Variation of mohair staple length across Angora goat fleeces : implications for animal selection and fleece evaluation

The present study aimed to determine how the average mohair staple length (SL) differences between nine sampling sites vary between sex and flock, to identify differences in SL variability between sampling sites as a result of between-animal and between-sire variability and to determine SL correlations between sampling sites in between-animal and between-sire variability. Australian Angora goats (n=301) from two farms in southern Australia were sampled at 12 and 18 months of age at nine sites (mid side, belly, brisket, hind flank, hip, hock, mid back, neck and shoulder). Staples were taken prior to shearing at skin level and stretched SL determined. For each shearing, differences in SL between sampling sites, how these differences were affected by farm, sex and sire, and the covariance between sites for sire and individual animal effects were investigated by restricted maximum likelihood (REML) analyses. The median mid-side SL at 12 and 18 months of age was 110 and 130 mm, respectively, but the actual range in mid-side SL was 65–165 mm. There was an anterior–posterior decline in SL with the hock being particularly short. There was no evidence that the between-site correlation of the sire effects differed from 1, indicating that genetic selection for SL at one site will be reflected in SL over the whole fleece. However, low heritabilities of SL at the hock, belly and brisket or at any site at 12 months of age were obtained. There was more variability between sites than between sires, but the between-animal variation was greater. The hip and mid-back sites can be recommended for within-flock (culling) and genetic selection for SL due to their low sampling variability, moderate heritability and ease of location.

A review of cashmere nutrition experiments with suggestions for improving their design and conduct

The scientific literature contains divergent views about the effects of nutrition on cashmere. The consequences of ignoring nutrition will be an increase in the number of goats suffering lower production, increased welfare risks and premature mortality. This review evaluated published reports to identify current knowledge and best practice in regard to the design and management of cashmere nutrition experiments. The ability of experiments to distinguish between treatments was evaluated based on their statistical evidence. Many experiments had serious deficiencies in their design, conduct and reporting. Six of 16 papers did not provide statistical information that would enable a reader to verify differences between treatments. For most experiments to detect nutrition affects at P < 0.05, they required a difference between treatments of 0.2–0.8 μm in cashmere mean fibre diameter and 15–42 g in clean cashmere production. Government Research Institutes research was characterised by more experienced authors conducting longer (P < 0.05) and larger (P < 0.05) experiments than those conducted by Universities. Much of the “debate” regarding the affects of nutrition on cashmere production arises from the misinterpretation of both experiments that did not detect statistically significant effects and of experiments that did detect statistically significant effects. Based on a comparison between experiments reporting responses to nutrition with those reporting no response, 13 design and management features were identified that are related to the ability of experiments to detect significant treatment affects. Methods must be adopted to reduce the variance in cashmere production within treatments, by using sufficient animals per treatment, and having replication to provide sufficient degrees of freedom to reduce error terms in analysis. The power of experimental designs should be evaluated before experiments commence. Cashmere production records from a previous full production year could be used as co-variants during statistical analyses but this requires that potential experimental goats are managed in one flock, without variations resulting from different grazing, reproduction or other management for a year prior to an experiment. It is preferable to use more productive and older goats, and goats that are used to handling, and to the conditions and feed to be used. Allocation of animals to treatments must take into account live weight. Nutrition treatments need to be sufficiently different to produce different growth curves. An appropriate control is needed such as live weight maintenance. Evidence of both nutrition intake and growth curves must be published with cashmere production data so the claims made can be verified by the actual responses. As cashmere production is an order of magnitude less than fibre production of Merino sheep or Angora goats and is more difficult to measure, the requirements for measurement, sampling and testing cashmere fleeces are summarised. The use of mid side cashmere patches to determine cashmere growth and quality is seriously biased and must be avoided, preferably by shearing goats prior to and at the end of experiments. In order to obtain higher fleece growth responses and improve the ability of experiments to detect treatment effects it is preferable to start cashmere growth experiments by midsummer and conduct experiments for at least 4 months. These requirements make it difficult for many university students to plan, undertake and complete long-term cashmere nutrition experiments without considerable management support. It is not possible for experiments to disprove the Null hypothesis regarding the effects of nutrition on cashmere production as they can only report a failure to detect treatment effects. Researchers and journals need to be more rigorous in providing statistical information including: degrees of freedom for error terms, treatment variances, standard error of differences or similar to enable readers to compare treatment effects. Publications that do not provide sufficient statistical information should be disregarded from future discussions. Claims that an experiment shows no responses to nutrition should be subject to rigorous examination using the issues identified in this review.

