Type

Journal Article

Authors

Stephen T. Butler
P. Lonergan
A.C.O. Evans
Richard J. Dewhurst
A. A. Hennessy
Ian A. Hutchinson

Subjects

Veterinary

Topics
conjugated linoleic acid dairy production estrous cycle dairy cattle milk production milk fat reproduction energy balance

The effect of strategic supplementation with trans-10,cis-12 conjugated linoleic acid on the milk production, estrous cycle characteristics, and reproductive performance of lactating dairy cattle (2012)

Abstract The objective was to determine the effects of a protected (lipid-encapsulated) conjugated linoleic acid (LE-CLA) supplement on milk production, estrous cycle characteristics, and reproductive performance in lactating dairy cows on a pasture-based diet. Spring calving dairy cows (n = 409) on a single pasture-based commercial dairy farm were used in a completely randomized block design. Cows were assigned to 1 of 2 dietary supplements [LE-CLA (n = 203) or no supplement (control, n = 206)]. The LE-CLA cows received 51 g/d of a lipid supplement containing 5 g of both trans-10,cis-12 and cis-9,trans-11 CLA from 0 to 60 d in milk. Milk samples were collected 3 times weekly, and each sample was analyzed for progesterone to determine the interval to first ovulation and estrous cycle characteristics. Milk yield and concentrations of fat, protein, and lactose were measured every 2 wk. Cows were inseminated following visual observation of estrus. The breeding season commenced on April 8, 2009 and continued for 16 wk. Transrectal ultrasonography was carried out at 30 to 36 d and 60 to 66 d post-AI to diagnose pregnancy. The LE-CLA treatment resulted in a decrease in milk fat concentration (36.9 ± 0.06 g/kg vs. 30.7 ± 0.06 g/kg for control and LE-CLA, respectively) and yield (0.91 ± 0.02 kg/d vs. 0.84 ± 0.02 kg/d for control and LE-CLA, respectively); however, milk yield was increased by LE-CLA supplementation (24.7 ± 0.7 kg/d vs. 27.2 ± 0.7 kg/d for control and LE-CLA, respectively), resulting in no overall difference in milk energy output. No effect of LE-CLA was observed on any estrous cycle characteristics or measures of reproductive performance. These results support that in pasture-based systems of dairy production, where energy intake limits milk production, energy spared by CLA-induced milk fat depression is partitioned toward increasing milk yield rather than toward body reserves.
Collections Ireland -> Teagasc -> Animal & Bioscience
Ireland -> Teagasc -> Animal & Grassland Research & Innovation Programme

Full list of authors on original publication

Stephen T. Butler, P. Lonergan, A.C.O. Evans, Richard J. Dewhurst, A. A. Hennessy, Ian A. Hutchinson

Experts in our system

1
S T Butler
Teagasc
Total Publications: 81
 
2
P. Lonergan
University College Dublin
Total Publications: 190
 
3
A.C.O. Evans
University College Dublin
Total Publications: 92
 
4
Richard J. Dewhurst
Teagasc
Total Publications: 10
 
5
A. A. Hennessy
Teagasc
Total Publications: 19
 
6
I A Hutchinson
Teagasc
Total Publications: 10