bluuebunny/crossref_metadata_2025_split huggingface dataset:
565. A study of variation in twin cattle: III. Growth
Authors: King J. W. B. , Donald H. P. 
Published: June 2009

1. Polynomial coefficients have been fitted to data on growth in live weight to 19 months and on height at withers to 27 months of age shown by one-egg (MZ) and two-egg (DZ) twins and pairs of half-sisters (HZ). The coefficients obtained (a0, a2 and a3) have been subjected to analysis of variance.2. For growth in live weight, the ratio of intrapair variances for MZ, DZ and HZ pairs was 1:6·8:10 for a1, which gives the straight line best fitting the observed curve. Unrelated pairs, it is calculated, would have had an intrapair variance 20·9 times as great as MZ pairs. From the point of view of minimizing the intrapair variance, the advantage of the MZ pairs was usually a little less for a0, and considerably less for a2 and a3.3. For height at withers, the results were similar to those for weight.4. The contribution of environmental variance to total intrapair variance increased from a0 to a3, while that due to additive genetic effects diminished. Owing to the wide fiducial limits applicable, the results can be accommodated assuming only additive genetic effects in addition to environmental effects as estimated from one-egg twins. The extent to which HZ pairs exceeded the variance expected, however, suggests that this simple assumption may prove inadequate.
592. Studies of the secretion of milk of low fat content by cows on diets low in hay and high in concentrates: VI. The effect on the physical and biochemical processes of the reticulo-rumen
Authors: Balch C. C. , Balch D. A. , Bartlett S. , Bartrum M. Patricia , Johnson V. W. , Rowland S. J. , Turner Jill 
Published: June 2009

1. Two Shorthorn cows with rumen fistulas were used to investigate the effect of diets high in concentrates and low in hay on the physical and biochemical processes of the reticulo-rumen.2. During the initial control period of the investigation the cows received daily 16 lb. hay and 20 lb. concentrates (flaked maize 50%, weatings 35%, decorticated ground-nut cake 15%) and during the final control period 18 lb. hay and 10 lb. concentrates. There were three intervening experimental periods, in each of which the cows received 2 lb. hay daily. In the first experimental period they received, in addition to the hay, 24 lb. concentrates; in the second, 20 lb. concentrates and 5 lb. of dried delignified straw pulp in a finely macerated form; and in the third, 20 lb. concentrates. The experiment lasted 27 weeks.3. In the experimental periods the mean milk-fat percentage remained below 2·0 for 10 weeks, whereas the mean value for the control periods was about 3·5. Addition of the straw pulp to the diet low in hay brought about no recovery in milk-fat percentage. It is calculated that in the two cows the losses in the yield of fat were 62·2 and 51·2% in the first experimental period and 62·5 and 58·7% in the second. In the experimental periods there were increases in the milk solids-not-fat percentage amounting in the two cows to upwards of 0·75 and 0·40 respectively. The composition of the butterfat was influenced by the diets low in hay, the main changes being a marked fall in the Reichert value, and a rise in the iodine value.4. Digestibility trials showed that in the initial control period and the first and second experimental periods the mean daily intake of digestible crudefibrewas 2·6,0·6 and 3·0 lb. respectively. A tentative estimate of the extent of digestion in the reticulo-rumen, based on the lignin-ratio method, showed that a marked depression in values for the digestibility of the cellulosic constituents of the diet given during the first experimental period took place in the reticulo-rumen. In all experimental periods, even the first, the digestion of starch in the reticulo-rumen was virtually complete, only traces passing undigested to the remainder of the gut. In these three periods the mean daily intake of ether extract remained at 0·4·0·5 lb.
611. The steam stripping of taints from liquids: IV. An analysis of continuous counterflow equipment
Authors: Scott J. K. 
Published: June 2009

