Dorper Sheep Research Articles

Production performance of sheep and goat breeds at a farm in a semi-arid region of Namibia.

This study retrospectively investigated the effect of breed and season on the lambing/kidding dynamics, growth performance, neonatal viability, and weaning dynamics of sheep (Damara, Dorper, and Swakara) and goats (Boer goat and Kalahari Red) at a farm in the Khomas Region of Namibia between 2004 and 2015. Litter size was dependent on breed (X2(12, N = 3388) = 796, p < 0.001), with twinning more frequent in Dorper sheep and Kalahari Red and Boer goats than in the Damara and Swakara sheep (p < 0.05), while triplets were more prevalent in the Dorper sheep and Kalahari Red goats (2.8% and 1.0%, respectively; p < 0.05). Distribution of birth weight categories was dependent on breed. There was a significant difference in the proportions of birth weight categories between breeds (X2(12, N = 3388) = 467, p < 0.001) whereby Dorper lambs were mostly born weighing below 3kg (2.6%, p < 0.05); Boer goat kids, Kalahari Red kids, and Damara lambs were mostly born weighing 3 to < 4kg (4.3%, 6.3% and 19.9%, respectively; p < 0.05); Swakara lambs were mostly born weighing 4 to < 5kg (12.2%, p < 0.05), and Swakara lambs were mostly born weighing ≥ 5kg (3.3% and 2.3%, respectively, p < 0.05). Weaning age categories were dependent on breed (X2(12, N = 3388) = 241, p < 0.001) whereby Dorper lambs were mostly weaned at below 3months of age (2.8%, p < 0.05); Damara lambs were mostly weaned at 3 to < 5months of age (12%, p < 0.05), and Boer goat kids were mostly weaned at ≥ 5months of age (0.9%, p < 0.05). Neonatal viability was dependent on breed (X2(8, N = 3388) = 49.2, p < 0.001) whereby Dorper lambs were more susceptible to abortions and neonatal deaths (0.6% and 1.5%, respectively; p < 0.05) than the rest of the breeds. Breed and lambing season interacted to produce effects on the birth weight of offspring although lambing season alone did not have a significant effect on Boer goat and Kalahari Red kids' birth weights.

Crosstalk between androgen and Wnt/\u03b2-catenin leads to changes of wool density in FGF5-knockout sheep

Fibroblast growth factor 5 (FGF5) is a famous dominant inhibitor of anagen phase of hair cycle. Mutations of FGF5 gene result in a longer wool in mice, donkeys, dogs, cats, and even in human eyelashes. Sheep is an important source of wool production. How to improve the production of wool quickly and effectively is an urgent problem to be solved. In this study, we generated five FGF5-knockout Dorper sheep by the CRISPR/Cas9 system. The expression level of FGF5 mRNA in knockout (KO) sheep decreased significantly, and all FGF5 proteins were dysfunctional. The KO sheep displayed a significant increase in fine-wool and active hair-follicle density. The crosstalk between androgen and Wnt/β-catenin signaling downstream of FGF5 gene plays a key role. We established downstream signaling cascades for the first time, including FGF5, FGFR1, androgen, AR, Wnt/β-catenin, Shh/Gli2, c-MYC, and KRTs. These findings further improved the function of FGF5 gene, and provided therapeutic ideas for androgen alopecia.

АНАТОМО-ТОПОГРАФИЧЕСКИЕ ОСОБЕННОСТИ КОСТЕЙ ПОЯСА ТАЗОВОЙ КОНЕЧНОСТИ ОВЕЦ ПОРОДЫ ДОРПЕР

Movement is a characteristic and in-herented property of the animal organism. Without the implementation of musculoskel-etal work, it becomes impossible for the animal to move in the environment, search for food, protect themselve and procreate. This work in the body is performed by the musculoskeletal system, which accounts for most of the body weight. The basis for the research at the Department of animal anato-my of Saint Petersburg state university of veterinary medicine was post-mortem mate-rial from animals slaughtered at the farm "Gzhelskoe Podvorye", Moscow region. Three age groups were formed. The first group included newborn animals. The sec-ond group included young animals of five to six months. The third group consisted of sheep from one year and older. During the study, a set of anatomical methods was used, including: fine anatomical dissection, macer-ation, computer tomography and macropho-tography. Based on our research, we first established anatomical and topographical features of the pelvic area of dorper sheep. These features have a common anatomical pattern, which is characteristic for ruminants. However, dorper sheep are characterized by typical topographical breed features of that area, determined by their genetic predisposi-tion. The main morphometric parameters of the pelvic bones of dorper sheep reach their maximum values by the age of one year and older, while the most intensive growth of the pelvic area is typical for the age period from five to seven months to a year.

