Weight Traits Research Articles

Correlation of 20 Single-Nucleotide Polymorphisms with Weight and Wool Traits in Alpine Merino Sheep.

SNPs associated with important traits of fine-wool sheep that were previously obtained through genome-wide association analysis screening were verified and analyzed. A total of 20 SNPs related to birth weight, bundle strength, cleaning rate, and fiber diameter were screened using whole-genome resequencing, and the SNPshot assay was used to detect and analyze polymorphisms. This study found that, among the 20 SNPs associated with important traits in Alpine Merino sheep, 8 were monomorphic and 12 were polymorphic, of which 6 showed moderate polymorphisms and 6 showed low polymorphisms. The heterozygosity of the 12 polymorphic loci ranged from 0.10 to 0.49, the effective number of alleles ranged from 1.11 to 1.98, and the polymorphic information content ranged from 0.09 to 0.37. The chi-square test showed that only RHPN2:g.42678119T>G and RALYL:g.90030866A>G were in Hardy-Weinberg disequilibrium (p < 0.05); the other loci were in equilibrium (p > 0.05). These SNPs associated with important traits in Alpine Merino sheep provide a theoretical basis for genomic selection and molecular design breeding.

Morphological Characterization of Gadik Sheep in North East Part of Afghanistan

The Gadik sheep, the local breed in Afghanistan, is reared mainly for meat. The sheep is a native breed in Badakhshan and Panjshir provinces of Afghanistan and has good adaptation to cold weather and mountainous regions. It also plays a vital role in the income of households, this study investigated the documentation and morphological traits of the sheep, a survey was conducted during the research that examined the sheep's habitat, body biometry, management procedures, and reproductive and productive performance. To examine the sheep's morphological characteristics, 40 sheep 20 ewes and 20 rams from one to four years old had their morphological features measured. Morphological characteristics that are included in measurements are: head and neck traits; back and tail traits; teats and testes; height, length, and depth traits; coat covert; and coloring. Gadik had a characteristically three-color coat: brown, white, and black. All data were collected from 40 flocks, with an average of 28.1±1.9 heads per flock. They lambed twins at about 45.0±3.33% and remain single, and they also followed a restricted breeding pattern, i.e., they got just one lambing per year in the spring but others lambed twice per year. The flocks graze for 10±0.2 h daily during the summer. Shearing was done twice a year, in spring and fall, with an average wool production of 0.4±0.02 kg/clip animal.&#x0D; Gadik is a small breed among other sheep breeds in Afghanistan and possesses a small, thin, short-tail sheep with an average weight of 25.35±0.0 kg (males: 26.6±0.40 kg; females: 24.1±0.40 kg) and a slightly convex nose. Males had horns, Females were hornless. Birth weight averaged 1.2±4.39 kg. The average body length was 50.85±0.03 cm. Sex and age were important contributors to differences in most traits; however, location differences also affected a few of the traits. Location differences existed for weight traits, and animals at Wiyar and Bashar were slightly bigger and heavier as compared to Shedoj, Dashar, and Sarchashma villages. Animals had medium-sized heads with a slightly bulging forehead, a tapering face, and shining eyes. Rams carried horns, 21.9±0.44 cm long, affected by sex and age. In mature males, horns run backward and grow outward somehow spirally. The adult population had fully developed, floppy (semi-pendulous), laterally protruded, and free of any pricks, small-sized ears with an average length of 7.00±0.13 cm and a blade width of 7.00±0.12 cm, and was affected by age and sex factors. Lambs in Wiyar and Bashar had higher respective body weights, while lambs in Shedoj, Dashar, and Sarchashma were inferior to those in the remaining villages.

GRAIN - BRAN QUALITY PARAMETERS and AGRONOMIC TRAITS of BREAD WHEAT CULTIVARS

Wheat (Triticum avestivum L.) has a wide adaptation limit and it is used as an important source of essential nutrients for both humans and animals. Wheat bran is also a by-product of the milling of wheat grain. It has a unique nutritional composition due to the amount and quality of proteins, mineral content and B complex vitamins content and dietary fiber content. One of the aims of this study was to determine the grain yield, yield components and quality traits of 36 wheat cultivars between 2019-2020 and 2020-2021. The other aim was to determine the nutritional properties of the bran obtained from these cultivars. Plant height, spike length, number of spikelets per spike, number of grains per spike, grain yield, thousand grain weight, test weight, wet gluten and sedimentation value traits were determined only in the whole grain, while ash content, protein content, starch content, fat content, acid detergent fiber, neutral detergent fiber, potassium, phosphorus, and magnesium traits were determined both in the whole grain and in the bran. It is expected that the data obtained in this study will be reported in the literature, evaluated in terms of product quality and taken into account in breeding programs.

