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

Estimation of 305-day yields from total milk yields in Bunaji and Friesian-Bunaji crosses

Lactation data of 207 cows comprising 91 Bunaji and 116 Friesian x Bunaji crosses milking for over 305 days were collected and analysed on the basis of the following variables: Average daily yield (ADY), actual 305-day yield (305-Y), total yield (TY) and lactation length (LL). The objective was to fit a suitable equation that would estimate 305-day yield from TY and to develop estimation factors. The linear regression equations for estimating 305-day yield from TY are Y = 185.229 + 0.804TY (R2 = 0.971) and Y = 366.176 + 0.775TY (R2 = 0.827) for Bunaji and Friesian x Bunaji cows respectively. Various combinations of TY, ADY and LL were used in multiple regressions to estimate 305-day yield with R2 values of over 90%. Factors for the estimation of weight records at birth, and at 3, 6, 9 and 12 months of age of half Friesian-Bunaji cows that calved over a twenty-three year (1967-1989) were computed. Least squares means ± S.E. of LL, TLY, 305DY, DDRY, AFC and CI were 250.563 ± 5.8 days, 1988.695 ± 108.7 kg, 2420.756 ± 93.8 kg, 102.333 ± 2.5 days, 35.638 ± 2.3 months and 390.312 ± 3.7 days, respectively. Parity, season and year of calving significantly affected LL, TLY (P<0.01) and 305DY (P<0.05), but not CI. DDRY was only affected by season of calving (P<0.01). Year of birth was highly significant (P<0.01) in affecting body weights at all ages, while month of birth was not. Season of birth was significant (P<0.05) for birth weight and body weights at 3 and 6 months of age

Feed intake variation in crossbred lambs applied to livestock production

Genetically divergent prime lambs were supplemented with Spirulina and had ad libitum access to Lucerne hay in a nine-week feeding trial. The main objective was to model residual feed intake, liveweight gain, standardised daily feed intake (SDFI), feed conversion ratio and daily feed intake (DFI) and test for sire breed and sex variations. Level of Spirulina supplementation and sex were found to have no independent effects on lamb feed intake (P>0.05). However, DFI and SDFI in Merino sired lambs were lower than in their crossbred counterparts (P<0.023). Merino ewe lambs consumed more Lucerne hay than wethers (P<0.05). These findings could prove useful when balancing feed resources to match Spirulina supplementation levels and lamb breeding management goals

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

Spirulina platensis (Arthrospira spp.): a potential novel feed source for pasture-based dairy cows

The Australian dairy industry is heavily reliant on pasture as the main feed base for milk production. However, dietary energy intake is limited in pasture-based dairy systems and lactating cows tend to suffer from negative energy balance due to insufficient dry matter intake. As a result, low milk production and reproduction performances occur later on in the cow’s life-cycle. Spirulina is a highly nutritious feed source rich in proteins, lipids, minerals and vitamins, thus meeting the criteria as a potential and novel alternative feed source for the dairy industry. To our current knowledge, experimental and anecdotal information on the productive response of pasture-based dairy cows to the inclusion of Spirulina to lactating diets is lacking and warrants further elucidation. There is the need to understand the influence of Spirulina inclusion in a lactating cow’s diet on lactation and Live-weight parameters. This paper reviews the past and present research results on the effect of supplementation with Spirulina on animal production outcomes, summarises identified knowledge gaps and highlights future directions for research in the dairy industry

Sire genetics, protein supplementation and gender effects on wool comfort factor in Australian crossbred sheep

Aims: To investigate the effects of sire genetics, nutrition, level of supplementation, gender and their interactions on wool comfort factor (CF) and its correlation with other wool quality traits in crossbred sheep either grazing or supplemented with dietary protein. Study design: A 5 x 2 x 2 x 2 factorial experimental design comprising five sire breeds, two dietary protein sources, two supplementation levels and two sexes respectively, was utilized. Place and Duration of Study: University of Tasmania Farm, Cambridge, Hobart, Tasmania, Australia, between April 2008 and November 2010. Methodology: Texel, Coopworth, White Suffolk, East-Friesian and Dorset sires were joined with 500 Merino ewes at a mating ratio of 1:100 in individual paddocks. Five hundred of the crossbred progeny were raised on pastures until weaning at 12 weeks of age. Forty of the weaners with an initial body weight (BW) range of 23-31 kg (average of 27 ± 3.2 kg) were fed with lupins or canola at 1 or 2% BW for 6 weeks in individual metabolic crates. CF and other wool quality traits were commercially measured at the Australian Wool Testing Authority, Melbourne. The data were analyzed in SAS using MIXED model procedures with sire fitted as a random effect, while sire breed, nutrition, supplement, level of supplementation and gender and their interactions were fitted as fixed effects. Results: CF was significantly correlated with fiber diameter (-0.89), spinning fineness (-0.95) and wool curvature (0.33). Grass-fed sheep produced wool with significantly higher comfort factor (93.1±0.3%) than supplemented sheep (CF=85.9±1.1%). Sire genetics was a significant source of CF variation; White Suffolk crosses had the highest CF (90.1±8.7) and East-Friesian crosses the least (81.5 ± 10.1%). Males fed canola at 1% BW had the highest CF (90.8 ± 7.0%), while females fed lupins at 1% BW had the least (81.1±10.8%). Conclusion: From a practical point of view, sheep farmers engaging in prime lamb production with wool comfort factor as an additional breeding objective should concentrate their effort on grass-feeding White Suffolk x Merino wethers. During the winter feed gap, supplementing the wethers with canola at 1% BW will not compromise wool CF

