| Abstrakt: |
Feed intake is the cornerstone of animal productivity. The consequences of inadequate intake include inhibited growth, delayed puberty, infertility, reduced milk production, and lowered resistance to parasites and disease. Factors that influence intake include age, metabolic demand (gestation, lactation, and level of physical activity), thermal environment, photoperiod, disease, and psychosocial stress. Under some conditions intake is adequate for health and wellbeing but is limiting for optimum performance and productivity. The role of the central nervous system, particularly the hypothalamus, has long been recognized in the control of appetite. A variety of hormones and neurotransmitters are involved in the modulation of neural pathways that stimulate or suppress appetite. Complementary DNA sequences and clones for these regulatory factors in livestock are rapidly being generated, providing new tools for physiological studies and the production of recombinant/synthetic hormones and analogs. An understanding of the interactions between environmental factors and the mechanisms of appetite control is fundamental to the development of practical approaches to optimize feed intake, which will usher in a new era of research in redefining the limits of productivity. An important component of this future research will be to ensure that enhanced intake is used efficiently for the production of high-quality food products. |
