Final answer:
The concept of 'Optimal growth' is violated when there's decreased rate of gain, decreased feed efficiency, and undesirable carcass composition, reflecting issues with nutrient balance and growth efficiency in organisms.
Step-by-step explanation:
The concept violated when there is a decreased rate of gain, decreased feed efficiency, and undesirable carcass composition is B) Optimal growth. Optimal growth refers to the most favorable progression for an organism's size or number, taking into consideration the well-being and function of the organism. When this growth is compromised, it means the organism isn't receiving the right balance of nutrients to grow effectively and efficiently.
Good nutrition is essential for achieving optimal growth, as it requires healthy eating that encompasses a wide range of nutritious foods providing the right balance of nutrients. Nutrient balance and nutrient density are critical in ensuring that the organism, such as a livestock animal, is growing at an appropriate rate, using feed effectively, and producing a desirable carcass composition.
When malnutrition, overnutrition, or an imbalance in nutrition occurs, it can result in a negative impact on the biological and economic efficiency of growing livestock. Therefore, a shift away from these efficient states can yield poor growth outcomes, poor feed utilization, and ultimately undesirable carcass quality.