Carlo Renieri

Typical products of the small ruminant sector and the factors affecting their quality

Abstract At the present time, the farmers have to diversify the production types to maintain their market position and to fall in with consumers demands. They have privileged the typicality to create a fidelity with the consumers in the small ruminant production system, because of the long tradition and its less industrialisation. Of course the mean of this term varies according with people culture and tradition and with production (cheese, meat, fibre). In cheese field the differences between geographic areas, culturally homogeneous, are evident. In United Europe the historical and traditional motivations prevail and these products are protected by low. Some cheeses give their typicality to a breed, some other to the cellar, to a technique or to a feeding system. In USA, safety is the most important condition for the consumer. In Latin American countries people are giving more and more importance to the typicality even if there is a lake of regulations. In meat sector the situation is the same. The meaning of quality and typicality changes according to the local customs. In the more developed areas carcass quality is evaluated by grids that determine the price of the product. The quality indicated on many labels is made according to some grid evaluation. Quite different is the situation of the fibre sector. In the last years, the textile industry is discovering certain interest towards the typicality as regards the home-made, the ecological production and the naturally coloured wool. Consumers appear to be attracted by the typicality message if this term has some contents. Research is trying to study some factors influencing the typicality and in this report we referred about theirs. The future of a lot of small ruminant production depends from the capacity of research organisations to explore and to find the scientific reasons of typicality.

Genetics of fibre production and fleece characteristics in small ruminants, Angora rabbit and South American camelids.

This paper reviews genetics of fibre production and fleece characteristics in small ruminants, Angora rabbit and South American camelids with a special distinction between single-coated (SC) and double-coated (DC) species. Considering the biology of fibre production, there are variations in coat composition and structure, fibre growth pattern and fibre structure and quality between these two main kinds of fibre-producing animals. In SC species, all fibres are nearly similar in dimensions and are produced from individual follicles that have a very long period, essentially permanent, of active growth without a synchronous phase of rest between follicles. In contrast, in DC species the fleece comprises a coarse outer coat and a fine inner coat with variations of coat composition and structure, and fibre growth pattern according to the season with a well-defined duration of fibre growth. Genetic basis of hair growth pattern, coat composition and fibre structure are different between species. In small ruminants, these coat characters are additive and because of several genes whereas in rabbit, several autosomal recessive genes determine fibre growth, coat composition and structure. In alpaca, the fleece type (Suri or Huacaya) is determined by a single dominant gene. This paper also reviews genetic parameters of fibre production traits in Angora goat, Angora rabbit and alpaca in which many aspects of the genetic basis of fibre production are analogous. There are many traits controlling both fibre quality and fibre quantity, and most of these traits tend to be moderately to strongly inherited so that a rapid genetic progress in any traits is possible and indeed has been achieved. However, there are differences in breeding programmes. In DC Angora rabbit, selection for one single trait, the easy measurable total fleece weight has general beneficial effects on fleece quality. However, because of antagonistic relations between qualitative and quantitative traits in SC species, achieving this goal requires a multi-trait selection index approach. Gene mapping studies have recently identified several putative quantitative trait loci and major genes affecting fibre and fleece characteristics in sheep, goat and rabbit are reviewed. The whole genome sequence of sheep and rabbit will be available in the near future and the use of high-density single nucleotide polymorphism chip will allow fine mapping and dissection of the genetic basis of many production traits including fibre production and fleece characteristics. The application of these techniques will thus contribute to improving the efficiency, profitability and sustainability of small ruminant and rabbit fibre production.

Meat fatty acid composition of llama (Lama glama) reared in the Andean highlands

This study reports the results of the chemical analysis of the Longissimus thoracis and lumborum taken from 20 llama males, reared in the Andean highlands. The animals were slaughtered at 25 months and had a mean final body weight of 63kg. Llama meat shows a low fat (3.51%) and cholesterol content (56.29mg/100g). The fatty acid composition in llama meat contains 50.34% saturated fatty acids, 42.48% monounsaturated fatty acids and 7.18% polyunsaturated fatty acids. Llama meat appears to be a healthy alternative red meat choice.

