The food requirements of dairy animals
are of two types: (a) (maintenance
requirement, which is the food required to
support the animal to live a healthy me, and
(b) milk producing requirement, which is the
type of food required during the lactation
period. Animal feed includes: (a) roughage,
which is largely fibre, and (b) concentrates,
which are low in fibre and contain relatively
high levels of proteins and other nutrients.
Cattle need balanced rations containing all
nutrients in proportionate amounts. Besides
such nutritious food material, certain feed
additives containing micronutrients promote
the health and milk output of dairy animals.
Answers
Answer:
Food supplies proteins, carbohydrates, fats, vitamins and minerals, all of which we require for body development, growth and health.
• Different crops require different climatic conditions, temperature and photoperiods for their growth and completion of their life cycle. Photoperiods are related to the duration of sunlight. Growth of plants and flowers are dependent on sunlight.
• Successful crop production depends upon many factors such as:
(i) Understanding how crops grow and develop.
(ii) Effect of various nutrients, climate, water on the growth of the plant.
(iii) Modification and management of each factor for increasing the yield of the crop.
• The crops which are grown in rainy season (the kharif season, from June to October) are called as kharif crops.
Example: Paddy, soyabean, pigeon pea, maize, cotton, green gram and black gram are kharif crops.
• The crops which are grown in winter season (the rabi season, from November to April) are called rabi crops.
Example: Wheat grain, peas, mustard and linseed are rabi crops.
• Crop variety improvement: It can be done either by hybridisation or by introducing a gene.
(i) Crop improvement by hybridisation: Hybridisation refers to crossing between genetically dissimilar plants. This crossing may be intervarietal (between different varieties), interspecific (between two different species of the same genus) or intergeneric (between different genera).
(ii) Crop improvement by introducing a gene: This provides the desired characteristics and results in genetically modified crops.
• Cultivation practices and crop yield are related to weather, soil quality and availability of water. Since weather conditions such as drought and flood situations are unpredictable, varieties that can be grown in diverse climatic conditions are useful.
• The factors for which variety improvement is done are:
(i) Higher yield: To increase productivity of the crop per acre.
(ii) Improved quality: The quality of crop products vary from crop to crop. E.g., protein quality is important in pulses, oil quality in oilseeds, preserving quality in fruits and vegetables.