Sex effects on lamb wool quality under pasture and lucerne hay basal diets

Wool quality traits are routinely used for price discrimination. This has prompted many selection and nutritional management tools to be tailored towards best exploiting these traits for better profitability. Within Australia, the wool industry is spread across regions prone to seasonal change, and analysis of pasture-fed and Lucerne hay basal diets can provide a summation of this variation. The effect of sex and basal diet on wool quality traits is the objective of this research. Experimental lambs used were concurrently studied with a 9 week feeding trial detailed by Holman (2013), and an overview of research methodology follows. Over 2 years, a total of 48 lambs were allocated to either ryegrass pasture (Year 1; n = 24) or Lucerne hay (Year 2; n = 24) basal diets as balanced by sex (ewes, wethers). All lambs were run on these basal diets together with midside wool sampled at the commencement and conclusion of the feeding trial. Wool samples were commercially analysed (AWTA, VIC) and raw data was transformed to express change in wool quality trait over the feeding trial. This was fitted into a factorial ANOVA model in ‘Statistical Analysis System, Version 9.1’ software to identify significant effects.Ewe lambs’ wool quality traits under Lucerne hay tended to change lesser over the feeding trial than those under pasture-fed basal diets. However, no significant change was observed (P>0.05). This is thought to stem from the relative brevity between commencing and concluding wool sampling which limited the effectiveness of any sex and basal diet interaction on wool quality trait change. The sample size is also thought to have contributed to the observed variation (SE) and highlights a need for more experimental work. We can conclude that lamb wool quality under pasture-fed or Lucerne hay basal diets is unaffected by sex over a 9 week period

Effect of spirulina supplementation on haematological biomarkers of lamb productivity

Spirulina (Arthrospira platensis) is a protein-rich and highly nutritious cyanobacterium which is a recognised livestock feed supplement (Holman & Malau-Aduli 2013). Protein supplementation to lambs generally results in a positive shift in productivity, liveweight and growth. These effects can be objectively assessed using specific haematological biomarkers (Braun et al 2010). The emergence of Spirulina supplementation has made it necessary to investigate its effects on haematological biomarkers of productivity. Twenty-four, 6 month old lambs were randomly assigned Spirulina levels (CONTROL, LOW, HIGH) within a 9-week supplementation trial. All lambs were run together and supplemented Spirulina daily as a 1:10 g/mL suspension via oral drenching. Blood was sampled at the completion of the supplementation trial, using jugular venipuncture, and plasma was separated and commercially analysed for haematological metabolite concentrations (DPIPWE, TAS). Returned data was fitted into a Factorial ANOVA model in Statistical Analysis System, Version 9.1 software for interpretation, with means compared with normal ranges. GGT indicates liver health. It was observed to be highest in CONTROL lambs, possibly because Spirulina supplementation has been previously associated with improved animal liver health (Holman 2013). Creatinine indicates muscle mass and was highest in MEDIUM Spirulina supplemented lambs suggesting these lambs to be larger than their experimental counterparts. This proves true, Holman et al 2012 corroborating MEDIUM Spirulina supplemented lambs to have highest liveweights. Heightened glucose concentrations found with HIGH Spirulina supplementation is thought to stem from its effects on dietary energy intake and consequential flow on effects. Spirulina supplementation does affect lamb productivity haematological biomarkers, albeit limited as several key productivity biomarkers failed to respond to Spirulina supplementation

World beef production

[Extract] Beef cattle, like other ruminants, have a complex digestive system inhabited by rumen microorganisms that can effectively convert pastures and other plant-derived products to meat and milk for human consumption (Chapters 15 and 16). To be able to appreciate the diversity in cattle performance in global beef production systems, a firm understanding of beef cattle performance indices and unique climatic, management and production systems around the world is essential. For example, in Australia, specialised beef breeds and crossbred cattle dominate beef production, whereas in New Zealand, Europe and the USA (Chapter 5), dairy beef constitutes a substantial percentage of finished beef production because land is too expensive to run cattle specifically for producing beef. An estimated 8-8.5% contribution of Holstein genetics to finished steers, representing the largest recognisable single-breed source to beef production in the USA, has been reported (USDA 2011; Schaefer 2005). Holstein steers also represent 15-20% of lot-fed steers in the USA (Rust and Abney 2005). In New Zealand, dairy breeds also dominate beef production, providing approximately half the weight of beef produced and slightly less than 50% of the value of beef produced (Charteris et al. 1998). In Australia, nearly 75% of the land mass is suitable only for beef production as the soil is too poor and rainfall is too low for cropping and the returns from wool are too small due to the labour-intensive nature of the production system. This chapter gives an overview of global beef production systems, industry characteristics and outlooks for the beef industries in Australia (Chapters 9 and 10), India, Argentina, Brazil (Chapter 6), the USA (Chapter 5), Canada and the European Union, to represent selected regions in Oceania, Asia, South America, North America and Europe. Descriptions of the operational peculiarities and diversity in management practices that integrate genetics, nutrition and other environmental key drivers of profitability are presented

