ORIGINAL PAPER
The effect of pre- and post-pubertal feeding levels on
the growth, reproduction, and future milk production of
Simmental dairy heifers
1 |
National Research Institute of Animal Production, Department of Animal Nutrition,
32-083 Balice, Poland |
2 |
The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences,
05-110 Jabłonna, Poland |
J. Anim. Feed Sci. 2007;16(2):155–167
Publication date: 2007-05-02
KEYWORDS
ABSTRACT
The effect of pre- and post-puberty feeding of rations diversified in terms of energy and protein
content on the growth rate, body condition, fatness, milk yield and reproduction efficiency of
Simmental heifers was investigated. The experiment was carried out on 40 Simmental heifers from
6 months of age to day 100 of lactation, allotted to 5 groups according to age and body weight.
During pre- (from 6 to 11 months of age) and post-puberty (from 12 to 13 months of age) the animals
were fed rations of different or the same levels of energy (UFL) and protein (PDI) as the control
Group K, which was fed according to IZ-INRA (2001). The respective levels of UFL and PDJ in
the rations for the experimental groups in both periods were, % of control Group K : Group A, 85/85
and 115/115; Group B, 85/115 and 100/100; Group C, 115/85 and 100/100; Group D, 115/115 and
115/ 115. From 14 months of age to day 100 of lactation the animals of all groups were fed the
same as the control group. Heifers that received higher UFL and lower BTJ (Group C) or increased
levels of energy and protein (Group D) in their pre-puberty rations than the control group, at 11-18
months of age and in the period from 6 months of age to calving, achieved higher body weight gain
than the animals of the remaining groups (P<0.05). Heifers fed rations with high pre-puberty energy
levels (Groups C and D) and lower protein levels (Group C) calved about 40 days earlier and had
a worse conception rate and insemination index (P>0.05) than animals in other groups. Total milk
production per cow in Groups A and B was about 11% higher than in Groups K and D, and about 6%
higher than in Group C, but the differences were not statistically significant (P>0.05). Independently of the protein level, feeding Simmental heifers pre-puberty period ration with a low energy level
followed by high-energy ration caused somewhat slower BWG from 6 months to calving, increased
the age of first mating and calving but stimulated milk production in primiparous cows.
CORRESPONDING AUTHOR
J. Strzetelski
National Research Institute of Animal Production, Department of Animal Nutrition,
32-083 Balice, Poland
CITATIONS (1):
1. |
Influence of green grass-based diets on growth and reproductive performance in dairy heifers M.R. Habib, M.H. Rashid, M.A. Islam, S. Majumder, K.M.S. Islam, S. Ahmed, M.S. Alam, E. Vargas-Bello-Pérez Tropical Animal Health and Production
|