The use of gluconeogenic supplements for dairy cows during the transition period has produced contradictory responses in the literature, making it difficult to recommend them. The objective of this trial was to evaluate supplementation with propylene glycol (PG), calcium propionate (CP), and "Dairy Power Drench ® " (DR) on the transitional period of Holstein cows. Parameters studied were variation of body condition score (BCS), body weight (BW), milk production (MP), reproductive efficiency and nonesterified fatty acid concentration (NEFA). One hundred and sixty five animals from two commercial herds were used. Treatments consisted of: C-Control; DR-administration of "Dairy Power Drench ® " (3 applications) during postpartum; CP-daily administration of calcium propionate (500 g); PG-daily administration of propylene glycol (500 mL). Variation sources studied were the effect of treatments and blocks as function of farm and parity. No interaction between time (weeks) and treatments, or treatment effects, were found for BCS. However, there was a quadratic effect of time. Body weight and its variation were not affected by treatment nor by the time × treatment interaction. However, a quadratic effect of time was observed. An interaction time × treatment was observed on MP, but possible differences within each week were not detected. Treatments also did not affect reproductive efficiency parameters. On average, the number of days to first detected postpartum estrus was 69.5, with 2.23 services per conception and 172.6 days open. The mean concentration of nonesterified fatty acids was 376.6 mmol L -1 and no effect of the interaction time × treatment, or of treatment, was observed. However, a linear effect was observed with time, with a decrease of 48.2 mmol L -1 per week. Key words: propylene glycol, calcium propionate, dairy power drench, Holstein cow, reproductive efficiency
PRODUTOS GLICONEOGÊNICOS NÃO AFETAM RESPOSTAS PRODUTIVAS, REPRODUTIVAS E SANGÜÍNEA DE VACAS HOLANDESAS EM TRANSIÇÃORESUMO: O uso de produtos gliconeogênicos para vacas leiteiras no período de transição tem gerado respostas contraditórias na literatura, dificultando a sua recomendação. O objetivo deste experimento foi avaliar a suplementação de propileno glicol (PG), propionato de cálcio (PC) e "Dairy Power Drench ® " (DR) no período de transição de vacas leiteiras sobre a variação do escore da condição corporal (ECC), peso vivo (PV), produção de leite (PL), eficiência reprodutiva e concentração plasmática dos ácidos graxos livres (AGL). Foram utilizadas 165 fêmeas de dois rebanhos comerciais. Os tratamentos foram: C-Controle; DR-3 aplicações de "Dairy Power Drench ® " no pós-parto; PC-500 g diários de PC e PG-500 mL diários de PG, até o 50º dia pós-parto, em média. As causas de variação estudadas foram efeito de tratamento e efeito dos blocos formados em função da fazenda e do número de partos. Não foi observado efeito de interação de tempo (semanas) × tratamento ou de tratamento sobre ECC. Entretanto, houve efeito quadrático de tempo. ...