Regulation mechanisms of positive cold tolerance in Mongolian sheep

Abstract Mongolian sheep survive well on the Mongolian plateau during tremendously cold winters, but their cold response mechanisms are not well understood. By comparing with Dorper sheep originating from South Africa, we expected to reveal the cold tolerance mechanisms of Mongolian sheep on the basis of transcriptome data, further providing molecular evidence for the targeted breeding of sheep. Based on the mRNA data of RNA-seq, we selected candidate genes among the differentially expressed genes; 7 from adipose tissue, 33 from skeletal muscle, and 10 from the liver. According to enriched KEGG pathways and previous research results, the effects of the above candidate genes mainly involved weakening the synthesis of long-chain fatty acids, raising the adaptive thermogenesis and browning adipogenesis in fat, reducing glucose 6-phosphate, stimulating citrulline generation and enhancing lipid metabolism in skeletal muscle, and postponing cell senescence in the liver. The findings also demonstrate the regulation mechanisms of cold tolerance in different tissues of Mongolian sheep.

Modeling and comparison of the maturing rates of Damara, Dorper and Swakara sheep at Neudamm Farm

Although sheep play an important role in the Namibian livestock industry, there is a paucity of information on their production performance. The objective of the study was to compare the mature weights, and maturing rates for Damara, Dorper and Swakara sheep reared at Neudamm Farm. Four hundred and eight (408) sheep (84 Swakara, 296 Damara and 28 Dorper) were weighed monthly for 6 months. The Brody, Van Bertalanffy, Gompertz and logistic growth models were fitted to the data to determine the mature size and maturing rate. Based on the R2 and the BIC, the Brody growth function gave the best fit. The estimated mature weights for Damara, Dorper and Swakara sheep were 46.8±1.1 kg, 53.9±1.0 kg and 48.8±1.1 kg, respectively, with the corresponding maturing rates of 0.0037±0.0001, 0.0025±0.0003 and 0.0021±0.0001 kg/day. Although the Damara sheep have a smaller size compared to Dorper sheep, they mature faster, making them a better breed for mutton production. The Dorper had the largest mature sizes, although their rate of maturation was lower than the Damara sheep.

PSX-38 Reproductive performance of Dorper ewes with varying days post-partum to ram introduction in the non-breeding season

Abstract With the decrease of a wool favored market, hair type sheep have become increasingly popular for lamb markets. In Texas, the most popular hair type breed of sheep is the Dorper. Various breed characteristics make the Dorper sheep an excellent candidate for an accelerated lambing system. Reproductive performance of Dorper ewes with various lengths of post-partum interval, during the traditional non-breeding season, was determined. During May (13L:11D), 2+ yr-old multiparous ewes (n = 28) were joined with a fertile ram for 30 d. Weekly blood samples were taken for progesterone analysis. Ewes were blocked according to length of post-partum interval (lamb to ram): short (SPP; n = 10, 100 ± 2.7 d), mid (MPP; n = 11, 130 ± 0.68 d) and long (LPP; n = 7, &amp;gt;200 d). Weaning age of lamb(s) from previous parturition was similar for SPP (62 ± 3.2 d) and MPP (67 ± 0.6 d). Interestingly, 11% of the ewes had a functional CL at initiation of the study (P4 &amp;gt; 1.5 ng/mL). Mean body condition score for SPP, MPP, and LPP ewes were 2.8 ± 0.08, 3.1 ± 0.09, and 3.7 ± 0.08, respectively. Pregnancy rates were similar between MPP (100%), LPP (100%) and SPP (60%). Overall, pregnancy rate was 87% and a lamb crop (lambs per ewe exposed) was 1.3 ± 0.09. Twinning rate for SPP, MPP, and LPP was 20%, 73%, and 43%, respectively. Pregnancy rate in SPP ewes may indicate carryover of the suppressive effects of lactation and suckling. Results suggest a lamb to ram interval of &amp;gt;100 d is sufficient for response to the ram effect and resumption of estrous cycles in a majority of ewes during photoperiod of 13L:11D. We conclude Dorper sheep have the reproductive capacity to successfully meet the production goals of accelerated lambing systems and thus, the potential for optimized lamb production.

