Nutrient Requirements for Calves, Heifers, Dry and Milking Cows and Buffaloes | Animal Husbandry & Veterinary Science Optional for UPSC PDF Download

Nutrient Requirements for Cattle and Buffaloes

• The term "nutrient requirement" refers to the amount of nutrients needed in the diet to meet the needs of a healthy animal under normal conditions.
• This amount varies depending on the size of the animal and its level of production.

• Nutrient requirements are established through experiments with animals at different physiological stages.
• Feeding standards are set based on these experiments and are periodically updated.
• Various countries have their own nutrient requirement standards.

• In the United Kingdom, the Agricultural Research Council (ARC) publishes nutrient requirements for animals.
• In the United States, the National Research Council (NRC) sets nutrient requirements for animals.

• In India, Sen, Ray, and Ranjhan developed nutritional requirements for dairy cattle and buffaloes.
• These requirements are based on mid-Morrison values and are overseen by the ICAR.
• Cattle requirements are generally applicable to buffaloes except for milk production needs.

Maintenance Requirements in Animals 

• Maintenance requirements refer to the amount of nutrients needed to sustain body weight and normal physiological functions in non-producing animals.
• Energy requirements for maintenance are determined through fasting catabolism studies, energy balance determinations, and feeding trials.
• Protein requirements for maintenance are complex and are calculated using nitrogen balance trials and the factorial method.
• Indian cattle maintenance requirements are based on the feeding standard by Sen, Ray, and Ranjhan 1977, which provides values for TDN, DCP, and NE.

Nutrients for Dry Animals

• The energy requirements for maintenance in dry animals range from 61 to 104 kcal/W 75.
• Protein requirements for maintenance vary from 1.97 g to 4.21 g per kg metabolic body size.
• Non-protein-nitrogenous compounds like urea can replace around 30% of the protein requirements for dairy cattle and buffaloes.
• Table 1 provides daily nutrient requirements for maintenance for cattle and buffaloes.

• Factors such as feed intake level, concentrate to roughage ratio, and ration quality affect energy requirements for milking cows.
• Gross energy content of milk is a measure of net energy requirement for milk production.
• The average energy requirement per kg of 4% fat milk ranges between 1039 ME to 1230 ME.

• The protein requirement for milk production, as suggested by Sen, Ray, and Ranjhan in 1978, is 132 grams of digestible nitrogen for every 100 grams of milk nitrogen for calculating the DCP requirement for milk production.
• A deficiency of protein can decrease the solids-non-fat content of the milk and the yield. Conversely, an excessive amount of protein can slightly increase the protein content of milk without impacting the milk yield.
• The quality of protein is not crucial because microorganisms in the rumen can synthesize essential amino acids from poor-quality protein and NPN sources.

• Table 2 provides the requirements of TDN and DCP needed for kilogram of milk production, based on NRC recommendations.
• The TDN and DCP requirements are determined considering 1188 kcal of ME per kilogram of 4% fat corrected milk and 132 grams of digestible nitrogen for every 100 grams of milk nitrogen.

Requirements for Pregnancy

• During pregnancy, nutrients are essential for the development of the fetus. Around 25 to 35 kilograms of live weight is typically gained in the last 60 days of pregnancy.
• Nutrients are also stored as reserves for potential utilization in early lactation for milk production.

Feeding of Dairy Cattle for Reproduction: 

• The NRC recommends specific amounts of DCP, TDN, Ca, P, and Carotene for dairy cattle during reproduction, beyond the maintenance requirements.
• When additional feed is required, particularly with poor-quality roughages like straw, a balance of high-energy concentrates is needed. However, practical experience often shows that lesser amounts suffice.

Feeding after Calving:

• Immediately after calving, it is advisable to avoid high-protein feeds, especially oil cakes, as they can be harmful.
• Feed that stimulates milk production should be introduced gradually, meeting the cow's maintenance requirements and milk yield.

Nutrient Recommendations for Buffaloes

• Buffaloes generally require an allowance ranging from 2.5th to half of their milk yield, with a significant portion of energy coming from lower-quality roughages.
• Unlike cattle, limited research has been conducted on nutrient requirements specific to buffaloes, with cattle requirements often being applied to buffaloes.
• The MFN value for buffaloes is determined to be 0.34 g/100g dry water intake, with a reported energy requirement of 103 kcal of ME/W0.75 for dry buffaloes, similar to that of dry cows.
• Urea and other nitrogenous compounds can replace up to 30% of protein requirements in buffaloes.
• Specific nutrient requirements for milk production in buffaloes can be found in nutritional tables.

Nutrient Requirements for Calves:

• Calves have distinct nutrient needs during two growth phases: pre-ruminant period (before rumen development) and post-ruminant period (after rumen maturation).
• Pre-ruminant calves (birth to two months) primarily rely on whole and skim milk for energy and protein. They gradually transition to solid foods like calf starter and hay.
• Duration and quantity of milk feeding vary in India, impacting nutritional requirements. Studies show varied milk feeding strategies influencing calf growth rates.
• After 60 days, whole or skim milk may not be necessary, with a total milk quantity not exceeding 140 kg in 60 days. Quality calf starters should be introduced early.
• Energy, DCP, mineral, and vitamin requirements for pre-ruminant calves are summarized in Table 4, based on different age ranges and body weight gains.

Nutrient Requirements for Calves and Heifers

When determining nutrient requirements for calves and heifers, various factors such as protein and energy content in feed play a crucial role. Below are the summarized points:

• The nutritional values of different feed types are crucial: milk, calf starter, skim milk, and hay each have varying percentages of DCP and TDN.
• Standards from NRC (1971) and other sources guide the energy and protein needs for calves over three months based on Morrison's standards.
• Zebu calves can have reduced protein requirements (10-40%) from Morrison's standards without affecting growth if TDN levels are maintained.
• Reports suggest that crossbred calves can thrive on reduced protein and energy levels compared to current standards without compromising growth rates.
• While higher nutrition levels promote faster growth, feeding on minimum standards is economical and can lead to early calving at reduced costs.

• Studies at IVRI Izatnagar on various cattle breeds showed daily growth rates of 409 to 564 g when fed specific concentrate mixtures.
• Another study observed a growth rate of 600 g when concentrates and roughages were fed in specific proportions, meeting DCP and TDN standards.
• Research conducted at different centers has determined specific nutrient requirements for calves of varying weights, as detailed in Tables 5 and 6.