Arash Kashani

Growth and body conformation responses of genetically divergent Australian sheep to Spirulina (Arthrospira platensis) supplementation

The hypothesis that supplementation with Spirulina will increase liveweight, growth and body conformation with significant interactions between sire breed and sex was tested using purebred Merino weaners and first-cross weaners from Merino dams sired by Dorset, Black Suffolk and White Suffolk rams under the same pasture-based management system. Our experimental objective was to evaluate the effects of varying levels of Spirulina supplementation, sire breed and gender on liveweight and body conformation traits. We utilized a complete randomized block experimental design balanced by 4 sire breeds, 3 supplementation levels and 2 sexes in which weaned prime lambs with an average liveweight of 37.6 ± 5.2 kg and body condition score of 3.1 ± 0.4 at 6 months of age were balanced by sire breed and gender and randomly allocated into 3 treatments (8 lambs per treatment) – the control group grazing without Spirulina (0%), low (10%wt/vol) and high (20%wt/vol) Spirulina. Lambs in the low and high Spirulina treatment groups were drenched daily with Spirulina prior to being released for grazing with the control group of lambs over a 6-week trial period, following a 3-week adjustment phase. Weekly measurements of chest girth, withers height, body length, body condition score and liveweight were taken. Mixed linear model procedures in SAS with sire breed, sex, Spirulina level and their second order interactions as fixed effects and sire as a random variable, were used for statistical analysis. Spirulina level significantly influenced lamb liveweight (P<0.018), body condition score (P<0.001) and body length (P<0.015). Lambs on Spirulina levels of 10% recorded the highest mean liveweight of 41.9 ± 0.7 kg. Spirulina levels of 20% did not significantly improve liveweight compared to the control group (0%). Highly significant sire breed interactions with Spirulina level (P<0.001) resulted in the heaviest (47.08 kg) and lightest (35.14 kg) average liveweights in Black Suffolk-sired crossbreds and purebred Merino lambs respectively, supplemented at the 20% Spirulina level. Body conformation (P<0.001) and liveweight (P<0.014) responses to Spirulina supplementation significantly varied between ewe and wether lambs. It was evident that a cost-effective supplementation strategy with Spirulina for optimal liveweight gains in weaner lambs was achieved at the 10% level. These findings will aid sheep farmers in making informed choices about appropriate sire breed and gender combinations in their enterprises when supplementing with Spirulina for growth improvement as a strategic pathway for the early attainment of market weights in prime lambs. We concluded that based on the empirical experimental evidence within the scope of this study, the tested hypothesis is acceptable.

Effect of dietary supplementation with Spirulina on the expressions of AANAT, ADRB3, BTG2 and FASN genes in the subcutaneous adipose and Longissimus dorsi muscle tissues of purebred and crossbred Australian sheep

BackgroundThe demand for healthy, lean and consistent meat products containing low saturated fatty acid content and high quality polyunsaturated fatty acids (PUFA), especially long-chain (≥C20) omega-3 PUFA, has increased in recent times. Fat deposition is altered by both the genetic background and dietary supplements, and this study aimed to assess the effect of dietary Spirulina supplementation levels on the mRNA expression patterns of genes controlling lipid metabolism in the subcutaneous adipose tissue (SAT) and Longissimus dorsi (ld) muscle of Australian crossbred sheep.MethodsTwenty-four weaned lambs belonging to four breeds under the same management conditions were maintained on ryegrass pasture and fed three levels of Spirulina supplement (control, low and high). In terms of nutrient composition, Spirulina is a nutrient-rich supplement that contains all essential amino acids, vitamins and minerals. It also is a rich source of carotenoids and fatty acids, especially gamma-linolenic acid (GLA) that infer health benefits. After slaughter, subcutaneous adipose tissue (SAT) and ld samples were subjected to mRNA extraction and reverse transcription using quantitative polymerase chain reaction (RT-qPCR) to assess the mRNA expression levels of the Aralkylamine N-acetyltransferase (AANAT), Adrenergic beta-3 receptor (ADRB3), B-cell translocation gene 2 (BTG2) and Fatty acid synthase (FASN) genes, which are associated with lipid metabolism.ResultsBoth low and high Spirulina supplementation levels strongly up-regulated the transcription of all the selected genes in both SAT and ld tissues (mostly in the subcutaneous adipose), but sheep breed and sex did not influence the gene expression patterns in these tissues.ConclusionsThe evidence indicates that high Spirulina supplementation level resulted in a decrease in intramuscular fat content in Australian purebred and crossbred sheep due to the enhanced production of melatonin in sheep muscle tissues and strong up-regulation of mRNA expression of BTG2 in SAT which negatively affected fat deposition. In contrast, low Spirulina supplementation level strongly up-regulated the ADRB3 and FASN genes responsible for fat production. These findings are consistent with the observed phenotypic data suggesting that low Spirulina supplementation level can increase lamb production, with higher long-chain PUFA content.

