bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of abomasal infusions of sodium caseinate and of casein hydrolysates varying in the relative proportions of peptides and free amino acids on milk production in dairy cows
Authors: Choung Jai-Jun , Chamberlain David G. 
Published: June 2009

SummaryTwo experiments were conducted to test the hypothesis that responses of milk production to the abomasal infusion of casein or hydrolysates of casein can be influenced by the proportion of peptide-bound amino acids in the infusate. Eight lactating cows were used in two Latin square experiments with period lengths of 10 d. In Expt 1, the four cows were at a late stage of lactation and the four treatments were a basal diet of silage and a barley–soya supplement alone or with infusions into the abomasum of 180 g/d of sodium caseinate, an enzymic hydrolysate of casein or an acid hydrolysate of casein; all treatments supplied equivalent amounts of all the amino acids, this being achieved by addition of free amino acids as required. As infused, the three treatments contained 89 (caseinate), 40 (enzymic hydrolysate) and 15 (acid hydrolysate) % of their amino acids as peptides. The increase of milk production in response to infusion was small and there were no significant differences between the infusion treatments. In Expt 2, the cows received a basal diet of grass silage and a supplement containing feather meal as the main source of protein. Treatments were the basal diet alone and with three infusion treatments as in Expt 1, except that the amount infused was 230 g/d. The response to infusion was greater in this experiment, there were significant differences between infusions and the yield of milk protein with the infusion treatments was linearly related (P = 0·001) to the proportion of peptide-bound amino acids in the infusate. Moreover, there was a close inverse relation (P = 0·007) between the proportion of peptide-bound amino acids in the infusate and the concentration of total peptidebound amino acids in blood plasma.
Oscillatory rheological study of the effects of pH and salts on gel development in heated whey protein concentrate solutions
Authors: Tang Qingnong , McCarthy Owen J. , Munro Peter A. 
Published: June 2009

SummaryThe effects of pH and added NaCl or CaCl2 on gel development in heated whey protein concentrate (WPC) solutions were studied by oscillatory rheometry using a Bohlin rheometer, and by qualitative visual and tactile observations. The storage modulus (G′) exhibited maxima at pH values of about 4 and 7, while the phase angle (δ) exhibited minima at the same pH values. At pH 5·5, which lies within the range of the isoelectric points of the whey proteins, G′ was a minimum while δ was a maximum. At pH 7 and 8 G′ increased to a maximum and then decreased as added ionic strength was increased. At pH 4 G′ decreased steadily but slowly with increasing added ionic strength. The effects of CaCl2 were essentially the same as those of NaCl, but occurred at much lower added ionic strength. All the results are discussed in physicochemical terms. The main conclusions were, firstly, that changes in pH and salt concentration both affected gel development by altering the balance between attractive and repulsive protein-protein interactions, and secondly, that the effects of pH, salt concentration and salt type were interactive. Interaction both partly explains the wide variation in gel character and rheological properties among commercial WPC and potentially provides means of tailoring the gelling behaviour of a WPC so that it functions in a desired way in a given food system.
Identification of fibroblast growth factors in bovine cheese whey
Authors: Rogers Mary-Louise , Belford David A. , Francis Geoffrey L. , Ballard F. John 
Published: June 2009

SummaryAcidic and basic fibroblast growth factors (FGF) were identified in bovine cheese whey after partial purification using a two step procedure. Cation-exchange chromatography produced a mitogen-rich extract which was loaded on to a heparin-sepharose column and eluted stepwise with 0·8, 1·2 and 2·0 M-NH4HC03. Mitogenic activity was found in all three fractions by cell growth assays using Balb/c-3T3 fibroblasts. Immunoblotting identified acidic FGF in the 1·2 M-eluate and basic FGF in the 2·0 M-eluate, but neither acidic nor basic FGF was detected in the 0·8 M-fraction. Quantitative radioreceptor assays indicated 5·8 ng of acidic FGF-like activity and 19·8 ng of basic FGF-like activity per 1 whey in the appropriate eluates. This study represents the first direct demonstration of FGF in milk.
Occurrence of five αs1-casein variants in ovine milk
Authors: Chianese Lina , Garro Giuseppina , Mauriello Rosalba , Laezza Pasquale , Ferranti Pasquale , Addeo Francesco 
Published: June 2009