Genome-Wide Association Study for Somatic Skeletal Traits in Duroc × (Landrace × Yorkshire) Pigs.

The pig bone weight trait holds significant economic importance in southern China. To expedite the selection of the pig bone weight trait in pig breeding, we conducted molecular genetic research on these specific traits. These traits encompass the bone weight of the scapula (SW), front leg bone weight (including humerus and ulna) (FLBW), hind leg bone weight (including femur and tibia) (HLBW), and spine bone weight (SBW). Up until now, the genetic structure related to these traits has not been thoroughly explored, primarily due to challenges associated with obtaining the phenotype data. In this study, we utilized genome-wide association studies (GWAS) to discern single nucleotide polymorphisms (SNPs) and genes associated with four bone weight traits within a population comprising 571 Duroc × (Landrace × Yorkshire) hybrid pigs (DLY). In the analyses, we employed a mixed linear model, and for the correction of multiple tests, both the false discovery rate and Bonferroni methods were utilized. Following functional annotation, candidate genes were identified based on their proximity to the candidate sites and their association with the bone weight traits. This study represents the inaugural application of GWAS for the identification of SNPs associated with individual bone weight in DLY pigs. Our analysis unveiled 26 SNPs and identified 12 promising candidate genes (OPRM1, SLC44A5, WASHC4, NOPCHAP1, RHOT1, GLP1R, TGFB3, PLCB1, TLR4, KCNJ2, ABCA6, and ABCA9) associated with the four bone weight traits. Furthermore, our findings on the genetic mechanisms influencing pig bone weight offer valuable insights as a reference for the genetic enhancement of pig bone traits.

Genetic Architecture of Abdominal Fat Deposition Revealed by a Genome-Wide Association Study in the Laying Chicken.

Fat has a high energy density, and excessive fatness has been recognized as a problem for egg production and the welfare of chickens. The identification of a genetic polymorphism controlling fat deposition would be helpful to select against excessive fatness in the laying hen. This study aimed to estimate genomic heritability and identify the genetic architecture of abdominal fat deposition in a population of chickens from a Dongxiang blue-shelled local breed crossbred with the White Leghorn. A genome-wide association study was conducted on abdominal fat percentage, egg production and body weights using a sample of 1534 hens genotyped with a 600 K Chicken Genotyping Array. The analysis yielded a heritability estimate of 0.19 ± 0.04 for abdominal fat percentage; 0.56 ± 0.04 for body weight at 72 weeks; 0.11 ± 0.03 for egg production; and 0.24 ± 0.04 for body weight gain. The genetic correlation of abdominal fat percentage with egg production between 60 and 72 weeks of age was -0.35 ± 0.18. This implies a potential trade-off between these two traits related to the allocation of resources. Strong positive genetic correlations were found between fat deposition and weight traits. A promising locus close to COL12A1 on chromosome 3, associated with abdominal fat percent, was found in the present study. Another region located around HTR2A on chromosome 1, where allele substitution was predicted to be associated with body weight gain, accounted for 2.9% of phenotypic variance. Another region located on chromosome 1, but close to SOX5, was associated with egg production. These results may be used to influence the balanced genetic selection for laying hens.

The polymorphism of the ovine insulin like growth factor-2 (IGF2) gene and their associations with growth related traits in Tibetan sheep.

In the current study, the role of the ovine IGF2 as a potential candidate gene was investigated as though marker-assisted selection in Chinese Tibetan sheep. The Sanger DNA sequencing method explored five single nucleotide polymorphisms (SNPs) in 5'UTR of the ovine IGF2 gene (C15640T, G15801A, G15870A, C15982G and G15991A) in Chinese Tibetan sheep. The frequencies of four SNPs were within the Hardy-Weinberg Equilibrium (chi-square test) except C15982G. The statistical analysis indicated that the C15640T and G15801A were significantly associated with body height, body length, chest circumference, and body weight (P < 0.05 or P < 0.01). Furthermore, C15982G variant exhibited significant correlation with the body weight (P < 0.01). These findings suggests that the promoter variants of IGF2 gene could be used as a candidate gene through marker-assisted selection for the body weight and body measurement traits in Tibetan sheep breeding program.