Association analysis of immune response loci related to Haemonchus contortus exposure in sheep and goats using a targeted approach

Haemonchus contortus infections are an important source of animal production loss to livestock industry. Genetics of helminth resistance involves a complex set of factors related to the host immune response. The increasing use of genetic markers such as single nucleotide polymorphisms (SNPs) in genome wide association studies (GWAS) offers the potential to identify loci or regions associated with nematode resistance in small ruminants. The aims of this study were: (1) to use a targeted sequencing approach to identify SNPs in 100 genes related to immune response during Haemonchus contortus exposure in growing males of St. Croix, Katahdin and Dorper sheep, and in Kiko, Boer and Spanish goats, and (2) to perform an association analysis for fecal egg count (FEC), packed cell volume (PCV), immunoglobulin levels (IgA, IgG and IgM) and average daily gain (ADG) in the populations under study. After quality control (call rate < 95%, MAF < 0.05), 1356 SNPs (sheep) and 1,029 SNPs (goats) were used for the association analysis. A mixed model was used to analyze the phenotypic information. To control for population structure, the genomic relationship matrix (G) calculated from marker information was included in the model. Fixed effects included year and breed. Bonferroni correction was used to control for multiple testing. For sheep, SNPs located on OAR1 (42487870, 42489606) and OAR2 (192231080, 26321541) were significantly associated with IgM, ADG, and FEC. For goats, SNPs on CHR3 (42898132) and CHR22 (23066762) were associated with ADG and IgM. In both species, no significant associations were found for IgA, IgG and PCV. The results from this study revealed genes involved in the immune response to H. contortus exposure and provide additional SNP marker information that has potential to aid selection of resistance to gastrointestinal parasites in sheep and goats from different breeds. Significant SNPs within IL12RB2, NFIL3 and STAT4 genes could be potential markers for IgM, FEC and ADG in sheep populations. For goats, potential markers for IgM and ADG were identified within IL5RA and IL12RB2 genes. These results could be directly implemented in the populations used in this study, however, they should be validated before using these markers in other sheep and goat populations.

199 Effects of high heat load conditions on Dorper, Katahdin, and St. Croix sheep from different regions of the USA

Abstract Forty-six Dorper, 46 Katahdin, and 43 St. Croix female sheep (initial BW of 58, 59, and 46 kg, respectively, SEM = 1.75; 3.3 ± 0.18 yr of age, 2.6 - 3.7) from 45 commercial farms in four regions of the USA (Midwest, Northwest, Southeast, and central Texas) were used to evaluate responses to high heat load index (HLI) conditions in a central facility. The four trials entailed sequential 2-wk periods with target HLI during day/nighttime of 70/70 (thermoneutral zone conditions during the day and night), 85/70, 90/77, and 95/81, with weekly measures at 0700 (before increased daytime HLI), 1300, and 1700 h (preceding lower nighttime HLI). Rectal temperature (ºC) in period 3 (38.64, 38.66, and 38.48 at 0700 h, 39.08, 39.23, and 38.84 at 1300 h, and 39.20, 39.15, and 38.99 at 1700 h) and period 4 (38.71, 38.90, and 38.51 at 0700 h, 39.18, 39.12, and 38.83 at 1300 h, and 39.45, 39.34, and 39.07 at 1700 h for Dorper, Katahdin, and St. Croix, respectively) (SEM = 0.054, 0.037, and 0.038 at 0700, 1300, and 1700 h, respectively) ranked St. Croix &lt; Katahdin &lt; Dorper. Nonetheless, there were corresponding differences in respiration rate (breaths/min) in period 3 (63.1, 56.8, and 49.6 at 0700 h, 133.8, 125.8, and 115.7 at 1300 h, and 125.5, 114.7, and 106.8 at 1700 h) and period 4 (81.6, 72.2, and 54.5 at 0700 h, 149.2, 143.6, and 137.3 at 1300 h, and 147.0, 141.4, and 134.2 at 1700 h for Dorper, Katahdin, and St. Croix, respectively) (SEM = 3.12, 4.11, and 3.62 at 0700, 1300, and 1700 h, respectively). In conclusion, based on rectal temperature and respiration rate the overall impact of region was minimal and resilience to high HLI was greatest for St. Croix and lowest for Dorper sheep