SummaryFive ovine αsl-casein variants (A–E) were identified in an Italian population sample using gel electrophoresis at alkaline pH, gel isoelectric focusing, two dimensional gel electrophoresis, and immunoblotting with polyclonal antibodies against αs1-casein. Each casein sample produced two peaks by fast reversed-phase HPLC. Gel isoelectric focusing and electrospray mass spectrometry were used to demonstrate that the first HPLC peak contained the 191 residue αsl-casein molecular species and the second the 199 residue species, in proportions of ∼20:80. Only in the case of the sample containing αsl-casein CE was the method for the separation of the single short and long forms of each variant unsuccessful. Both two dimensional electrophoresis followed by staining with polyclonal antibodies against αsl-casein and electrospray mass spectrometry showed a heterogeneity consistent with that expected from a protein chain with three levels of phosphorylation and two different lengths. However, especially for αsl-caseins D and E, a further uncharacterized heterogeneity was detected.
Milk protein standardization by ultrafiltration for Cheddar cheese manufacture
Authors: Guinee Timothy P. , O'Callaghan Donal J. , Mulholland Edward O. , Harrington Dermot 
Published: June 2009

SummarySkim milks were concentrated by ultrafiltration. Cream was added to the retentates to give cheesemilks standardized to a casein: fat ratio of ∼ 0·74 with protein levels ranging from 30 to 46 g/1. Pasteurized cheesemilks were renneted on a volume basis (22 ml single strength calf rennet/100 1) and converted to Cheddar cheese in 500 1 cheese vats. Set temperatures were reduced from 31 to 28 °C with increasing milk protein level to normalize curd firming rates and prevent curd shattering on cutting the curds. Cheesemaking was otherwise as normal for Cheddar cheese. The proportions of milk fat and protein lost in the cheese whey were not significantly influenced by milk protein level. Moisture-adjusted cheese yields increased with milk protein at a rate similar to that predicted by the Van Slyke cheese yield equation. However, owing to the negative correlation between cheese moisture and milk protein concentration, actual yields increased at a lower rate with respect to milk protein than moisture-adjusted yields. Increasing milk protein levels resulted in significant (P < 0·01–0·001) decreases in the concentrations of moisture, moisture-in-non-fat cheese solids and fat-in-dry matter in the cheese and increases (P < 0·05–0·001) in the levels of protein, salt-in-moisture, Ca and P. While increasing milk protein concentration resulted in significant (P < 0·05–0·01) reductions in the levels of water-soluble N at all stages of the 270d ripening period, it had little influence on the sensory scores awarded for aroma/flavour at 180 or 270d.
Field study on the relationship between teat thickness changes and intramammary infections
Authors: Zecconi Alfonso , Bronzo Valerio , Piccinini Renata , Moroni Paolo , Ruffo Gianfranco 
Published: June 2009

SummaryThe aim of this study was to describe the results of teat thickness measurement applied routinely in three commercial dairy herds and to evaluate the influence of machine-induced teat thickness changes on intramammary infection and the frequency of new infection. A total of 1018 fore milk samples and the same number of teat apex measurements have been evaluated. Overall, relative teat thickness changes were normally distributed (mean −0·16%, SD 10·15%), while a specific pattern could be observed within herds. Increases in teat thickness of > 5% were significantly associated with infection and new infection (odds ratio > 1), but the association was not significant when teat thickness decreased by more than 5%. When results were classified according to aetiology, analysis showed that coagulase-negative staphylococcal infections were significantly associated with both increases and decreases in teat thickness numerically greater than 5%.
Cisternal milk in the dairy cow during lactation and after preceding teat stimulation
Authors: Pfeilsticker Hans-Ulrich , Bruckmaier Rupert M. , Blum Jürg W. 
Published: June 2009