The use of a column to give countercurrent contact of steam and cream to strip taints from the cream is explained. An analysis based on the engineering concept of a transfer unit is presented, and generalized curves are given which can be used for any counterflow column using fresh steam. The generalized curves give the percentage reduction in taint for values of the stripping factor (mV/L) when the number of transfer units is known.It is further shown that the number of transfer units for any particular design of column depends on the value of the stripping factor. The total resistance to the transfer of taint (HTU)L depends on a liquid-side resistance (HTU)l and a steam-side resistance (HTU)g such that (HTU)L=(HTU)l+L/mV(HTU)g.Results are given for an experimental column in which the liquid flows as (a) a spray, (b) a falling film or wetted wall. A strong deodorizing effect occurs at the bottom of the column and the resistances to transfer areResistances for a full-size plant 3 ft. diameter processing at 10,000 lb./hr. are assessed from the above figures as:Restriction of the process of taint transfer is controlled largely by the liquid-side resistance. Because the minimum obtainable taint level depends on the liquid-side resistance (no matter how much steam is used) a low liquid-side resistance or a tall column must be used for satisfactory deodorization. A minimum of 4 transfer units is suggested, as this will allow a taint to be reduced to nearly 1·8% of the original value.A design method is given based on hypothetical taint conditions, the generalized curves, and the characteristics of any proposed counterflow column.
615. Colour changes in heated and unheated milk V. The effects of temperature of measurement, pH, and the addition of certain ions on the reflectance of separated milk
Authors: Burton H. 
Published: June 2009

Variation in the temperature of measurement, pH, and concentration of calcium, citrate and phosphate ions have been consistently found to affect the reflectance of separated milk in such a way that the entire curve of reflectance versus wave-length in the visible spectrum is raised or lowered. At temperatures between 10 and 50°C. the reflectance rises reversibly with temperature. The change is not instantaneous, and if the temperature is changed abruptly the reflectance change to the new value is exponential, with a time constant of about 40 min.Reflectance is independent of pH in the range 5·8–6·6, but for greater values it drops sharply.Added calcium ions increase the reflectance of separated milk, and added citrate and phosphate ions decrease it, independently of the simultaneous changes in pH.It is suggested that the reflectance changes which have been found to occur are all caused by changes in the sizes of the casein particles in milk which are brought about by the factors considered. The results given by other authors on viscosity and bound water content, and on direct electron-micrographic observation of casein, are cited to support this contention.It is further suggested that the change in casein particle size with temperature may be due to a change in the calcium-ion distribution between solid and liquid phases.The viscosity and reflectance results for separated milk heated to 70°C. and above are apparently anomalous, but they can be explained on the hypothesis that denatured soluble proteins aggregate into particles having a high ration of length to breadth.
633. The effect of commercial sterilization on the nutritive value of milk as determined in experiments with rats and baby pigs
Authors: de Groot A. P. , Engel C. 
Published: June 2009

1. The nutritive value of milk sterilized according to the Stork procedure has been studied in laboratory experiments by the method of Mitchell, the rat-repletion method and growth trials with rats and baby pigs.2. Determinations of biological value of the milk proteins with three groups of six rats by the Mitchell method yielded mean values of 87·0, 88·0 and 85·1 for raw, pasteurized and sterilized milk respectively. The corresponding digestibilities amounted to 96·8, 96·3 and 94·4. The differences were not statistically significant.3. The relative nutritive value of the three types of milk for the repletion of protein-depleted rats was studied with three groups of eight rats. The average weight gain on feeding daily 40 ml. of either raw, pasteurized or sterilized milk during 5 days was 27·7, 26·3 and 22·9 g. respectively. Again these differences were not statistically significant.4. No differences in growth rate were obtained if three groups of twelve male and twelve female young rats were fed on raw, pasteurized or sterilized milk supplemented with trace minerals for a period of 6 weeks. The growth rate of rats on exclusive milk diets was, however, far below normal.5. In growth experiments with baby pigs, fed equal amounts of pasteurized or sterilized milk supplemented with trace minerals, small but statistically non-significant differences in weight gain were found, in favour of the pasteurized milk. The average weight gain on sterilized milk in four separate growth trials amounts to 97, 95, 98 and 98% of that on pasteurized milk. The average 3% less gain on sterilized milk was ascribed partly to more difficult adaptation and less intake of milk solids.6. These experiments failed to demonstrate a significant decrease in nutritive value of milk sterilized according to the Stork procedure.
660. Properties and composition of colostrum from Egyptian buffaloes and cows
Authors: El Negoumy A. M. 
Published: June 2009

