Effect of genotype and sex on fiber growth rate of alpacas for their first year of fleece production

The sale of alpaca fiber is the main income for thousands of families in the Central Andes of Peru. Little information exists on the fiber length growth rate of alpaca (FLG), especially throughout their first year of life when the fiber is most valuable. We aimed to determine the monthly FLG of 22 alpaca offspring of two genotypes (9 Suri, 13 Huacaya) and considering sex differences (10 females, 12 males) in the High Andes of Peru. FLG growth was determined using dye-bands. An additive lineal model with three factors (genotype, sex, month) was used for statistic analysis. To evaluate the effect of genotype and sex on the profile of the FLG throughout the year a two factor repeated-measures model was used. The results showed that FLG was affected by genotype and month but not sex. The Suri genotype had 20% higher FLG than Huacaya genotype alpacas (1.34 vs 1.10 cm/month, P < 0.001). FLG increased over each of the first three months (P < 0.05) and then maintained a near constant rate for the remainder of the first year. The resulting staple length indicates that shearing at ages from 8 to 12 months of age will provide fleeces of sufficient length for textile processing.

Effects of site of assessment and variation in wool quality traits on the tactile assessment of textural greasy wool handle

Variation in textural greasy wool handle across the fleece of Merino sheep was explored. Results demonstrate that there were significant differences across nine sites on the fleece. The inclusion of the covariates fibre diameter, fibre diameter co-efficient of variation, staple length, dust penetration, staple structure, greasy wool colour and resistance to compression, helped to explain some of the variation in textural greasy wool handle between sites such that site of assessment was no longer a significant factor (P ≤ 0.065). However, in practice, those involved with clip preparation or sheep selection based on textural greasy wool handle assessment are unlikely to have these measurements available. The results highlight the importance of nominating a site of assessment when recording textural greasy wool handle. © CSIRO 2014.

Would Chrysomya albiceps (Diptera: Calliphoridae) be a beneficial species?

Chrysomya albiceps (Widemann) é uma mosca que se desenvolve em carcaças e opcionalmente pode causar miíase secundária. Larvas de segundo estádio foram removidas de uma lesão existente em uma ovelha da raça Merino em Botucatu. Entre a lã, ao redor da lesão, foram encontradas larvas de primeiro estádio. Também no interior da lesão foi obtida uma larva de terceiro estádio. As larvas foram mantidas em laboratório e delas obtidos insetos adultos, com 50 casais formados e mantidos em gaiolas por oito gerações. de cada geração, 100 adultos eram sacrificados e examinados morfologicamente, com os seus caracteres confrontados com os de Chrysomya rufifacies. A larva de terceiro estádio deu origem a Cochliomyia hominivorax e as demais a C. albiceps. Foi verificado que C. albiceps, além de ser capaz de danificar tecido integro, é também uma possível predadora de larvas de C. hominivorax. A importância de C. albiceps para os animais domésticos e sua associação com C. hominivorax é aqui discutida.

A stereotaxic, population-averaged T1w ovine brain atlas including cerebral morphology and tissue volumes

Standard stereotaxic reference systems play a key role in human brain studies. Stereotaxic coordinate systems have also been developed for experimental animals including non-human primates, dogs, and rodents. However, they are lacking for other species being relevant in experimental neuroscience including sheep. Here, we present a spatial, unbiased ovine brain template with tissue probability maps (TPM) that offer a detailed stereotaxic reference frame for anatomical features and localization of brain areas, thereby enabling inter-individual and cross-study comparability. Three-dimensional data sets from healthy adult Merino sheep (Ovis orientalis aries, 12 ewes and 26 neutered rams) were acquired on a 1.5 T Philips MRI using a T1w sequence. Data were averaged by linear and non-linear registration algorithms. Moreover, animals were subjected to detailed brain volume analysis including examinations with respect to body weight (BW), age, and sex. The created T1w brain template provides an appropriate population-averaged ovine brain anatomy in a spatial standard coordinate system. Additionally, TPM for gray (GM) and white (WM) matter as well as cerebrospinal fluid (CSF) classification enabled automatic prior-based tissue segmentation using statistical parametric mapping (SPM). Overall, a positive correlation of GM volume and BW explained about 15% of the variance of GM while a positive correlation between WM and age was found. Absolute tissue volume differences were not detected, indeed ewes showed significantly more GM per bodyweight as compared to neutered rams. The created framework including spatial brain template and TPM represent a useful tool for unbiased automatic image preprocessing and morphological characterization in sheep. Therefore, the reported results may serve as a starting point for further experimental and/or translational research aiming at in vivo analysis in this species.

