The effect of long-chain polyunsaturated fatty acid and vitamin E supplementation of ewes on neonatal lamb behaviour and performance

Three experiments investigated the effect of long-chain polyunsaturated fatty acid (PUFA) and vitamin E supplementation of ewes upon lamb vigour and performance. In Experiment One, four diets were fed to 48 ewes in a two-by-two factorial design. Each diet contained either fish oil (high in C20:5n-3 and C22:6n-3) or Megalac® (control fat, C16:0) and a basal (50 mg/kg) or supranutritional (500 mg/kg) concentration of vitamin E. Fish oil supplementation significantly increased ewe gestation length, deposition of C22:6n-3 in lamb brain tissue and neonatal lamb vigour. It also had significant detrimental effects upon milk composition and lamb growth. Vitamin E supplementation of the ewe increased the concentration of the vitamin in lamb brain and muscle tissue, and improved lamb birthweight. Within Experiment Two, three treatment diets based on algae (high in C22:6n-3), linseed (high in C18:3n-3) or Megalac® were fed to sixty pregnant ewes. After parturition, thirty ewes were changed onto diets containing either linseed or Megalac®. Gestation length and brain C22:6n-3 content were unaffected by diet, although lamb vigour was improved by maternal PUFA supplementation. The use of strategic supplementation abrogated the effects of PUFA supplementation upon lamb growth rate. Nevertheless, significant effects of algal supplementation were observed upon milk composition after a 28-day change-over period. Experiment Three employed three diets, each containing either fish oil or Megalac® plus basal or supranutritional vitamin E, followed by Megalac® supplementation during lactation. Gestation length and lamb behaviour were unaffected by treatment diet. Differences in milk composition were observed 28 days after the diet change. Long-chain PUFA supplementation of the pregnant ewe appears to improve neonatal lamb vigour, although effects upon milk composition cannot be negated by changing the dietary fat source during lactation. The vitamin E status of the neonatal lamb may be manipulated by maternal supplementation

Effects of foal presence at milking and dietary extra virgin olive oil on jennet milk fatty acids profile

TwelveRagusanajennetswerestudiedtoinvestigatetheeffectsof dietaryextra Twelve Ragusana jennets were studiedtoinvestigatetheeffectsof dietaryextra studied to investigatetheeffectsof dietaryextra the effects of dietaryextra dietary extra virgin olive oil and thepresenceofthefoal duringmilkingonmilkfattyacids(FA)profile.At20, 50 thepresenceofthefoal duringmilkingonmilkfattyacids(FA)profile.At20, 50 he presence of the foal during milking on milk fatty acids (FA) profile. At 20, 50 and 90 days post-foaling, each jennet was milked 4 times per day. The feeding system and the milking procedures are given by Alabiso et al. (2009). FA profiles of the composites from milkings without foals (1MNF+3MNF) and with foals (2MYF+4MYF) were analyzed by gas chromatography. Dietary oil had no significant effect on milk yield or fat content but increased the proportion of C18:1 (n-9) in milk. Jen- net milk had a beneficial FA profile compared to bovine milk and thus would be suitable for consump- tion by infants suffering from cows milk protein allergy, however, augmentation of the long-chain n-3 polyunsaturated FA content warrants further study

The impact of controlling diseases of significant global importance on greenhouse gas emissions from livestock production

Abstract Background A considerable body of evidence has reported the beneficial effects of improving productivity on reducing environmental impacts from livestock production. However, despite the negative impacts of animal diseases on reproduction, growth and milk production, there is little information available upon the impacts of animal disease on greenhouse gas emissions (GHGe). This study aimed to partially address this knowledge gap by investigating the effects of globally important vaccine-preventable diseases on GHGe from various livestock systems, namely: intensive dairy, extensive beef, commercial swine and backyard poultry production. Methods Simple deterministic models were developed within Microsoft Excel to quantify the impacts of livestock disease on productivity (defined as total milk and/or meat yield, MMY) adjusted for disease prevalence both at the population level (high or low), and at the herd or flock level. Disease-induced changes in MMY were applied to the GHGe per kg of milk or meat according to the consequent changes in livestock populations required to maintain milk or meat production. Diseases investigated comprised foot and mouth, brucellosis, anthrax, lumpy skin disease, classical swine fever, porcine reproductive and respiratory syndrome (PRRS), low and high pathogenicity avian influenza (LPAI and HPAI), avian infectious bronchitis and Newcastle disease. Results All diseases investigated had multifactorial impacts on total MMY, yet diseases that increased mortality in breeding or growing livestock (e.g. anthrax, classical swine fever and HPAI) showed greater impacts on GHGe per unit of milk or meat produced than those that primarily affecting yields or reproduction (e.g. brucellosis or LPAI). Prevalence also had considerable effects on potential GHGe. For example, maintaining backyard poultry meat production from a 100,000 hen population with 70% prevalence of HPAI increased GHGe by 11,255 MT CO2eq compared to a 30% prevalence at 3475 MT CO2eq above the baseline (0% prevalence). Effective reduction of the prevalence of PRRS in swine from 60 to 10%, FMD in beef cattle from 45 to 5% prevalence, or AIB in poultry from 75 to 20% prevalence would reduce GHGe intensities (CO2eq/kg CW) by 22.5%, 9.11% and 11.3% respectively. Conclusions Controlling livestock disease can reduce MMY losses at the farm level, which improves food security, reduces GHGe and enhances livestock system sustainability

