158. The nutritive value of raw and pasteurized milk for mice

1937 ◽  
Vol 8 (2) ◽  
pp. 203-217 ◽  
Author(s):  
G. S. Wilson ◽  
Irene Maier

1. Experiments were carried out during the years 1931–5 in which mice on a basal diet of raw milk and white-flour biscuit were compared with mice on a similar diet except that the raw milk was replaced by commercially holderpasteurized (145–150° F. for 30 min.) milk belonging to the same batch. Each group of mice comprised in aggregate about 1100 animals, which were usually 4–6 weeks old at the commencement of observation. For reasons given on p. 206 no attempt was made to standardize the volume of milk consumed by the individual mice. Except in the preliminary experiments, when the milk was given in excess, the amount supplied was regulated more or less in accordance with the requirements of the average animal.

1937 ◽  
Vol 37 (2) ◽  
pp. 243-253 ◽  
Author(s):  
G. S. Wilson ◽  
F. C. Minett ◽  
H. F. Carling

1. An experiment on the feeding of calves is described, which lasted over 2 years, and which was carried out on a healthy Shorthorn herd free from tuberculosis and contagious abortion.2. Alternate animals as they were born were allocated, without any selection whatever, to one or other of two groups. One of these was fed on raw, the other on pasteurized milk. Every animal received its mother's colostrum for 3 days before being put on the milk diet.3. The milk used was taken from the mixed morning's milk of the whole herd. It was divided into two parts, one of which was given raw, the other of which was submitted to low-temperature pasteurization at 145° F. (628° C.) for 30 nun, and subsequently cooled. The animals were fed morning and evening on measured quantities that were in strict relationship to their body weight.4. In addition to the milk, hay was allowed ad lib. Observations showed that practically none was eaten during the first month, after which each animal consumed about 1 lb. a day, rising to 3 lb. by the eighth week.5. With the exception of two weaklings which died after 15 and 23 days respectively from causes apparently unconnected with the nature of their diet, all the animals—twenty-five in the raw and twenty-three in the pasteurized group—throve well, and showed no obvious signs of rickets or anaemia.6. The average increase in weight over the 8-week period for the animals in the raw group was 53·72 lb., and in the pasteurized group 53·86 lb., or 61·18 and 62·94 per cent respectively. This practical identity in weight increase is all the more surprising in view of the fact that the number of bull calves was very much less in the pasteurized than in the raw group.7. The highest individual gain among the bull calves—one of 80 lb.—and the highest individual gain among the heifer calves—one of 63 lb.—both occurred in animals fed on pasteurized milk.8. At no time throughout the experiment was any observer, lay or professional, able to distinguish between the two groups of animals.9. The diet given, though permitting of good skeletal development, was insufficient to fatten the animals. After they had been transferred, however, to a normal diet at the conclusion of their 8 weeks in the experiment, they soon put on weight and within 2 or 3 months were indistinguishable in size or condition from animals that had received a more generous diet from birth.10. There is nothing in these results to suggest that the nutritive value of pasteurized milk for calves is in any way inferior to that of raw milk.


1938 ◽  
Vol 9 (2) ◽  
pp. 188-206 ◽  
Author(s):  
K. M. Henry ◽  
E. W. Ikin ◽  
S. K. Kon

1. The effect of commercial sterilization on the total nutritive value of milk was studied in five separate experiments.2. In the first experiment raw and sterilized milks supplemented with minerals were given in equal amounts to pairs of litter-mate male rats. No differences were found in the growth performance of the rats, but the rats on sterilized milk consumed it more readily than their mates on raw milk. This difference was statistically significant.3. Rats getting limited but equal amounts of milk in addition to a basal diet which supplied only protein, energy and minerals grew better on raw than on sterilized milk.4. When the basal diet contained in addition 5% brewer's yeast and the milk intakes were the same as in the previous experiment no difference was found between the two groups.5. Rats receiving raw milk to which 15 g. of cane sugar was added per 100 ml. grew better than rats receiving equal quantities of similarly treated sterilized milk.6. Rats given raw milk containing 30 g. per 100 ml. of sugar grew as well as the rats on sterilized milk in the preceding experiment, but rats receiving similarly treated sterilized milk took much less milk than the raw milk rats, grew very poorly and some of them developed symptoms of beri-beri.7. The difference between raw and sterilized milk is discussed and it is concluded that in these experiments on the total nutritive value of milk vitamin B1 was the first limiting factor of sterilized milk.


