Adaptive profiles of Nellore sheep with reference to farming system and season: physiological, hemato-biochemical, hormonal, oxidative-enzymatic and reproductive standpoint.

This paper outlines the effect of farming systems with reference to season on the body condition score (BCS) and adaptive profile (physiological, hemato-biochemical, hormonal, enzymatic and reproductive parameters) of Nellore sheep. In trial 1, sixty ewe-lambs were allotted to extensive, semi-intensive, and intensive rearing systems (n = 20) and evaluated for BCS at puberty, mating, 2 weeks pre-lambing and 2, 4, 8, and 12 weeks post-lambing. In trial 2, eighteen rams were distributed evenly to three farming systems (n = 6) and evaluated for physiological, hemato-biochemical, hormonal, enzymatic, and reproductive parameters concerning three seasons. Although the scores did not differ among the groups, the Kruskal-Wallis ranks of BCS revealed a higher energy status of intensive ewes at different physiological conditions. The sheep reared under extensive and semi-intensive systems displayed higher temperature, pulse rate and respiratory rate with predominant effects in summer season. Similarly, both systems exhibited higher WBC and lower haemoglobin, PCV, and RBC contents without affecting MVC, MCH, MCHC, and differential leucocyte count. The percent haemoglobin and RBC count were higher in winter compared to summer months, whereas WBC count followed an exactly opposite pattern. The sheep reared in intensive system showed higher glucose, total protein, albumin, cholesterol, T3, T4, calcium, and phosphorus; however, the globulin, creatinine, uric acid, aspartate amino transferase (AST), alanine amino transferase (ALT), superoxide dismutase (SOD), malondialdehyde (MDA), glutathione peroxidase, and catalase levels were elevated in extensive and semi-intensive systems. The dartos muscle extension (DME) and scrotum sweating rate (SSR) were higher for the sheep reared under extensive system, especially during summer season; while the seminal parameters viz., total sperm count, progressive sperm motility, and plasma membrane integrity were lower for extensive and semi-intensive sheep. No interactions were noticed for any of the parameters, except for cortisol, DME, and SSR, which showed significant interactions for rearing system vs. season. Our results showed dynamic adaptive mechanisms of the Nellore sheep in relation to different stressors like grazing for long distances, inadequate nutrition, and heat stress, revealing the heat resilient ability in harsh environmental conditions. Further, the analyzed vector plot showed that the AST, GPx, Cortisol, SOD, Catalase, WBC, PR, T4, total abnormalities, and major abnormalities were the major contributors for adapting during combined stressors.

Farming systems in sheep rearing: Impact on growth and reproductive performance, nutrient digestibility, disease incidence and heat stress indices.

The experiment was conducted with an intent to know the effect of different farming systems on the growth performance, nutrient digestibility coefficients, reproductive traits, disease incidence, heat stress indices, and cost economics of Nellore sheep. The study includes two parallel trials to prevent the influence of age on heat stress indices (panting score and erythrocyte osmotic fragility (EOF)). One hundred and twenty lambs (60 ram-lambs and 60 ewe-lambs) were allotted in a randomized block design under extensive, semi-intensive, and intensive systems for trial I, whereas trial II include eighteen rams assigned to the three respective farming systems in a completely randomised design. Both, season (summer) and grazing practice increased the panting score and EOF. The heat stress indices were positively correlated (P<0.01) with dry-bulb temperature and temperature-humidity index (THI) and inversely correlated (P<0.01) to relative humidity. Allotting the sheep to intensive system increased (P<0.001) weight gain and average daily gain with higher effect in males compared to females. The parameters of asymptotic weight (A), integration constant (B), and maturation rate were higher for intensive males. The male Nellore lambs had higher asymptotic weight and lower maturity rate than females, irrespective of the rearing system. Intensive sheep revealed a higher dry matter intake, digestibility coefficients, feed conversion ratio. The instantaneous bite mass (IBM) was higher for Commelina benghalensis, while instantaneous bite frequency (IBF), instantaneous intake rate (IIR) were higher for Cyanodon dactylon and amaranthus viridis, respectively. The proportion of intakes were highest for Stylo hemata followed by Cynodon dactylon and Tridax procumbens species. No differences were observed for the weight at puberty, oestrus cycle length, oestrus duration, conception percent, gestation period, and lambing percent in three rearing systems; however, the age at puberty was lower (P<0.001) and the birth weight was higher (P<0.001) for sheep reared under intensive farming system. Highest disease incidence was observed in rainy and winter seasons, particularly in sheep reared under extensive system. The capital expenditure was same for the three rearing systems, while the recurring expenditure was higher for Intensive farming system. The gross income and net income were higher for intensive system on account of higher weight gains. However, the higher returns per rupee of expenditure project the extensive farming as an ideal rearing system for small farmers and entrepreneurs with a low initial capital.

