The Role and Impacts of Growth Hormones in Maximizing Animal Production- A review

The purpose of the study is to examine the role and impacts of growth hormone in maximizing animal products. Growth hormones are biological stimulants that are found either naturally in the organism or synthetically manufactured. Phytoestrogens, phytoprogestrons and Phenolic compounds are hormones from plants. Drugs from of placenta and colostrums of cow`s contain progesterone, estrogene, gonadotropin, and prostaglandins hormones. Growth hormones have got popular applications in dairy, beef, feed improvement and Biopharmaceutical productions with the aim of producing valuable products: fat free meat (Porcine Somatotropin hormone in pigs), nutritionally and medicinally reach milk (Bovine Somatotropin hormone in cattle), palatable and disease and insect pest resistant forage crop production. They have got also contribution in maximizing livestock production by involving in adjusting animals’ reproductive process such as oestrus synchronization and superovulation mainly during artificial insemination and embryo transfer. Controversially, these hormones have wide impacts on human being, animal welfare, environment and etc. Contamination of ground water by hormones that are found in the animals` excreta will cause deleterious effects such as cancer, loss of fertility, and some imbalance of minerals in the water and soil.

431 Increasing IGF-1 concentrations in late pregnancy stimulates mammary development of gilts

The goal of this project was to determine if increasing insulin-like growth factor-1 (IGF-1) concentrations in late pregnancy can stimulate mammogenesis in gilts. Yorkshire x Landrace gilts (196.2 ± 6.2 kg BW on day 89 of gestation) were separated in two groups: 1) controls (CTL, n = 17) injected with sterile water, and 2) porcine somatotropin-treated (pST, n = 20) injected daily with 5 mg of pST (Reporcin®) from days 90 to 109 of gestation. Gilts were slaughtered on day 110 to collect mammary glands and blood samples were obtained on days 89, 96, 103 and 109 of gestation. Treated gilts gained more BW (P < 0.05) and lost more backfat (P < 0.05) than CTL gilts during treatment. There was a treatment x day effect (P < 0.01) on IGF-1, glucose and urea concentrations in blood. Concentrations of IGF-1 increased fourfold (P < 0.01) in pST compared with CTL gilts on days 96, 103 and 109 of gestation. Insulin values were also greater on days 96 (P < 0.01) and 103 (P = 0.01), and tended to be greater (P < 0.10) on day 109 of gestation in pST gilts. Glucose was greater in pST than CTL gilts on days 96 (P < 0.01), 103 (P < 0.01) and 109 (P = 0.01). Injections of pST did not affect weight of mammary extraparenchyma (P > 0.10) but increased mammary parenchymal mass (1922.2 vs 1576.1 ± 123.9 g, P < 0.05). Mammary parenchyma contained more (P < 0.05) protein, DNA and RNA and less fat (P < 0.05) and dry matter (P < 0.01) in pST than CTL gilts. These findings demonstrate that increasing circulating IGF-1 in late-pregnant gilts can stimulate mammary development both in terms of total parenchymal mass and of parenchymal tissue composition.