Mining Genes Related to Single Fruit Weight of Peach (Prunus persica) Based on WGCNA and GSEA

Single fruit weight is an important goal of crop production and horticultural species domestication, but its genetic mechanism is still unclear. In this study, the fruits of different peach fruit types in their first rapid development period were used as materials. First, the differentially expressed genes were analyzed by RNA-seq data. Secondly, weighted gene co-expression network analysis (WGCNA) was used to calculate the correlation between genes and modules, the genes with different expression patterns were divided into 17 modules, the modules were correlated with the phenotype of single fruit, and a highly correlated blue module was obtained. Then, the possible differentially expressed genes and signal pathways among different fruit types were compared by gene set enrichment analysis (GSEA) and 43 significant pathways were obtained. Finally, 54 genes found to be repeatedly expressed in 3 of the methods were screened, and 11 genes involved in plant hormone signal transduction were selected for subsequent analysis according to their functional annotations. Combined with the changing trend of phenotype, three genes (Prupe.7G234800, Prupe.8G079200 and Prupe.8G082100) were obtained as candidate genes for single fruit weight traits. All three genes are involved in auxin signal transduction, with auxin playing an important role in plant growth and development. This discovery provides a new perspective for revealing the genetic law of single fruit weight in peach.

Polymorphisms and expressions of ADSL, MC4R and CAPN1 genes and their effects on economic traits in Egyptian chicken breeds

In recent years, strategic plans for poultry production have emphasized quantitative traits, particularly body weight and carcass traits (meat yield), in response to overpopulation challenges. Candidate genes such as adenylosuccinate lyase (ADSL), melanocortin-4-receptor (MC4R), and calpain 1 (CAPN1) have played vital roles in this context due to their associations with muscle growth and body composition. This study aims to investigate the influence of polymorphisms and gene expressions of the aforementioned genes on body weight (BW), growth rate (GR), breast weight (BrW), and thigh weight (TW) across four distinct chicken breeds: Fayoumi, Matrouh, Mamourah, and Leghorn. The use of PCR-SSCP analysis revealed genetic polymorphisms through the identification of various patterns (genotypes) within the three examined genes. The ADSL, MC4R, and CAPN1 genes exhibited five, three, and two different genotypes, respectively. These polymorphisms displayed promising connections with enhancing economically significant production traits, particularly BW, BrW and TW. Furthermore, gene expression analyses were conducted on breast and thigh tissues obtained from the chicken breeds at 60 days of age, where ADSL and MC4R exhibited a noteworthy up-regulation in Fayoumi and Matrouh breeds, and down-regulation in Mamourah and Leghorn. In contrast, CAPN1 expression decreased across most breeds with a slight increase noted in Fayoumi breed. In conclusion, this investigation underscores the substantial impact of ADSL, MC4R, and CAPN1 genes on economically important production traits within Egyptian domestic chicken breeds. Consequently, these genes emerge as significant molecular markers, holding potential utility in avian selection and breeding programs aimed at enhancing productive performance.

Heterotic Effect on Body Weight, Reproductive, Morphometric and Carcass Traits of Crossbred Kits of New Zealand White and Chinchilla Rabbits