SummaryExperiments were designed to determine the cisternal milk during machine milking in unfamiliar surroundings, which has previously been shown to inhibit milking-related oxytocin (OT) release and milk ejection. The first experiment was performed with 22 cows in early, mid and late lactation. After cisternal milk was removed, 10 i.u. OT were twice injected intravenously to remove the remaining milk. Total milk yield, cisternal milk yield, cisternal milk fraction (17 and 12% in early and late lactation) and the milk yield obtained in response to the first OT injection significantly decreased from early to late lactation. Cisternal milk yield was similar in front and rear udder halves. However, owing to higher total yield, the cisternal milk fraction was lower in rear than in front halves. Cisternal milk yield and cisternal milk fraction were smaller in primiparous than in older cows. In a further experiment milk distribution in the bovine udder was evaluated after preceding teat stimulation and milk ejection. Teats of 12 cows were manually stimulated for 1 min at 15, 60 or 120 min before milking. Total milk yield was not significantly different with or without teat stimulation. However, cisternal milk yield and fraction were significantly higher in teat stimulated cows than in unstimulated controls but were similar whether cows were stimulated 15, 60 or 120 min before milking.
Temperature-induced effects on crystallization behaviour, solid fat content and the firmness values of milk fat
Authors: Foley John , Brady John P. 
Published: June 2009

SummaryThe temperature at which milk fat was crystallized was found to influence its firmness values, crystalline conformation and the percentage solid fat at 5 °C. Extremely rapid cooling of milk fat using liquid N2 (LNT) gave a product which, although it contained a relatively high solid fat content, was less firm and possessed a wider plastic range than milk fat crystallized at 15, 5 or –20 °C. Polymorphic transitions occurred in the LNT milk fat when it was subsequently held at 15 °C but not at 5 °C. Apparently the particular polymorphic modification has an important role in rheological behaviour.
Acetolactate synthase ofLeuconostoc lactisand its regulation of acetoin production
Authors: Cogan Timothy M. , Fitzgerald Richard J. , Doonan Shawn 
Published: June 2009

SummaryThe acetolactate synthase ofLeuconostoc lactisNCW1 was studied. The Mn2+content of cell free extracts was 3·2 µ/mg protein. The enzyme did not require Mn2+for activity, had an optimum pH between 5 and 6 and was labile. Incubation at 21 °C or addition of thiamine pyrophosphate followed by storage at 4 °C stabilized the enzyme. It was allosteric with at least two binding sites for pyruvate and was inhibited by several products of glucose metabolism (6-phosphogluconate, 3-phosphoglycerate, 2-phosphoglycerate, PEP and ATP) at pH 5·4. Except for ATP, which became more inhibitory, the inhibition disappeared completely (6-phosphogluconate, 2-phosphoglycerate, and PEP) or partly (3-phosphoglycerate) at pH 4·7. The role of these compounds in the regulation of acetoin production from citrate by leuconostocs is discussed.
A new calculation of the kinetics of the renneting reaction
Authors: Dalgleish Douglas G. 
Published: June 2009

SummaryA detailed calculation of the growth of molecular weight during the renneting of milk is given, based on a first-order breakdown of κ-casein followed by development of instability caused either by a decrease in the intermicellar repulsive potential or by the formation of holes in the stabilizing surface layer of the micelles. Unlike most of the models which have been described, this model allows a complete analytical solution. The solution is, however, complex and difficult to use simply, although it is shown that the calculations are in accord with experimental observations of the dependence of the coagulation process upon the enzyme concentration and the concentration of the milk. The calculations are also compared with those from other models of the reaction.
Field studies show associations between pulsator characteristics and udder health
Authors: Østerås Olav , Rønningen Odd , Sandvik Leiv , Waage Steinar 
Published: June 2009

SummaryFour different field studies including 64, 140, 850 and 180 herds were used to investigate the association between pulsator characteristics and udder health. The results indicate that the best udder health is found in herds with a d phase > 330 ms and a pulsation rate > 55 min-1. A d phase of < 250 ms was associated with significant elevation in bulk milk somatic cell count, a higher incidence of acute clinical mastitis and a higher frequency of cows having mastitis associated with major pathogens (mainly Staphylococcus aureus) as compared with a d phase of > 331 ms. There was also a significant positive association between a shorter d phase and a high incidence of teat lesions needing veterinary treatment. Herds having no such teat lesions had pulsators with significantly longer d phase than herds with teat lesions (300 ms ν. 288 ms). These results strongly suggest that in high-line milking machines the d phase should not be as short as 250 ms and should preferably be ∼ 300 ms, and the pulsation rate should be at least > 55 cycles min-1. There was a strong relationship between the effect of d phase and the rate of pulsation.
Distribution of plasminogen activator in different fractions of bovine milk
Authors: White Jeffrey H. , Zavizion Boris , O'Hare Kristen , Gilmore James , Guo Ming R. , Kindstedt Paul , Politis Ioannis 
Published: June 2009

