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THE EFFECT OF DIETARY ENERGY CONTENT ON PERFORMANCES OF HIGH YIELDING COWS
Marija Uremović
; Agronomski fakultet Sveučilišta u Zagrebu, Zavod za specijalno stočarstvo, Zagreb, Republika Hrvatska
Zvonimir Uremović
; Agronomski fakultet Sveučilišta u Zagrebu, Zavod za specijalno stočarstvo, Zagreb, Republika Hrvatska
Ivan Katalinić
; Poljoprivredni centar Hrvatske, Zagreb, Republika Hrvatska
Sažetak
Effects of different energy levels in rations on production indexes were studied with two groups of HF cows (N=22) during 50 days of dry period and with four groups of cows during 90 days of lactation. First group of cows consumed 50.23 MJ/day of net energy during the dry period, whereas the second group consumed 62.91 MJ day or 25.24% more. First group of cows gained 30 kg between the 50ᵗʰ and the 15ᵗʰ day to parturition, the other group gained 39 kg. The difference in body weight gain (9 kg) was nonsignificant (P>0,05). During the 90 days of lactation daily net energy consumption per group of cows (low-low, low-high, high-low) was: 119.78, 137.86, 125.28 and 143.1 MJ/day, Average daily milk production and average milk fat percentages during the 90 days of lactation were: 33.0, 40.5, 35.7, 38.1, kg and 3.55, 3.37, 3.50 and 3.54% respectively. Differences in milk production were highly significant (P<0,01), whereas in percent of lactic fat were nonsignificant (P>0.05). Average daily body weight loss in periods between the 3rd and the 20th and the 3rd and the 60th day after calving were: 0.94, 2.76, 2.0, 2.88 and 0.46, 0.84, 0.74 and 1.05 respectively. Effect of energy level in a ration on body weight of cows change was significant (P<0,05) at the end of the investigation (the 80ᵗʰ day) of lactation. The highest milk production at lesser body weight loss was found in cows fed low energy level in dry period and high energy level during lactation. Milk production level and cows body weight after calving had highly significant effect on cows body weight loss after calving (r=0.551 ** and 0.571 **).
Ključne riječi
cow, body weight,; milk production; lactation
Hrčak ID:
164787
URI
Datum izdavanja:
10.7.1993.
Posjeta: 576 *