Metabolic effect of orotic acid in calves

Genetic analysis of orotic acid predicted with Fourier transform infrared milk spectra

Fourier transform infrared spectral analysis is a cheap and fast method to predict milk composition. A not very well studied milk component is orotic acid. Orotic acid is an intermediate in the biosynthesis pathway of pyrimidine nucleotides and is an indicator for the metabolic cattle disorder deficiency of uridine monophosphate synthase. The function of orotic acid in milk and its effect on calf health, health of humans consuming milk or milk products, manufacturing properties of milk, and its potential as an indicator trait are largely unknown. The aims of this study were to determine if milk orotic acid can be predicted from infrared milk spectra and to perform a large-scale phenotypic and genetic analysis of infrared-predicted milk orotic acid. An infrared prediction model for orotic acid was built using a training population of 292 Danish Holstein and 299 Danish Jersey cows, and a validation population of 381 Danish Holstein cows. Milk orotic acid concentration was determined with nuclear magnetic resonance spectroscopy. For genetic analysis of infrared orotic acid, 3 study populations were used: 3,210 Danish Holstein cows, 3,360 Danish Jersey cows, and 1,349 Dutch Holstein Friesian cows. Using partial least square regression, a prediction model for orotic acid was built with 18 latent variables. The error of the prediction for the infrared model varied from 1.0 to 3.2 mg/L, and the accuracy varied from 0.68 to 0.86. Heritability of infrared orotic acid predicted with the standardized prediction model was 0.18 for Danish Holstein, 0.09 for Danish Jersey, and 0.37 for Dutch Holstein Friesian. We conclude that milk orotic acid can be predicted with moderate to good accuracy based on infrared milk spectra and that infrared-predicted orotic acid is heritable. The availability of a cheap and fast method to predict milk orotic acid opens up possibilities to study the largely unknown functions of milk orotic acid.

Polyamines in goat's colostrum and milk

The concentration and secretion of putrescine (PTR), spermidine (SPD), and spermine (SPM) was examined in colostrum and milk of 60 dairy goats (Polish White and German Brown) during 90 days of lactation. It has been found that milk polyamine pattern is related to breed, age, offspring number, lactation period, milking time, and individual goat-to-goat variations. The mean level of PTR and SPD was significantly higher, whereas SPM level was significantly lower in German Brown than Polish White goats. These differences were maintained during whole observation period (90 days after parturition). Elder goats, bearing two and three kids, secreted colostrum with a higher concentration of PTR and a lower concentration of SPD than young goats having one kid. There was a highly significant positive relationship between the age or litter total weight and PTR concentration in colostrum of Polish White goats. In contrast to PTR, the SPD level was negatively correlated with the age or litter total weight. The daily secretion of PTR, SPD, and SPM progressively increased from the 1st to 90th day of lactation. It was dependent on the increase of milk secretion rate, which could be illustrated by the highly significant correlation between daily milk yield and secretion of SPD in milk of German Brown and Polish White goats. The concentration of SPD in milk sampled in the evening was usually higher than in that from morning milking, however, significant only in the case of German Brown goats. In general, goat's colostrum and milk are rich in polyamines, which the total concentration is the highest when compared to milk of other mammals examined so far (e.g., human, rat, sow, and cow).

Polyamines in cow's and sow's milk

There were considerably interspecies, individual, lactation and age related variabilities in the concentration of spermidine and spermine in cow's and sow's milk. Concentration of spermidine was similar in cow's and sow's milk, whereas spermine level was higher in sow's milk. The level of spermine was higher than spermidine throughout the lactation in sow's milk, whereas spermine in cow's milk was secreted only at the beginning of lactation (collostrum and milk of the first month of lactation). The peak of spermidine and spermine concentration occurred in the collostrum and milk between the 1st and 3rd week of lactation in cow and sow, respectively. There was a significant positive relationship between milk yield and spermidine secretion in cow as well as between the number of piglets and milk spermidine concentration in sow.

Polyamines and pyrimidines in blood plasma and urine of dogs bearing mammary tumours

The blood plasma and urinary pattern of polyamines and pyrimidines in dogs bearing mammary tumours was examined. A large variability of pyrimidines in blood plasma and spermidine, spermine and pseudouridine in urine of healthy and tumour-bearing dogs was observed. The blood plasma level of uracil and uridine as well as urinary concentration of pseudouridine and spermidine/spermine ratio were significantly elevated in dogs with mammary tumours.