[Flock book]

Mode of access: Internet.

Fabric and greasy wool handle, their importance to the Australian wool industry: a review

Handle-related properties of woollen fabrics have been demonstrated to be major factors affecting consumer buying attitudes. Handle is the combination of both textural and compressional attributes. Compressional handle has demonstrated processing advantages in woven and knitted fabrics. The handle of processing lots can be manipulated using a variety of technologies but direct manipulation of textural greasy wool handle pre-processing is still crude. On-farm, there is documented evidence that including handle assessment in a selection index provides additional improvements in genetic gain. However, the assessment of greasy wool handle is based on a tactile evaluation of the wool staple by sheep and wool classers, and its application is affected by a lack of framework that instructs assessors on a standard method of assessment. Once a reliable and repeatable protocol is developed, further understanding of the effect greasy wool handle has on final garment quality will be possible.

Percutaneous vertebroplasty: a new animal model.

Background Context Percutaneous vertebroplasty (PVP) is a minimally invasive surgical procedure and is frequently performed in humans who need surgical treatment of vertebral fractures. PVP involves cement injection into the vertebral body, thereby providing rapid and significant pain relief. Purpose The testing of novel biomaterials depends on suitable animal models. The aim of this study was to develop a reproducible and safe model of PVP in sheep. Study Design This study used ex vivo and in vivo large animal model study (Merino sheep). Methods Ex vivo vertebroplasty was performed through a bilateral modified parapedicular access in 24 ovine lumbar hemivertebrae, divided into four groups (n=6). Cerament (Bone Support, Lund, Sweden) was the control material. In the experimental group, a novel composite was tested—Spine-Ghost—which consisted of an alpha-calcium sulfate matrix enriched with micrometric particles of mesoporous bioactive glass. All vertebrae were assessed by micro-computed tomography (micro-CT) and underwent mechanical testing. For the in vivo study, 16 sheep were randomly allocated into control and experimental groups (n=8), and underwent PVP using the same bone cements. All vertebrae were assessed postmortem by micro-CT, histology, and reverse transcription-polymerase chain reaction (rt-PCR). This work has been supported by the European Commission under the 7th Framework Programme for collaborative projects (600,000–650,000 USD). Results In the ex vivo model, the average defect volume was 1,275.46±219.29 mm3. Adequate defect filling with cement was observed. No mechanical failure was observed under loads which were higher than physiological. In the in vivo study, cardiorespiratory distress was observed in two animals, and one sheep presented mild neurologic deficits in the hind limbs before recovering. Conclusions The model of PVP is considered suitable for preclinical in vivo studies, mimicking clinical application. All sheep recovered and completed a 6-month implantation period. There was no evidence of cement leakage into the vertebral foramen in the postmortem examination.