SUMMARYThe type and relative amounts of plasminogen activator (PA) in different fractions of bovine milk obtained from 15 Holstein cows were examined. Raw milk was centrifuged to separate skim milk and a somatic cell pellet. PA was mainly localized within the casein fraction, being 42 times that in the serum, and in association with somatic cells. The predominant form of PA in milk casein was isolated from SDS-PAGE gel extracts and had a molecular mass of ∽75 kDa. Its activity was increased 41-fold (P < 0·01) in the presence of fibrin but was unaffected by the presence of amiloride, indicating that it was due to tissue-PA. The predominant forms of PA associated with milk somatic cells were isolated from SDS-PAGE gel extracts and had molecular masses of ∽ 30 and ∽ 50 kDa. The activity of both proteins was unaffected by the presence of fibrin but was dramatically reduced by the presence of amiloride, indicating that they represented urokinase-PA.
Effect of temperature on diacetyl and acetoin production byLactococcus lactissubsp.lactisbiovardiacetilactisCNRZ 483
Authors: Bassit Naïma , Boquien Clair-Yves , Picque Daniel , Corrieu Georges 
Published: June 2009

SUMMARYWe have investigated the effect of culture temperature on the growth ofLactococcus lactissubsp.lactisbiovardiacetilactis, on its acidifying power, on diacetyl and acetoin production, and also on the activities of the principal enzymes involved in the synthesis of these two compounds. The rates of growth and lactic acid production decreased by a factor of ∼ 2 when the temperature decreased from 30 to 18°C. At 18°C, the maximal concentration of diacetyl (0·3mM) was 1·7 times that at 30°C, while that of acetoin was unchanged (5·2 mM). These results are explained by the behaviour of the principal enzymes involved in pyruvate metabolism. The activities of lactic dehydrogenase and acetolactate synthase varied little for culture temperatures between 18 and 30·C. However, the activity of NADH oxidase for a culture temperature of 18°C was 3·7 times that for 30°C, while that of diacetyl reductase for 30°C was 2·7 times that for 18°C. The net effect of temperature on these two activities was an increase in diacetyl production at lower temperature.
Managers’ and Investors’ Responses to Media Exposure of Board Ineffectiveness
Authors: Joe Jennifer R. , Louis Henock , Robinson Dahlia 
Published: June 2009

AbstractWe analyze the impact of the press on the behavior of various economic agents by examining how media exposure of board ineffectiveness affects corporate governance, investor trading behavior, and security prices. Our focus on board quality is motivated by the strong media criticism to which corporate boards and corporate America, in general, have been recently subjected. The results indicate that media releases of (noisy) information have significant economic consequences. In particular, media exposure of board ineffectiveness forces the targeted agents to take corrective actions and enhances shareholder wealth. Individual investors appear to react negatively to the media exposure, whereas investment firms act as if they anticipate the targeted firms’ corrective actions.
The Role of the Media in the Internet IPO Bubble
Authors: Bhattacharya Utpal , Galpin Neal , Ray Rina , Yu Xiaoyun 
Published: June 2009

AbstractWe read all news items that came out between 1996 and 2000 on 458 Internet initial public offerings (IPOs) and a matching sample of 458 non-Internet IPOs (a total of 171,488 news items) and classify each news item as good news, neutral news, or bad news. We first document that the media were more positive for Internet IPOs in the period of the dramatic rise in share prices and more negative for Internet IPOs in the period of the dramatic fall in share prices. We then document that media hype is unable to explain the Internet bubble: A 1,646% difference exists in returns between Internet stocks and non-Internet stocks from January 1, 1997, through March 24, 2000 (the market peak), and the media can explain only 2.9% of that.
The response of hamsters to primary and secondary infection withTrichinella spiralisand to vaccination with parasite antigens
Authors: Behnke J.M. , Dehlawi M.S. , Rose R. , Spyropoulos P.N. , Wakelin D. 
Published: June 2009