Factors affecting birth weight and body weights at 3, 6 and 12 months in Friesian x Bunaji Zebu calves

Calving records for the years 1984-1989 were studied to determine the influence of rearing method, sex of calf, season of birth, dam breed and year of birth on birth weight and growth performance to yearling in Friesian x Bunaji crossbred calves. Sex of calf had a significant effect, with male calves being heavier (P<0.05) at birth and at 3 and 6 months than female calves. Year of birth had a highly significant effect (P<0.001) on calf birth weight and weights at 3, 6 and 12 months. The influence of rearing method, season of birth and dam breed on birth weight and calf growth performance were generally not significant except in body weights at 6 months, where seasonal effects were significant (P<0.01). The factors were discussed and suggestions were made to improve the management of crossbred dairy calves

Wool quality and growth traits of Tasmanian pasture-fed crossbred lambs and relationships with plasma metabolites

Wool quality, growth and plasma metabolite traits of 500 F1 progeny from Merino dams sired by 5 ram breeds were investigated to study the influences of sire breed, sex and their interactions with plasma metabolites aimed at dual-purpose crossbreeding options. Coopworth, Texel and White Suffolk sired progeny had significantly (P<0.05) heavier weaning weights (WWT) and average daily gains (ADG) than those sired by Dorset or East-Friesian rams. Coopworth-sired sheep had the highest WWT (31.3±1.7Kg) and East-Friesian sired sheep the lowest (22.9±3.1Kg) with ADG ranging from 0.15kg/day in East-Friesian to 0.23 Kg/day in Texel and White Suffolk sire breeds. Highly significant (P<0.01) sex by sire breed interaction were evident; Coopworth-sired ewe lambs had the highest WWT and ADG (34Kg, 0.27 Kg/day) and Dorset-sired ewe lambs the least (22kg, 0.15 Kg/day). Greasy fleece weight ranged from a minimum of 964g to a maximum of 1303g in Dorset and Coopworth-sired lambs respectively, with Coopworth and Texel sire breeds having significantly heavier (P<0.05) fleece weights than either Dorset, White Suffolk or East-Friesian. Texel-sired sheep had significantly larger (P<0.05) micron fibre diameter (23.4μm) than the 21μm recorded in White Suffolks and East-Friesians. There were also highly significant differences (P<0.01) between sire breeds in staple length (range 50-68mm) and staple strength (range 39-52Nktex), with males having finer fibre diameter (21 vs 23μm) and shorter staple length (55 vs 60mm). Regardless of sire breed or gender, blood plasma metabolites were well within the normal range. A strong, positive and significant phenotypic correlation of 0.72 existed between marking and weaning weights. There were no significant correlations between the wool quality and growth traits, essentially implying that producers can select for finer wool without compromising growth. Coopworth x Merino first cross was the overall best performing sheep breed studied because of its heavier liveweight, faster daily gain, heavy fleece weight and a comparatively lower micron fibre diameter than the other crossbreds

Factors affecting temperaments in Zebu and Friesian-Zebu crossbred cattle

The influence of breed, sex, season, age, liveweight and body condition on temperament scores was investigated. All variables, except age, had significant (P<0.05) effect on temperament. Progeny of crossbred dams had lower temperament than those of purebred Zebu dams. Female animals had higher temperament and so also were animals with better body condition. Temperament was lowest in the hot, dry season. Phenotypic correlations between measurements of temperament were positive and significant (P<0.05), with vigour of movement having the highest correlation with the overall temperament score. Liveweight was negatively correlated with temperament while there was a positive correlation between temperament and body condition. Regression equations for predicting overall temperament using vigour of movement are presented

Effects of weather variables on weaning weights and growth rates of Friesian x Bunaji heifer calves

Data consisting of birth weights at 3, 6 and 12 months records of 309 Friesian x Bunaji heifer calves born between 1980 and 1991 were analysed to determine the effects of weather variables on weaning weights and growth rates. Calves were raised by either bucket feeding or suckling methods. Under the bucket feeding system, calves were separated from the dams after 3-5 days postpartum and fed fresh whole milk until 3 months of age. They were moved to an outdoor herd and fed free-choice with concentrate and hay rations until they attained 6 months of age. The average calf weights at birth, 3, 6 and 12 months of age were 21.7 ± 0.27, 60.9 ± 0.9, 86.4 ± 1.3 and 134.0 ± 1.9 kg respectively. Average rainfall, relative humidity and temperature were 910.78 mm, 43.1 % and 24.6°C respectively. The relationships between these variables and weaning weights and growth rates were discussed