The properties and composition of buffaloes' colostrum have been compared with those of cows' colostrum. The most significant differences found between the two may be summarized as follows:(1) Buffaloes' colostrum was richer in total solids, lactose, total N, globulin N and proteose-peptone N than cows' colostrum.(2) Buffaloes' colostrum had a much wider range of fat content than cows' colostrum. A distinct difference between the two colostrums lay in the fact that while buffaloes' colostrum was definitely poorer in fat content than normal buffaloes' milk, cows' colostrum was richer in fat content than is normal cows' milk.Changes in buffaloes' mammary secretion during the transition period from colostrum to milk.The following is a summary of the most significant trends in the properties and composition of buffaloes' mammary secretion during the transition period:(1) The specific gravity, acidity and chlorine decreased until they reached a normal value at the fifth milking. This compares well with the trends reported in the literature for cows' mammary secretion during the transition period.(2) The pH increased gradually until it reached its normal level before the fifth milking.(3) The highest level of total solids occurred at the first and second milking, and dropped sharply at the third milking to the level normally found in buffaloes' milk.(4) Changes in the lactose content from the second milking onwards were very slight. This contrasts with the known trend during the transition period in cows, when a gradual increase from a low level at the first milking to higher levels at the following milkings is noticeable.(5) The total N, globulin N, albumin N and proteose-peptone N decreased from relatively high levels at the first and second milkings to lower levels at later milkings, and thus closely followed the trend shown by the total solids.Buffaloes' mammary secretion may be considered comparable in its composition to normal buffaloes' milk and suitable for human consumption from 5 to 7 days after parturition.
669. Steam distillation of taints from cream: III. Factors affecting rate of removal of the reference substances, diacetyl and acetoin
Authors: McDowall F. H. 
Published: June 2009

1. The vapour/liquid equilibrium coefficient for diacetyl in 35–40% cream has been found to be of the order of 26–28, compared with 39·3 for water. In a 5% aqueous solution of lactose, equivalent to that present in milk and in cream serum, the coefficient was 30. The depression of the equilibrium coefficient by lactose in solution was shown to be independent of the concentration of diacetyl present in the liquid at time of partition, over the range 1–65 p.p.m.2. The slower rate of removal of diacetyl from cream, per unit weight of steam condensed as compared with its removal from water, was observed to be due mainly to this depressing effect of lactose on the equilibrium coefficient; but there was some evidence that delay in re-establishment of the solubility partition equilibrium as between butterfat and cream serum also contributed to the lowering of the equilibrium coefficient for diacetyl in cream as measured in the laboratory continuous vaporization equilibrium still.3. Sodium chloride in the solution caused a rise in the equilibrium coefficient for diacetyl from the value of 39·3 for water to about 69 for a 10% salt solution and 82 for a 20% salt solution.4. Lactose had no effect on the equilibrium coefficient for acetoin, but salt caused a rise from 1·29 for water to approximately 1·75 for a 10% salt solution.5. The possible effect of lactose on the effectiveness of steam in cream deodorization equipment is referred to.
683. Factors influencing the vitamin content of milk fat: VI. The effect of reduced carotene intake
Authors: McGillivray W. A. , Worker N. A. 
Published: June 2009

1. The results of an investigation into the efficiency of utilization by dairy cows of carotene from New Zealand summer pasture and from arachis oil are reported.2. A 50-fold decrease in the intake of carotene from pasture over a short period was shown to have only a small effect on the vitamin A potency of milk fat, carotene content being reduced by approximately 2μg./g. fat and vitamin A ester by approximately 1·5μg./g. fat. No change was observed in vitamin A alcohol content.3. Sample-to-sample variations in both the control and treated animals were observed in many cases to exceed the differences due to treatment except during the period of extreme carotene deprivation. Sample-to-sample variations of control and treated animals were also observed to be highly correlated, and it is suggested that variations in the external environment of the animal may have a marked effect on carotene utilization.4. Carotene in arachis oil was shown to be relatively more effective in maintaining the vitamin A potency of milk fat than summer pasture.The results of this investigation form a section of a thesis submitted by one of us (N.A.W.) in partial fulfilment of the requirements for the degree of Ph.D. of the University of New Zealand. The authors are indebted to the Department of Scientific and Industrial Research for a grant towards the investigation, and to Mr D. J. Dobson and the farm staff of The Dairy Research Institute (N.Z.) for assistance with the feeding and dosing of the animals and the collection of milk samples. The technical assistance of Miss Fay Frecklington is also thankfully acknowledged.
687. Changes in size of fat globules in cream during Vacreator treatment
Authors: Dolby R. M. 
Published: June 2009