Sire breed and sex effects on the fatty acid composition and content of heart, kidney, liver, adipose and muscle tissues of purebred and first-cross prime lambs

The present study investigated sire breed and sex effects on the fatty acid (FA) composition and content of subcutaneous adipose, Longissimus lumborum muscle, kidney, heart and liver tissues in prime lambs. Tissue samples were taken from 40 Merino ewe and wether lambs sired by Black Suffolk, Dorset, Merino and White Suffolk rams. FA proportion (% total FA) showed significant variations. The highest relative concentrations of total saturated fatty acid (SFA) were in adipose tissue, concentrations of monounsaturated fatty acids (MUFA) were highest in muscle and concentrations of two nutritionally important omega-3 long-chain (≥C20) polyunsaturated FA (LC-PUFA), namely, eicosapentaenoic (EPA, 20:5n-3) and docosahexaenoic (DHA, 22:6n-3) acids, were highest in kidney tissue (10.4% total FA), as were those of total PUFA in heart tissue. Sire breed variations in kidney for 18:3n-3, 22:6n-3, 16:0, 16:1n-7c and total omega-6 PUFA, and in muscle for 17:0, 18:3n-3 and 18:1n-7 were evident. Adipose tissue concentrations of 16:1n-9c, 17 : 0 and 16 : 0 in the heart and liver were affected by sire breed. The effect of sex on most major individual FA and totals of SFA, MUFA, omega-3 and omega-6 PUFA were, for the most part, negligible. These results suggest that consumption of lamb heart, liver and kidney can prove beneficial because of their high total PUFA composition and, in particular, concentration (mg/100 g) of key health-benefitting n-3 LC-PUFA. The fact that there were significant sire-breed variations implies that the manipulation of FA composition and content of lamb products and their associated nutritional and sensory qualities will need a deliberate breeding management that matches product goals with available sire breeds.

Effect of level of Spirulina supplementation on the fatty acid compositions of adipose, muscle, heart, kidney and liver tissues in Australian Dual-Purpose lambs

Abstract This study investigated the effect of level of Spirulina supplementation on the fatty acid (FA ) compositions of subcutaneous adipose, longissimus dorsi muscle, kidney, heart, and liver tissues in purebred and crossbred Australian Merino sheep. Forty-eight lambs sired by Black Suffolk, White Suffolk, Dorset and Merino rams were assigned into 4 treatment groups of daily Spirulina supplementation levels per lamb of 0 mL (control), 50 mL (low), 100 mL (medium) and 200 mL (high) referred to as 0, 5, 10 and 20% groups. The lambs were slaughtered after 9 weeks of supplementation and heart, kidney, adipose, liver and muscle tissue samples were collected. The results demonstrated significant variations in growth and body conformation traits and tissue and organ FA composition in response to the Spirulina supplementation. The medium-level Spirulina treatment group increased the ω-3 and ω-6 polyunsaturated fatty acid (PUFA ) composition in all tissues and organs significantly. The results suggest the use of medium level (100 mL/head/day) of Spirulina supplementation in order to increase lamb production with more ω-3 and ω-6 PUFA and therefore higher nutritional meat quality.

Gene Expression Profiles of Aralkylamine N-Acetyltransferase, B-cell Translocation Gene-2 and Fatty Acid Synthase in Pasture-based Primiparous Holstein-Friesian Dairy Cows Supplemented with Crude Degummed Canola Oil

The effect of oil-rich supplements on the expression of genes involved in lipogenesis and reproduction in pasturebased dairy cows is currently unknown, or at best, scanty and limited to impacts on cow liveweight, body condition score, milk composition, fatty acid and plasma metabolite profiles only. This research investigated the gene expression patterns of Aralkylamine N-acetyltransferase (AANAT), B-cell translocation gene-2 (BTG2) and Fatty Acid Synthase (FASN) genes in response to incremental levels of dietary crude degummed canola oil (CDCO). We tested the hypothesis that the relative mRNA abundance and gene expression profiles of AANAT, BTG2 and FASN in primiparous Holstein-Friesian cows will be up-regulated in response to post-partum dietary supplementation with CDCO in a typical pasture-based dairy production system. Thus, the primary objective of this study was to investigate the expression of AANAT, BTG2 and FASN genes in response to incremental levels of CDCO. A random allocation of primiparous Holstein-Friesian dairy cows into four treatment groups comprising wheat-based pelleted with no supplemental CDCO (control), or with CDCO added at 25 ml kg-1 DM (low), 35 ml kg-1 DM (medium) and 50 ml kg-1 DM (high) was utilized in a ten-week experimental feeding trial including two weeks of adjustment. Both level of supplementation and their interaction with duration were significant sources of variation (P 0.05). The high (0.67 fold), medium (0.87 fold) and low (0.56 fold) treatments had suppressed BTG2 expressions compared to the control (1.0 fold) group. The low expression of BTG2 might be important when the reproductive system of cows is recovering from the effect of gestation and new cell growth is required.