There is need for breeders and farmers to know the best mating method to employ and the breeding goals to expect in rabbit breeding programmes. However, information on which breed should be used as male or female in crossbreeding rabbit for commercial purpose is limited. This study was conducted to evaluate the effect of reciprocal crossing on body weight (BW), reproductive, morphometric and carcass characteristics of two breeds of rabbits, New Zealand White (NZW) and chinchilla (CHA) raised in tropics. Offspring from the crossing of NZW x CHA and CHA x NZW were studied for body weight (BW) and reproductive traits for twelve weeks. Reproductive traits studied were litter size at birth (LSB), litter size at weaning (LSW), Average birth weight (ABWT), Average weaning weight (AWWT), Gestation length(GSTL) and percent mortality. Morphometric traits studied were body width (BWD), body length (BL), heart girth (HG) and tail length (TL). While carcass characteristics were dressed weight, foreleg, thoracic, loin, hind and skin. The heterotic values and their percentages were calculated in the two genetic groups using the linear contrast procedure. The direct and percent heterosis for reproductive traits were all positive for the two genetic groups except in gestation length and percent mortality which showed negative heterosis (-1 and 3.2%; 3.19;10.12% for gestation length and -7.19 and -19.07; -9.36 and -24.83% for percent mortality in CHA X NZW and NZW X CHA respectively). Body weight at different ages studied, morphometric and carcass traits were also positive for NZW x CHA off springs while CHA x NZW off springs had negative values for all these parameters measured indicating that CHA sired off springs had no improvement for BW at various ages, reproductive, morphometric and carcass traits studied. It could therefore be concluded that rapid improvement in Body weight, Reproductive, morphometric and carcass could be achieved by crossbreeding involving mating of New Zealand White male and Chinchilla does.&#x0D; &#x0D; &#x0D; &#x0D; &#x0D; Il est nécessaire que les éleveurs et les agriculteurs connaissent la meilleure méthode d'accouplement à utiliser et les objectifs d'élevage à attendre dans les programmes d'élevage de lapins. Cependant, les informations sur la race qui doit être utilisée comme mâle ou femelle dans les croisements de lapins à des fins commerciales sont limitées. Cette étude a été menée pour évaluer l'effet du croisement réciproque sur le poids corporel (PC), les caractéristiques reproductives, morphométriques et de carcasse de deux races de lapins, le New Zealand White (NZW) et le chinchilla (CHA), élevés sous les tropiques. La progéniture issue du croisement NZW x CHA et CHA x NZW a été étudiée pour son poids corporel (PC) et ses caractéristiques de reproduction pendant douze semaines. Les caractères reproductifs étudiés étaient la taille de la portée à la naissance (TPN), la taille de la portée au sevrage (TPS), le poids moyen à la naissance (PMN), le poids moyen au sevrage (PMS), la durée de la gestation (DGS) et le pourcentage de mortalité. Les traits morphométriques étudiés étaient la largeur du corps (LC), la longueur du corps (LC), la circonférence du cœur (CC) et la longueur de la queue (LQ). Les caractéristiques des carcasses étaient le poids paré, la patte antérieure, la poitrine, la longe, l'arrière et la peau. Les valeurs hétérotiques et leurs pourcentages ont été calculés dans les deux groupes génétiques en utilisant la procédure de contraste linéaire. L'hétérosis direct et le pourcentage pour les caractères reproductifs étaient tous positifs pour les deux groupes génétiques, sauf pour la durée de gestation et le pourcentage de mortalité qui présentaient une hétérosis négative (-1 et -3,2% ; 3,19 ; 10,12 % pour la durée de gestation et -7,19 et -19,07 ; - 9,36 et -24,83 % pour le pourcentage de mortalité dans CHA X NZW et NZW X CHA respectivement). Le poids corporel à différents âges étudiés, les caractéristiques morphométriques et de carcasse étaient également positifs pour NZW x CHA hors printemps, tandis que CHA x NZW hors printemps avaient des valeurs négatives pour tous ces paramètres mesurés, indiquant que CHA engendré hors printemps n'avait aucune amélioration du poids corporel à différents âges, de la reproduction. , caractères morphométriques et carcasses étudiés. On pourrait donc conclure qu'une amélioration rapide du poids corporel, reproducteur, morphométrique et carcasse pourrait être obtenue par un croisement impliquant un accouplement de mâles blancs de Nouvelle-Zélande et de chèvres Chinchilla.

Association of microsatellite genotypes with layer economic traits in a selected strain of Rhode Island Red chicken

Randomly selected 76 pullets of RIR selected strain were screened for microsatellite polymorphs and investigated for their association with layer economic traits. Microsatellite alleles were separated from genomic DNA samples through 3.4% MetaPhor® agarose gel electrophoresis. Data were recorded on age at first egg (AFE), egg weights and egg production (EP) at certain age. Microsatellite analysis revealed nine polymorphic loci (EW) and genotypes at ADL0020 locus were significantly associated with EP at 40 and 64 weeks of age, CC (110 bp/110 bp) genotype had the highest EP, whereas, AD (126 bp/102 bp) and BD (118 bp/102 bp) genotypes recorded the lowest EP. Genotypes at ADL0023 locus were associated with AFE, EP at 40 weeks of age, CC (176 bp/176 bp) genotype followed by AB (202bp/188bp) genotype had earlier AFE, whereas, AC (202bp/176bp) genotype followed by BB (188bp/188bp) genotype demonstrated late AFE. ADL0210 locus had significant impact on AFE, egg weight at 28/40/64 weeks of age; BB (124bp/124bp) genotype followed by AA (132 bp/132 bp) genotype had earlier AFE than AB (132 bp/124 bp) genotype. Both AB and AA genotypes revealed significantly higher egg weight at 28/40/64 weeks of age than BB genotype. The BB (176 bp/176 bp) genotype followed by AB (192 bp/176 bp) genotype at MCW0014 locus revealed higher egg weight at 28 weeks of age in comparison to AA (192bp/192bp) genotype. Allele C (110 bp) at ADL0020 and A (132 bp) at ADL0210 either in homozygous or heterozygous condition were linked to the traits of egg weight and egg production performance, respectively. The results might impact on genomic selection aided poultry breeding programme.

Dietary supplementation with β-mannanase and probiotics as a strategy to improve laying hen performance and egg quality.

