Plane of nutrition and folic acid supplementation between birth and four months of age on mammary development of dairy heifers

Abstract

. 1999. Plane of nutrition and folic acid supplementation between birth and 4 months of age on mammary development of dairy heifers. Can. J. Anim. Sci. 79: 227-234. Forty-seven dairy heifers of approximately 10 d of age were assigned randomly to a 2 × 2 factorial design to study the effects of folic acid supplementation (0 vs. 40 mg) administered weekly i.m. and levels of feed intake after weaning on mammary development. Folic acid treatment started immediately and all heifers were weaned 5 wk later. Heifers were then either fed ad libitum grass hay and concentrates or restricted to a body weight gain of approximately 700 g d -1 until slaughter at 4 mo of age. Average daily gain was affected by feed intake level after weaning (615 vs. 954 g d -1 ; P < 0.01); however, folic acid supplementation increased weight gain only during the 5-wk period following weaning (P < 0.05). Heifers fed ad libitum were 33 % heavier before slaughter (P < 0.001) but there was no effect due to folic acid supplementation (P > 0.05). There was no effect of treatments on serum prolactin and growth hormone concentrations (P > 0.05); overall, prolactin increased and growth hormone decreased over the 16-wk sampling period. However, serum IGF-1 concentrations were significantly higher in heifers fed ad libitum following weaning as compared with the feed-restricted animals (P < 0.001); overall, IGF-1 concentrations increased linearly between weeks 2 and 16 (P < 0.001). Plane of nutrition did not have any effect (P > 0.05) on the total volume of parenchymal tissue in the mammary gland (61.6 vs. 63.6 cm 3 ); however, ad libitum feeding increased significantly (P < 0.001) the volume of extraparenchymal tissue in the gland (262.0 vs. 1067.6 cm 3 ). After adjusting data for the difference in body weight at slaughter, the amount of parenchymal tissue was smaller in animals fed ad libitum (P < 0.05); this adjustment did not change the effect of plane of nutrition on mammary extraparenchymal tissue. In conclusion, a fast rate of gain after weaning up to 4 mo of age induced a large accumulation of mammary fat, but did not negatively affect the total amount of parenchymal tissue in the mammary gland of dairy heifers.Key words: Plane of nutrition, folic acid, mammary gland, IGF-1 Petitclerc, D., Dumoulin, P., Ringuet, H., Matte, J. et Girard, J. 1999. Taux de croissance et supplémentation en acide folique entre la naissance et l'âge de 4 mois sur le développement de la glande mammaire de génisses laitières. Can. J. Anim. Sci. 79: 227-234. Quarante-sept génisses âgées approximativement de 10 jours ont été distribuées aléatoirement selon un dispositif factoriel 2 × 2. Les deux facteurs étudiés ont été la quantité d'acide folique injectée i.m. par semaine (0 ou 40 mg) pendant 16 semaines et le niveau d'alimentation suivant le sevrage. Suite au sevrage, les génisses ont été alors alimentées à volonté de foin et de concentrés ou restreintes pour permettre un gain de poids moyen de 700 g jour -1 jusqu'à leur abattage à l'âge de quatre mois. Le gain moyen quot...

Effects of a high rate of gain for increasing lengths of time on body and mammary growth in prepubertal dairy heifers

“…Results from this current study are similar to those reported previously in that the high diet increased fat deposition in extraparenchymal fat and this was also found to be evident in perirenal fat. Parenchymal tissue adjusted for carcass weight also followed a similar trend to that reported in the literature (Sejrsen et al, 1982;Petitclerc et al, 1999). However, analysis of mammary tissue composition is ongoing and must be completed before fi nal conclusions are made.…”

“…But, mammary development and milk yield potential are hindered when prepubertal dairy heifers are fed for a high rate of gain for lengths of time greater than 3 months (Sejrsen et al, 1982;Petitclerc et al, 1999;Radcliff et al, 2000). However, the effects of a high rate of gain for shorter periods have not been reported.…”

Effects of rumen‐protected folic acid and dietary protein level on growth performance, ruminal fermentation, nutrient digestibility and hepatic gene expression of dairy calves

“…Similarly, Lee et al, () found that plasma IGF‐1 increased with increasing dietary CP level in steers. However, Petitclerc et al, () found that serum GH and IGF‐1 were unaltered with 40 mg FA intramuscular injection weekly in dairy heifers. The higher FA supplementation dose (about 176 mg weekly) of the current study should be the reason for the divergent results.…”

“…Dietary FA supplementation could promote milk protein synthesis by elevating the transfer efficiency of one‐carbon units (Girard, Lapierre, Matte, & Lobley, ; Graulet et al, ). Average daily gain (ADG) was increased with intramuscular injection of FA in calves (Dumoulin, Girard, Matte, & StLaurent, ; Petitclerc, Dumoulin, Ringuet, Matte, & Girard, ). Yields of milk and milk protein were increased with FA supplementation in dairy cows (Graulet et al, ).…”

Effects of rumen-protected folic acid on ruminal fermentation, microbial enzyme activity, cellulolytic bacteria and urinary excretion of purine derivatives in growing beef steers

“…However, literatures have demonstrated that folic acid administered by intramuscular injections or dietary supplementation improved the growth of weaned dairy calves (Petitclerc et al, 1999) and heifers (Dumoulin et al, 1991) and increased milk yields and milk component production in dairy cows (Girard and Matte, 1998;Graulet et al, 2007;Li et al, 2016). Furthermore, some literatures reported that the synthesis of folic acid in the rumen ranged from 16.5 to 21.0 mg/d in dairy cows (Santschi et al, 2005;Schwab et al, 2006), while the estimated folic acid requirement of a cow with 650 kg BW and 35 kg of fat-corrected milk yield was 35 mg/d (NRC, 2001).…”