Characterizing the Wool Fiber Fineness and Crimps of Menz, Dorper and Their Crossbreed Sheep

Ethiopia possesses about 30 million of sheep population which could be taken as a source of raw material for textile industries as a wise strategy to manage their natural fibers scarcity. This work explored the possible wool fiber potentials on selected sheep breeds. Three representative breeds as indigenous (Menz), exotic (Dorper) and crossbreed (50% Dorper/50% Menz) sheep breeds were considered to characterize the wool fiber properties. Samples have been taken from four main body parts for four age categories of each sheep breeds. All samples were allowed to standard laboratory conditioning before testing, and then, properties are measured based on ASTM. The results revealed that the fibers diameter and crimp frequencies of wool fiber of the three sheep breeds in Ethiopia are significantly different from each other. The crossbreeding of the Menz sheep with Dorper provides fine wool fiber. The wool fiber properties particularly the fineness and crimps of Menz, Dorper and 50% Dorper sheep of different parts and age categories are significantly different. Hence, these wool fibers shall be classified and graded based on their breeds to use for different applications, and also it could help to explore more on wool fiber production.

Effects of Supplementation of Rumen Protected Fats on Rumen Ecology and Digestibility of Nutrients in Sheep.

Simple SummaryRising populations and urbanization are transforming into increased demand for livestock products, particularly in developing countries. The world will need more meat and more milk and in order to meet these demands, huge quantities of feed resources will be required. However, there is a substantial deficit of energy feeds affecting the growth and production of animals. The common method to increase energy value of ruminant diets is to provide them with fats. However, higher level of fats in the diet could prove toxic to rumen microbes and affect fibre digestibility, which ultimately results in reducing the feed intake and lowering animal production. These negative effects of fat supplementation can easily be overcome by feeding ruminants with specifically designed fats called rumen protected fats. In order to evaluate the efficacy of rumen protected fats (RPF), three different types of protected fats were examined in sheep. The results suggested that different types of protected fats have no unfavourable influences on the ruminal fermentation and productive parameters. Therefore, prilled fat, prilled fat with lecithin and calcium soaps did not improve animal performance as compared to the diet without protected fats in Dorper sheep.Rumen protected fats (RPF) are known to improve animal performance without affecting rumen metabolism in sheep. However, comparative effects of prilled fat, prilled fat with lecithin and calcium soap have not been fully studied. Hence this experiment was planned using 36 male Dorper sheep in a completely randomized design in four treatment groups. The diets included: Basal diet (70:30 concentrate to rice straw) with no added RPF as a control (CON), basal diet plus prilled fat (PF), basal diet plus prilled fat with lecithin (PFL) and basal diet plus calcium soap (CaS). The trial lasted 90 days following two weeks adaptation period. The body weights, average daily gain and gain to feed ratio were not affected by treatments. The intake and digestibilities of dry matter, organic matter, crude protein and neutral detergent fibre were not affected, while those for ether extract and crude fibre differed (p < 0.05). RPF had no effect on concentrations of ammonia nitrogen, total volatile fatty acids and total bacterial population. The concentrations of rumen total saturated fatty acids, unsaturated fatty acids, total n − 3, total n − 6, unsaturated fatty acids:saturated fatty acids and polyunsaturated fatty acids:saturated fatty acids differed (p < 0.05) among the treatments with RPF supplementation. Hence supplementation of different types of protected fats did not influence animal performance in Dorper sheep.

