the aims of this research were to estimate of genetic parameters for pre-weaning traits and lamb survival in iran-black sheep. for this purpose 6344 records for birth weight (bw) and lamb survival (ls) and 5264 records for weaning weight (ww), average daily gain (adg) and kleiber ratio (kr) were available, which collected by abbasabad animal breeding and rearing station, over the period from 19...

Interest in improving feed efficiency in cattle is intensifying. Residual feed intake (RFI), which is the difference between expected intake and that predicted based on energy demands, is now the most commonly used measure of feed efficiency over a given time period. However, RFI, as commonly defined, is independent of growth rate, which may affect its acceptance by industry. Residual BW gain (...

Feeding low concentrations of DDGS early in the nursery period does not help to maintain growth performance when high concentrations of DDGS are incorporated in the diets during the late nursery period. Summary The objective of this experiment was to evaluate growth performance of weanlingpigs introduced to low concentrations (5%) of DDGS duringphase 2 of the nursery period followed by high con...

Abstract Understanding the effects of high- and low-fiber diets on growth performance pigs with different feed efficiencies will help livestock industry develop new strategies to reduce costs pig production. In this study, 18 Landrace × Large White sows high low estimated breeding value conversion ratio (EBV-FCR) were inseminated semen from known EBV-FCR produce 9 litters efficiency pigs. A tot...

Maternal nutrient restriction during critical windows of fetal development alters postnatal growth, often in a sexually dimorphic manner. Intrauterine growth restriction is frequently characterized by accelerated growth and increased adiposity in later life. Thyroid hormones are implicated as part of the mechanism involved in this scenario via their actions within the hypothalamic-pituitary-thy...

Performance records were analyzed for 1,869 purebred Duroc and Yorkshire gilts tested in littermate groups of two to four pigs in 703 pens. Traits studied were average daily gain during a standard test period from 56 d of age to 90.7 kg (ADG), average daily feed consumption during the test period (ADF), average backfat thickness (ABF) measured from polaroid photos of ultrasonic scans at 90.7 kg...

Organic acids have been supplemented to weanling pig diets in an attempt to improve postweaning lag. Organic acids have proved beneficial in improving average daily gain (ADG) and increasing nutrient digestibility (Falkowski and Aherne, 1984; Edmonds et al., 1985; Geisting and Easter, 1985). There has also been interest in acidifying grower pig diets in an attempt to increase ADG and improve fe...

The inclusion of high concentrations of DDGS (30%) in both the nursery and growing-finishing periods may result in negative effects on growth performance and carcass characteristics. Summary The objective of this experiment was to evaluate the efiects of high concentrations of distillers dried grains with solubles (DDGS; 30%) on growth performance and carcass characteristics ofgilts, duringgrow...

The acceptance of eco-friendly black soldier fly larvae meal (BSFLM) as sustainable alternative protein ingredient in poultry feeds continues to gain momentum worldwide. This study evaluates the impact BSFLM layer chick and grower diets on growth, carcass quality economic returns. Mean weekly weight total live per varied significantly. highest final was achieved when birds were provided diet wi...

A completely randomized design, with 3×3 factorial arrangement, was conducted to test various ratios of dietary protein to energy (P/E) for rainbow trout, reared in brackish water. Three crude protein levels (35, 40 and 45%) and three energy levels (370, 400 and 430 Kcal/100g) at each protein level were utilized. Semi-purified diet containing fish meal, casein and gelatin as the sources of prot...