Partial dietary fish meal replacement with cotton seed meal and supplementation with exogenous protease alters growth, feed performance, haematological indices and associated gene expression markers (GH, IGF-I) for Nile tilapia, Oreochromis niloticus

No abstract

This study was conducted in a four-year rabbit project that aimed to develop a synthetic line named Moshtohor (M) by crossing Sinai Gabali breed (G) with the Spanish V-line (V). The G, V, F(1) (G x V), F(2) (G x V)(2) and M line were analysed. Traits of doe body weight at delivery (DBW), litter size at birth (LSB) and at weaning (LSW), milk production during the first, second, third and fourth week of lactation and total milk yield (TMY) were recorded. Data were analysed using a repeatability uni-trait animal model to estimate the genetic parameters and estimable functions of genetic group effects. Based on them and the matrix of their variance-covariance, the crossbreeding parameters were also estimated. Estimates of heritabilities for all the studied traits were low ranging from 0.06 to 0.11 for DBW, LSB and LSW and from 0.0 to 0.06 for milk production traits. Permanent environmental effects were very low ranging from 0.0 to 0.10 for all the traits, except for DBW (0.41). Least square means of V line were superior (p < 0.05) in DBW (3253 versus 3037 g) and LSB (6.71 versus 6.28 young) relative to G breed. M line had superiority in LSB (6.94 young) compared with G breed. M line and G breed were better than V line for milk production traits (3415 and 3236 versus 2893 g for TMY). Significant effects of direct additive were observed for most traits studied (ranged from -6.8 to 20.7%). Effects of individual heterosis for most milk production traits were significant and ranged from 2.1 to 13.9%, but they were not significant for DBW, LSB and LSW. On the opposite side, effects of maternal heterosis for all the traits were not significant.

Indigenous chicken breeds in developing countries have diverse benefits to rural economy as a source of high‐quality animal protein. However, there are few reports on the evaluation of economic traits in Egyptian indigenous breeds. Hence, this study aimed to investigate growth performance, carcass characteristics, body measurements and meat quality traits in two indigenous breeds of chickens (Benha line and Golden Montazah) versus Rhode Island Red as a reference worldwide breed. Besides, a time series expression profile of somatotropic axis genes including GH and IGF‐1 and their plasma level concentrations were investigated. Benha line chickens (BL) revealed the highest improved estimates of growth performance, carcass characteristics and meat quality traits. In the same manner, it displayed the highest levels of hepatic GH and IGF‐1 and muscle IGF‐1 gene expression compared to Rhode Island Red (RIR) and Golden Montazah (GM) chickens. Accordingly, BL exhibited the highest levels of plasma IGF‐1 and the lowest levels of plasma GH. This result suggests the direct association between growth performance, carcass characteristics and levels of IGF‐1 gene expression in the selected chicken breeds. BL is a superior Egyptian genotype with candidate productive traits and competing characteristics, it could be used widely as a proven ancestor of commercial hybrid breeds.

ABSTRACT:Data from 662 litters and 221 samples (two replicates per each sample) of rabbit milk were collected from three different genetic groups [Gabali (G), V-line (V) and G×V (F 1 )] to study the effect of line and of some non-genetic factors affecting production and milk composition traits. The studied traits were: number born alive (LSBA); litter size at weaning (LSW); litter weight born alive (LWBA); litter weight at weaning (LWW); total milk yield (TMY) and protein, fat, total solids (TS), ash, phosphorus (P), potassium (K), sodium (Na), calcium (Ca) and magnesium (Mg) milk content. The genetic group effect was significant for LSBA [V (7.3) and F 1 (7.3) were superior to G (6.6)); LWBA (higher values for V (416 g) and F 1 (405 g) than for G (382 g)]; TMY [G (3497 g) and F 1 (3486 g) higher than V (3042 g)]; milk fat [F 1 (26%) and G (25%) superior to V (23%)] and milkTS [F 1 (42%) superior to G (40%) and V (39%)]. The estimates of the heterosis effect ranged between 1.6% and 12.8% for production and milk gross chemical traits, being significant only for milk fat content (9.1%). The positive values of the heterosis estimates for those traits and the complementarity between the G breed and the V line, the G superior in milk related traits but the V superior in prolificacy, show the interest of their cross and of the synthetic lines derived from them. The heterosis was non-significant for milk mineral content traits. The parity effects were significant for LSBA, fat, TS, ash and K (the maxima were reached at 6 th or 5 th parity). The effect of week of lactation was significant for fat, ash and TS, corresponding the maximum values of fat and TS to the 3 rd and 4 th week. The year-season or the year-month effects were significant for all traits showing the importance of including these time-period factors into the statistical models proposed for the traits.