1937 ◽  
Vol 8 (3) ◽  
pp. 311-323 ◽  
Author(s):  
J. Wilkie ◽  
S. J. Edwards ◽  
A. B. Fowler ◽  
N. C. Wright

1. Bull calves from tuberculin-tested Ayrshire herds were fed on raw or commercially pasteurized milk up to 12 weeks of age, in amounts strictly in relation to their body weight. This diet was supplemented from the eighth week by hay at the rate of 2/3 lb. per head per day.The milk used was mixed milk from untested herds, the raw and pasteurized milk being derived from the same bulk sample. The quality of the milk was controlled by daily butterfat and phosphatase tests and by inoculation of grouped daily aliquots twice weekly into duplicate guinea-pigs.2. The total number of calves used in the experiment was ninety-two. Of these, forty-two received pasteurized milk and fifty raw milk. Nineteen calves died before completion of the experiment, five in the pasteurized milk-fed group and fourteen in the raw milk-fed group. The mean ages of these calves at death were 44 and 27 days respectively.Seventy-three calves completed the full 12 weeks of the experimental feeding. Of these, thirty-seven received pasteurized milk and thirty-six raw milk. The former group showed a mean percentage gain in live weight of 80·2 ± 3·1, the corresponding figure for the latter group being 74·5 ± 2·7. The difference, i.e. 5·7 + 4·1, was not significant. Reasons are given for the relatively low growth rate observed.3. No appreciable differences were noted in the skeletal growth of the two groups. Marks awarded by experienced stock judges showed consistent differences in favour of the pasteurized milk-fed group, although the significance of such differences cannot be assessed.4. Inoculations of grouped daily aliquots of raw milk twice weekly into duplicate guinea-pigs resulted in finding viable tubercle bacilli in 70% of the samples and Br. abortus in 38% of them. The pasteurized milk samples were uniformly negative to both tests.The differences in tuberculous infection of the two types of milk were reflected in the results of tuberculin tests and post-mortem examinations on the calves at the conclusion of the experiment. Twenty-four out of thirty-six calves fed on raw milk reacted to the test, and the presence of tuberculous lesions was confirmed in twenty-three by post-mortem examination. One calf in the pasteurized milk-fed group reacted to the test, but exhaustive post-mortem examination and inoculation of glandular material into guineapigs failed to confirm the presence of any tuberculosis.5. This work has failed to show any significant differences in the nutritive value of raw and of pasteurized milk for the rearing of young calves. The use of pasteurized milk, however, had a clear advantage in that it preserved the animals from infection through drinking milk containing living tubercle bacillli.


2001 ◽  
Vol 64 (7) ◽  
pp. 927-933 ◽  
Author(s):  
RAJESH MODI ◽  
Y. HIRVI ◽  
A. HILL ◽  
M. W. GRIFFITHS

The ability of Salmonella Enteritidis to survive in the presence of phage, SJ2, during manufacture, ripening, and storage of Cheddar cheese produced from raw and pasteurized milk was investigated. Raw milk and pasteurized milk were inoculated to contain 104 CFU/ml of a luminescent strain of Salmonella Enteritidis (lux) and 108 PFU/ml SJ2 phage. The milks were processed into Cheddar cheese following standard procedures. Cheese samples were examined for Salmonella Enteritidis (lux), lactic acid bacteria, molds and yeasts, coliforms, and total counts, while moisture, fat, salt, and pH values were also measured. Salmonella Enteritidis (lux) was enumerated in duplicate samples by surface plating on MacConkey novobiocin agar. Bioluminescent colonies of Salmonella Enteritidis were identified in the NightOwl molecular imager. Samples were taken over a period of 99 days. Counts of Salmonella Enteritidis (lux) decreased by 1 to 2 log cycles in raw and pasteurized milk cheeses made from milk containing phage. In cheeses made from milks to which phage was not added, there was an increase in Salmonella counts of about 1 log cycle. Lower counts of Salmonella Enteritidis (lux) were observed after 24 h in pasteurized milk cheese containing phage compared to Salmonella counts in raw milk cheese with phage. Salmonella Enteritidis (lux) survived in raw milk and pasteurized milk cheese without phage, reaching a final concentration of 103 CFU/g after 99 days of storage at 8°C. Salmonella did not survive in pasteurized milk cheese after 89 days in the presence of phage. However, Salmonella counts of approximately 50 CFU/g were observed in raw milk cheese containing phage even after 99 days of storage. In conclusion, this study demonstrates that the addition of phage may be a useful adjunct to reduce the ability of Salmonella to survive in Cheddar cheese made from both raw and pasteurized milk.


