Differences in the level of urea in milk between standard and extended lactation period and the impact on the environment
Journal Title: Acta Scientiarum Polonorum Zootechnica - Year 2015, Vol 14, Issue 2
Abstract
The N concentration of milk urea is one of several factors that allow prediction of ammonia emissions from dairy cattle manure. The aim of the study was to investigate the effect of selected environmental factors on urea content in milk in the standard and extended lactation period in Polish Holstein-Friesian cows of the Black-and-White variety. The study has analysed 30 839 full lactations, which were at least one day longer than the standard 305-day lactation, but not longer than 600 days. The highest percentage of milk samples with optimal protein and urea content was found in extended lactation periods (>305 days). The percentage of milk tested during this period, containing urea from 150 to 270 mg/l, was 49.26%. The calculations also indicated that a significant influence on the differences in the milk urea content between the average standard and extended lactation period had an average daily production of milk in the first 305-day lactation. The higher the efficiency of the cow, the greater the difference in the level of urea in milk in the comparable periods of lactation. On the basis of these data it was estimated that the milk of cows producing on average more than 30 kg of milk per day contained approximately 12 mg/l more of urea in the standard lactation period than the milk of cows from the same group acquired during the extension. Overall, the results demonstrate that the urea content is higher in the milk from the second phase of lactation, in the milk of youngest cows (first to fourth parity), and in the milk of high yielding cows. It was found that the amount of urea in milk during extended lactation period was lower than in the first 10 months after calving. Due to the fact that the longer lactations resulted in lower levels of urea in milk and lower ammonia emission in last weeks of lactation, it was concluded that the full extended lactation had no negative impact on the environment.
Authors and Affiliations
Ewa Salamończyk, Piotr Guliński
Fatty acids profile and health lipid indices in the longissimus lumborum muscle of different beef cattle breeds reared under intensive production systems
The aim of this study was the comparison of the fatty acids profile and health lipid indices of the longissimus lumborum muscle from 86 bulls of the Charolais (CH), Limousin (LM), Simmental (SM), Salers (SL), Hereford (H...
Study by scanning electron microscopy of the morphogenesis of filiform and fungiform papillae in the rabbit, Oryctolagus cuniculus f. domestica
Rudiments of fungiform papillae were observed at day 18 of prenatal development. They were arranged only on the dorsal surface of the apex of the tongue and its margins. The fungiform papillae looked like a hemispherical...
POLYUNSATURATED FATTY ACIDS IN IDIOPATHIC EPILEPSY TREATMENT IN DOGS
Epilepsy is both a primary disease and secondary sign of various neurological and metabolic disorders. Idiopathic epilepsy could be burdensome in its course. It requires often a multidrug therapy, that can lead to seriou...
FATTY ACID BINDING PROTEIN 4 (FABP4) AND THYREOGLOBULIN (TG) POLYMORPHISMS IN RELATION TO MILK PERFORMANCE TRAITS IN THE HOLSTEIN-FRIESIAN CATTLE
Cows of the Polish Holstein-Friesian black-white variety were tested to identify c.328G>A polymorphism in the FABP4 gene and g.422C>T polymorphism in the TG gene. Three different genotypes (GG, GA and GG) were identified...
COMPARISON OF GROWTH RATE AND BODY WEIGHT OF DUCKS OF DIFFERENT ORIGINS
The aim of the study was to compare growth rate and body weight of Pekin and Muscovy ducks and their hybrids (mulards). It was established that up to week 6 of life inclusive, Pekin ducks weighed more compared to Muscovy...