Gross margins in Australian mohair enterprises and relationships with farm inputs, productivity and mohair quality

In the absence of financial information on Australian mohair enterprises we aimed to determine the gross margins (per dry sheep equivalent, DSE) and their relationships with farm inputs, productivity and mohair quality in Australian mohair enterprises. Using established Victorian Farm and Sheep Monitor Project protocols we collected data for the financial years 200405, 200506 and 200607 from farmers in south-eastern Australia and made comparisons with data from wool enterprises of similar farm area. Over 3 years the financial returns from mohair exceeded that from wool in terms of $/DSE ($23.0 v. 11.3) and $/ha ($132 v. $116). This result was achieved despite the mohair enterprises grazing their goats far less intensively compared with the grazing intensity of sheep (5.9 v. 10.311.1 DSE/ha) and by using far less phosphate fertiliser than used in the wool enterprises (2.2 v. 4.66.1 kg P/ha). These differences were counterbalanced by higher prices for mohair compared with fine wool ($13.15/kg v. $8.35/kg clean fibre). Gross margin for the mohair enterprise did not increase as stocking rate increased. Income from mohair sales declined as the proportion of does in the flock increased. Increasing the proportion of does in the flock was associated with a decline in the average price of mohair ($16/kg greasy at 42% does to $8/kg greasy at 83% does in the flock). This decline was closely associated with the increasing proportion of the total amount of mohair coarser than 34.0 μm (either fine hair or hair) plus stained mohair. The variation in profitability between farms indicates significant scope for many mohair enterprises to increase profit. A focus on producing finer quality mohair will increase mohair profitability.

Variation in mohair staple length over the lifetime of Angora goats

Previous work has shown that, within an Angora goat flock, clean fleece weight is proportional to fleece-free liveweight (FFLwt)2/3 and for goats of the same age and cohort, the mean mohair fibre diameter is proportional to FFLwt1/3. This indicates that fibre length might not be related to the size of animals. This study examines how mohair staple length (SL) is related to FFLwt of Angora goats of different genetic origins over their lifetime and how the relationship varies with other lifetime factors. Measurements were made over 11 shearing periods on a population of Angora goats representing the current range and diversity of genetic origins in Australia, including South African, Texan and interbred admixtures of these and Australian sources. Records of breed, sire, dam, date of birth, dam age, birthweight, birth parity, weaning weight, liveweight, fleece growth and fleece quality were taken for castrated males (wethers) (n = 94 animals). FFLwt were determined for each goat at shearing time by subtracting the greasy fleece weight from the liveweight recorded immediately before shearing. The average of the FFLwt at the start of the period and the FFLWt at the end of the period was calculated. Liveweight change (LwtCh) was the change in FFLwt over the period between shearings. A restricted maximum likelihood model was developed for SL, which allowed the observations of the same animal at different ages to be correlated in an unstructured manner. Average SL differed from ~12.0 to ~14.5 cm, depending on age. There were no consistent effects of season. At any age, an increase of 10 kg LwtCh between animals results in about a 0.34 (s.e. = 0.087) cm increase in SL. There was no evidence of an effect of FFLwt on SL. The results confirm our hypothesis that within a single age cohort of Angora goats, there is very little, if any, relationship between the liveweight and SL of individual animals. This implies that the biological determinants of size of fibres related to cross-sectional area are substantially different to the size determinants of fibre length.

The relationship of the incidence of medullated fibres to the dimensional properties of mohair over the lifetime of Angora goats