The objective of this study was to assess the impact of β-mannanase and probiotic on the performance, serum biochemistry, gut morphometric traits, and fresh egg quality of laying hens. A total of 120 cages, housing light-weight laying hens (36 weeks old), were randomly assigned to four different treatments. These treatments included a control group fed non-supplemented diets; diets supplemented with 300 g/ton of beta-mannanase; diets supplemented with 50 g/ton of probiotic; or diets containing both 300 g/ton of β-mannanase and 50 g/ton of probiotics. The trial spanned a duration of 26 weeks and was divided into three productive phases, each lasting 28 days. The inclusion of β-mannanase resulted in a significant improvement in the laying rate by 11% (p < 0.05) compared to the control treatment. Similarly, the addition of probiotics also enhanced the laying rate by 7% (p < 0.05), as well as the supplementation with combined additives (11.5%). Combined additives showed an increase in egg masses, and additive association improved by 13.9% (p < 0.001) in contrast to the control treatment. Overall, β-mannanase and combined additives used during the supplementation period resulted in improvements in the weight of fresh eggs. These benefits were observed after a period of 14 weeks without supplementation (p < 0.05). Furthermore, significant differences were observed in the serum biochemistry and egg masses of birds that were fed diets containing both additives (β-mannanase + probiotics) compared to the control group. Parameters such as uric acid, total cholesterol, and triglycerides displayed notable variations. The villi height: crypt depth showed differences with combined additives (β-mannanase + probiotics). The β-mannanase improved specific gravity, yolk height, length, and pH, and yolk color traits compared to the control treatment. The use of probiotics helped to improve yolk height, pH, and color score. Besides, combined additives (β-mannanase + probiotics) improve yolk height, length, weight, pH, and better traits in yolk color. Hence, incorporating β-mannanase and probiotics into laying hen diets proves to be a highly effective strategy for enhancing laying rate and overall health status, while simultaneously elevating certain quality attributes of fresh eggs.

Study some Genetic Variance and Breeding Value on Productive Performance for Local Chicken Differ in Polymorphism of Growth Hormone Gene

To fix and detect some value of genetic selection parameters for hens of local chicken differ in growth hormone GH gene polymorphisms, PCR-RFLP technique used with MSP restriction enzyme, three genotype found as AA the wild, AB the heterosis and the mutant BB. Results of some genetic analysis indicating that based on breeding value BV for AA genotype was the highest one 79.913 for body weight at sexual maturity and 1.736 for average age at sexual maturity and 4.373, 5.894 and 0. 438 for average egg product at 100 days and average egg weight at 27 and 34 weeks respectively for the seam AA hens’ genotype. The lowest value for dominant deviation DD was 0.298 for traits of average first egg weight, for body weight at sexual maturity was – 6.659 and – 5.58 for average age at sexual maturity and 0.012 for average egg weight at 20 weeks and 0.042 for average egg weight at 34 weeks for hens with BB genotype. AB genotype was low in trait for average egg weight at 27 and 34 weeks with value of 8.044 and – 0.08 respectively. In conclusion molecular procedure result indicating that depending on some molecular genetic parameters RFLP for such gene of relation with productive performances and BV includes some genetic variances as DD, DV and VA and GV are good tools used in selection programs for local hen’s chicken either if their genotype is with one or two copies of allele A in order to achieve the best genetic group in the way of improving production efficiency for Iraqi local chickens.

Relationship of Lei0258 Marker on some Productive Traits of Iraqi Local Chickens

This study was used 100 laying hens, for the period from 10/26/2021 till 3/5/2022 to studying the effect of LEI0258 marker on some productive traits of Iraqi local chickens, Productive traits were measured from the sexual maturity up to 100 days for each chicken, the blood samples were collected from 100 laying hens at the age of 38 weeks from a brachial vein. The LEI0258 marker have 11 alleles were (A1, A2, A3, A4, B1, B2, B3, C1, C2, C3, D1). The results showed that there were a high significant differences (P ≤0.01) for (A1, B1) alleles compared with different alleles of percentage number and genetic distribution with a percentage of (18 %). there was a significant effect (P ≤0.05) in age at sexual maturity for different alleles, while in weight at sexual maturity there were non-significant difference between different alleles. Egg weight trait showed that there was a significant difference (P ≤ 0.05) for the periods (14, 42, 70, 100) day, and non-significant differences in the productive periods (28, 56, 84, 98) day. Feed intake ratio recorded non-significant differences in the period (14, 28, 42, 98, 100) day, while it recorded a significant difference (P ≤0.05) in the productive periods (56, 70, 84) day between different alleles. The qualitative traits revealed a significant difference (P ≤ 0.05) for (shell weight, yolk weight, yolk height, yolk diameter, egg white weight, egg diameter, egg white height, and HU unit), While non-significant differences in shell thickness between the different alleles.

Evaluation of Some Genotypes of Wheat (Triticum Durum L.) Under Conditions in Al Jabal Al Akhdar - Libya.