A review of the effects of dietary organic acids fed to swine.

Animal production depends on nutrient utilization and if done there is an accelerated momentum towards growth with a low cost to feed ratio Public concern over the consumption of pork with antibiotic residues of the animals fed with antibiotic growth promoters (AGP) has paved the way to use other additives like herbs and their products, probiotics, prebiotics etc. Numerous feed additives are in vogue for achieving this target and one such classical example is the usage of organic acids and their salts. Usage of organic acids was in progress for over four decades. Early weaned piglets are (3-4 weeks age) exposed to stress with a reduced feed intake, little or no weight gain. This post weaning lag period is due to a limited digestive and absorptive capacity due to insufficient production of hydrochloric acid, pancreatic enzymes and sudden changes in feed consistency and intake. Lowering dietary pH by weak organic acids was found to overcome these problems. The main activity of organic acids is associated with a reduction in gastric pH converting the inactive pepsinogen to active pepsin for effective protein hydrolysis. Organic acids are both bacteriostatic and bactericidal. Lactic acid has been reported to reduce gastric pH and delay the multiplication of an enterotoxigenic E. coli. These acids are the intermediary products in Kreb's cycle and thus act as an energy source preventing the tissue breakdown resulting from gluconeogenesis and lipolysis. Excretion of supplemental minerals and nitrogen are minimized with organic acids as these form complexes with minerals and aids for their bio-availability. Short chain fatty cids like acetic, propionic and n-butyric acid produced by microbial fermentation of dietary fibre in the large intestines may increase the proliferation of epithelial cells and have stimulatory effects on both endocrine and exocrine pancreatic secretions in pigs. Organic acids also enhances apparent total tract digestibility and improves growth performance. It is concluded that organic acids and their salts increase the protein utilization especially in weaner pigs and improves production indices.

Micronutrient content of certain tropical conventional and unconventional feed resources of Southern India.

The ash, silica and certain important micronutrients were estimated in conventional and unconventional feed and fodder resources available in Southern India. Commonly used dry roughages, such as paddy straw, ragi straw, maize kadbi/stalk, jowar kadbi/stalk, bajra stalk and wheat straw, were high in ash (9.9% +/- 0.77%) and silica (6.4% +/- 0.65%) and low in most of the other micronutrients, except iron, with paddy straw containing most silica (>9%). Cultivated non-leguminous (maize, jowar) and improved green crops (hybrid napier, guinea, green panic, NB-21, CO-1) were also high in ash (10.5% +/- 0.60% and 12.5% +/- 0.51%) but were moderate sources of P, Mg and Cu and good sources of Zn (98 +/- 13.8 ppm and 55 +/- 6.7 ppm). Leguminous green fodders (stylosanthus, lucerne, cow pea, soyabean) were excellent sources of Ca (1.9% +/- 0.16%), Mg (0.40% +/- 0.05%), Cu (30 +/- 5.2 ppm), Zn (121 +/- 14.7 ppm) and Fe (1234 +/- 166 ppm) and moderate sources of P. Mixed local grasses and weeds were high in silica (6.9% +/- 1.00%) but were good sources of Cu, Zn and Fe. Cereal grains (maize, wheat, rice, ragi) were low in ash (2.9% +/- 0.33%) and were relatively poor sources of Ca (0.22% +/- 0.03%), Mg (0.19% +/- 0.03%) and Cu (13 +/- 3.1 ppm). Pulses were low to medium sources of most minerals and good sources of Fe (1230 +/- 293 ppm). Oil seed cake/extractions (groundnut cake, cotton seed cake, soyabean meal, sunflower cake, safflower cake) and cereal by-products (rice polish, rice bran, wheat bran) were excellent sources of P (1.1% +/- 0.47% and 2.3% +/- 0.19%) and good sources of Zn (65 +/- 3.9 ppm and 66 +/- 10.7 ppm) and Fe (938 +/- 130 ppm and 662 +/- 126 ppm). Among the unconventional feeds screened, orange peel, sunflower heads, meat meal, rubber seed cake, spirulina algae and sea weeds contained plentiful Ca, Zn and Fe: tree leaves/top feeds (mulberry, erythrina, glyricidia, banana, subabul, groundnut haulms) were excellent sources of Ca (1.5% +/- 0.13%), Zn (120 +/- 22.9 ppm) and Fe (1033 +/- 133 ppm) but relatively poor sources of P. Soyabean husk, cocoa seed husk, rubber seed cake and meat meal were moderate to good sources of P (1.0% and 0.33%). The high Zn and Fe values of most feeds/fodders were probably due to soil contamination. This account of the micronutrient content of feed/fodder resources should help in strategic supplementation intended to alleviate local deficiencies.