal concentrations, milk flow ceased and IMP decreased to an intermediate level. Thus continuously elevated OT concentrations such as those during infusion or during normal milking are necessary for complete milk removal.

Animals↗

PubMed1990

Comparison of intestinal anaphylactic reactions in sensitized mice challenged with untreated bovine milk and homogenized bovine milk.

Outbred NMRI mice were sensitized for high IgE production either by subcutaneous injections of low doses of untreated bovine milk or homogenized bovine milk in combination with intraperitoneal injections of Freund's Complete Adjuvant or by oral administration of untreated or homogenized bovine milk without adjuvant. When analysed in murine passive cutaneous anaphylaxis test both types of milk resulted in production of reaginic antibodies against bovine milk proteins when given subcutaneously. When given orally, homogenized milk resulted in reagin production in 10 out of 14 mice, whereas untreated milk resulted in reagin production in only one out of 12 mice. The sensitized mice, and control mice, were orally challenged with either untreated milk, homogenized milk or 0.9% NaCl. Examination of the intestines 40 min after oral administration revealed that homogenized milk, contrary to untreated milk or 0.9% NaCl, resulted in a large increase in the mass of the proximal gut segment of mice sensitized orally with homogenized milk compared with control mice orally challenged with saline (P less than 0.001), and only mice both sensitized and challenged orally with homogenized milk showed degranulation of mast cells in the intestinal wall. By contrast, subcutaneously sensitized mice or mice sensitized orally with untreated bovine milk showed no significant intestinal reaction upon oral challenge with either homogenized or untreated bovine milk. These observations may indicate that the route of sensitization is of great importance when intestinal reactions are to be studied, and that homogenization of bovine milk may render the milk more aggressive with respect to its ability to induce intestinal reactions. The study indicates that mice may be an attractive experimental animal model for mimicking the intestinal anaphylactic reactions of cow milk-allergic humans.

Administration, Oral↗

PubMed1994

Relationship between milk acetone and milk yield in individual cows.

Correlations between acetone in milk and milk production during the first nine weeks postpartum were calculated in ten individual cows and for a whole herd. The decrease in milk production due to ketonaemia was evaluated using a mathematical model of the KaleidaGraph integrate area program. For determination of milk components, a milk sample was obtained twice a week from one to nine weeks postpartum. Milk yield was negatively correlated with acetone concentration in milk. In non-clinical ketotic cows the calculated loss of milk yield due to elevation of milk acetone was 2-9% and in clinical ketotic cow it was as high as 26%. The correlation between milk components and acetone level varied at different stages of ketosis. Thus the stage of lactation and of ketosis should be taken into consideration when the correlation between milk parameters and milk production is evaluated. Prior to clinical ketosis, milk acetone was negatively correlated with milk yield, percentage of protein and percentage of lactose, whereas it was positively correlated with percentage of fat and urea concentration. In addition, high levels of acetone tended to be associated with high cell count. It is concluded that 1) ketotic cows do not achieve the maximum potential milk yield and 2) high levels of milk acetone are harmful to the udder. For high milk production, the concentration of acetone in milk should not exceed 0.05 mmol/l at any stage of lactation.

Acetone↗

PubMed2005

Prevalence of enterotoxigenic Bacillus cereus and its enterotoxins in milk and milk products in and around Nairobi.

OBJECTIVES: To determine the prevalence of enterotoxigenic Bacillus cereus (B. cereus) and enterotoxins in milk and milk products. DESIGN: A random sampling of milk products was carried out. SETTING: Market milk and milk products were collected from retail shops in Nairobi and analysed for contamination with enterotoxigenic B. cereus and its enterotoxins using reverse passive latex agglutination and TECRA ELISA immunoassay tests. SUBJECTS: Ninety six milk samples including 36 raw milk, 42 pasteurised milk, 10 yogurt and eight fermented milk samples. Forty seven Bacillus cereus isolated from milk and milk products. MAIN OUTCOME MEASURES: Isolation of enterotoxigenic B. cereus from milk and milk products and detection of B. cereus hemolytic (hemolysin BL) and non-hemolytic enterotoxins in milk. RESULTS: Fifty seven percent of the samples were contaminated with B. cereus. Eighty one percent (38 out of 47) of the isolates produced non-hemolytic enterotoxins, while 25 (53.2%) of the isolates produced hemolysin BL. Eighteen (38.3%) of the isolates produced both hemolysin BL and non-hemolytic enterotoxins. About fourteen percent (14.3%) of the pasteurised milk samples tested positive for non-hemolytic enterotoxin. CONCLUSION: Enterotoxigenic B. cereus and enterotoxins occur in market milk and their presence poses a potential risk of causing food poisoning. The risk can be reduced if milk products undergo thorough quality control checks and are always kept at below 4 degrees C till consumption. Post pastuerisation contamination which is commonly blamed for spoilage of milk products by B. cereus is not necessarily the most important source of this organism.

Animals↗

PubMed2006

Effect of automatic milking systems on milk yield in a hot environment.

A comparative study was performed to evaluate differences in milk yield between an automatic milking system (AMS) and a conventional herringbone milking parlor system. Two herds of Italian-Friesian cows were reared in the same barn, located in the Po Valley in northern Italy. Twenty-five primiparous cows and 10 multiparous cows were milked with an AMS, while at the same time 29 primiparous and 9 multiparous were milked twice daily in a milking parlor on the other side of the barn. A selection gate allowed cows to access the AMS only if the interval from last milking was >5 h. Multiparous cows in the AMS yielded more milk than multiparous cows in the milking parlor (34.2 +/- 0.7 vs. 29.4 +/- 0.6 kg/d). There was no difference in milk yield between primiparous cows in the AMS and in the milking parlor (28.9 +/- 0.4 vs. 28.8 +/- 0.3 kg/d). Milking frequency in the AMS was significantly higher in primiparous (2.8 +/- 0.03) than in multiparous cows (2.5 +/- 0.04). The hot season negatively affected milk yield; the milk yield reduction was higher for cows milked with the AMS (-4.5 +/- 0.6 kg/d) than in the milking parlor (-3.0 +/- 0.8 kg/d). In the AMS, milking frequency decreased during the hot season in primiparous cows (-0.3 +/- 0.1). We concluded that a positive AMS effect on milk yield is possible, but that steps must be taken to alleviate the discomfort involved with attracting cows to the AMS.

Animals↗