Single nucleotide polymorphisms of the ovine ADRB3 gene in crossbred Australian sheep supplemented with spirulina (Arthrospira platensis) cyanobacterial microalgae

The adrenergic-receptor beta3 (ADRB3) gene is an obesity gene that is involved in the regulation of energy balance and a variety of physiological functions by increasing lipolysis and thermogenesis. Spirulina (Arthrospira platensis) is a blue-green cyanobacterial alga containing 60-70% protein with an extensive history of human consumption, and more recently, inclusion in animal feeds. We had earlier demonstrated that low level oral supplementation by drenching prime lambs with 100 mL/head/day of 1g of Spirulina powder dissolved in 10 mL of water (10%wt:vol) increased live weight and body conformation measurements in Black Suffolk (BS) x Merino crossbred sheep. The hypothesis that genetics-nutrition interactions between sheep breeds with fewer mutations at the ADRB3 locus and an optimal Spirulina supplementation level will increase lean meat production was tested in the current study. Forty-eight crossbred Australian prime lambs sired by four rams of diverse breeds under the same pasture-based management conditions were subjected to a nine-week feeding trial with Spirulina, followed by genomic DNA extraction and single nucleotide polymorphism (SNP) analysis. Eleven SNPs in both the coding and noncoding regions of the ovine ADRB3 gene were detected. Nine of the SNPs were in exon I and two in the intron. Variations in SNP frequencies were highly significant (P <0.0001) between all sheep breeds. The maximum and minimum number of SNPs were found in purebred Merinos (4.83) and Black Suffolk x Merino (BS) crossbreds (1.67). In total, one indel and six transverse mutations were detected that resulted in six amino acid substitutions. BS crossbreds had the lowest frequency of mutation and amino acid substitutions in their population in agreement with our hypothesis. In conclusion, BS sheep genetics matched with low level (100 mL/head/day) of Spirulina supplementation can lead to higher meat production with less fat content in a typical pasture-based sheep production system.

Wool quality traits of purebred and crossbred Merino lambs orally drenched with Spirulina (Arthrospira platensis)

The objective of this study was to evaluate the effect of Spirulina supplementation, sire breed and sex on the wool characteristics of purebred and crossbred Merino weaned lambs under a single pasture-based management system. Lambs sired by Merino, White Suffolk, Dorset, Black Suffolk breeds were randomly allocated into 3 treatments – the control group grazing without Spirulina (0 mL), low (100 mL) and high (200 mL) Spirulina groups. All lambs were kept as a single mob in paddocks, grazed for 9 weeks and wool samples analysed. Differences in wool quality between the control and supplemented groups were not significant (P>0.05). However, sire breed significantly (P<0.001) influenced fibre diameter, spinning fineness, comfort factor and fibre curvature with purebred Merinos having superior wool quality than crossbreds. Wethers grew higher quality wool than ewes. Spirulina has a potential as an alternative supplementary bioresource in dual-purpose sheep feeding because it does not compromise wool quality in supplemented weaner lambs.

Spirulina Supplementation, Sire Breed, Sex and Basal Diet Effects on Lamb Intramuscular Fat Percentage and Fat Melting Points

The effects of Spirulina supplementation, sire breed, sex and basal diet on intramuscular fat percentage (IMF) and fat melting point (FMP) in crossbred and purebred Merino lambs were investigated. Over two consecutive years, a total of 48 lambs was randomly allocated into feeding trials that utilised either ryegrass or Lucerne hay basal diets. Each treatment group had 8 lambs balanced by sire breed (Black Suffolk, Dorset, Merino, White Suffolk), sex (ewes, wethers), and Spirulina supplementation level (CONTROL - unsupplemented, LOW 50ml, MEDIUM – 100ml, and HIGH – 200ml). Each feeding trial lasted for 9-weeks after 21 days of adjustment. Post-slaughter, IMF content of the Longissimus dorsi et lumborum muscle was determined using solvent extraction and FMP measured using the ‘slip-point’ method. Spirulina supplementation level influenced both IMF content and FMP in which MEDIUM Spirulina supplementation led to a decrease in IMF (1.98%) and FMP (42.97°C) compared to 3.18% and 44.44°C, respectively, in the LOW supplementation treatment group. Sire breed was a significant source of variation in FMP as purebred Merinos had the highest (45.63°C) and Black Suffolk crossbreds the lowest (41.53°C). Ewe lambs had higher IMF than wether lambs (2.52 vs 2.12%). Lambs on the ryegrass basal diet had lower IMF and FMP than their counterparts on Lucerne. Significant interactions between sire breed and supplementation level suggest a variety of nutritional management combinations that prime lamb producers can utilise to optimise meat quality for increasingly health-conscious consumers.