1986 ◽  
Vol 66 (2) ◽  
pp. 483-494 ◽  
Author(s):  
R. M. TAIT ◽  
R. M. BEAMES ◽  
J. LITSKY

The digestibility of four types of grain screenings, No. 1 screenings, rapeseed screenings, mixed feed oats and refuse screenings was measured with pigs, rats and sheep. For the pig diets, hammermilled screenings replaced 60% of a complete basal diet, with the exception of the rapeseed screenings, where replacement level was 10% (hammermilled) and 20% (whole). Digestibility values were determined by difference. In the rat diets screenings were incorporated to provide 1.5 g N 100 g−1 dry matter (DM) and the biological value (BV) of the protein was also measured. In the sheep diets, all screenings except rapeseed were provided as the sole dietary component, with the No. 1 feed screenings and the mixed feed oats pelleted without prior grinding and the other screenings ground before pelleting. For rapeseed screenings, incorporation in the sheep diets was at a level of 30%. For No. 1 screenings, apparent digestibility of organic matter (OMD) and nitrogen (ND) for pigs was 82.3 and 83.2%, respectively; BV for rats was 77.4%, while OMD and ND for sheep was 73.9 and 72.7%, respectively. For rapeseed screenings, OMD and ND for pigs for the hammermilled screenings were 46.1 and 50.7%, respectively, and for the whole screenings were 30.3 and 11.5%, respectively. Biological value (rats) was 80.0%, while for sheep OMD and ND it was 63.9 and 77.4%, respectively. For mixed feed oats, OMD and ND for pigs were 63.8 and 82.6%, respectively; BV (rats) was 61.1% and OMD and ND for sheep were 64.2 and 73.4%, respectively. For refuse screenings, OMD and ND for pigs were 63.8 and 65.4%, respectively; BV (rats) was 83.8%, while OMD and ND for sheep were 59.9 and 65.3%, respectively. Number 1 feed screenings are of a high nutritive value and are suitable as a grain for both pigs and sheep. Unprocessed rapeseed screenings are unpalatable for pigs with both dry matter and protein poorly utilized. With sheep, pelleted rapeseed screenings are readily accepted, and the nitrogen is well digested. If mixed feed oats are ground, protein is well digested by both species although dry matter digestibility is low. Refuse screenings appear to be suitable only for ruminant diets. Key words: Grain, wheat, barley, oats, rapeseed, screenings


2016 ◽  
Vol 69 (2) ◽  
pp. 8007-8014 ◽  
Author(s):  
José G. Serpa ◽  
Tulia I. Pérez ◽  
Elvis J. Hernández

The effect of pasteurization and starter cultures on physicochemical, microbiological and sensorial characteristics of costeño cheese was determined. A completely randomized design was conducted, three treatments (T) and three replicates: Treatment 1 (T1): cheese manufactured with pasteurized milk without starter cultures, Treatment 2 (T2): cheese manufactured with pasteurized milk with Lactococcus lactis and Lactococcus cremoris (1:1) and Treatment 3 (T3): cheese manufactured with pasteurized milk with Lactococcus lactis, Lactococcus cremoris and Streptococcus thermophillus(0.5:0.5:1). Treatments were compared to a control sample that was prepared with raw milk without starter cultures. Concentration of 1.5% (v/v) of culture was used in relation to the amount of used milk in each treatment. Moisture content was higher in all treatments compared to the control and protein and fat content were significantly lower. Acidity was significantly higher in samples from T2 y T3 compared to T1 and control, due to the metabolism of starter cultures. Total coliforms, yeast and mold counts showed a significant reduction due to pasteurization process in all treatments. Regarding sensorial analysis, hedonic test showed a greater preference in cheese manufactured with T2 (P<0.05). There were no significant preferences between T1, T3 and control. Additionally, yield was significantly higher with T1 (22%) and T3 (23%) compared to control.