Population structure of a nucleus herd of Dorper sheep and inbreeding effects on growth, carcass, and reproductive traits

This study evaluated the pedigree structure of 3780 animals and assessed the inbreeding effect on the breeding values of body weight at 90 days (W90), longissimus muscle area (LMA), backfat thickness (BFT), and scrotal perimeter (SP) in a Dorper sheep flock. The pedigree completeness was 81.8% (1st generation), 56.6% (2nd generation), and 39% (3rd generation). The effective population sizes identified for complete, equivalent, and maximum generations were 83.07, 102.96, and 188.54, respectively. The flock included 62 effective founders and 57 effective ancestors, with 23 ancestors found responsible for 50% of the variability. The average inbreeding coefficient was 0.32%. The inbreeding effect was observed to be significant (P < 0.05) for LMA (0.0198 ± 0.0069) and BFT (0.0031 ± 0.0015). Thus, the pedigree under investigation showed reasonable completeness, but the generation interval (4.0 ± 1.7 years) needs to be decreased for the genetic gain per generation to be maximized. Moreover, in recent years there has been a dramatic reduction in effective population size (Ne) and increase in inbreeding in this flock, which can have consequences in the mid and long-term, although negative effects were not observed in the present study.

Insights into Sheep Genetic Improvement Practices Through Crossbreeding in Ethiopia: Achievements, Challenges and Future Prospects

Crossbreeding is one of the genetic improvement methods that enables to utilize between breed genetic variations. It is one of the main sheep genetic improvement strategies practiced for decades in Ethiopia. This review assessed achievements, challenges and future prospects of sheep genetic improvement through crossbreeding in Ethiopia. The crossbreeding scheme involves crossing of exotic breeds with indigenous as well as between indigenous sheep breeds. To improve growth performance of indigenous sheep, a number of exotic sheep breeds were imported from abroad although literature sources about the performance of crossbreeds is available only for Awassi and Dorper sheep crosses. Promising results have been reported in few areas where crossbreeding has been performed effectively. An evidence for this is the realization of up to 10kg yearling live weight superiority of crossbreeds with 50% and above Awassi and Dorper sheep blood levels over the indigenous sheep. As a national genetic improvement strategy, however, crossbreeding achievement in terms of improving productivity of indigenous sheep is generally minimal. Notably, Absence of well-deigned crossbreeding program, miss-match between genotypes and the environment, and resource limitation to maintain and multiply adequate number of exotic sheep and crossbreeds are the major challenges hindering the success of indigenous sheep genetic improvement through crossbreeding. In the future, the use of crossbreeding as a potential strategy for indigenous sheep genetic improvement relies on bringing long lasting solutions to the current problems. In general, implementing well-designed crossbreeding program, particularly between improved exotic sheep and indigenous sheep, should be the primary focus to improve productivity of indigenous sheep. In this way, the contribution of indigenous sheep resources for the smallholder farmers in particular and the country’s economic growth in general can be maximized. At the same time, protecting the valuable genetic resources of indigenous sheep should be an integral part of the crossbreeding program. Keywords: genetic improvement, indigenous sheep of Ethiopia, sheep crossbreeding DOI : 10.7176/ALST/75-01 Publication date :June 30 th 2019

Performance, rumen fermentation, and gastrointestinal microflora of lambs fed pelleted or unpelleted total mixed ration