Tenderization of wether lambs meat through pre-rigor infusion of calcium ions

A study involving 36 wether lamb carcasses was conducted in order to evaluate the effects of 0.3 M CaCl(2) injection on final tenderness in muscle Longissimus thoracis et lumborum. Injection of wether lamb carcasses with CaCl(2) accelerated the post mortem tenderization process. Both control and distilled water injected animals had similar Ca(2+)-dependent proteases (μ-calpain and m-calpain) and their inhibitor (calpastatin) activities, whereas these were all significantly decreased in CaCl(2) injected animals. The effect of CaCl(2) injection on tenderness was recorded by measuring shear force values 2 and 6 days post mortem. Tenderness was significantly improved by CaCl(2) injection at both at 2 and 6 days post mortem. It was concluded that activation of μ-calpain and m-calpain was responsible for the observed post mortem proteolysis and tenderization.

Purification, characterization and analysis of sepia melanin from commercial sepia ink (Sepia Officinalis)

At the moment melanins are still enigmatic bio-pigments with structure and determination methods not clearly understood for the international scientific community. Among biopolymers, melanins are unique in many aspects. Some essential biopolymers (proteins, nucleic acids and carbohydrates) are chemically well characterized and can be determined using well established analytical methodologies. On the contrary, no available methods allow us to accurately determine melanin, mostly due to the intrinsic chemical properties of melanins. These pigments, in fact, are insoluble in a broad range of solvents and pH as well as difficult to purify as a result of the heterogeneity in their structural features. Mammalian melanins exist in two chemically distinct forms: the brown to black Eumelanin and the yellow to reddish-brown Pheomelanin. Sepia melanin obtained from Sepia Officinalis consists of more than 98% of Eumelanin and is therefore used as standard material in the analysis of melanic black. Commercial sepia melanin is purified according to an undescribed procedure. In this research, extraction and purification studies were carried out on sepia melanin using a hydrochloric acid (0.5 - 3.0 M) treatment under mechanical or ultrasonic agitation. A high degree purity sepia melanin was obtained and further characterized using Elemental Analysis (EA), UltravioletVisible (UV-VIS) and Infrared (IR) spectroscopy and Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) for metal ion analysis. Finally, quantitative studies of the chemical degradation of Eu polymers to Pyrrole-2,3,5tricarboxylic acid (PTCA) and Pyrrole-2,3-dicarboxylic acid (PDCA) by High Performance Liquid Chromatography (HPLC) were performed. The procedure we developed can be used to obtain a considerably less expensive sepia melanin which could prove important as a standard in future determinations of eumelanin and pheomelanin as well as in a vast field of scientific and industrial applications in such fields as human and veterinary medicine, pharmacology and cosmetics.

Tenderness evaluation and mineral levels of llama (Lama glama) and alpaca (Lama pacos) meat

Tenderness and mineral levels were determined in the Longissimus thoracis taken from 20 llama and 30 alpaca males reared in Peru and slaughtered at 25 months of age. Mineral contents were determined using an inductively coupled plasma emission spectrometer. Tenderness evaluation was determined two and seven days post slaughter using a Warner-Bratzler shear force device. Potassium is the mineral with the highest content, with a significant difference (P<0.05) between the two species of camelids. The other mineral contents were, in decreasing order, phosphorus, sodium, magnesium and calcium, in addition to smaller percentages of zinc and iron. Shear force values determined seven days post slaughter were significantly (P<0.01) lower in both the species compared with the results obtained two days post slaughter.

Inheritance of Suri and Huacaya type of fleece in Alpaca

Abstract The inheritance of the two types of fleece, Suri and Huacaya, observed in Alpaca (Lama pacos L.) is still not clearly defined. The objective of this work is to investigate the patter of inheritance of these two phenotypes, throughout 588 Suri x Suri and 2126 Huacaya x Huacaya offspring. The single gene and the three two-phenotype epistatic models were tested in the 19 Suri x Suri segregating families. The single dominant gene hypothesis best fitted our segregation data and could be, therefore, accepted (Gt=20.276, P=0.378). The gene frequency of the recessive Huacaya allele was 0.295, being the frequency of the dominant Suri allele 0.705. The frequency of heterozygotes, estimated in the whole population and among dominant individuals, was 0.416 and 0.455, respectively, with a “carrier” Suri to Huacaya ratio of 4.780. In three Huacaya families, 3 Suri were born, as a result of a new dominant mutation on some germinal lines of Huacaya animals. The direct mutation rate can be estimated at 0.0014.