The size distribution of fat globules was determined microscopically in cream samples taken from different parts of the Vacreator during treatment of cream.A considerable increase in numbers of small globules (splitting) was found in samples which had passed the equilibrium valve. Smaller increases took place in the pasteurizing chamber and in the extractor pump. Increase in numbers of large globules (clumping) occurred in the cooler section.Splitting of globules could be reduced: in the pasteurizer by reducing velocity of incoming steam; at the equilibrium valve by reducing the vacuum drop across the valve or by introducing part of the steam at the infuser instead of into the pasteurizer.It is concluded that splitting of globules in the Vacreator is due to a homogenizing effect where steam and cream travel at a high velocity. Flash-boiling causes clumping but not splitting of globules. These conclusions should apply to any equipment for pasteurization or deodorization of cream with direct steam.The thanks of the author are due to Mr J. Singleton (Superintendent) and Mr B. Le Heron (Buttermaker) of the Institute factory for arranging and carrying out Vacreator treatments of cream, to Dr F. H. McDowall for helpful advice and criticism and to Mrs R. P. Haverkamp for assistance in measuring fat globules.
691. Oxygen consumption and lactose synthesis rates of mammary gland slices from lactating guinea-pigs
Authors: Naito M. 
Published: June 2009

The shape of the lactation curve in guinea-pigs has been studied. The peak was found to occur between days 2 and 3.The oxygen consumption and lactose synthesis rates were investigated in mammary gland slices and results expressed on both DNA and DW bases.Oxygen consumption rates on a DNA basis tended to be low at the onset of lactation and high at the peak. Lactose synthesis on a DW basis tended to decline linearly from the onset of lactation, but on a DNA basis showed a peak coinciding with that of the lactation curve.The significance of these findings has been discussed.
708. Phospholipids in New Zealand dairy products: II. Seasonal variations in the phospholipid content of butter and of milk and cream
Authors: McDowell A. K. R. 
Published: June 2009

Samples of milk, skim-milk and raw cream from one factory and of pasteurized cream, buttermilk and butter from two factories were taken twice monthly for varying periods for estimation of total phospholipids and (in butter only) of lecithin, cephalin and sphingomyelin.Seasonal variations in the phospholipid contents of milk, skim-milk and raw cream over 13 months probably were due to the greater proportion of small fat globules in autumn (late lactation) milk compared with spring (early lactation) milk.There were regularly recurring seasonal variations in total phospholipid content of the butters over 3 years. Maximum results were found during autumn and minimum results in winter. Lecithin, cephalin and sphingomyelin contents followed the same trends as the total phospholipid contents.Seasonal variations in phospholipid contents of buttermilks and butters were due mainly to variations in the amount of phospholipid per unit of fat in the cream. Differences in butter-making technique had little effect on the proportion of phospholipids from the cream retained in the butter.Average results for total phospholipid content of the products examined were: milk, 0·038% (0·031–0·050%); skim-milk, 0·018% (0·014–0·023%); buttermilk, 0·156% (0·103–0·191%); butter, 0·133% (0·099–0·181%). The average result for percentage of total phospholipid in the fat of the raw creams examined was 0·44% (0·38–0·51%); and in the fat of the pasteurized creams 0·41% (0·35–0·49%). Average weighted results for total phospholipid and for lecithin, cephalin and sphingomyelin contents of butter were 0·139, 0·041, 0·051 and 0·047% respectively.
713. The relation between the chemical composition of milk and the stability of the caseinate complex: II. Coagulation by ethanol
Authors: Davies D. T. , White J. C. D. 
Published: June 2009