Effect of Spirulina (Arthrospira plantensis) supplementation on wool quality in purebred and crossbred Merino lambs fed pasture and Lucerne Hay basal diets

This study investigated the effects of Spirulina (Arthrospira plantensis) supplementation level, basal diet, sire breed, and sex on wool quality parameters in purebred and crossbred Merino lambs. A total of 48 lambs, over two consecutive years (n=24 per year), was randomly allocated into Spirulina supplementation level (CONTROL, LOW, MEDIUM, HIGH) groups and balanced by sire breed (Black Suffolk, Dorset, Merino, White Suffolk) and sex (ewes, wethers). Lambs had ad libitum access to a basal diet of pasture and Lucerne hay, and had Spirulina supplement daily throughout the 42-day feeding trial, after a 21-day adjustment phase. Mid-side wool samples were removed from each lamb at the beginning and end of the feeding trial and commercially analysed for quality. The wool quality data were transformed into 'wool trait change over the feeding trial period' by the difference between the wool measurements at the beginning and end of the experiment prior to statistical analysis. Wool clean fleece weight (CFW) was significantly influenced by level of supplementation, basal diet and sex (P<0.05). Spirulina-supplemented lambs on Lucerne hay basal diet elicited higher CFW responses which increased with supplementation level. CONTROL lambs had the lightest CFW regardless of basal diet. Sire breed and sex variations were significant (P<0.05) as wool from Suffolk-sired lambs and ewes had the highest fibre diameter coefficient of variation (CV) and CFW, respectively. CV and fibre diameter standard deviation were the most affected wool traits by significant interactions between Spirulina supplementation level, sire breed and sex. It was concluded that Spirulina supplementation with Lucerne hay basal diet improves wool CFW without compromising wool fibre diameter, comfort factor and spinning fineness in dual-purpose prime lambs

Effect of Spirulina supplementation on plasma metabolites in crossbred and purebred Australian Merino lambs

The effect of supplementing purebred and crossbred Merino lambs with Arthrospira platensis (Spirulina) on plasma metabolite concentrations under pasture-based management system and the influences of sire breed and sex were investigated. A completely randomized experimental design balanced by 4 sire breeds (Merino, White Suffolk, Dorset and Black Suffolk), 3 Spirulina supplementation levels (0, 100 and 200 ml representing the control, low and high, respectively)and 2 sexes (ewe and wether lambs) was utilised. All lambs had ad libitum access to the basal diet of ryegrass pastures and barley. Lambs in the treatment groups were individually drenched daily with Spirulina prior to being released with the control group of lambs for grazing over a 6-week period following a 3-week adjustment phase. At the start and completion of the feeding trial, blood samples were centrifuged and plasma metabolites measured. Data were analysed with Spirulina supplementation level, sire breed, sex and their second-order interactions fitted as fixed effects and metabolite concentrations as dependent variables. Gamma-glutamyl transferase (GGT) concentrations decreased (from 79.40 to 69.25 UI) and glucose increased (from 3.81 to 4.19 mmol/L) as the level of Spirulina supplementation increased from0 ml in the control to 200 ml in the high treatment groups (P < 0.05). Lambs supplemented at low Spirulina levels had the highest creatinine concentrations (61.75 micro mol/L). Interactions between sex and supplementation level significantly affected glucose, aspartate aminotransferase (AST) and Mg concentrations (P < 0.05), while sire breed and supplementation level interactions influenced albumin to globulin (A/G) ratio, creatinine and GGT concentrations. It was demonstrated that Spirulina supplementation does not negatively impact lamb health and productivity

A review of sheep wool quality traits

The commercial value of unprocessed wool is determined by its intrinsic quality; an indication of capacity to meet both processor and consumer demands. Wool quality is evaluated through routine assessment of characteristics that include mean fibre diameter, coefficient of variation, staple characteristics, comfort factor, spinning fineness, fibre curvature and clean fleece yield. The association between these characteristics with wool quality stems from their correlation with raw wool processing performance in terms of speed, durability, ultimate use as apparel or carpet wool, and consumer satisfaction with the end-product. An evaluation of these characteristics allows wool quality to be objectively quantified prior to purchase and processing. The primary objective of this review was to define and explore these aforementioned key wool characteristics, focusing on their impact on quality, desirable parameters and methodology behind their quantification. An in-depth review of relevant published literature on these wool characteristics in sheep is presented