The objectives of this study were to evaluate the effects of feeding pelleted total mixed ration (PTMR) on growth performance, ruminal fermentation characteristics, and gastrointestinal microflora of fattening lambs. A total of 100 crossbred (Dorper sheep × Small-tail Han Sheep, DH) ram lambs at 120 d age with similar body weight (BW, 34.9 ± 0.5 kg) were randomly allocated to 10 pens. The pens were randomly assigned to 2 treatments with 5 replicates per treatment. Dietary treatments were PTMR and un-pelleted total mixed ration (UPTMR) with the same dietary ingredients and nutritional contents. The average daily gain (ADG), average daily feed intake (ADFI), and feed conversion ratio (FCR) were determined in a 32-d experimental period. Ruminal pH, volatile fatty acid (VFA) concentrations, microbes in the rumen and cecum, and carcass weight were measured at the end of the experiment. Lambs fed PTMR had a greater ADFI (P = 0.002) than these fed UPTMR, greater ADG (P = 0.003) and carcass yield (P = 0.003) than that fed UPTMR. However, no significant difference was observed on FCR (P = 0.259) between the two groups of lambs. Compared with UPTMR treatment, feeding PTMR increased acetate and propionate concentrations, while decreased acetate to propionate ratio in the rumen (P < 0.05). Feeding PTMR increased the relative abundance of Prevotellaceae (P < 0.05) and decreased the relative abundance of Ruminococcaceae (P < 0.05) in the rumen, and increased the relative abundance of Bacteroidales (P < 0.05) and decreased the relative abundance of Lachnospiraceae, Clostridiales and Erysipelotrichales (P < 0.05) in the cecum relative to that of UPTMR group. In conclusion, feeding PTMR improved the growth performance and carcass yield of fattening lamb, primarily due to improvements in ADFI and ruminal fermentation characteristics through changing the structure and abundance of ruminal beneficial microbiota in fattening lambs. Thus, it is a feasible strategy to feed PTMR to fattening lambs in the intensive feed-lot style feeding system.

Staphylococcus aureus enterotoxin genes detected in milk from various livestock species in northern pastoral region of Kenya

Staphylococcus aureus (SA) food poisoning results from consumption of preformed S. aureus enterotoxins in food. The enterotoxins are one of the most important virulence factors of the bacterium. The risk posed by contamination of milk intended for human consumption by pathogenic S. aureus in pastoral areas in Kenya is still generally not well documented yet this information is critical for ensuring safety to consumers who sometimes may take unpasteurized milk. This study, therefore determined the prevalence of S. aureus enterotoxin genes in raw milk from cattle, goats, sheep and camels intended for human consumption in northern Kenya. A total of 603 milk samples from 57 zebu cattle, 346 galla goats, 8 red Maasai and dorper sheep, 4 one-humped camel (Camelus dromedaries) and 188 pooled from all animals were collected from Isiolo and Marsabit counties of Kenya. S. aureus isolates were cultured from milk samples using a selective media, mannitol salt agar (MSA). Suspect colonies of SA were further analyzed using biochemical tests. Polymerase chain reaction and sequencing techniques were used to confirm SA and detect sea, seb, sec, sed and see enterotoxin genes.Overall, potentially pathogenic S. aureus harboring enterotoxic genes were detected in 85 (14.09%, 95% CI: 11.55–17.1%) of the total milk samples. Genes encoding enterotoxins were detected in the S. aureus bacteria isolated from the milk samples. At least one type of S. aureus enterotoxin gene (SE) was detected in 74.11% (95% CI: 63.91–82.24%) of the 85 isolates. The most frequently encountered gene in the two counties was see (51; 60%, 95% CI: 49.73–69.76%) followed by sea (22; 25.88%, 95% CI: 17.76–36.09%) and sec (19; 22.35%, 95% CI: 14.8–32.29%). None of the isolates tested positive for sed. Overall, 21 of the 85 (24.7%, 95% CI: 16.76–34.83%) strains harbored more than one enterotoxin gene. More than half of the S. aureus isolates harbored at least one of the enterotoxin coding genes, indicating milk samples contaminated by S. aureus could have a high chance of causing staphylococcal food intoxication.Consumption of raw and sour milk in the region could increase the risk of staphylococcal food poisoning and pastoral communities in the region are therefore advised to consume pasteurized milk.

Bioinformatics analysis of evolutionary characteristics and biochemical structure of FGF5 Gene in sheep