In a range of animals, increasing mean fibre diameter (MFD) of fibre is associated with an increasing incidence of medullated fibres (Med). It would thus be expected that Med in mohair fleeces, from animals in a flock, would be related to the MFD of those fleeces. MFD of mohair is not the only dimensional attribute of fibres. Med in mohair is phenotypically and genetically related to the size of animals. This study examined how Med is related to dimensional properties of mohair over the lifetime of Angora goats and how the relationship varies with other lifetime factors. The relationship found is then examined to determine the extent that the relationship can be explained by variations in animal size of the goats. Measurements were made over 11 shearing periods on a population of Angora goats representing the current range and diversity of genetic origins in Australia, including South African, Texan and interbred admixtures of these and Australian sources. Records of breed, sire, dam, date of birth, dam age, birth weight, birth parity, weaning weight, live weight, fleece growth and fleece attributes were taken for castrated males (wethers). Animals’ fleece-free live weight (FFLwt, kg) were determined for each goat at shearing time by subtracting the greasy fleece weight from the live weight recorded immediately prior to shearing. The average of the FFLwt at the start of the period and the FFLwt at the end of the period was calculated. Two restricted maximum likelihood (REML) models were developed to relate Med to MFD, staple length (SL) and other lifetime factors. One model allowed FFLwt in the model and the other excluded FFLwt. With the exception of the 1.5 years shearing, Med strongly increased with increasing MFD whether or not adjustments were made for FFLwt measurements. In particular Med increased by 2.0% for each 1 μm increase in MFD, with no adjustment for FFLwt measurements, and increased by 1.5% for each 1 μm increase in MFD, with adjustment for FFLwt measurements. Within each shearing interval increasing average FFLwt was associated with increasing incidence of Med in a similar way to that which has been previously reported without including MFD in the model. There was no evidence that SL needed to be included in the models for Med. Mohair grown by the goats of Mixed genetic background grew mohair which had a higher incidence of Med at ages 2 and 2.5 years and the trend was apparent in other shearing periods. We can conclude that there is both a large response of Med to live weight and a large response to MFD, and that these responses are largely functionally separate. While the response to MFD is in accord with earlier work, there is an unrelated and unreported physiological mechanism that favours the production of Med in larger Angora goats. Clearly, larger Angora goats are biologically different compared with smaller animals from the same flock, in ways that are not purely related to the allometrics of size.

The value of visual fleece assessment in addition to objective measurements in identifying Angora goats of greater clean mohair production

Visual assessment of the fleece of Merino sheep is an accepted method to aid genetic improvement but there is little evidence to support the use of visual assessment for improving mohair production. This paper examines the extent that visual traits, including staple length, character (staple crimp), staple definition, tippiness, style and staple entanglement, are related to clean fleece weight in animals of similar live weight and mean fibre diameter (MFD) from the same flock. Measurements were made over 9 shearing periods on a population of castrated Angora males (wethers) goats representing the current range and diversity of genetic origins in Australia, including South African, Texan and interbred admixtures of these and Australian sources (these different genetic origins are defined as Breed in this work). Data on genetic origin, sire, dam, lifetime characteristics (date of birth, dam age, birth weight, birth parity (single or twin), weaning weight), live weight, fleece growth and visual fleece attributes were recorded. A restricted maximum likelihood (REML) model was developed to relate clean fleece weight with age, MFD, average fleece-free live weight, lifetime characteristics and visual fleece attributes. There were separate linear responses of clean fleece weight to MFD and staple length for each age group, a quadratic response to the square root of average fleece-free live weight, an effect of sire breed and linear responses to dam age, staple definition score and character. Depending on age at shearing, the increase in clean fleece weight was between about 50 and 80. g for each increase of 1. μm in MFD. At similar MFD, clean fleece weight was generally greater at summer shearings compared with winter shearings. There was a strong increase in clean fleece weight with average fleece-free live weight up to around 50. kg but little response in clean fleece weight for animals larger than 50. kg. There was some evidence of a smaller increase in clean fleece weight as the age of dam increased. There was an effect of Breed in the model but this effect disappeared when a random sire effect was included in the model. There was a positive response to staple length at some age groups but the response did not differ from zero in other age groups. This response varied from negligible to about 70. g per 1. cm increase in staple length. Clean fleece weight increased about 40. g per unit increase in staple definition score and increased about 30. g for every 4 units increase in the number of staple crimps. There was no evidence that clean fleece weight was affected by staple style, staple tip score or staple entanglement score or lifetime factors such as birth weight, date of birth, birth parity, or weaning weight. The results show that using a combination of measuring MFD and visually assessing the fleece for staple length, staple definition and crimps can help identify the most profitable Angora goats. In this process, the objective measurement of MFD appears essential. Visual assessment will provide some extra benefit in identifying these animals above that provided by measuring MFD alone. Animal size should be considered by mohair producers when identifying more productive mohair producing animals. © 2014 Elsevier B.V.