Spirulina as a livestock supplement and animal feed

Spirulina (Athrospira sp.) is an edible microalga and a highly nutritious potential feed resource for many agriculturally important animal species. Research findings have associated Spirulina to improvements in animal growth, fertility, aesthetic and nutritional product quality. Spirulina intake has also been linked to an improvement in animal health and welfare. Its influence over animal development stems from its nutritive and protein-rich composition, thus leading to an increased commercial production to meet consumer demand. Consequently, Spirulina is emerging as a cost-effective means of improving animal productivity for a sustainable and viable food security future. However, our present knowledge of animal response to dietary Spirulina supplementation is relatively scanty and largely unknown. Therefore, the primary objective of this paper was to review past and current findings on the utilisation of Spirulina as a feed supplement and its impact on animal productivity and health. Only animals deemed to be of agricultural significance were investigated; hence, only ruminants, poultry, swine and rabbits and their responses to dietary Spirulina supplementation are covered

Effects of Spirulina (Arthrospira platensis) supplementation level and basal diet on liveweight, body conformation and growth traits in genetically divergent Australian dual-purpose lambs during simulated drought and typical pasture grazing

This study tested the effects of Spirulina supplementation level, basal diet and their interactions with sire breed and sex on liveweight, body conformation and growth traits in dual-purpose Australian lambs. In two concurrent feeding trials utilising typical pasture-based and simulated-drought basal diets, a total of 48 lambs was randomly allocated to treatment groups of Spirulina supplementation levels (CONTROL – 0 ml, LOW – 50 ml, MEDIUM – 100 ml and HIGH – 200 ml), balanced by sire breed (Black Suffolk, Dorset, Merino and White Suffolk) and sex (ewes and wethers). In both feeding trials, Spirulina was supplemented daily for 9-weeks, following a 3-week adjustment phase. Weekly data of liveweight and body conformation measurements; chest girth (CG), wither height, body length, and body condition score (BCS), were taken throughout the trials. These were transformed into changes between initial and final periods of the feeding trial. Average daily liveweight gain (ADG) was computed from the differences in liveweight divided by duration in days. All data were analysed using Factorial ANOVA analysis in SAS. Medium and high Spirulina supplementation levels were found to improve the liveweight and ADG of White Suffolk- and Merino-sired lambs on simulated-drought basal diets. BCS improved with Spirulina supplementation in lambs on simulated-drought basal diets. Under typical pasture-based basal diet, supplemented lambs had comparatively higher CG, BCS, liveweight and ADG than their counterparts on simulated-drought basal diets. These findings are of practical significance to the sheep industry because of the potential selection aid to Australian farmers in identifying the usefulness of Spirulina as a supplement and the optimal sire breed choice for the best performance response that is cost-effective when using dietary protein-rich supplements for their dual-purpose prime lamb operations

Influence of sire breed, protein supplementation and gender on wool spinning fineness in first-cross Merino lambs

Our objectives were to evaluate the effects of sire breed, type of protein supplement, level of supplementation and sex on wool spinning fineness (SF), its correlations with other wool characteristics and prediction accuracy in F1 Merino crossbred lambs. Texel, Coopworth, White Suffolk, East Friesian and Dorset rams were mated with 500 purebred Merino dams at a ratio of 1:100 in separate paddocks within a single management system. The F1 progeny were raised on ryegrass pasture until weaning, before forty lambs were randomly allocated to treatments in a 5 x 2 x 2 x 2 factorial experimental design representing 5 sire breeds, 2 supplementary feeds (canola or lupins), 2 levels of supplementation (1 or 2 of liveweight) and sex (wethers or ewes). Lambs were supplemented for six weeks after an initial three weeks of adjustment, wool sampled at the commencement and conclusion of the feeding trial and analyzed for SF, mean fibre diameter (FD), coefficient of variation (CV), standard deviation, comfort factor (CF), fibre curvature (CURV), and clean fleece yield. Data were analyzed using mixed linear model procedures with sire fitted as a random effect, and sire breed, sex, supplementary feed type, level of supplementation and their second-order interactions as fixed effects. Sire breed (P<0.001), sex (P<0.004), sire breed x level of supplementation (P<0.004), and sire breed x sex (P<0.019) interactions significantly influenced SF. SF ranged from 22.7 ± 0.2µm in White Suffolk-sired lambs to 25.1 ± 0.2µm in East Friesian crossbred lambs. Ewes had higher SF than wethers. There were significant (P<0.001) correlations between SF and FD (0.93), CV (0.40), CF (-0.94) and CURV (-0.12). Its strong relationship with other wool quality traits enabled accurate predictions explaining up to about 93 of the observed variation. The interactions between sire breed genetics and nutrition will have an impact on the choices that dual-purpose sheep producers make when selecting sire breeds and protein supplementary feed levels to achieve optimal wool spinning fineness at the farmgate level. This will facilitate selective breeding programs being able to better account for SF and its interactions with other wool characteristics

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