Izvorni znanstveni članak
https://doi.org/10.33128/s.77.1-2.4
The estimate of energy intake and reproductive activity in high producing dairy cows
Matija Vrtarić
; Agronomski fakultet Sveučilišta u Zagrebu, Zagreb, Hrvatska
Krešimir Salajpal
; Agronomski fakultet Sveučilišta u Zagrebu, Zagreb, Hrvatska
Sažetak
Establishing the ovarian cycle in high-yielding dairy cows after calving is a common problem on farms with intensive milk production. High milk production requires an increased intake of energy and other nutrients necessary for milk synthesis, and in case of their deficiency, metabolic and reproductive disorders occur during lactation. In this paper we analyzed the energy intake and the reproductive indicators of high yielding dairy cows. Based on the protein and urea content and the ratio of milk fat and protein content, it was determined that 17.5% of the milk samples came from cows with insufficient energy intake. The period of early lactation (the first 60 days) is the most sensitive period in cows regarding to the sufficient energy and proteins intake. Results showed that 45% of the milk samples analyzed in this period have a deficit in energy intake, and in 16.5% of the samples, IMB was higher than 1.5, which suggests extensive mobilization of fat from body storages and the appearance of metabolic disorders. The establishment of the ovarian cycle expressed as the period until the first mating, in most cows was within 90 days after calving (74%), while in only 9% of cows this period was longer than 120 days. Despite this, in more than 32% of cows, pregnancy occurred after the 120th day of lactation, which indicates the absence of ovulation and/or the existence of unfavorable conditions for embryo survival (early embryonic mortality).
Ključne riječi
dairy cows; negative energy balance (NEB); milk protein; milk urea; ketosis
Hrčak ID:
304140
URI
Datum izdavanja:
19.6.2023.
Posjeta: 197 *