The experiment was conducted at the research farm of the College of Agriculture during the season (2019-2020) to evaluate the performance of six genetic compositions under semi-arid conditions using the green fodder. These compositions were obtained from the International Center for Agricultural Research in Dry Areas (ICARDA) and the International Maize and Wheat Improvement Center (CIMMYT), compared to the local variety "Ain Al-Faras." The treatments were planted according to a randomized complete block design (RCBD) with three replications. Significant differences were observed among all the genetic compositions for all the studied traits. The variety "Ain Al-Faras" outperformed the other genetic compositions in plant height, spike length, number of grains per spike, grain yield, straw yield, and biological weight, with values of 86 cm, 9.65 cm, 61 grains/spike, 1.14 tons/ha, 10.68 tons/ha, and 11.82 tons/ha, respectively. Genetic composition 2020-741 also excelled in the trait of number of grains per spike (52.33), while genetic composition D2020-72 exhibited superiority in the trait of thousand-grain weight (63.35 g). Moreover, genetic composition D2020-4 showed a higher harvest index compared to the other genetic compositions, with a value of 12.91. The results indicated that the values of phenotypic variance were close to the values of genetic variance for most of the studied traits. The highest heritability ratio was observed for the traits of number of grains per spike and grain yield. High relative genetic advance values were recorded along with high values of specific combining ability for both the number of grains per spike and grain yield. Therefore, it is possible to infer the genetic composition through morphological data, and such traits can be considered as selection criteria for improving these crops.

Differences in the choice of beef artificial insemination sires used by dairy producers versus beef producers

The growing demand among dairy producers for suitable beef sires to mate to their females creates the possibility of separate breeding programs to generate beef sires for the dairy sector versus those for the beef sector. Informing such a decision is the extent of the genetic differences among beef sires used by dairy producers relative to those used by beef producers. The objective therefore of the present study was to use a large national database of artificial insemination (AI) records in dairy and beef cow herds to establish the difference in mean genetic merit of beef AI sires used by dairy producers versus those used by cow-calf beef producers. The traits explored were gestation length, calving difficulty, and perinatal mortality as well as the 3 carcass traits of carcass weight, conformation, and fat score. Carcass conformation and fat score are mechanically assessed on a scale of 1 (poor conformation and low fat cover) to 15 (excellent conformation and high fat cover). Sire genetic merit differences for feed intake and docility were also examined. Estimates of genetic merit for all 8 traits on individual AI sires available at the time of service were used. A total of 1,230,622 AI records comprised 909,719 services from dairy herds and 320,903 services from beef herds were used. Of the 1,802 beef AI sires represented in the entire dataset, over half were used by both dairy and beef herds representing ≥98% of the services in each production system. However, the usage rate of individual AI sires differed between dairy and beef herds with the Spearman rank correlation between the quantity of inseminations per sire in dairy and beef herds being just 0.38. This correlation means that beef AI sires used heavily in the beef herd were not always those heavily used in dairy herds. A clear difference in the mean genetic merit of beef AI sires selected by dairy producers relative to those selected by beef cow-calf producers was obvious with the extent of the difference being a function of whether the female served was a nulliparous heifer or a cow. Much of the differences in genetic merit of chosen beef AI sires between dairy and beef producers was actually attributable to differences in breed choice, albeit some within-breed selection was also evident. Irrespective, dairy producers, on average, chose shorter gestation length sires whose progeny were genetically less predisposed to require intervention during the birthing process; these sires had genetic merit estimates expected to result in lighter and less conformed progeny carcasses relative to the beef AI sires used by beef producers. Results point to large differences in genetic merit of the beef AI sires chosen by dairy versus beef producers, much of which actually reflected differences in breed choice among dairy and beef producers.

Genetic Analysis of Malkangiri Goats in its Native Tract

Background: In the present study, genetic analysis of Malkangiri goat, a native goat population of southern Odisha is made. Methods: The present study area was under south eastern ghat agro climatic zones in Odisha. These goat type is raised under semi-intensive system of management with a flock size ranging from 5 to 35. The body weight and some biometric traits were recorded from birth to 12 months at an interval of 3 months. Estimation of heritability, genetic and phenotypic correlation also were reported in this research article. Result: Overall body weight of this goat type were found to be 16.31±0.17 kg with height of 57.44±0.50 cm at marketable weight of 12 months. The heritability estimate of body weight was recorded as 0.19±0.13 and 0.22±0.15, respectively at birth and 12 month of age. The heritability estimates of HW, BL, HG and PG at 12 month of age were 0.13, 0.32, 0.22, 0.13, respectively. The genetic correlation among the body weight and body measurement traits ranged from 0.21 to 0.91, whereas, the phenotypic correlation range from 0.18 to 0.52 at 12 month of age. This information on the genetic analysis may be helpful in developing further breed improvement strategies and conservation.

