Program Puberty with Nutrition
High-concentrate diets can help program heifers to reach puberty at a younger age.
RUIDOSO, NEW MEXICO (Aug. 29, 2018) — At the Applied Reproductive Strategies in Beef Cattle symposium in Ruidoso, N.M., it was no surprise that reproduction was a hot topic. Rodolfo Cardoso, however, took the unique approach of encouraging ranchers to look at the vital process occurring before reproduction: puberty.
“High-concentrate diets will lead to those metabolic changes that create puberty at a younger age,” said Rodolfo Cardoso, Texas A&M University.
Cardoso said while most females hit puberty when they reach 65% of their mature weight, ranchers should still understand the various needs their cattle will have as they undergo puberty.
Puberty differs for Bos taurus and Bos indicus cattle, Cardoso noted. Ranchers should first understand the different timelines cattle of different origins have in pubertal development and nutritional requirements.
Cardoso said the traditional cattle operation should set a goal to have all heifers calve by the time they are 2 years old. With this goal in mind, Cardoso explained that ranchers have the means to help their heifers hit puberty early and should strive to do so.
Before telling ranchers how to go about achieving this goal, Cardoso first ensured ranchers understood the process of development females undergo in the early stages of life before pubertal development.
Preceding the start of puberty, reproductive regions in the animal’s brain will begin to mature, secreting gonadotropins, hormones crucial to ovarian stimulation. After uterine development and ovulation, the female is capable of maintaining and raising a fertilized egg.
While ranchers might be quick to believe this segment of Mother Nature is out of their control, Cardoso challenged cattlemen and women to start thinking differently.
Similar to the way parents play classical music to babies to help with brain development, Cardoso said ranchers can also “program the brains” of their heifers. This process is referred to as nutritional programming.
Nutritional programming does not include playing Mozart, but instead focuses on utilizing feeding programs to increase the amount of hormones produced by these developing heifers.
Cardoso identified insulin, IGF-1 and leptin as hormones responsible for triggering puberty in cattle. Using nutritional programming, Cardoso says ranchers can create a metabolic imprint at the hypothalamic level to accelerate puberty in heifers.
In one of his recent studies, Cardoso fed four groups of heifers between 4 and 6 months of age various levels of concentrated feeds. The females were continued on the diet until they reached 14 months of age.
The study showed females consuming the higher-concentrate diet exhibited higher levels of leptin and, therefore, experienced puberty sooner than females fed lower-concentrate diets.
“High-concentrate diets will lead to those metabolic changes that create puberty at a younger age,” Cardoso said.
In the study, 100% of heifers fed the higher-concentrated diet at 4 months of age and 90% of heifers started on the diet at 6 months of age were pubertal by the start of the breeding season.
Besides nutritional programming, Cardoso said genetics (such as breed), pre- and postweaning nutrition, and critical body weight also affect when heifers start to reach sexual maturation.
To build strong herds, Cardoso said females should experience multiple estrous cycles before the target first breeding, as this will increase their fertility. Furthermore, females calving within the first 21 days of the breeding season have a higher probability of continued early calving and long-term herd retention.
Whether ranchers engage in nutritional programming or not, Cardoso said the ability of a female to reach puberty and then go on to raise a calf is crucial to long-term productivity. He explained females have to wean between three to five calves to pay for the cost of their own development.
For details on Cardoso’s presentation — including the proceedings, PowerPoint and video of his presentation — visit the Newsroom at www.appliedreprostrategies.com.
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