Energy metabolism of pregnant zebu and crossbred zebu dairy cattle.

Autor: Lage HF; Veterinary School, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil., Borges ALDCC; Veterinary School, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil., Silva RRE; Veterinary School, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil., Borges AM; Veterinary School, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil., Ruas JRM; Departament of Animal Science, Unimontes, Janaúba, Minas Gerais, Brazil., Carvalho PHA; Veterinary School, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil., Fonseca MPD; Veterinary School, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil., Vivenza PAD; Veterinary School, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil., Gonçalves LC; Veterinary School, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil., Souza AS; Veterinary School, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil., Carvalho AÚ; Veterinary School, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil., Facury Filho EJ; Veterinary School, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil., Silva EA; Empresa de Pesquisa Agropecuária de Minas Gerais, Uberaba, Minas Gerais, Brazil., Glória JRD; Veterinary School, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil., Ferreira AL; Veterinary School, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil., Meneses RM; Veterinary School, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil., Saliba EOS; Veterinary School, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
Jazyk: angličtina
Zdroj: PloS one [PLoS One] 2021 Feb 04; Vol. 16 (2), pp. e0246208. Date of Electronic Publication: 2021 Feb 04 (Print Publication: 2021).
DOI: 10.1371/journal.pone.0246208
Abstrakt: 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 (P<0.05) F1 HxG compared to Gyr animals. However, when expressed as L/kg dry matter (DM) or as percentage of GEI there were no differences between the groups (P>0.05). 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) at all gestational stages compared to Gyr cows when expressed in Mcal/d. However, when expressed in kcal/kg of metabolic BW (BW0,75), the F1 HxG cows had MEI 11% greater (P<0.05) at 240 days of gestation and averaged 194.39 kcal/kg of BW0,75. Gyr cows showed no change in MEI over time (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 (P<0.05) with a mean of 0.84. The heat increment (HI) accounted for 22.74% and 24.38% of the GEI for F1 HxG and Gyr cows, respectively. The proportion of GEI used in the basal metabolism by pregnant cows in this study represented 29.69%. However, there were no differences between the breeds and the evaluation periods and corresponded to 29.69%. The mean NE for pregnancy (NEp) was 2.76 Mcal/d and did not differ between groups and gestational stages (P>0.05).
Competing Interests: The ‘Empresa de Pesquisa Agropecuária de Minas Gerais (EPAMIG)’ cannot be classified as a commercial company. It was established as a public company in 1974 with the purpose of developing research and experimentation directly and indirectly related to agriculture and with the objective of becoming the main instrument for carrying out agricultural research activities in the State of Minas Gerais, Brazil. The author ‘Edilane Aparecida Silva’ associated with EPAMIG, provided support by donating research material. EPAMIG made the experimental animals available (all of them was originated from the experimental EPAMIG farm located at Felixlândia, Minas Gerais), but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript and that no competing or conflict of interests exists.
Databáze: MEDLINE
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