Major differences between single or twin hair lambs in the immediate postpartum period: Metabolic and thermodynamic patterns detected by infrared thermography

• Published in: Journal of thermal biology 2022-07, Vol.107, p.103258-103258, Article 103258
• Main Authors: Paula de Sousa, Marco Antonio, Novita Esteves, Sérgio, Guimarães Maciel e Silva, André, Zandonadi Brandão, Felipe, Celi Chaves Daher, Luciara, Macedo Pezzopane, José Ricardo, Volante, Caio Augusto, do Nascimento Barreto, Andréa, Rossetto Garcia, Alexandre
• Format: Article
• Language: English
• Subjects: Adipose tissue (brown); Birth weight; Births; Body temperature; Cortisol; Hair; Hair sheep; Latency; Metabolism; Neonates; Newborn lamb; Ovis aries; Parturition; Postpartum; Precision livestock farming; Suckling behavior; Surface temperature; Thermography; Thermoregulation; Thyroid hormones; Triiodothyronine
• ISSN: 0306-4565; 1879-0992
• DOI: 10.1016/j.jtherbio.2022.103258

The objective was to evaluate the differences between hair lambs, born from single or twin births, regarding the latency periods for standing up and suckling, the vitality, glycemic, cortisol, and triiodothyronine concentrations, as well as the phenotypic characteristics related to the maintenance of homeothermy in the immediate postpartum. Single (n = 10) or twin (n = 12) Morada Nova lambs were evaluated after birth, during the first successful suckling (M0 = Timepoint 0), and at regular intervals of 20 min (M20, M40, M60). Lambs from single births had higher birth weight (3.09 vs 2.58 kg; P ≤ 0.05) and higher serum triiodothyronine concentration (267 vs 209 ng/dL; P ≤ 0.05) compared to twin lambs. There was a positive correlation between weight and blood glucose (0.57; P ≤ 0.05) for both single and twin lambs. The type of birth did not affect vitality, which was negatively associated with cortisol concentration (−0.53; P ≤ 0.05). Twin lambs had higher internal and ocular temperatures (39.29 vs 38.67 °C and 38.84 vs 38.13 °C; P ≤ 0.05, respectively). Body surface temperatures increased over time in both groups (P ≤ 0.05). An increase in the temperature of the hips region (ysingle = 27.88 + 0.019*time; R2 = 0.96; P = 0.019 and ytwin = 28.74 + 0.019*time; R2 = 0.94; P = 0.029) was observed for both single and twin lambs, which coincides with the region of brown adipose tissue deposition. The lowest absolute thermal variabilities between twin and single lambs in M0 and M60 were recorded in the midloin and integral dorsal area. The parturition type did not influence the latencies to stand up (P = 0.908) and for the first suckling (P = 0.888), and the vitality score (P = 0.353). Thus, single and twin lambs do not differ in neonatal behavior, but they presented specific metabolic strategies to regulate body temperature over time. Midloin and integral dorsal areas are anatomical regions suggested for use in serial thermographic monitoring. Infrared thermography may be an important complementary resource in neonatal care. •Vitality of single or twin lambs does not differ, but plasma cortisol was associated with vigour score at birth.•Twin lambs have higher rectal and ocular surface temperatures than single lambs.•Thermograms reveal an increase in body surface temperature (within 60 min after suckling).•Midloin and dorsal area are regions of interest for thermographic monitoring.•New applications using infrared thermography for the evaluation of individuals and fl