Effects of far-off and close-up transition cow feeding on uterine health, postpartum anestrous interval, and reproductive outcomes in pasture-based dairy cows

S Meier; J K Kay; B Kuhn-Sherlock; A Heiser; M D Mitchell; M A Crookenden; M Vailati Riboni; J J Loor; J R Roche

doi:10.1186/s40104-019-0416-8

Effects of far-off and close-up transition cow feeding on uterine health, postpartum anestrous interval, and reproductive outcomes in pasture-based dairy cows

J Anim Sci Biotechnol. 2020 Feb 6:11:17. doi: 10.1186/s40104-019-0416-8. eCollection 2020.

Authors

S Meier¹, J K Kay¹, B Kuhn-Sherlock¹, A Heiser², M D Mitchell³, M A Crookenden^{2

4}, M Vailati Riboni⁵, J J Loor⁵, J R Roche^{1

6

7}

Affiliations

¹ DairyNZ Limited, Private Bag 3221, Hamilton, 3240 New Zealand.
² 2AgResearch, Hopkirk Research Institute, Grasslands Research Centre, Palmerston North, 4442 New Zealand.
³ 3Centre for Children's Health Research, Queensland University of Technology, Level 6, 62 Graham Street, South Brisbane, Queensland 4101 Australia.
⁴ 4DairyNZ Limited, c/o University of Auckland, 3A Symonds St, Auckland, 1010 New Zealand.
⁵ 5Department of Animal Sciences, University of Illinois, Urbana, 61801 USA.
⁶ 6Ministry for Primary Industries-Manatū Ahu Matua, Charles Ferguson Tower, Pipitea, Wellington, 6140 New Zealand.
⁷ 7School of Biological Sciences, University of Auckland, Private Bag 92019, Auckland, 1142 New Zealand.

Abstract

Background: In seasonal, pasture-based, dairy production systems, cows must recover from calving and become pregnant within two to 3 months. To achieve this, the uterus must involute and ovulation must occur and continue at regular intervals. As these processes are affected by the cows' nutritional or metabolic status post-calving, the objective of this study was to evaluate the effect of cow feeding strategies on uterine health, the length of postpartum anestrous interval, and reproductive outcomes. The treatments consisted of two feeding strategies during late-lactation and early dry period (far-off period; starting 4-month pre-calving) and three close-up dry period feeding regimes (1-month pre-calving) in a 2 × 3 factorial arrangement. We randomly assigned 150 cows to one of two far-off treatments. During late lactation, the herds (n = 75 cows per herd) were either control-fed (Controlfed) or over-fed (Overfed) to achieve a low or high body condition score (4-month pre-calving; BCS; ~ 4.25 and ~ 4.75; 10-point scale) at cessation of lactation. Within each of these treatments, three feeding levels were applied during the close-up period (1-month pre-calving): ~ 65% (Feed65), ~ 90% (Feed90), or ~ 120% (Feed120) of metabolizable energy (ME) intakes relative to pre-calving requirements.

Results: Uterine health improved (i.e. polymorphonucleated (PMN) cells declined) with increased feeding during the close-up period for cows in the Overfed group. The reverse was evident for the Controlfed group with the greatest PMN at the highest intakes during the close-up period. The postpartum anoestrous interval (PPAI) was shorter in cows from the Overfed group when moderately fed (Feed90) during the close-up period; in comparison, the PPAI was shorter in the Controlfed group, when those cows were overfed in the close-up period (Feed120). The cows in the Overfed treatment had greater conception and pregnancy rates if cows had moderate dry matter intakes (Feed90) during the close-up period; these reproductive variables were less under excessive feed intakes (Feed120); yet, close-up dry matter intake had little effect on conception and pregnancy rates for the Controlfed group.

Conclusions: The far-off feeding strategies increased early reproductive outcomes at 3 weeks of mating. Additionally, the interaction between far-off and close-up feeding strategies resulted in high six-week pregnancy rate with a slight restriction during the close-up period but only in the far-off Overfed group. Thus, our hypothesis is supported under these conditions.

Keywords: Close-up; Dairy cows; Far-off; Reproduction; Transition period.