Effects of a parenteral supplement of folic acid and its interaction with level of feed intake on hepatic tissues and growth performance of young dairy heifers

• Published in: Journal of animal science Vol. 69; no. 4; p. 1657
• Main Authors: Dumoulin, P.G. (Universite Laval, Quebec, Canada), Girard, C.L, Matte, J.J, St-Laurent, G.J
• Format: Journal Article
• Language: English
• Published: United States 01.04.1991
• Subjects: ACIDE FOLIQUE; ACIDO FOLICO; ADN; ALIMENTACION AD LIBITUM; ALIMENTATION A SATIETE; Animals; ARN; Cattle - blood; Cattle - growth & development; Cattle - metabolism; DNA - analysis; Eating - physiology; Female; FOIE; Folic Acid - administration & dosage; Folic Acid - analysis; Folic Acid - blood; Folic Acid - pharmacology; GAIN DE POIDS; GANANCIA DE PESO; Hematocrit - veterinary; HEMOGLOBINA; HEMOGLOBINE; Hemoglobins - analysis; HIGADO; INGESTION DE PIENSO; INJECTION; Injections, Intramuscular - veterinary; INYECCION; Liver - chemistry; Liver - drug effects; PESO; POIDS; PRISE ALIMENTAIRE (ANIMAUX); RNA - analysis; SERUM SANGUIN; SUERO SANGUINEO; TERNERO; VACAS LECHERAS; VACHE LAITIERE; VEAU; Weaning; Weight Gain - drug effects
• ISSN: 0021-8812; 1525-3163
• DOI: 10.2527/1991.6941657x

Forty-seven dairy heifers of approximately 10 d of age were assigned to a factorial experiment in which a supplement of folic acid (0 or 40 mg) administered weekly by i.m. injection and level of feed intake were the two factors studied. The heifers were weaned after 5 wk of experimentation. Following weaning, and until the end of the experiment, 11 wk later, they had ad libitum access to grass hay and concentrates at two different levels, ad libitum or restricted, to allow a body weight gain of 700 g/d. A supplement of folic acid (P .05) and ad libitum access to feed (P .05) increased the mean concentration of serum folates. Blood hemoglobin and packed cell volume were not affected by the level of feed intake. However, they were both increased (P .05) by the supplement of folic acid. Average daily gain was analyzed over three different periods: 0 to 5 wk (before weaning), 5 to 10 wk, and 10 to 16 wk Average daily gain was increased by the supplement of folic acid during the second period (P .05) and by ad libitum access to feed during the last two periods (P .05). Ad libitum access to feed increased (P .05) weight of the liver, decreased the (P .05) concentrations of RNA and DNA, and increased (P .05) the ratios of protein/DNA and RNA/DNA. The supplement of folic acid decreased (P .05) weight of the liver and increased the ratio RNA/DNA (P 05). These effects of supplement of folic acid on growth performance and on hematological cells may reflect a lack of folic acid during the weeks after weaning