Influence of lupins and canola supplement on short loin fatty acid profiles within genetically divergent first cross merino lambs

Australian consumers are becoming increasingly aware of the health benefits of long-chain omega-3 polyunsaturated fatty acids [LC-PUFA] - eicosapentanoic acid (EPA), 20:5(n-3) and docosahexanoic acid (DHA), 22:6(n-3). The most common dietary source of long-chain omega-3 is through consumption of seafood and fish oil supplements. Common Australian commercial crops of canola and lupin both offer good sources of LC-PUFA precursors,including -linolenic acid [ALA, 18:3(n-3)] and their potential as animal feeds to manipulate LC-PUFA concentrations within animal meat is of great interest to the livestock and human health sectors. This study investigated the LC-PUFA profiles of 38 first cross Merino weaner lambs sired by five genetically divergent rams supplemented with canola meal or cracked lupins at 1% or 2% of body weight feeding levels for 60 days. Results demonstrated that all animals had ‘source’ content of omega-3 (EPA+DHA) in muscle samples taken from the short loin (loin chop) equal to or greater than 30mg per 100g serve. 18 animals were in excess of ‘good source’ content of 60mg per 100g serve with a whole flock mean of 67mg/100g EPA+DHA. When docosapentaenoic acid (DPA) is added to EPA+DHA, only two animals do not reach the ‘good source’ content of long-chain omega-3. Supplement type significantly (P<0.05) affected the level of ALA, with canola meal-supplemented sheep producing 91mg/100g compared to 66mg/100g in lupin-fed sheep. Total saturated fatty acid levels also showed a significant (P<0.05) interaction with sex and supplement indicating that males fed lupins had the lowest levels of SFA 3860mg/100g compared to males fed canola which had 5180mg/100g SFA. Overall the mean long-chain omega-3 content (mg) per 100g for each breed was: East Friesian 75 mg/100g, Dorset 73 mg/100g, Coopworth 68 mg/100g, Texel 59 mg/100g and White Suffolk 58 mg/100g. In conclusion feed supplementation markedly enhanced long-chain omega-3 content of Australian lamb. Level of supplementation, breed and type of supplement had no significant relationship with short loin content of long-chain omega-3 FA. However, when supplementing wethers and ewes with canola meal or lupins, attention should be paid to the significant interactions that exist between sexes and supplement type

Milk yield of Holstein-Friesian and Jersey x Holstein-Friesian cows supplemented with canola meal and cracked lupins

Milk yield is a key selection trait in dairy cows. During the course of lactation, milk yield follows a typical curvilinear pattern characterized by an initial increase immediately after calving, a rise to peak before an eventual decline. Cows in mid-lactation are typically in the decline phase and would require supplementation to ensure persistency in milk yield, particularly during summer when pasture availability is limited. This study evaluated the milk yield responses of purebred and crossbred dairy cows to two levels (1 or 2 kg/cow/day) of canola meal or cracked lupins supplementation in a pasture-based production system. Fifty Holstein-Friesian (HF) and Jersey x Holstein-Friesian (JHF) dairy cows (10 unsupplemented control and 40 supplemented) were randomly assigned to treatment groups after balancing for initial milk yield, BCS and days in milk (mean initial milk yield, body weight and body condition scores were 122.5 ± 12.1 litres/d, 352.6 ± 31 kg, and 2.5 respectively). A 2 x 2 x 2 balanced factorial experimental design representing 2 breeds, 2 supplements and 2 feeding levels was utilized. All cows had ad libitum access to the basal diet of barley and ryegrass while supplemented cows had three weeks of adjustment before the 12 weeks of feeding trial commenced. All cows were milked twice daily and milk yield individually recorded automatically at milking. Data were tested for significance by fitting the fixed effects of breed, supplement, feeding level and their first order interactions using mixed model procedures in SAS with cow and days in milk as random effects. Overall differences between treatment means were declared significant at P0.26). Supplementing with lupins at 1kg/cow/day gave the best milk yield response and would be a far cheaper option for supplementing mid-lactation cows than canola

Milk composition and somatic cell counts in pasture-based dairy cows supplemented with cracked lupins and canola meal

The price paid to dairy farmers on the basis of protein and butterfat is higher than milk volume averaging $9.31/kg of protein and$4.98/kg of butterfat compared to 49.69 cents/litre of milk. Supplementing lactating dairy cows with protein and energy sources such as canola and lupins could be a key income driver, but what feeding level is considered optimal for milk composition in pasture-based dairy cows in mid-lactation? This study evaluated the protein, fat, lactose, solids-not-fat and somatic cell counts of purebred and crossbred dairy cows fed 1 or 2 kg/cow/day of cracked lupins supplements or canola meal over a 12-week period. Fifty Holstein-Friesian (HF)and Jersey x Holstein-Friesian (JHF) dairy cows (10 unsupplemented control and 40 supplemented) were randomly assigned to treatment groups after balancing for initial milk yield, BCS and days in milk (mean initial milk yield, body weight and body condition scores were 122.5 ± 12.1 litres/d, 352.6 ± 31 kg, and 2.5 respectively). A 2 x 2 x 2 balanced factorial experimental design representing 2 breeds, 2 supplements and 2 feeding levels was utilized. All cows had ad libitum access to the basal diet of barley and ryegrass while supplemented cows had three weeks of adjustment. All cows were milked twice daily but milk samples for composition analysis was taken once a month and analysed at TasHerd milk testing laboratory in Hadspen, Tasmania. Data were tested for significance by fitting the fixed effects of breed, supplement, feeding level and their first order interactions using mixed model procedures in SAS with cow and days in milk as random effects. Overall differences between treatment means were declared significant at P<0.05. Protein, fat and somatic cell counts were significantly higher in JHF crossbreds than purebred HF, while breed differences in solids-not-fats were negligible. Supplementing with lupins at 1kg/cow/day led to a significantly low milk fat content (1.2%), low somatic cell count (97) but high protein content (3.4%) while canola fed at 2kg/cow/day gave the highest milk lactose content. The overall cheaper and more profitable option for optimal milk composition appears to be cracked lupins fed at 1kg/cow/day