Fleece variation in alpaca (Vicugna pacos): a two-locus model for the Suri/Huacaya phenotype

BackgroundGenetic improvement of fibre-producing animal species has often induced transition from double coated to single coated fleece, accompanied by dramatic changes in skin follicles and hair composition, likely implying variation at multiple loci. Huacaya, the more common fleece phenotype in alpaca (Vicugna pacos), is characterized by a thick dense coat growing perpendicularly from the body, whereas the alternative rare and more prized single-coated Suri phenotype is distinguished by long silky fibre that grows parallel to the body and hangs in separate, distinctive pencil locks. A single-locus genetic model has been proposed for the Suri-Huacaya phenotype, where Huacaya is recessive.ResultsTwo reciprocal experimental test-crosses (Suri × Huacaya) were carried out, involving a total of 17 unrelated males and 149 unrelated females. An additional dataset of 587 offspring of Suri × Suri crosses was analyzed. Segregation ratios, population genotype frequencies, and/or recombination fraction under different genetic models were estimated by maximum likelihood. The single locus model for the Suri/Huacaya phenotype was rejected. In addition, we present two unexpected observations: 1) a large proportion (about 3/4) of the Suri animals are segregating (with at least one Huacaya offspring), even in breeding conditions where the Huacaya trait would have been almost eliminated; 2) a model with two different values of the segregation ratio fit the data significantly better than a model with a single parameter.ConclusionsThe data support a genetic model in which two linked loci must simultaneously be homozygous for recessive alleles in order to produce the Huacaya phenotype. The estimated recombination rate between these loci was 0.099 (95% C.L. = 0.029-0.204). Our genetic analysis may be useful for other species whose breeding system produces mainly half-sib families.

Quantitative variation of melanins in alpaca (Lama pacos L.)

The amount of melanin pigments was investigated in 95 Peruvian alpaca, representative of six different fleece colours, by means of spectrophotometry assays: SpEM (Spectrophoto-metric Eumelanin), SpPM (Spectrophotometric Pheomelanin), SpASM (Spectrophotometric Alkali Soluble Melanin), and SpTM (Spectrophotometric Total Melanin). It was found that these melanin pigments were suitable for identifying three homogeneous groups, each consisting of two closely related colours. A low, an intermediate, and a high amount of SpASM, SpTM, and SpPM characterize pinkish grey and light reddish brown, brown and reddish brown, dark reddish brown and black fleeces, respectively. SpEM and SpTM provide a further split within this latter group; higher concentrations of these pigments distinguish black fleece from dark reddish brown.

Wool quality in Gentile di Puglia sheep breed as measure of genetic integrity

Abstract The Gentile di Puglia is a breed created in the 15th century by crossing Merino Spanish rams and “gentile” ewes reared in some areas of Southern Italy, mainly Apulia and Basilicata. The crisis of the wool industry, the poor quantity of milk, the inadequacy of Gentile di Puglia to be milked by machine and the passage from transhumant to permanent rearing caused a dramatic reduction of this population, which was largely crossed with other breeds and declined from about one million heads in the sixties to 5,000 at the present time. In order to save the ancient typical Gentile di Puglia breed, the aim of this work was to estimate the “genetic integrity” of the remaining Gentile di Puglia population by means of an analysis of wool quality measured through the diameter of the fibre and the homogeneity of the fleece. Our hypothesis was that the animals originated from outcrosses to other Merino derived breeds specialised for meat would show larger diameters of the fibres and a reduced homogeneity of the fleece. The research was carried out using Herd Book registered animals from 9 farms: 1 from Isernia, 2 from Campobasso and 6 from Foggia province. The statistical analysis on the diameter of the fibre was carried out on a dataset of 38,200 observations (200 records x 191 animals) divided in four classes (ultrafine, fine, croisè, ordinary). The high frequencies of ultrafine and fine fibre classes show that the quality of the wool is still good in the population. This consideration can be extended to all the farms involved in the study that could therefore be suitable in the conservation programs for this breed. The homogeneity of the fleece was also good in providing further evidence of the genetic integrity of the population. Other analysis carried out on the quality of the wool in relation to the body size confirmed that the observed Gentile di Puglia is well representative of the ancient breed.