Wear of permanent incisors with age on commercial Australian Angora goat farms

OBJECTIVE: To quantify if, and to what extent, permanent incisor wear differed with age of goat and farm of origin on commercial Australian Angora goat farms. DESIGN: Observations were made on three Angora goat farms in the wheat-sheep zone of Victoria, each managed according to the farmer's practices. Farmers provided a representative flock of does. METHODS: The proportion and pattern of wear of permanent incisors were recorded and percentage wear calculated. After log(y + 10) transformation, a parsimonious general linear model was developed to relate wear to farm and age, with age considered as a continuous variate. RESULTS: The range in wear of the permanent incisors was 0-100%. For each farm, the most parsimonious model for permanent first incisor wear and average wear of all permanent incisors was a separate straight line relating the transformed incisor wear to the age of doe. The models accounted for 66-73% of variance. On each farm the incisor wear was similar and low for ages up to approximately 4 years. On all farms, the amount of incisor wear increased dramatically with age, although the rate of increase differed with each farm. CONCLUSIONS: Permanent incisor wear increased with age of goat and differed with farm of origin. Angora goat farmers need to be aware of the potential for incisor wear to affect doe production and health.

Flocking and feeding in the fiddler crab (UCA tangeri): prey availability as risk-taking behaviour

For a full understanding of prey availability, it is necessary to study risk-taking behaviour of the prey. Fiddler crabs are ideally suited for such a study, as they have to leave their safe burrow to feed on the surface of the intertidal flats during low tide, thereby exposing themselves to avian predators. A study in an intertidal area along the coast of Mauritania showed that small crabs always stayed in the vicinity of their burrow, but large crabs wandered in large flocks (also referred to as droves) to feed on sea-grass beds downshore. Transplanting downshore feeding substrate to the burrowing zone of the small crabs proved that they too preferred to feed on it. Since small crabs can be preyed upon by more species of birds, this suggests that the decision not to leave the burrowing zone might be related to the risk of being fed upon by birds. We calculated predation risk from measurements on the density and feeding activity of the crabs, as well as the feeding density, the intake rate and the size selection of the avian predators. Per hour on the surface, crabs in a flock were more at risk than crabs feeding near their burrow. Thus, though flocking crabs may have benefited from ‘swamping the predator’ by emerging in maximum numbers during some tides only, this did not reduce their risk of predation below that of non-flocking crabs. Furthermore we found that irrespective of activity, large crabs suffered a higher mortality per tide from avian predators than small crabs. This suggests that large crabs could not sufficiently reduce their foraging time to compensate for the increased risk while foraging in a flock, even though they probably experienced better feeding conditions than small crabs staying near their burrow. The greater energy demands of large crabs were reflected in a greater surface area grazed. Thus, with increasing size a fiddler crab has to feed further away from its burrow and so may derive less protection from staying near to it. It seems that growing big does not reduce the risk of predation for fiddler crabs, as it does in many other species with indeterminate growth. As in such species, the most probable advantage of growing big is increased mating success. Ultimately, therefore, prey availability must be understood from the life-history decisions of the prey species.

Feeding ecology of wintering terns in Guinea-Bissau

We studied the feeding ecology of Little Terns Sterna albifrons, Sandwich Terns S. sandvicensis and Royal Terns S. maxima in the Archipélago dos Bijagós (11°40′N, 15°45′W) in Guinea-Bissau (West Africa) during the winter of 1992/1993. More than 95% of all prey taken by these terns were roundfish, ranging in weight from 0.3 to 40 g. Birds usually fed alone, but sometimes they were observed feeding in mixed-species flocks consisting of 15-200 individuals. Capture rate (n fish per hour foraging) in these flocks was higher than that of solitary birds. However, smaller fish were caught by birds foraging in flocks, so food intake rate (g/h) did not differ between solitary and flock-feeding birds. The relationships between foraging behaviour of the three tern species and abiotic factors, such as time, tide and water clarity, have been investigated. Capture rate of Royal Terns increased with water clarity. For Little Terns and Sandwich Terns, food intake rate was lower in the most turbid waters compared to clearer waters. There was very little foraging activity during high tide. For Little Terns and Royal Terns, food intake rate was about twice as high during receding and low tides as during an incoming tide. Food intake rate averaged 8 g/h in Little Terns, 60 g/h in Sandwich Terns and 45 g/h in Royal Terns. With a rough model, we estimate the maximum rate of daily energy expenditure of terns wintering in the tropics at 3 x BMR (defined as energy expenditure of inactive bird at thermoneutrality in a post-absorptive state during the resting phase of the daily cycle). From an energetic viewpoint, wintering Sandwich Terns in Guinea-Bissau seem to have an easy living.

