PLoS ONE (Jan 2021)

Energy metabolism of pregnant zebu and crossbred zebu dairy cattle.

  • Helena Ferreira Lage,
  • Ana Luiza da Costa Cruz Borges,
  • Ricardo Reis E Silva,
  • Alan Maia Borges,
  • José Reinaldo Mendes Ruas,
  • Pedro Henrique Araújo de Carvalho,
  • Marcelina Pereira da Fonseca,
  • Paolo Antônio Dutra Vivenza,
  • Lúcio Carlos Gonçalves,
  • André Santos de Souza,
  • Antônio Último de Carvalho,
  • Elias Jorge Facury Filho,
  • Edilane Aparecida Silva,
  • Joana Ribeiro da Glória,
  • Alexandre Lima Ferreira,
  • Rodrigo Melo Meneses,
  • Eloísa de Oliveira Simões Saliba

DOI
https://doi.org/10.1371/journal.pone.0246208
Journal volume & issue
Vol. 16, no. 2
p. e0246208

Abstract

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The purpose of this study was to determine the energy partition of pregnant F1 Holstein x Gyr with average initial body weight (BW) of 515.6 kg and Gyr cows with average initial BW of 435.1 kg at 180, 210 and 240 days of gestation, obtained using respirometry. Twelve animals in two groups (six per genetic group) received a restricted diet equivalent to 1.3 times the net energy for maintenance (NEm). The proportion of gross energy intake (GEI) lost as feces did not differ between the evaluated breeds and corresponded to 28.65% on average. The daily methane production (L/d) was greater for (P0.05). The daily loss of energy as urine (mean of 1.42 Mcal/d) did not differ (P>0.05) between groups and ranged from 3.87 to 5.35% of the GEI. The metabolizable energy intake (MEI) of F1 HxG animals was greater (P 0.05), with a mean of 146.66 kcal/kg BW0. 75. The ME used by the conceptus was calculated by deducting the metabolizable energy for maintenance (MEm) from the MEI, which was obtained in a previous study using the same cows prior to becoming pregnant. The values of NEm obtained in the previous study with similar non-pregnant cows were 92.02 kcal/kg BW0.75 for F1 HxG, and 76.83 kcal/kg BW0.75 for Gyr (P = 0.06). The average ME for pregnancy (MEp) was 5.33 Mcal/d for F1 HxG and 4.46 Mcal/d for Gyr. The metabolizability ratio, averaging 0.60, was similar among the evaluated groups (P>0.05). The ME / Digestible Energy (DE) ratio differed between groups and periods evaluated (P0.05).