Fibroblast growth factor (FGF) 5 regulates the development and periodicity of hair follicles, which can affect hair traits. Loss-of-function mutations associated with long-hair phenotypes have been described in several mammalian species. Sheep is an important economic animal, however, the evolution characterizations and biological mechanism of oFGF5 (Ovis aries FGF5) gene are still poorly understood. In this study, oFGF5 gene was obtained by resequencing the whole genome of three Dorper sheep and RACE of two Kazakh sheep FGF5. We proposed FGF5 was phylogenetically related to FGF4 family and oFGF5 clearly orthologed to goat FGF5. Six loci were found from the positive selection results of FGF5 and half of them located on signal peptide. The basically similar rates of function-altering substitutions in sheep and goat lineage and the rest of the mammalian lineage of 365 SNPs indicated that the FGF5 gene was quite conservative during evolution. Homology modeling of the oFGF5 suggested that it has a highly conserved FGF superfamily domain containing 10 β-strands. Furthermore, the protein–protein docking analysis revealed that oFGF5 have the potential to form heterodimers with oFGFR1, the predicted interaction interface of FGF5-FGFR1 heterodimer was formed mainly by residues from FGF superfamily domain. Our observations suggested the evolutionary and structural biology features of oFGF5 might be relevant to its function about hair follicle development and modulating hair growth, and we confirmed our speculation by using the FGF5 gene editing sheep produced by CRISPR/Cas9 technology.

Effects of corn supplementation on the antioxidant activity, selected minerals, and gene expression of selenoprotein and metallothionein in serum, liver, and kidney of sheep-fed palm kernel cake: urea-treated rice straw diets.

This study aimed to determine influence of corn inclusion on glutathion peroxidase (GPx) activity, selected minerals concentration, and gene expression in sheep-fed palm kernel cake (PKC) and urea-treated rice straw. Twenty-seven of Dorper sheep were divided into three groups and fed a basal diet of (20% rice straw and 80% concentrate) with addition of ground corn at either 0% (T1), 5% (T2), or 10% (T3), respectively. After 120days feeding trial, all animals were slaughtered and tissue samples of kidney, liver, and muscles were taken for enzyme and mineral analyses. The results showed that Cu concentration in the liver was lower treatment T3 compared to the control and T2. The serum activity of GPx was higher in T2 than in T3 at day 120 of experiment. Serum malondialdehyde (MDA) concentrations decreased at day 80 in sheep on T3, whereas MDA of liver increased linearly with increasing corn supplementation. The qRT-PCR analyses revealed significant up-regulation of ATP7A and MIa genes in T3, while hepatic Cu/Zn SOD, GPx1, and GPx4 mRNA showed a higher expression in lamb hepatocytes in T3 compared to those on T1. Present study results suggest that feeding PKC as basal diet can increase antioxidant activity, but cause liver dysfunction in sheep. Inclusion corn was found to regulate transcriptional levels of the GPx family and metallothionein genes. These genes may play a role in the antioxidant protection response and reduce incidence of toxicity associated with Cu.

Nucleotide variation in the ovine KRT31 promoter region and its association with variation in wool traits in Merino-cross lambs

AbstractKeratins are the main structural proteins of wool fibres, and it is thought that variation in the keratins may affect wool fibre characteristics. Polymerase chain reaction-single stranded conformational polymorphism (PCR-SSCP) analyses were used to investigate four regions of the ovine keratin gene KRT31 including a portion of the promoter, the exon 1, exon 3 and exon 7 regions. Initially, in a screening panel of 300 New Zealand Romney, Merino and White Dorper sheep obtained from 26 farms, three, two, two and two PCR-SSCP banding patterns were observed for these four regions, respectively. The promoter region, the exon 1 and exon 3 regions contained two single nucleotide polymorphisms (SNPs) and the exon 7 region contained one SNP. The effect of the variation found in the promoter region on wool traits was subsequently investigated in 485 Southdown × Merino-cross lambs from seven sire-lines. The three variants identified in the original 300 sheep (named A, B and C) were observed with frequencies of 56, 29 and 15%, respectively. The presence of A and B had no significant effect on wool traits, but the presence of C was found to be associated with an increase in greasy fleece weight (GFW), clean fleece weight (CFW) and mean staple length (MSL). There was an effect of genotype on CFW and MSL, with BC sheep producing wool of higher CFW and MSL than AA, AB, AC and BB sheep. These results suggest that ovine KRT31 might be a useful candidate gene for improving wool traits.