1. The variation in the stability of milk protein to ethanol and the relationship between milk composition and ethanol stability were examined.2. Samples of herd bulk milk were very similar in stability to ethanol; the range of aqueous ethanol solutions required to coagulate the caseinate complex in an equal volume of milk was only 80–84% (v/v) ethanol. Samples from individual cows showed a wide variation in stability; coagulation was caused by ethanol solutions ranging in strength from 66 to 90% (v/v) ethanol.3. Colostrum was very unstable to ethanol but stability rapidly increased during the post-colostrum period to higher levels in mid-lactation. Late lactation and subclinical mastitis milk showed no definite bias towards stability or instability.4. The strength of ethanol required to coagulate the caseinate complex in an equal volume of milk was inversely related to the concentration of ionized calcium in the milk. The correlation coefficient was –0·76 (significant at 0·001 level) indicating that approximately 60% of the variation in stability was accounted for by the variation in the concentration of ionized calcium.5. The relationships between the concentrations of other milk constituents and stability to ethanol could be attributed to the interrelations of the concentrations of these constituents and the concentration of ionized calcium.
724. Levels of feeding of concentrates for dairy heifers before and after calving
Authors: Broster W. H. , Ridler B. , Foot A. S. 
Published: June 2009

1. Two levels of steaming-up and two levels of concentrates feeding during the first 84 days of lactation have been compared in a 2 x 2 factorial experiment over three winter seasons, using fifty-two Shorthorn and thirty-six Friesian heifers. The levels of steaming up were 2 cwt. and ½ cwt. of concentrates fed over the last 21 and 14 days of pregnancy, respectively. The levels of concentrates during lactation were 5 and 3 lb. per 10 lb. milk per day. Roughages were fed for maintenance. After the 84th day of lactation all animals were given the same treatment for the remainder of the lactation. Milk yield, milk composition and live weight were measured throughout the lactation.2. The treatments were annotated as HH, HL, LH and LL, the first letter indicating level of steaming-up and the second the level of concentrates feeding in the first 12 weeks of lactation.3. Mean milk yields were as follows:4. The LH treatment reqiuird 3 cwt. more concentrates than HL to produce the same amount of milk.5. The response to additioal concentrates on the LH treatment after calving was l lb. additional milk per l lb. additional starch equivalent.6. Butterfat percentages were higher (3·69%) in both groups on low-lactation feeding than in the two groups on high-lactation feeding (3·43%). The HL group (i.e. the group that received high steaming-up and low-lactation feeding) combined high milk yield with a higher butterfat percentage, and at current milk and feedingstuff prices and under the conditions of the trials, this group showed a greater cash return than the groups on the other three treatments.
726. Histological changes in the mammary gland of guinea-pigs during lactation
Authors: Naito M. 
Published: June 2009

Certain histological factors of the mammary gland and the DNA content unit per dry weight were studied at four stages of lactation in guinea-pigs.The porosity index, the number of alveoli per field, the number of cells per field and the DNA content, showed maximal values at parturition and minimal values at the peak of lactation, whereas the opposite trend was shown by the value for modal alveolar diameter and the number of cells per modal alveolus.The relationships between these results are discussed.
738. Phospholipids in New Zealand dairy products: III. Effect of storage on the phospholipids and on the partition of phosphorus in butter
Authors: McDowell A. K. R. 
Published: June 2009

Average values for the total phosphorus content of sera from unsalted butter samples and for the phosphorus contents of the various fractions of the sera after partition with trichloroacetic acid were: total P, 83·6 mg./100g.; acid-soluble P, 32·4 mg./100 g.; inorganic P, 28·8 mg/100 g.; acid-insoluble P, 51·2 mg./100 g.; and phospholipid p, 33·6 mg./100 g.There was no evidence that decomposition of the phospholipids or other organic phosphorus compounds occurred in salted or unsalted sweet-cream butters during storage at –10° C. for 8 months.