PREDICTION OF BODY WEIGHT OF NIGERIAN NON-DESCRIPT GOATS FROM MORPHOMETRIC TRAITS USING CLASSIFICATION AND REGRESSION TREE MODEL

This study was conducted to evaluate the relationship between body weight and eleven (11) morphometric traits (body weight, body length, height at withers, rump height, chest girth, hind leg, fore leg, head length, ear length, neck length, and tail length) of non-descript goats using classification and regression tree technique. The data were generated from 120 non-descript goats randomly selected from different herds in three LGA areas of Kaduna State, North West Nigeria. Pearson’s moment correlation (r) between body weight and morphometric traits ranged from low to high values (r = 0.21-0.97; P≤0.05, P≤0.01). Based on the importance of the independent variables in predicting the body weight of goats, six body measurements namely; chest girth, body length, rump height, height at withers, head length and neck length were found to be more efficient. Thus, they were the variables entered to obtain the optimal regression tree. Among these six variables, chest circumference was found to be the primary splitting variable; and together with neck length accounted for about 84.20% of the variation in body weight. The regression tree analysis indicated that animals with chest circumference &gt; 60.00cm and neck length &gt;15cm could be expected to have higher body weights. This information could be exploited by livestock producers and researchers for determining the feed amount, drug dose, and market price of an animal, management, selection and genetic improvement of Nigerian non-descript goats.

154 Antibody and Cell-Mediated Responses Associated with Bvdv and Interferon-Gamma Expression in Reciprocal Angus-Brahman First Generation Crosses

Abstract The influence of sex and reciprocal cross type were evaluated in Brahman-sired (B × A) and Angus-sired (A × B) F1 cattle following modified-live viral vaccination regarding virus neutralization titers (VNT) and cell-mediated immune (CMI) responses following in vitro exposure to Bovine Viral Diarrhea Virus (BVDV) Type 1 (BVDV1) and Type 2 (BVDV2) genotypes. VNT against BVDV were based on virus neutralization assay, and CMI responses were measured using the PrimeFlow mRNA assay for determination of the frequency of BVDV and interferon-gamma (IFN-γ) positive cells. Mixed model procedures utilized individual calf ID as a random effect with fixed effects of F1 cross type, calf sex, evaluation date, and potential 2-way interactions; models for frequency of BVDV and IFN-γ positive cells, stimulation conditions (BVDV1, BVDV2, mitogen, none) and potential two-way and three-way interactions of fixed effects. Relationships of immune responses with calf birth weight and weaning weight and steer carcass traits were also investigated. This study found several CMI traits differed due to the type of cross and calf sex; however, no differences in VNT were attributed to these effects. Cells from B × A animals consistently ranked approximately 20% greater for BVDV positive cells (BVDV+) than those from A × B animals pre-MLV vaccination; however, post-MLV vaccination, cells from A × B animals ranked 20% greater (P &amp;lt; 0.05) for CD2+, CD4+, and CD8+ cells. Post- MLV steers consistently had 30 to 35% greater (P &amp;lt; 0.05) frequencies of BVDV+ cells following viral exposure; steers had greater frequencies (P &amp;lt; 0.05) of CD4+ and CD335+ cells expressing IFN-γ and ranked greater for CD2+ and CD8+ cells when compared with heifers in both crosses. Only vaccination timing affected BVDV VNT. No significant correlations involving VNT and CMI responses were observed among A × B animals when stimulated with BVDV1, but among B × A animals, positive correlations were observed with IFN-γ in CD4+ (r = 0.406, P = 0.049) and CD335+ (r = 0.472, P = 0.020). When stimulated with BVDV2, positive correlations of 0.33 to 0.39 (P &amp;lt; 0.05) were observed between BVDV and IFN-γ frequency within cell type; these were not significant when stimulated with BVDV1, except for CD335+ cells (r = 0.41, P = 0.003). No correlations for VNT and CMI responses were observed when stimulated with BVDV2. No major correlations between immune responses and weight or carcass traits were observed, and immune response category for BVDV or IFN-γ frequency did not influence birth weight or weaning weight. Differences in CMI responses involving reciprocal cross types and sex observed in this project may relate to widely reported reciprocal cross differences in birth weight in Bos indicus - Bos taurus crossbred cattle and warrant additional study.