Dorper sheep cross breeding with Indigenous sheep breed in Ethiopia

The objective of this review paper was to review dorper sheep cross breeding with indigenous sheep breed in Ethiopia. The paper reviewed and discussed the history of dorper breed introduction, research and development efforts in crossbreeding and their performance under on-station and on-farm management. Formal survey on farmers perception on Dorper cross sheep indicated that the crossbred dorper sheep have non selective feed behavior and excellent in meat production under farmer`s management. On other study showed that dorper sheep was not meet farmer interest in breeding sheep aspect because of black coat color. The performance of indigenous sheep and their crosses with Dorper varied as per the location, management, farming conditions and percentage of exotic blood level inheritance. Different research output by team of researchers on farm and on station performance evaluation of dorper indicated that crossbreds often outperformed their local contemporaries. Under on farm condition, body weight at different ages was significantly higher in 50% Dorper crosses as compared to their 25% and75% counter parts.On station birth weight of Dorper (3.39 3.8 kg) better than crossbreed (3.0 3.24 ± 0.04 kg) and local sheep (2.36 2.77 kg), respectively.While the mean weaning weight (14 16 kg) and yearling weight (26.95 32.43 ± 0.46 kg) of 50% Dorper crossbreed was better than indigenous sheep breeds. However, crossbred ewes and local sheep breeds did not differ in litter size. Dorper crosses with Afar under on station is not economically important due to lower weight in all aspects. Crossbreeding programs of dorper with indigenous sheep require strong research and development support from public service and non-governmental institutions for sustainable design, optimization, and implementation in clearly defined production environments.

ETHOLOGICAL BEHAVIOR OF CREATED SHEEP IN THE SUN AND SHADE IN THE SEMI-ARID REGION OF PARAIBA

Sheep breeding displays high potential, but, in order to maximize productivity, the exploitation of the entire genetic potential of these animals, combined with diets tailored to meet their nutritional requirements, is required. Knowledge on sheep ingestive behavior is important for diet evaluations, which allows for adjustments regarding dietary management, in order to obtain superior productive performance. In this context, the aim of the present study was to evaluate the interference of two distinct environments in the behavioral responses of Santa Inês and Dorper sheep breeding activities during the dry period at the Paraíba Cariri region. The study was carried out in the municipality of Caturité, Paraíba, with 20 male sheep, 10 Santa Inês breeds and 10 Dorper breeds. The animals were subdivided into four lots, containing five animals each, and placed in two different environments, in the sun and in the shade. Feeding behavior was determined by quantifying parameters for 10 hours/day, at 5 min intervals. A completely randomized design (CRD) in a 2 x 2 factorial scheme was applied, of two breeds and two environments, with three replicates. The data were analyzed by SAS, applying the chi-square test. The main daily sheep activities comprised alternate periods of feeding, rumination and idleness, and behavioral activities were exhibited the worse results in the sun environment.

Alveolar restoration following rapid maxillary expansion with and without corticotomy: A microcomputed tomography study in sheep.

ObjectiveThis study examined bone microstructure restoration after rapid maxillary expansion (RME) with and without corticotomy over multiple retention periods.MethodsEighteen male Dorper sheep were randomly distributed into three groups (n = 6 each group): group 1, RME with corticotomy on the buccal and palatal sides; group 2, conventional RME treatment; and group 3, no treatment. Post-RME, trabecular bone microstructure and new bone formation were evaluated by using microcomputed tomography (microCT) and histomorphometry after a 4- or 12-week retention period. Intergroup differences in bone quality and bone remodeling were analyzed by using two-way analysis of variance with Bonferroni post-hoc test.ResultsThe bone volume fraction (bone volume [BV]/total volume [TV]) values relative to the control in groups 1 and 2 were 54.40% to 69.88% after the 4-week retention period and returned to approximately 80% after the 12-week retention period. The pooled BV/TV values of the banded teeth in groups 1 and 2 were significantly lower than those of the control after the 4-week retention period (p < 0.05). However, after the 12-week retention period, the pooled BV/TV values in group 2 were significantly lower than those in groups 1 and 3 (p < 0.05). Histomorphological analysis showed that the new bone formation area in group 1 was approximately two to three times of those in group 2 and control.ConclusionsCorticotomy significantly enhanced the restoration of bone quality after the retention periods for banded teeth. This benefit might result from the increased new bone formation after corticotomy.