(a) Nervous control of respiration in animals. 10 (b) National Livestock Health and Disease Control Programme. 10 (c) Factors…

(a) Nervous Control of Respiration

Respiratory rhythm is generated by the pre-Bötzinger complex in the medulla, which acts as the pacemaker. The Dorsal Respiratory Group (DRG) integrates afferent signals from pulmonary stretch receptors and drives inspiration via the phrenic nerve. The Ventral Respiratory Group (VRG) controls forced expiration. Pontine centers, the Pneumotaxic and Apneustic, modulate the rate and depth of breathing. Chemoreceptors monitor blood gases; central chemoreceptors in the medulla detect changes in CSF pH (driven by CO₂), while peripheral chemoreceptors in the carotid and aortic bodies sense O₂, CO₂, and pH. The Hering-Breuer reflex prevents lung over-inflation by inhibiting inspiration when stretch receptors are activated. This neural integration ensures rhythmic breathing matched to metabolic demands.

(b) National Livestock Health and Disease Control Programme (NLHDCP)

NLHDCP is an umbrella Central Sector Scheme launched to enhance livestock health. It comprises several components: Assistance to States for Control of Animal Diseases (ASCAD), National Animal Disease Control Programme (NADCP) for FMD and Brucellosis, PPR Eradication, Classical Swine Fever control, and Establishment and Strengthening of existing Veterinary Hospitals and Dispensaries (ESVHD) including Mobile Veterinary Units. Funding structures vary by component. NADCP, PPR and CSF control are 100% centrally funded, while ESVHD is 100% central for non-recurring costs and 60:40 for recurring costs. In contrast, ASCAD follows a 60:40 Centre-State sharing pattern, with 90:10 for North-Eastern and Himalayan States and 100% for Union Territories. The scheme aims to reduce disease burden, improve productivity, and ensure food safety by providing vaccines, diagnostic support, and extension services to farmers across all major livestock species. In 2025 the programme (LHDCP) was revised with an outlay of ₹3,880 crore for 2024–26 and a new Pashu Aushadhi component for affordable generic veterinary medicines.

(c) Factors Affecting Pre- and Post-natal Growth

Pre-natal growth is determined by maternal nutrition, placental efficiency, and genetic imprinting. Adequate maternal protein and energy intake during gestation is critical for fetal development; deficiencies lead to low birth weight. Placental blood flow and nutrient transport capacity directly influence fetal size. Post-natal growth depends on colostrum intake for immunity, creep feeding for early nutrition, and the hormonal axis involving Growth Hormone (GH) and Thyroid hormones. Environmental temperature also plays a role; heat stress reduces feed intake and growth rate. Genetic potential sets the upper limit, but environmental factors like disease control and management practices determine the realized growth rate. Optimizing both phases is essential for maximizing lifetime productivity in livestock.

(d) AIV Method of Silage Preparation

The AIV method (named after Finnish Nobel laureate Artturi Ilmari Virtanen) is a preservation technique for low-sugar forages where natural fermentation is insufficient. Dilute mineral acids (a mixture of hydrochloric and sulphuric acid) are sprayed on each layer of green forage as the silo is filled, in quantities sufficient to bring the pH to about 3.5–4.0. This rapidly inhibiting the growth of spoilage bacteria like clostridia and molds. Unlike traditional silage, AIV does not rely on lactic acid fermentation for preservation but on direct acidification. It is suitable for forages with low soluble carbohydrate content, such as certain grasses and legumes. The method ensures better nutrient retention and palatability, though it requires careful handling of corrosive acids and precise application rates to avoid over-acidification.

(e) Essential Amino Acid Index (EAAI)

The Essential Amino Acid Index (EAAI) is a metric used to evaluate protein quality by comparing the essential amino acid (EAA) profile of a test protein to a reference protein, usually egg protein. The formula is EAAI = [(aa₁/AA₁)(aa₂/AA₂)...(aaₙ/AAₙ)]^(1/n) × 100, where 'aa' represents the amount of each EAA in the test protein and 'AA' in the reference. The geometric mean of these ratios is calculated. An EAAI value greater than 0.9 (or 90%) indicates high-quality protein with a balanced EAA profile suitable for animal growth. Values between 70–89% indicate good quality, while values below 70% suggest poor quality due to limiting amino acids. This index helps in feed formulation by identifying deficiencies and guiding the supplementation of synthetic amino acids to optimize protein utilization and reduce costs.