Author(s):  
Bojan GOLIĆ ◽  
Milijana GOLIĆ ◽  
Tanja ILIĆ

The process hygiene criterion is a microbiological criterion that applies to the process offood production and processing and indicates the proper functioning of the production process byrepresenting the value of the contamination above which corrective measures are taken to maintainthe process hygiene. Pasteurized milk is a product obtained by heat treatment of raw milk at atemperature of 63° C for 30 minutes or 72° C for 15 seconds. Pasteurization has two purposes, thefirst one is to elimination of all pathogenic microorganisms, and the second is to reduce the numberof saprophytic microorganisms, which prolongs the shelf life without changing the nutritional andbiological value of the milk.The aim of the study is to examine the safety of pasteurized milk and the conditions of hygiene inthe production process based on the results of the examination of pasteurized milk on the criteria ofhygiene in the production process, as well as to develop a proposal for the recommendedmicroorganisms to be tested in the process of the production of pasteurized milk.Samples of pasteurized milk come from a pasteurizing plant that purchases milk from the territoryof Republika Srpska, and were sampled in the six-month period (January-June), within self-controland official control. For microbiological testing of raw milk, standard BAS ISO methods were used.The results of pasteurized milk testing in relation to the hygiene criteria in the production processare satisfactory in relation to the Rulebook on Microbiological Criteria for Food. The results of selfcontrolon the recommended microbiological criteria in the process of obtaining pasteurized milk,which are given in the Guideline on the Application of Microbiological Criteria for Food, aresatisfactory in relation to the finding of Listeria monocytogenes, Salmonella spp. and coagulasepositive staphylococci, and unsatisfactory for a number of microorganisms.The results of official controls in the production process of pasteurized milk are unsatisfactory dueto the increased number of microorganisms in 12.50% of the samples. 22.20% of pasteurized milksamples had the number of microorganisms larger than 105CFU/ml within self-control and officialcontrols. Examination of pasteurized milk in the self-control of the production process should beperformed on enterobacteria and the total count of microorganisms, and in the interpretation of theresults the recommended limit values from the Guideline on the application of microbiologicalcriteria for food should be used.


2019 ◽  
Vol 70 (3) ◽  
pp. 1669
Author(s):  
S. KAMINARIES ◽  
A. SCORDOBEKI ◽  
E. ZOIDOU ◽  
G. MOATSOU

Novel reduced-fat goat-cheese (R) was produced from high-pasteurized milk using Penicillium candidum as an adjunct. A full-fat goat-cheese (F) from pasteurized milk without mold addition was produced for comparison reasons. Physicochemical analyses of the two cheeses were performed through the 14-d period of ripening. The effect of P.candidum on proteolysis of goat-cheese caseins and the production of hydrophilic and hydrophobic peptides during cheese ripening were investigated. To our knowledge, similar results for reduced-fat, mold-ripened, goat-milk cheeses have not been previously reported before. R-cheese exhibited a higher organoleptic score and developed properties similar to Kopanisti, which is a Protected Designation of Origin Greek soft cheese with specific intense flavour manufactured from raw milk without the use of starters. Moreover, R-cheese had significantly higher moisture, protein in dry matter and water soluble nitrogen contents than F-cheese and was less adhesive. The high-pasteurization improved the texture and cheese yield, while the use of P. candidum as an adjunct improved the flavour, increased and accelerated proteolysis in R-cheese. According to the results, the technology for R-cheese employed in the present study can be easily adopted and could be used to produce a reduced-fat goat-cheese.


2019 ◽  
Vol 157 (2) ◽  
pp. 176-181
Author(s):  
Mahmoud S. El-Tarabany ◽  
Akram A. El-Tarabany ◽  
Mostafa A. Atta ◽  
Omar A. Ahmed-Farid ◽  
Mohamed M. Mostafa

AbstractUse of antibiotics as feed additives has been reduced to avoid the hazard of drug residues, and consequently, the search for alternative natural additives has developed. Thus, the aim was to evaluate the influence of royal jelly (RJ) supplementation on milk composition, blood biochemical and antioxidant parameters of lactating ewes. Thirty-six Ossimi ewes were divided randomly into two groups (18 animals each). For a period of 4 weeks, the control group (CON) was fed a basal diet only, while the other group was fed the basal diet and supplemented with a single bolus of RJ (1000 mg/head). The RJ-supplemented ewes produced significantly higher milk protein, fat and total solids than the CON group. The RJ group had a significantly higher red blood cell count, haemoglobin content, haematocrit value and total leucocyte counts, but lower neutrophil to lymphocyte ratio when compared with the control treatment. The RJ group showed significantly higher concentrations of total antioxidant capacity, superoxide dismutase activity and glutathione in the serum compared with the control treatment. In conclusion, RJ supplements can improve the nutritive value of milk fat and the serum antioxidant activities in lactating ewes.


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