Polyunsaturated fats in meat from Merino, first- and second-cross sheep slaughtered as yearlings

This study examined the level of long chain omega-3 and omega-6 polyunsaturated fats, the ratio of polyunsaturated fat to saturated fat (PUFA/SFA) and the ratio of omega-6 to omega-3 (n-6/n-3) fat in sheep grown under grazing conditions in Australia. The sheep genotypes used were Poll Dorset_growth × Border Leicester Merino (PDg × BLM), Poll Dorset_growth × Merino (PDg × M), Poll Dorsetmuscling × Merino (PDm × M), Border Leicester × Merino (BL × M) and Merino × Merino (M × M). Loin muscles (Longissimus lumborum) collected from 40 ewe and wether sheep slaughtered at 14 months of age were processed for fatty acid determination. After frozen storage, 20 g samples were minced and a 7 g homogenate was processed for muscle lipid extraction using a chloroform:methanol (2:1) procedure. There was an increase in PUFA/SFA as the proportion of Merino genetics increased in the progeny (second-cross < first-cross < Merino), but this was not shown in the n-6/n-3 ratio. The PUFA/SFA trend appeared to be associated with an increase in the level of total polyunsaturated fats, but not a decrease in the level of total saturated fats. The results demonstrate that there is a need to improve the PUFA/SFA content in first- and second-cross animals which are mainly used for meat production in Australia so as to maintain the healthy lipids in meat. Nutritional manipulation through feeding systems or selection of sires for greater heritability of omega-3 fat deposition may be suitable pathways to elevate the ratio of polyunsaturated fatty acids, and in particular omega-3.

Pressure, oxygen tension and temperature in the periosteal callus during bone healing - An in vivo study in sheep

Adequate blood supply and sufficient mechanical stability are necessary for timely fracture healing. Damage to vessels impairs blood supply; hindering the transport of oxygen which is an essential metabolite for cells involved in repair. The degree of mechanical stability determines the mechanical conditions in the healing tissues. The mechanical conditions can influence tissue differentiation and may also inhibit revascularization. Knowledge of the actual conditions in a healing fracture in vivo is extremely limited. This study aimed to quantify the pressure, oxygen tension and temperature in the external callus during the early phase of bone healing. Six Merino-mix sheep underwent a tibial osteotomy. The tibia was stabilized with a standard mono-lateral external fixator. A multi-parameter catheter was placed adjacent to the osteotomy gap on the medial aspect of the tibia. Measurements of oxygen tension and temperature were performed for ten days post-op. Measurements of pressure were performed during gait on days three and seven. The ground reaction force and the interfragmentary movements were measured simultaneously. The maximum pressure during gait increased (p=0.028) from three (41.3 [29.2-44.1] mm Hg) to seven days (71.8 [61.8-84.8] mm Hg). During the same interval, there was no change (p=0.92) in the peak ground reaction force or in the interfragmentary movement (compression: p=0.59 and axial rotation: p=0.11). Oxygen tension in the haematoma (74.1 mm Hg [68.6-78.5]) was initially high post-op and decreased steadily over the first five days. The temperature increased over the first four days before reaching a plateau at approximately 38.5 degrees C on day four. This study is the first to report pressure, oxygen tension and temperature in the early callus tissues. The magnitude of pressure increased even though weight bearing and IFM remained unchanged. Oxygen tensions were initially high in the haematoma and fell gradually with a low oxygen environment first established after four to five days. This study illustrates that in bone healing the local environment for cells may not be considered constant with regard to oxygen tension, pressure and temperature.

A randomised controlled trial of amniotic membrane in the treatment of a standardised burn injury in the merino lamb

Burn injury is associated with disabling scar formation which impacts on many aspects of the patient's life. Previously we have shown that the fetus heals a deep dermal burn in a scarless fashion. Amniotic membrane (AM) is the outermost fetal tisue and has beeen used as a dressing in thermal injuries, though there is little data to support this use. To assess the efficacy of AM in scar minimisation after deep dermal burn wound, we conducted a randomised controlled study in the 1-month lamb. Lambs were delivered by caesarian section and the amniotic membranes stored after which lambs were returned to their mothers post-operatively. At 1 month, a standardised deep dermal burn was created under general anaesthesia on both flanks of the lamb. One flank was covered with unmatched AM, the other with paraffin gauze. Animals were sequentially euthanased from Day 3-60 after injury and tissue analysed for histopathology and immunohistochemically for alpha-smooth muscle actin (alphaSMA) content. AM resulted in reduced scar tissue as assessed histopathologically and reduced alphaSMA content. This study provides the first laboratory evidence that AM may reduce scar formation after burn injury.

