Login | Request Account (DAF staff only)

Relationships among calving season, heat load, energy balance and postpartum ovulation of dairy cows in a subtropical environment

View Altmetrics

Jonsson, N.N., McGowan, M. R., McGuigan, K., Davison, T.M., Hussain, A.M., Kafi, M. and Matschoss, A. (1997) Relationships among calving season, heat load, energy balance and postpartum ovulation of dairy cows in a subtropical environment. Animal Reproduction Science, 47 (4). pp. 315-326. ISSN 0378-4320

Full text not currently attached. Access may be available via the Publisher's website or OpenAccess link.

Article Link: https://doi.org/10.1016/S0378-4320(97)00014-6


The study was designed to examine the relationships among calving season, energy balance, temperature humidity index (THI), and postpartum ovulation in high producing cows in a subtropical environment. Holstein cows calving in a feedlot dairy in southeast Queensland during winter (n = 23) and summer (n = 21) were monitored during the first 9 weeks of lactation. Cows were weighed and blood samples collected twice weekly; plasma progesterone, plasma metabolites related to energy and mineral balance, and haematological measurements were performed. Milk production was measured, body condition score was estimated, and trans-rectal ultrasound examinations of the ovaries were each undertaken once a week. The interval between calving and first ovulation was significantly longer in cows calving in summer (22.8 vs. 17.6 days, P < 0.05). Interval from calving to the first postpartum ovulation (FOVL) was inversely related to the mean plasma glucose concentration for the first 9 weeks after calving (GLU): FOVL = 80.0 − 17.9GLU, (R2 = 0.25, P < 0.001). Plasma progesterone concentration during the life of the second corpus luteum after calving was negatively correlated with THI during the first 2 weeks after calving (r = 0.55, P < 0.001). Plasma glucose concentration (GLU) was negatively correlated with milk yield (MYD) and rectal temperature (RT), and positively correlated with plasma calcium concentraction (Ca) according to the following regression equation. GLU = 33.1 − 0.02MYD + 0.91Ca − 0.48RT, (R2 = 0.58, P = 0.0001).

Item Type:Article
Keywords:Cattle; Energy balance; Temperature humidity index; Postpartum ovulation; Seasonal dynamics
Subjects:Animal culture > Breeding and breeds
Animal culture > Cattle
Live Archive:19 Mar 2024 00:58
Last Modified:19 Mar 2024 00:58

Repository Staff Only: item control page