ملخص البحث :

The present study was conducted to measure the genetic diversity and population genetic structure of fourIranian sheep breeds, namely; Ghezel, Makui, Kurdi and Baluchi (utilizing 20 animals per breed from bothsexes) using 12 short tandem repeats markers. Our results demonstrated that the observed number of allelesand the median number of effective alleles for the Ghezel Makui, Kurdi, and Baluchi breeds were (50, 48,44 and 43) and (2.49, 2.46, 2.45 and 2.47), respectively. Also, the mean Shannon Index was 0.982, 0.939,0.965, and 0.959 values for Ghezel, Makui, Kurdi, and Baluchi breed, respectively. Moreover, the polymorphic information content (PIC) values were ranked from 0.09 (ILSTS011) to 0.75(TGLA13). Additionally, the average inbreeding coefficient (FIS) was from 0.144 (Kurdi) to 0.306 (Makui). Furthermore, the lowest genetic distance was seen between Makui and Baluchi breeds (0.120), but thehighest was between Ghezel and Kurdi breeds (0.884). The outcomes of this research showed the normal‘L’-shaped distribution of the mode-shift analysis test and the lack of bottleneck in the studied populations. On this basis, we conclude that the investigated Iranian sheep breeds carry reasonable within andbetween genetic diversity.

ملخص البحث :

Typically, lambing percentage is classified as a composite trait and is crucial to profitability in domestic sheep farming. In breeding programs, out-of-season reproduction of sheep is an important tool because seasonal reproduction limits productivity and flexibility. Understanding the complexities of genetic aspects of the none- seasonal reproduction has received significant critical attention in the literature. In this puzzle, the arylalkylamine-N-acetyltransferase (AA-NAT) is a rate-limiting enzyme of the melatonin synthesis pathway and is highlighted as a candidate gene that is responsible for melatonin synthesis and is thus directly associated with out-of-season reproduction in sheep. With this scenario research, we aimed to examine the allele frequency of the polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) polymorphism in the AA-NAT gene in 11 native and exotic sheep populations. A total of 220 blood samples were taken from 11 breeds of sheep, including the exotic breeds Romanov (ROMV) and [Awassi (AWAS), Arabi (ARAB), Naaimi (NAIM) Iraqi native sheep] and [Ghezel (GHZL), Makui (MAKU)], Kurdi (KURD), Baluchi (BALCH), Afshari (AFSR) Iranian native sheep] and two Afshari-Booroola and Romanov-Ghezel F1 cross). Here, we describe the Smal-RFLP genotypes and allele frequency patterns of the (c.486A>G) casual single nucleotide polymorphism (SNP) in the exon of AA-NAT within and between the examined sheep breeds. In addition, PCR sequencing methods were used to double-check A/G and confirmation of PCR-RFLP results. This mutation changed the Arg > Gly structure from helix to helix-effective in improving non-seasonal reproduction. Interestingly, the observed variation of G allele ranged from 0.1 to 0.43 in all study breeds. ROMV is a candidate for non-seasonal sheep breeds and its cross expresses the highest G allele frequency among other breeds studied. The frequency of the AA-NAT genotype was significantly different between breeds in this study. Therefore, the exotic 486A>G mutation created a useful mirror to identify genomics aspects of seasonal/non-seasonal reproduction in sheep.

ملخص البحث :

The study aimed to research the genetic variation of the Awassi and Naimi sheep breeds using the two genes myostatin (MSTN) and calpastatin (CAST). Blood samples were collected from 100 animals of the two breeds, and then DNA was extracted using a commercial kit. We used the PCR and RFLP techniques to determine genotypes and allele frequencies. The results showed that the MSTN and CAST genes are polymorphic. The MSTN gene has allelic frequencies (M and m) of 0.81, 0.19, and 0.76, 0.24 in the Awassi and Naimi breeds, respectively. The frequencies of the genotypes MM, Mm, and mm in the Awassi breed were 0.70, 0.19, and 0.11, but in the Naimi breed, they were 0.67, 0.13, and 0.20, respectively. Moreover, the number of alleles observed (Na), the effective number of alleles (Ne) and observed (Ho), and expected (He) heterozygosity were found to be 3, 2.30, 0.24, and 0.35 in the Awassi breed and 2, 1.62, 0.17, and 0.26 in the Naimi breed, respectively. The allelic frequencies (M and N) of the CAST of the Awassi and Naimi breeds are 0.86, 0.14, and 0.88, 0.12, respectively. The frequencies of the genotypes MM, MN, and NN in the Awassi breed were 0.94, 0.04, and 0.02, respectively, while for the Naimi breed, they were 0.95, 0.02, and 0.03, respectively. Also, the Na, Ne, Ho, and He were found to be 2.8, 1.72, 29.6, and 28.57 in the Awassi breed and 1.10, 1.23, 0.17, and 0.15 in the Naimi breed, respectively. According to the chi-square of MSTN and CAST genes, both breeds were not in Hardy-Weinberg equilibrium balance.

ملخص البحث :

Objective: This research assesses whether probiotics could enhance growth performance and improve nutrient digestibility in birds fed with low-protein diets. Materials and Methods: A total of 250 1-day-old ROSS chicks were used in a completely randomized design consisting of 5 treatments with 5 replicates and 10 birds for each replicate. The experimental diets were as follows: basal diet containing 100% crude protein (CP) according to Nutrition Research Council recommendation (control diet); basal diet containing CP 10% less than the control diet low protein (LP); LP with addition of probiotic by 50 mg/kg diet (LP + P1); LP with addition of probiotics by 100 mg/kg diet (LP + P2); LP with an addition of probiotics by 150 mg/ kg diet (LP + P3). Results: Broilers fed with the control, LP + P2, and LP + P3 diets had greater body weight and weight gain than broilers fed with the LP during starter, finisher, and total periods (p < 0.01). The feed conversion ratio was the best (p < 0.01) in the control and LP + P3 treatments compared with the LP and LP + P1 treatments throughout the experiment. The European production efficiency factor was the lowest in the LP treatment compared with other treatments from 1 to 42 days. Protein efficiency ratio and protein retention were both higher in birds fed with the LP + P2 and LP + P3 diets compared to birds given the control and LP diets (p < 0.01). Conclusion: Adding probiotics to the diet remarkably improved the productive performance and nutrient digestibility of broiler-fed low-protein diets.