AbstractThe duration of primary infections withT. spiraliswas dose-dependent with greater proportional loss of worms from heavily infected hamsters and longer persistence of worms in syngeneic DSN hamsters carrying initially low intensity infections. Intestinal worms were lost more rapidly from challenged immunized animals with over 80% loss of established worms by day 6 post infection, but survival of residual worms for a further 2 weeks. Hamsters carrying initially more than 140 intestinal worms began to lose weight during the second week indicating severe pathology at this stage of infection. Mucosal mast cell numbers increased from 50 cells/20 villus crypt units in uninfected animals to a peak in excess of 150 during week 4 pi, although intestinal mastocytosis persisted long after the loss of the majority of adult worms. Serum antibody responses to muscle stage larval antigen were detected in week 3 and increased subsequently. Both mastocytosis and antibody responses were more intense on secondary exposure to infection. Hamsters vaccinated with muscle stage larval antigen showed only a moderately accelerated loss of the intestinal phase but the fecundity of worms was severely suppressed. Overall it was concluded that the hamster host provided a model of trichinellosis that, in many respects was closer than mice and rats to the pattern of infection seen in economically and clinically important host species.
Immunological Studies on Experimental Infection of Pigs withAscaris suumGoeze, 1782 I. An Introduction with a Review of the Literature and the Demonstration of Complement-fixing Antibodies in the Serum
Authors: Taffs L. F. 
Published: June 2009

1. An introduction to a study of immunity againstA. suumin the pig is given. A review of the literature on the life cycle, a note on terminology and a general discussion on immunity to helminths has also been included.2. By first removing the procomplementary activity of pig serum to guineapig complement with hydrochloric acid, it was possible to apply the complement fixation test to a study of the antibody response to experimental infection withA. suum.3. Using an alcoholic extract of uterus, oviducts and ovaries of the adult femaleAscarisworm as antigen, antibodies against this nematode were first detected in two experimentally infected pigs ten days after infection. A peak of antibody concentration from the thirteenth to the seventeenth day of infection was followed by a decline in the antibody content of the serum to the forty-first day; after which no antibody was detected.
Studies with Brugia pahangi. 15. Cobalt 60 irradiation of the worm
Authors: Oothuman Pakeer , Denham D. A. , McGreevy P. B. , Nelson G. S. 
Published: June 2009

ABSTRACTInfective larvae of Brugia pahangi were irradiated at 10, 25 or 45 krads by means of a Cobalt 60 source. In cats, 10 krads caused the worms to be stunted and sterile but allowed them to become 5th stage, migrate posterioly into the afferent lymphatic, and produce pathology.25 krads prevented the worms from developing beyond the early fourth stage and from migrating away from the popliteal lymph node. No gross pathological reactions were evident. 45 krads produced the same effects as 25 krads but the longevity of the worms was much reduced.
Dioctowittus spp. Chabaud and Le Van Hoa 1960 (Nematoda: Adenophorea) from Australian snakes
Authors: Jones H. I. 
Published: June 2009

ABSTRACTDioctowittus denisoniae n. sp. from Denisonia punctata differs from D. wittei and D. chabaudi in the smaller size, lack of vestigeal male precloacal sucker, short egg-filaments, the presence of lateral expansions at the posterior end in the male, and in the expansions of the oesophageal tissue between the stichocytes. Dioctowittus sp. from Liasis amethystinus differs from the three described species in the possession of lateral lobes at both extremities.
Balanotaeniidae fam. n. and Balanotaenia newguinensis sp. n. (Cestoidea; Caryophyllidea) from Tandanus (Siluriformes: Plotosidae) in New Guinea
Authors: Mackiewicz J. S. , Blair D. 
Published: June 2009

ABSTRACTBalanotaenia newguinensis sp. n. is described from Tandanus brevidorsalis from Papua New Guinea. It differs from B. bancrofti from Australia primarily in being much smaller, having the testes and vitellaria beginning at the same level, and in having the gonopore posterior to the ovarian commissure. On the basis of this new species and B. bancrofti a new family of the order Caryophyllidea is described. Unlike any of the other three families the vitellaria and testes are in the cortical parenchyma. Drawings of the new species, comparative muscle distribution within all families of the Caryophyllidea, and photographs of the inner longitudinal muscles of B. bancrofti complement the description.