Growth responses of lactating first-parity dairy cows to canola and lupin supplementation

The effect of supplementing young, first-parity dairy heifers in mid-lactation with canola meal and cracked lupins on growth traits was investigated. The objective was to evaluate body condition scores (BCS), liveweight (LWT) and average daily gain (ADG) responses in purebred Holstein-Friesian and Holstein-Friesian x Jersey crossbreds and to ascertain variation due to breed, supplement and feeding level. A 2 x 2 x 2 balanced factorial experimental design representing 2 breeds, 2 supplements and 2 feeding levels (1 or 2 kg/cow/day) was utilized in randomly allocating fifty (10 unsupplemented control and 40 supplemented) cows to treatment groups after balancing for LWT, BCS and days in milk. All cows had ad libitum access to ryegrass pasture and barley and had a 3-week adjustment period to the supplements. The feeding trial lasted for 12 weeks commencing from October 2008 and ending in February 2009. LWT and BCS measurements were taken monthly. Average daily gain was computed and all data statistically analysed using mixed models procedure in SAS. Our results demonstrated that Holstein-Friesian cows gained 10kg more LWT than Holstein-Friesian x Jersey crossbreds and 20kg more than the unsupplemented cows at the end of the experiment. In all breeds, liveweight increased from 352kg in October, reached a peak in January and began to decline in February. BCS followed a similar pattern rising from an initial score of 2.5 to 3.5 in all breeds with the Holstein-Friesian in better condition than the crosses and control group. In contrast to LWT, ADG declined from an initial 0.6kg/day in October to 0.0kg/d in February in Holstein-Friesian while the unsupplemented cows lost weight as the feeding trial progressed. It was clearly demonstrated that the highest responses in ADG and LWT were in cows fed canola at 1kg/cow/day closely followed by 2kg/cow/day of lupins. In conclusion, supplementing mid-lactation dairy cows with canola elicits a better LWT and ADG response than lupins. Also, supplementing at 1kg/cow/day is cheaper and triggers the same response as 2kg/cow/day. Supplementation would be beneficial in maintaining liveweight and good body condition for better conception rates in young breeding cows

The role of airspeed variability in fixed-time, fuel-optimal aircraft trajectory planning

With the advent of improved aircraft situational awareness and the need for airlines to reduce their fuel consumption and environmental impact whilst adhering to strict timetables, fixed-time, fuel-optimal routing is vital. Here, the aircraft trajectory planning problem is addressed using optimal control theory. Two variants of a finite horizon optimal control formulation for fuel burn minimization are developed, subject to arrival constraints, an aerodynamic fuel-burn model, and a data-driven wind field. In the first variant, the control variable is expressed as a set of position-dependent aircraft headings, with the optimal control problem solved through a reduced gradient approach at a range of fixed airspeeds. The fuel optimal result is taken as the lowest fuel use recorded. In the second variant, both heading angle and airspeed are controlled. Results from three months of simulated flight routes between London and New York show that permitting optimised en-route airspeed variations leads to fuel savings of 0.5% on an average day (and up to 4% on certain days), compared with fixed airspeed flights. We conclude that significant fuel savings are possible if airspeeds are allowed to vary en route to take optimal advantage of the wind field

Genetic association of delta-six fatty acid desaturase single nucleotide polymorphic molecular marker and muscle long chain omega-3 fatty acids in Australian lamb

To better understand the genetic variability in sheep muscle long-chain omega-3 polyunsaturated fatty acids and relationships with lipid synthesis and fat metabolism-related genes, this study investigated the association between polymorphisms of the fatty acid binding proteins (FABP1, FABP2) and Delta-6 desaturase (FADS2) gene clusters. Thirty-one single nucleotide polymorphisms (SNPs) were genotyped in Longissimus dorsi muscle samples from 362 crossbred prime lambs sired by five genetically divergent rams. Total intramuscular lipid long chain fatty acid levels were analysed using gas chromatography. Mixed model statistical analyses revealed that only FADS2 SNP was significantly associated (P<0.01) with intramuscular levels of eicosapentaenoic (C20:5n-3) and docosahexaenoic (C22:6n-3) acids. The results suggest that this SNP is in linkage disequilibrium with functional lipid synthesis pathway associated with higher delta-six desaturase activity. For the first time, this study provides evidence for an association between genetic variants of FADS2 and omega-3 PUFA in sheep muscle. This SNP could potentially be a novel marker of choice for prime lamb producers to effectively select for enhanced muscle omega-3 fatty acid content in their breeding flock