Survival and Growth of Damara, Dorper, Dorset, Rambouillet, South African Meat Merino First Cross Lambs in Semi Arid Queensland

The recent introduction to Australia of superior sheep meat breeds from South Africa provides a basis for improving the quality and amount of sheep meat grown in Queensland’s semi arid area. Alternatively suitable breeds from existing Australian stocks of dual purpose and traditional terminal meat sheep may bring the desired attributes required by the market place. There has been no critical assessment of sheep meat breeds suitably adapted to the rangeland environment of western Queensland. Animal production for a consuming world : proceedings of 9th Congress of the Asian-Australasian Association of Animal Production Societies [AAAP] and 23rd Biennial Conference of the Australian Society of Animal Production [ASAP] and 17th Annual Symposium of the University of Sydney, Dairy Research Foundation, [DRF]. 2-7 July 2000, Sydney, Australia.

Adaptability of Damara, Dorper and Traditional Meat Sheep Breeds in Semi-Arid Queensland

Reproductive rate is a major contributing factor to the profitability of a sheep meat enterprise. Low reproduction rate is a feature of sheep husbandry in semi-arid Queensland. High ambient temperatures are implicated in poor fertility (Moule 1970) where variation in response can be due to breed and to animals within a breed (Hopkins and Stephenson 1978). Breeds recently imported from South Africa were selected in arid environments and may be better adapted to pastoral conditions of northern Australia than traditional breeds. Animal production for a consuming world : proceedings of 9th Congress of the Asian-Australasian Association of Animal Production Societies [AAAP] and 23rd Biennial Conference of the Australian Society of Animal Production [ASAP] and 17th Annual Symposium of the University of Sydney, Dairy Research Foundation, [DRF]. 2-7 July 2000, Sydney, Australia. This study will investigate (a) the thermoregulatory ability of Damara, Dorper, Poll Dorset, Rambouillet, South African Meat Merino and Queensland medium wool Merino rams prior to joinings in the autumn and spring of 1999, 2000 and 2001 and (b) the association between thermoregulatory parameters (rectal temperature and respiration rate) and ewe fertility. Results for the initial autumn joining are reported in this paper.

Fibre Transfer in Merino Ewes Mated with Damara, Merino or Dorper Rams in Central Western Queensland

Considerable concern has been expressed by the Australian wool industry regarding the contamination of the clip with coloured or kempy fibres from imported breeds of sheep. As part of the evaluation of imported sheep meat breeds in western Queensland, a study is examining fibre growth and transfer of fibres and the potential to cause physical contamination of Merino fleeces. The breeds of concern in this study are the Damara, a fat-tailed breed with a hairy, coloured fleece and the Dorper which has both pigmented fibres and a kempy fleece which is shed cyclically. Three groups of Merino 27 ewes were mated to Merino, Damara and Dorper rams respectively and fibre transfer to the Merino ewes during mating, from lambing to weaning and during grazing, assessed. Both a direct field method and a laboratory method (Hatcher 1995) are being used. Those measured by direct count were measured immediately after joining and 2, 4 and 8 weeks subsequently. and the other ewes were shorn and sampled and measured in the laboratory using the dark fibre detector. This paper presents preliminary findings of those ewes monitored by the direct field method. Animal production for a consuming world : proceedings of 9th Congress of the Asian-Australasian Association of Animal Production Societies [AAAP] and 23rd Biennial Conference of the Australian Society of Animal Production [ASAP] and 17th Annual Symposium of the University of Sydney, Dairy Research Foundation, [DRF]. 2-7 July 2000, Sydney, Australia.