Effect of rumen-protected choline on performance, blood metabolites, and hepatic triacylglycerols of periparturient dairy cattle

Abstract

The effects of a dietary supplement of rumen-protected choline on feed intake, milk yield, milk composition, blood metabolites, and hepatic triacylglycerol were evaluated in periparturient dairy cows. Thirty-eight multiparous cows were blocked into 19 pairs and then randomly allocated to either one of 2 treatments. The treatments were supplementation either with or without (control) rumen-protected choline. Treatments were applied from 3 wk before until 6 wk after calving. Both groups received the same basal diet, being a mixed feed of grass silage, corn silage, straw, and soybean meal, and a concentrate mixture delivered through transponder-controlled feed dispensers. For all cows, the concentrate mixture was gradually increased from 0 kg/day (wk -3) to 0.9 kg of dry matter (DM)/d (day of calving) and up to 8.1 kg of DM/d on d 17 postcalving until the end of the experiment. Additionally, a mixture of 60 g of a rumen-protected choline supplement (providing 14.4 g of choline) and of 540 g of soybean meal or a (isoenergetic) mixture of 18 g of palm oil and 582 g of soybean meal (control) was offered individually in feed dispensers. Individual feed intake, milk yield, and body weight were recorded daily. Milk samples were analyzed weekly for fat, protein, and lactose content. Blood was sampled at wk -3, d 1, d 4, d 7, d 10, wk 2, wk 3, and wk 6 and analyzed for glucose, nonesterified fatty acids, and β-hydroxybutyric acid. Liver biopsies were taken from 8 randomly selected pairs of cows at wk -3, wk 1, wk 4, and wk 6 and analyzed for triacylglycerol concentration. We found that choline supplementation increased DM intake from 14.4 to 16.0 kg/d and, hence, net energy intake from 98.2 to 109.1 MJ/d at the intercept of the lactation curve at 1 day in milk (DIM), but the effect of choline on milk protein yield gradually decreased during the course of the study. Choline supplementation had no effect on milk yield, milk fat yield, or lactose yield. Milk protein yield was increased from 1.13 to 1.26 kg/d at the intercept of the lactation curve at 1 DIM, but the effect of choline on milk protein yield gradually decreased during the course of the study. Choline supplementation was associated with decreased milk fat concentration at the intercept of the lactation curve at 1 DIM, but the effect of choline on milk fat concentration gradually decreased as lactation progressed. Choline supplementation had no effect on energy-corrected milk yield, energy balance, body weight, body condition score, and measured blood parameters. Choline supplementation decreased the concentration of liver triacylglycerol during the first 4 wk after parturition. Results from this study suggest that hepatic fat export in periparturient dairy cows is improved by choline supplementation during the transition period and this may potentially decrease the risk for metabolic disorders in the periparturient dairy cow.

Efeito da suplementação com colina protegida sobre parâmetros bioquímicos, produção e reprodução de vacas leiteiras no periparto

“…Quanto ao efeito da colina, Piepenbrink e Overton (2003) também não detectaram diferença nos teores de BHBA em animais no periparto em nenhuma das doses testadas. A colina diminui a deposição de gordura no fígado (Zom et al, 2011), maximizando a função hepática e, por consequência, reduzindo a formação de corpos cetônicos e o risco de cetose. Os teores de BHBA foram elevados no presente estudo em comparação aos valores encontrados para animais nos primeiros 30 dias de lactação (Alvarenga et al, 2015 Variáveis: BHB = beta-hidroxibutirato; AGNE = ácido graxo não esterificado; AST = aspartato aminotransferase; GGT = gamaglutamiltransferase; IGF = fator de crescimento semelhante à insulina; TOS = status oxidante total.…”

“…De acordo com essa relação, os resultados do presente estudo foram similares ao observados por Zom et al (2011), que também não detectaram efeito da suplementação com colina nos teores de glicose em vacas leiteiras. Guretzky et al (2006) descreveram uma correlação positiva entre os teores de colesterol sérico e o consumo de matéria seca, sendo este um marcador metabólico confiável de ingestão para ruminantes.…”

“…A média de produção para os dois grupos ao final dos primeiros 30 dias de lactação foi de 26,7 ± 1,1L/dia para o grupo controle e de 25,7 ± 0,6L/dia para o grupo tratado. Resultados semelhantes foram descritos por Davidson et al (2008) e por Zom et al (2011). No entanto, Zahra et al (2006) detectaram um aumento médio de 1,2kg nos primeiros 60 dias pós-parto, quando os animais foram suplementados com colina, e Pinotti et al (2003) descreveram um aumento médio de 2,9kg no primeiro mês de lactação em vacas tratadas com colina.…”

Dietary effects of linseed on fatty acid composition of milk and on liver, adipose and mammary gland metabolism of periparturient dairy cows

“…Liver biopsies were performed as explained by Zom et al. (). Approximately 2 g of liver tissue in total was collected.…”

“…During the biopsies, the cows were in a standing position, fixed in a headlock feed barrier. Liver biopsies were performed as explained by Zom et al (2012). Approximately 2 g of liver tissue in total was collected.…”