Enxertos ósseos liofilizados e impactados humano e bovino em revisão de artroplastia total de quadril

O presente estudo é uma coorte não concorrente em 63 pacientes (66 quadris) submetidos à revisão de artroplastia total de quadril (RATQ), com enxerto ósseo liofilizado moído e impactado. Foi realizado no Serviço de Ortopedia e Traumatologia do Hospital de Clínicas de Porto Alegre (HCPA), no período de maio de 1997 a setembro de 2003. O objetivo do estudo foi comparar clínica, radiográfica e cintilograficamente a capacidade de osteointegração dos enxertos ósseos liofilizados humano e bovino impactados em RATQs cimentadas e não-cimentadas. Os pacientes foram divididos em dois grupos: o Grupo 1 (n=35) foi composto pelos que receberam enxerto ósseo liofilizado de origem humana e o Grupo 2 (n=31) por aqueles que receberam enxerto de origem bovina. O tempo médio de seguimento foi de 33 meses. Os enxertos ósseos purificados e liofilizados foram produzidos pelo Banco de Tecidos do HCPA. A análise clínica baseou-se no escore de Merle, d’Aubigné e Postel; a radiográfica, nos critérios de radioluscência, densidade, formação de trabeculado ósseo, migração dos componentes e floculação, formulando-se um escore radiográfico de osteointegração (EROI). Foram escolhidos, aleatoriamente, como forma complementar de análise por imagem, 35 (53%) pacientes assintomáticos para realizarem cintilografia óssea com Tecnécio, sendo 17 (48,5%) do Grupo 1 e 18 (51,5%) do Grupo 2. Não foram encontradas diferenças clínicas, radiográficas ou cintilográficas relevantes entre os grupos, obtendo-se em torno de 85% de integração do enxerto, tanto no componente acetabular quanto femoral. Estes resultados são comparáveis aos relatados na literatura com o uso de enxerto alogênico congelado e confirmam a adequacidade do uso de enxertos liofilizados de origem bovina e humana em RATQ.

Causas de variação nos preços de bovinos nelore elite no Brasil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Prevalence of newcastle disease virus in broiler chickens (Gallus gallus) in Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Occurrence of Salmonella sp in laying hens

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Ocorrência de leucose enzoótica bovina na microrregião da Serra de Botucatu

The aim of this study was characterize the positivity of the bovine leukosis virus in the Microregion of the Serra de Botucatu. Sera from 1193 bovine from 65 properties of the Microregion of the Serra de Botucatu were evaluated throught ELISA test. All the evaluated animals were adult and 16 of them only were male; 85.5% were crossbred, 6.45% Nellore and 8% dutch. of the analyzed samples, 618 sera had resulted positive to the test. In only one flock it was not found seroreagents animals, the regional positivity was 52% (the seropositivity in the properties varied of 10% to 67%), the higher the percentage of positivity was in the animals of the dutch race (94.7%), followed for the crossbred (43.7%). The high percentage of positivity of the disease in our region is distinguished.

Avaliação da produção de leite e contagem de células somáticas em bovinos leiteiros suplementads com Saccharomyces cerevisiae como fonte de zinco orgânico

The aim of the evaluation of milk production and somatic cell count of dairy cow supplemented with Saccharomyces cerevisiae as a source of organic zinc for 180 days, 25 Holstein cows were selected, randomly chosen from a flock of 189 lactating cows. The animals were distributed in two groups, namely group 1 (G1) which holded 10 cows supplemented and group 2 (G2) with 15 animals without supplementation. The production of milk was measured by the control official milkman of the Assocition Paranaense of Creators of Bovine of the Holstein in seven moments during the 180 days. The samples of milk were collected of each animal, being submitted to the electronic counting of somatic cells. The results demonstrate that the supplemented of organic zinc didn't alter the production of milk, however it was capable to maintain low the counting of somatic cells. The data of the present work suggest that to use supplemented of organic zinc in the diet of cows milk, increase the quality of the produced milk and consequently the remuneration for the producer.