title: Does supplementation of beef calves by creep feeding systems influence milk production and body condition of the dams?
abstract: The aim of this study was to evaluate the effects of beef calves' supplementation in creep feeding systems on milk yield, body weight (BW), and body condition score (BCS) of their dams on tropical pastures using a meta-analytical approach. The database was obtained from 11 experiments conducted between 2009 and 2014 in Brazil, totaling 485 observations (cows). The database consisted of 273 Nellore and 212 crossbred (7/8 Nellore × 1/8 Holstein) cows. All experiments were carried out in the suckling phase (from 3 to 8 months of age of calves) during the transition phase between rainy and dry seasons from February to June of different years. The data were analyzed by a meta-analytical approach using mixed models and taking into account random variation among experiments. Calves' supplementation (P ≥ 0.59) and the calves' sex (P ≥ 0.48) did not affect milk yield of cows. The average fat-corrected milk (FCM) yield was 6.71 and 6.83 kg/day for cows that had their calves supplemented and not supplemented, respectively. Differences were observed (P < 0.0001) for milk yield due to the genetic group where crossbred cows presented greater FCM yield (7.37 kg/day) compared with Nellore cows (6.17 kg/day). There was no effect of the calves' supplementation on BW change (P ≥ 0.11) and BCS change (P ≥ 0.23) of the cows. Therefore, it is concluded that supplementation of beef calves using creep feeding systems in tropical pastures does not affect milk yield, body weight, or body condition of their dams.
authors.affiliation: Department of Animal Science, Universidade Federal de Viçosa, Viçosa, MG, 36570-900, Brazil.
authors.forename: Sidnei Antônio
authors.initials: SA
authors.lastname: Lopes
authors.affiliation: Department of Animal Science, Universidade Federal de Viçosa, Viçosa, MG, 36570-900, Brazil.
authors.forename: Mário Fonseca
authors.initials: MF
authors.lastname: Paulino
authors.affiliation: Department of Animal Science, Universidade Federal de Viçosa, Viçosa, MG, 36570-900, Brazil. detmann@ufv.br.
authors.forename: Edenio
authors.initials: E
authors.lastname: Detmann
authors.affiliation: Department of Animal Science, Universidade Federal do Oeste do Paraná, Marechal Cândido Rondon, PR, 85960-000, Brazil.
authors.forename: Ériton Egídio Lisboa
authors.initials: ÉE
authors.lastname: Valente
authors.affiliation: Department of Animal Science, Universidade Federal do Mato Grosso, Cuiabá, MT, 78060-900, Brazil.
authors.forename: Lívia Vieira
authors.initials: LV
authors.lastname: de Barros
authors.affiliation: Department of Animal Science, Universidade Federal de Viçosa, Viçosa, MG, 36570-900, Brazil.
authors.forename: Luciana Navajas
authors.initials: LN
authors.lastname: Rennó
authors.affiliation: Department of Animal Science, Universidade Federal de Viçosa, Viçosa, MG, 36570-900, Brazil.
authors.forename: Sebastião
authors.initials: S
authors.lastname: de Campos Valadares Filho
authors.affiliation: Department of Animal Science, Universidade Federal de Viçosa, Viçosa, MG, 36570-900, Brazil.
authors.forename: Leandro Soares
authors.initials: LS
authors.lastname: Martins
mesh_terms: D000821:Animal Feed / Q000032:analysis*; D000822:Animal Husbandry; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D000833:Animals, Suckling / Q000502:physiology; D001823:Body Composition; D001835:Body Weight; D001938:Brazil; D002417:Cattle / Q000502:physiology*; D003612:Dairying; D019587:Dietary Supplements; D005260:Female; D007774:Lactation; D008892:Milk / Q000378:metabolism*; D000069466:Red Meat / Q000592:standards; D012621:Seasons; D014329:Tropical Climate
keywords: Beef calves; Beef cows; Nellore; Supplements