Is the Grass Always Greener? Comparing the Environmental Impact of Conventional, Natural and Grass-Fed Beef Production Systems

This study compared the environmental impact of conventional, natural and grass-fed beef production systems. A deterministic model based on the metabolism and nutrient requirements of the beef population was used to quantify resource inputs and waste outputs per 1.0 × 109 kg of hot carcass weight beef in conventional (CON), natural (NAT) and grass-fed (GFD) production systems. Production systems were modeled using characteristic management practices, population dynamics and production data from U.S. beef production systems. Increased productivity (slaughter weight and growth rate) in the CON system reduced the cattle population size required to produce 1.0 × 109 kg of beef compared to the NAT or GFD system. The CON system required 56.3% of the animals, 24.8% of the water, 55.3% of the land and 71.4% of the fossil fuel energy required to produce 1.0 × 109 kg of beef compared to the GFD system. The carbon footprint per 1.0 × 109 kg of beef was lowest in the CON system (15,989 × 103 t), intermediate in the NAT system (18,772 × 103 t) and highest in the GFD system (26,785 × 103 t). The challenge to the U.S beef industry is to communicate differences in system environmental impacts to facilitate informed dietary choice

The environmental and economic impact of removing growth-enhancing technologies from U.S. beef production

The objective of this study was to quantify the environmental and economic impact of withdrawing growth-enhancing technologies (GET) from the U.S. beef production system. A deterministic model based on the metabolism and nutrient requirements of the beef population was used to quantify resource inputs and waste outputs per 454 × 106 kg of beef. Two production systems were compared: one using GET (steroid implants, in-feed ionophores, in-feed hormones, and beta-adrenergic agonists) where approved by FDA at current adoption rates and the other without GET use. Both systems were modeled using characteristic management practices, population dynamics, and production data from U.S. beef systems. The economic impact and global trade and carbon implications of GET withdrawal were calculated based on feed savings. Withdrawing GET from U.S. beef production reduced productivity (growth rate and slaughter weight) and increased the population size required to produce 454 × 106 kg beef by 385 × 103 animals. Feedstuff and land use were increased by 2,830 × 103 t and 265 × 103 ha, respectively, by GET withdrawal, with 20,139 × 106 more liters of water being required to maintain beef production. Manure output increased by 1,799 × 103 t as a result of GET withdrawal, with an increase in carbon emissions of 714,515 t/454 × 106 kg beef. The projected increased costs of U.S. beef produced without GET resulted in the effective implementation of an 8.2% tax on beef production, leading to reduced global trade and competitiveness. To compensate for the increase in U.S. beef prices and maintain beef supply, it would be necessary to increase beef production in other global regions, with a projected increase in carbon emissions from deforestation, particularly in Brazil. Withdrawing GET from U.S. beef production would reduce both the economic and environmental sustainability of the industry.This article is from Journal of Animal Science 90, no. 10 (October 2012): 3527–3537, doi:10.2527/jas.2011-4870.</p

A case study of the carbon footprint of milk from high-performing confinement and grass-based dairy farms