176 Relationships Among Early Life Weight and Growth Among Halfblood Bos Indicus Male Calves and Associations with Carcass Weight

Abstract Nellore-Angus steers (n = 572) born in 2009-2013, 2015, and 2019 and Brahman-Angus reciprocal steers (n = 73) born in 2019 and 2020 were evaluated for calf and carcass weights (HCW). Calves were born and reared at the McGregor Research Center and included F2, F3, F4, and F5 Nellore-Angus and F1 Brahman-Angus. Calves were weighed at 4 approximate times: within 48 h of birth (BWT), 50 d age (spring-working, SWWT, not available for 2009-2010), 180 d age (pre-weaning, PRWWT), and approximately 210 d age (weaning, WWT). Animals born in the same year were managed similarly, and cow herds were managed together in most cases except during annual natural service, multi-sire breeding seasons. Animals born in the same year were managed as contemporaries post-weaning and for feedlot finishing. Mixed model analyses of variance for calf traits included genetic type (nested within calf birth year), calf birth year, age of dam category, and covariates of Julian birth date (BWT, SWWT) or calf age (PRWWT and WWT) as fixed effects. In each year at least 2 genetic types were present; however, because of imbalance across years, only genetic types produced in the same years were compared following significant F-tests. For these analyses cow age category did not affect calf BWT or SWWT, but showed influence for PRWWT (P = 0.006) and WWT (P &amp;lt; 0.001); cow age category did not affect calf ADG. Differences in calf weights (P &amp;lt; 0.001) and calf ADG (P &amp;lt; 0.001) due to the genetic type were driven by reciprocal differences between Brahman-Angus crosses and potential maternal hybrid vigor advantages for F2 Nellore-Angus calves from F1 dams vs. other genetic types. Brahman-sired F1 (B × A) males were 12.7 to 14.1 kg heavier for BWT (P &amp;lt; 0.001) and 14.9 to 19.2 kg heavier for SWWT (P &amp;lt; 0.001) than Angus-sired F1 males (A × B), but persistence to weaning varied across years. It appears in these data that some genetic types may be more sensitive to individual year effects, but it is uncertain why. Correlations of calf weight traits with HCW were inconsistent across genetic types. No calf weight was associated with HCW in A × B crosses, and only PRWWT in B × A related to HCW (r = 0.44, P = 0.007). Among Nellore-Angus crosses, BWT showed small to moderate correlation to HCW (0.23 &amp;lt; r &amp;lt; 0.46); however, among the F4 and F5 calves, later weights (SSWT, PRWWT and WWT) had large correlations with HCW (0.50 &amp;lt; r &amp;lt; 0.79) whereas these correlations ranged from 0.24 to 0.37 in F2 and F3 steers. It appears animals of similar Bos indicus percentage may have quite different calf growth patterns related to HCW.

Genetic analysis of growth parameters and optimum age and weight slaughter prediction in Kurdi sheep

The objective of this study was twofold: first, it aimed at estimating genetic parameters related to growth curve using nonlinear models (Brody, Gompertz, Logistic, Von Bertalanffy, and Richards); secondly identifying an optimum age and weight for both male and female Kurdi sheep breed. To this end, the information related to the pedigree (n = 17,669) due to sires (n = 162) and dams (n = 1968) for body weight traits Viz. birth weight (BW), 3-month-old weight (3 MW), 6-month-old weight (6 MW), 9-month-old weigh (9 MW) and 12-month-old weight (12 MW) were used. To find the best-fitted model, several measures were employed including the Akaike information criterion (AIC), root mean square error (RMSE), coefficient of determination (R2), mean absolute deviation (MAD), and Bayesian information criterion (BIC). The DMU software was employed to determine the growth genetic variance components. Given AIC, MSE, and R2, the Brody model was selected as the best-fitted one for describing the growth curve in the Kurdi sheep breed. The fitted parameters A (estimated mature weight), B (an integration constant related to initial animal weight), and K (maturation rate) were estimated for models by sex separately. However, since Brody does not have a turning point to determine the appropriate turning point, we used the results of the second best-fitted model, viz Von Bertalanffy model, to find the optimum age and weight slaughter in Balafrej, (2019) equations. According to the results, there was a greater variance in weight between males and females at 12 MW compared to other ages. The optimal slaughter weights for males and females were 28.14 and 22.44 kg, respectively, and the corresponding ages were 120.49 and 90.31 days. By utilizing a multivariate animal model, the prediction of heritability for parameters A, B, and K was calculated to be 0.055, 0.117, and 0.012 respectively; indicating that genetic variation is relatively insignificant in these growth parameters. Further analysis revealed negative genetic correlations between growth parameters at rates of − 0.200 (A-B), − 0.471 (A-K), and, − 0.220 (B-K). The prediction of genetic trends for A, B, and K parameters was obtained as 0.043, 0.043, and 0.001gr/yr which could reflect different modes of selection pressure over these parameters. Despite not being the best-fitted model for Kurdi growth data, the Von Bertalanffy model can still be utilized to predict the live weight of the Kurdi sheep breed. Nonetheless, for genetic-based decision-making aimed at picking out superior animals based on accurate growth parameter predictions, it is recommended that findings from the Brody model be adapted for downstream genetic analysis in the Kurdi sheep breed.