Efficiency of Animal Production—Molding the Biological Components
Major biological objectives in reducing production costs per unit of animal product value seem to be (1) greater total product value per female (e.g., milk, wool, eggs) relative to metabolic body size, (2) higher rate of reproduction, especially in cattle and sheep, to reduce breeding herd costs per meat animal marketed, (3) more efficient lean growth to market live weight and earlier sexual maturity, with minimum increase in mature size of females, especially in cattle, and (4) combining female (milk or wool) production and progeny lean meat production under intensive management.Changes in management systems and in product values will modify specific biological objectives and hence need to be anticipated as well as possible. Breeding programs need balanced emphasis on (1) evaluation and utilization of existing breed differences in commercial livestock production, and (2) continuing genetic improvement within the pure breeds or strains.
Effects of climate changes on animal production and sustainability of livestock systems
The effects of climate change are controversial. This paper reviews the effects of climate change on livestock following the theory of global warming. Although, the effects of global warming will not be adverse everywhere, a relevant increase of drought is expected across the world affecting forage and crop production. Hot environment impairs production (growth, meat and milk yield and quality, egg yield, weight, and quality) and reproductive performance, metabolic and health status, and immune response. The process of desertification will reduce the carrying capacity of rangelands and the buffering ability of agro-pastoral and pastoral systems. Other systems, such as mixed systems and industrial or landless livestock systems, could encounter several risk factors mainly due to the variability of grain availability and cost, and low adaptability of animal genotypes. Regarding livestock systems, it will be strategic to optimise productivity of crops and forage (mainly improving water and soil management), and to improve the ability of animals to cope with environmental stress by management and selection. To guide the evolution of livestock production systems under the increase of temperature and extreme events, better information is needed regarding biophysical and social vulnerability, and this must be integrated with agriculture and livestock components.
Management to reduce nitrogen losses in animal production
Reduction of nitrogen loss in animal production requires whole-farm management. Reduced loss from one farm component is easily negated in another if all components are not equally well managed. Animal excretion of manure N can be decrerased by improving the balance of protein or amino acids fed to that required by individual animals or animal groups or by improving production efficiency. Management to increase milk, meat, or egg production normally improves efficiency by reducing the maintenance protein required per unit of production. Large losses of manure nitrogen occur through the ammonia and nitrous oxide that are emitted into the atmosphere and the nitrate leached into groundwater. Up to half of the excreted nitrogen is lost from the housing facility, but this loss can be decreased through frequent manure removal and by avoiding deep litter systems and feedlots. Techniques such as acid treatment of manure, scrubbing of ventilation air, and floor designs for separating feces and urine substantially reduce ammonia emissions, but these practices are often impractical or uneconomical for general use. Manure storage units improve nutrient utilization by allowing better timing of nutrient application with crop needs. At least 70% of the nitrogen entering anaerobic lagoons is typically lost, but a less than 10% loss can be maintained using slurry storage with a natural crust or other cover, or by drying poultry manure to at least 50% dry matter. Irrigation and surface spreading of manure without soil incorporation often ensures the loss of all remaining nonorganic nitrogen (typically, 20 to 40% of remaining nitrogen). Rapid incorporation and shallow injection methods decrease this loss by at least 50%, and deep injection into the soil essentially eliminates this loss. For grazing animals, excessive loss can be avoided by not overstocking pastures and avoiding late fall and winter grazing. Reducing emissions between the animal and the soil can lead to greater leaching and denitrification losses from the soil if this additional nitrogen is not used properly. The use of a crop rotation that efficiently absorbs these nutrients and applying nitrogen near the time it is needed by crops reduce the potential for further loss. Maintaining the proper number of animals per unit of land available for manure application is always crucial for efficient recycling of nitrogen. Our understanding of nitrogen loss processes is improved through modeling, and computer models assist in the development of integrated systems for efficient and economical nitrogen use in animal production.
Constraints of Pig Production in Nigeria: A Case Study of Edo Central Agricultural Zone of Edo State
The study examined constraints of pig production in Edo Central Agricultural Zone of Edo State. Data were collected through interview schedule administered to forty one (41) private pig farmers in the study area. Descriptive statistics and multiple regression were used to analyse data for the study. Results showed that majority (85.4%) of the pig producers were male. The stock kept ranged between 1 and 50 pigs for small scale producers who formed 58.4% of surveyed farms, 51-100 pigs for medium scale producers (15%) and above 100 pigs for large scale producers (26.6%). Major obstacles identified among pig producers in the study area were difficulties in securing institutional loans (61.0%), high cost of feed and feed ingredients (46.3%). Flock size (t = 3.313; p = 0.002) had a significant effect on returns accruing to farmers in pig production. Institutional loan scheme to promote pig production should be established and properly managed by government and stakeholders in the livestock industry in Edo State. 
Heritability Estimates for Growth Traits in the Nigerian Local Chicken
F1 pedigreed chicks from a like by like mating of normal feathered (NF), frizzled feathered (FF) and naked neck (Na) Nigerian local chickens were monitored for growth characteristics from hatch to 20 weeks of age. Similarly, heritability estimates from sire variance components were computed 4-weekly to 20 weeks of age of the birds. Heritability estimate ranged from 0.17±0.07 to 0.26±0.19; 0.28±0.16 to 0.40±0.14; 0.42±0.21 to 0.53±0.23; 0.34±0.25 to 0.65±0.16 and 0.52±0.07 to 0.54±0.26 for 4, 8, 12, 16 and 20 weeks of age respectively in the genetic groups. Heritability estimate for body weights from the 8th week of age were moderate to high. Thus, appreciable genetic progress for body weight gain can be achieved in the Nigerian local chicken through concerted selection.
 Dickerson, G., 1970. Efficiency of animal production—molding the biological components. Journal of Animal Science, 30(6), pp.849-859.
 Nardone, A., Ronchi, B., Lacetera, N., Ranieri, M.S. and Bernabucci, U., 2010. Effects of climate changes on animal production and sustainability of livestock systems. Livestock Science, 130(1-3), pp.57-69.
 Rotz, C.A., 2004. Management to reduce nitrogen losses in animal production. Journal of animal science, 82(suppl_13), pp.E119-E137.
 Uddin, I.O. and Osasogie, D.I., 2016. Constraints of Pig Production in Nigeria: A Case Study of Edo Central Agricultural Zone of Edo State. Asian Research Journal of Agriculture, pp.1-7.
 Rotimi, E.A., Egahi, J.O. and Momoh, O.M., 2016. Heritability estimates for growth traits in the Nigerian local chicken. Journal of Applied Life Sciences International, pp.1-4.
Efficiency of Animal Production—Molding the Biological Components