A 12-week feeding trial was conducted to evaluate the effect of dietary probiotic, Saccharomyces cerevisiae and Lactobacillus acidophilus at a concentration of (10 8 cfu/ml).Three isonitrogenous (300 g CP kg -1 dry matter, DM) and isocaloric (3500Kcal metabolizable energy kg -1 DM) diets were formulated and probiotics was supplemented in the experimental diets. Fingerlings averaging 2.80±0.05g were randomly distributed into 18 glass aquaria (160 liter) and each aquarium holding 15 fish and randomly assigned to one of six replicates of the diets and offered feed at a daily rate of 5% of the total fish biomass. After 12 weeks, fish fed the diets supplemented with the two probiotics showed significantly better final weight, body length, specific growth rate, weight gain, feed intake, feed conversion ratio and protein efficiency ratio than those fed the control diet. The highest red blood cells count (RBCs), Hemoglobin (Hb), hematocrite (Hct), and the lowest mortality rate were recorded for fish fed the diet supplemented with S. cerevisiae supplemented compared to the other two groups. Fish fed the diet supplemented with S. Cerevisiae followed by L. acidophilus recorded the lowest (P<0.001) serum transaminase enzymes (alanine transaminase, ALT and aspartate transaminase, AST). Fish fed S. cerevisiae and L. acidophilus supplemented diets showed the lowest significant (P<0.001) count of microbial content in surface and muscles of Nile tilapia.

Background and Objective: Poultry industry aims mainly to produce genetically superior animals with high productivity of egg and meat.On a commercial scale, the purpose of most quail genetic improvement programs is to select genetically superior birds for meat and egg production. The objective of this study was to investigate the effect of short-term selection through four generations of selection in Japanese quail on egg number at the first 90 days of laying, estimate genetic parameters of egg production traits and estimate the correlated response to selection. Materials and Methods: Data of 1,352 female Japanese quails were collected through five consecutive generations (base and four selected generations) to estimate genetic gain, depending on breeding values, for Age at First Egg (AFE), Body Weight at Sexual Maturity (BWSM), Weight at First Egg (WFE), Egg Number at first 90 days (EN90D) and Average Egg Weight (AEW). Results: Estimates of heritability for egg production traits were ranged from 0.17 to 0.26. Moreover, positive genetic correlations were detected (0.18 to 0.43) between all studied egg production traits, except the correlation between AFE and EN90D (-0.32). The contrast among estimates was significant (p<0.05), favoring the selected generations over the base. The cumulative selection response was favorable for all unselected traits with the superiority of the selected generations to the base generation. Conclusions: It can be concluded that early selection based on breeding value for a cumulative egg number at first 90 days of egg production can effectively improve the total egg production and other egg traits in Japanese quail through four selected generations.

1. Four gallinacin (GAL) genes were assessed by Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) to characterise these genes in Fayoumi (F) and Rhode Island Red (R) breeds and their crosses of Rhode Island Red × Fayoumi (½R½F) and Fayoumi × Rhode Island Red (½F½R). 2. Genes examined were GAL2, GAL3, GAL4 and GAL5. The molecular associations between the SNPs of the gallinacin genes and body weight, caecal bacterial count and the serum antibody titres of IgA, IgG and IgM were determined. In the R breed, the frequency of TC genotype was higher than TT and CC genotypes for the GAL3 gene. The GG genotype frequency was higher than AA and AG genotypes for the GAL4 gene in the other genetic groups, and the CA genotype frequency was higher than CC and AA genotypes in crosses for the GAL5 gene. 3. In all populations, the frequency of the C allele was higher than the T allele for the GAL3 gene, the G allele was higher than the A allele for the GAL4 gene and the C allele was higher than the A allele for the GAL5 gene. The observed heterozygosity in R, ½R½F and ½F½R was 0.476, 0.375 and 0.158 for the GAL3 gene, 0.458, 0.615 and 0.250 for the GAL4 gene and 0.053, 0.792 and 0.739 for the GAL5 gene, while the expected heterozygosities were 0.490, 0.430 and 0.145 for the GAL3 gene, 0.430, 0.348 and 0.219 for the GAL4 gene and 0.229, 0.478 and 0.496 for the GAL5 gene, respectively. 4. On a molecular level, the genotype TT was significantly higher for body weight than TC and CC genotypes in the GAL3 gene. Birds with the GG genotype had a significantly lower Salmonella typhimurium count than birds with AA genotype in the GAL4 gene. Birds with the genotype AA had higher significant body weights than those with CC and CA genotypes in the GAL5 gene. 5. The results indicated that the GAL3, GAL4 and GAL5 genes are potential candidates for selection programmes to improve S. typhimurium resistance and body weight in chickens.