Life-cycle assessment (LCA) is the preferred methodology to assess carbon footprint per unit of milk. The objective of this case study was to apply an LCA method to compare carbon footprints of high-performance confinement and grass-based dairy farms. Physical performance data from research herds were used to quantify carbon footprints of a high-performance Irish grass-based dairy system and a top-performing United Kingdom (UK) confinement dairy system. For the US confinement dairy system, data from the top 5% of herds of a national database were used. Life-cycle assessment was applied using the same dairy farm greenhouse gas (GHG) model for all dairy systems. The model estimated all on- and off-farm GHG sources associated with dairy production until milk is sold from the farm in kilograms of carbon dioxide equivalents (CO2-eq) and allocated emissions between milk and meat. The carbon footprint of milk was calculated by expressing GHG emissions attributed to milk per tonne of energy-corrected milk (ECM). The comparison showed that when GHG emissions were only attributed to milk, the carbon footprint of milk from the Irish grass-based system (837 kg of CO2-eq/t of ECM) was 5% lower than the UK confinement system (884 kg of CO2-eq/t of ECM) and 7% lower than the US confinement system (898 kg of CO2-eq/t of ECM). However, without grassland carbon sequestration, the grass-based and confinement dairy systems had similar carbon footprints per tonne of ECM. Emission algorithms and allocation of GHG emissions between milk and meat also affected the relative difference and order of dairy system carbon footprints. For instance, depending on the method chosen to allocate emissions between milk and meat, the relative difference between the carbon footprints of grass-based and confinement dairy systems varied by 3 to 22%. This indicates that further harmonization of several aspects of the LCA methodology is required to compare carbon footprints of contrasting dairy systems. In comparison to recent reports that assess the carbon footprint of milk from average Irish, UK, and US dairy systems, this case study indicates that top-performing herds of the respective nations have carbon footprints 27 to 32% lower than average dairy systems. Although differences between studies are partly explained by methodological inconsistency, the comparison suggests that potential exists to reduce the carbon footprint of milk in each of the nations by implementing practices that improve productivity

The fate of Lyngbya majuscula toxins in three potential consumers

Blooms of Lyngbya majuscula have been reported with increasing frequency and severity in the last decade in Moreton Bay, Australia. A number of grazers have been observed feeding upon this toxic cyanobacterium. Differences in sequestration of toxic compounds from L. majuscula were investigated in two anaspideans, Stylocheilus striatus, Bursatella leachii, and the cephalaspidean Diniatys dentifer. Species fed a monospecific diet of L. majuscula had different toxin distribution in their tissues and excretions. A high concentration of lyngbyatoxin-a was observed in the body of S. striatus (3.94 mg/kg⁻¹) compared to bodily secretions (ink 0.12 mg/kg⁻¹; fecal matter 0.56 mg/kg⁻¹; eggs 0.05 mg/kg⁻¹). In contrast, B. leachii secreted greaterconcentrations of lyngbyatoxin-a (ink 5.41 mg/kg⁻¹; fecal matter 6.71 mg/kg⁻¹) than that stored in the body (2.24 mg/kg⁻¹). The major internal repository of lyngbyatoxin-a and debromoaplysiatoxin was the digestive gland for both S. striatus (6.31 ± 0.31 mg/kg⁻¹) and B. leachii (156.39 ± 46.92 mg/kg⁻¹). D. dentifer showed high variability in the distribution of sequestered compounds. Lyngbyatoxin-a was detected in the digestive gland (3.56 ± 3.56 mg/kg⁻¹) but not in the head and foot, while debromoaplysiatoxin was detected in the head and foot (133.73 ± 129.82 mg/kg⁻¹) but not in the digestive gland. The concentrations of sequestered secondary metabolites in these animals did not correspond to the concentrations found in L. majuscula used as food for these experiments, suggesting it may have been from previous dietary exposure. Trophic transfer of debromoaplysiatoxin from L.majuscula into S. striatus is well established; however, a lack of knowledge exists for other grazers. The high levels of secondary metabolites observed in both the anaspidean and the cephalapsidean species suggest that these toxins may bioaccumulate through marine food chains.\u

Inflammatory Signalling in Fetal Membranes: Increased Expression Levels of TLR 1 in the Presence of Preterm Histological Chorioamnionitis.

Histological chorioamnionitis (HCA) is an established marker of ascending infection, a major cause of preterm birth. No studies have characterised the global change in expression of genes involved in the toll-like receptor (TLR) signalling pathways in the presence of HCA in the setting of preterm birth (pHCA). Fetal membranes were collected immediately after delivery and underwent histological staging for inflammation to derive 3 groups; term spontaneous labour without HCA (n = 9), preterm birth 2; p<0.1). Expression of identified genes was validated individually for all samples, relative to GAPDH, using RT-PCR. Expression of TLR 1, TLR 2, lymphocyte antigen 96, interleukin 8 and Interleukin-1 receptor-associated kinase-like 2 was increased in pHCA (p<0.05). Degree of expression was positively associated with histological staging of both maternal and fetal inflammation (p<0.05). The inflammatory expression profile at the maternal/fetal interface associated with pHCA, a reflection of ascending infection, is extremely heterogeneous suggesting polymicrobial involvement with activation of a common pathway. Antagonism of TLR 1 and TLR 2 signalling in this setting warrants further assessment