Open AccessRelationship between feed efficiency indexes and thermography, blood, and ruminal parameters in pre-weaning dairy heifers
Author(s) -
C.F.A. Lage,
Sandra Gesteira Coelho,
H.C. Diniz Neto,
Victor Marco Rocha Malacco,
João Paulo Pacheco Rodrigues,
J. P. Sacramento,
V. A. Teixeira,
F. S. Machado,
Luiz Gustavo Ribeiro Pereira,
Thierry Ribeiro Tomich,
Mariana Magalhães Campos
Publication year - 2020
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0236118
Subject(s) - residual feed intake , zoology , propionate , feed conversion ratio , weaning , hay , feedlot , biology , morning , total mixed ration , ice calving , body weight , pregnancy , lactation , endocrinology , biochemistry , botany , genetics
The objective of this study was to evaluate whether pre-weaning heifer calves divergent for residual feed intake ( RFI ) or residual feed intake and body weight gain ( RIG ) exhibit differences in thermography, blood, and ruminal parameters. Thirty-two Gyr heifer calves were enrolled in a 63-d trial and classified into 2 feed efficiency ( FE ) groups based on RFI and RIG (mean ± 0.5 SD). The groups were classified as high efficiency ( HE ) RFI (HE RFI, n = 9), HE RIG (HE RIG, n = 10), low efficiency ( LE ) RFI (LE RFI, n = 10), and LE RIG (LE RIG, n = 11). The amount of whole milk provided for each calf was calculated based on their metabolic weight at birth (42% x BW 0.75 ). The liquid diet was divided into two meals at 0700 and 1400 h. The total solid diet ( TSD ) was composed of 92% concentrate and 8% of Tifton 85 hay chopped in 5-cm lengths, as fed. Intake was measured daily. Blood concentrations of insulin, beta hydroxybutyrate, urea, and glucose, and ruminal pH, N-NH 3 , and volatile fatty acids ( VFA ) were evaluated at 14, 28, 42, 56, and 70 days of age. Thermal images of the calves were taken with an infrared camera (FLIR T420, FLIR Systems Inc., Wilsonville, OR) on d 56 (±3) at 0600 h, before the morning feeding. Total VFA concentration and propionate as % of total VFA were 24.2% and 22.2% lower in HE RFI compared to LE RFI calves, respectively. On the other hand, acetate as % of total VFA was 10.6% greater in HE RFI than LE RFI calves. Blood urea concentration tended to be greater in LE RFI than HE RFI calves. High efficiency HE RIG tended to have 6.8% greater acetate and 15.4% lower propionate as % of total VFA than LE RIG. Blood insulin concentration was greater and blood glucose tended to be greater for LE RIG than HE RIG group. Low efficiency RIG group had greater left rib, left flank, and anus surface temperature measured by infrared thermography than the HE RIG group. Differences in ruminal fermentation do not seem to be associated with pre-weaning calves efficiency, while differences in protein metabolism seem to affect RFI during this phase. Infrared thermography appears to be correlated to RIG in pre-weaning heifer calves.