Fat partition and distribution in the carcasses of cattle, sheep and pigs: A review

Results from recent Meat and Livestock Commission studies on fat partition and distribution are reviewed, together with those from other published work. Attention is drawn to the commercial importance of these characteristics and to the fact that little is known about their variability, in particular the extent to which fat partition is influenced by environmental factors. Information available from breed trials indicates that there is substantial genetic variation for all three species in the partitioning of fat between depots, although there is less variation in the way in which a given weight of subcutaneous fat or intermuscular fat is distributed through the carcass.     

Sex differences in the response of pigs to dietary amino-acid supplementation, with reference to growth and body composition

A study is made of the response of gilts and castrate male pigs to diets containing different levels of lysine and methionine supplements at growth stages 40–110 lb and 110–260 lb liveweight. Results are given for rate of growth, food conversion efficiency and body composition on the various diets. In the discussion of sex differences. it is suagested that different recommendations should be made for the diets of hogs, gilts and castrate males.     

The relationship between conformation and the yield and distribution of lean meat in the carcasses of British pigs, cattle and sheep: A review

Information available on the value of conformation as a predictor of carcass composition in the British livestock population is reviewed, particular reference being made to recent Meat and Livestock Commission (MLC) trials using the visual conformation assessments employed in national carcass classification schemes. In mixed breed populations, the visual conformation assessments are positively related to lean to bone ratio and muscle thickness, although the correlations are generally low. Their relationship with carcass lean content depends on the effectiveness with which variation in fatness is eliminated since fatter carcasses tend to be given higher conformation scores. Conformation provides little information about the proportion of total lean occurring in the higher priced joints. The value of conformation in a mixed breed population depends to an important extent on its ability to identify breed differences in carcass characteristics. Although of some value in this respect, it is less effective than actual breed identification. Within-breed regressions on conformation are generally in the same direction as those in the mixed breed populations, although the precision of prediction is lower. The results indicate that conformation has little practical value as a predictor of carcass composition within breed.     

Growth and development of water buffalo and Friesian crossbred cattle, with special reference to the 'entire' and 'boneless' cuts

Twelve buffaloes, nine Friesian × Baladi and nine Friesian × (Friesian × Baladi) bulls were slaughtered over the live weight ranges 161–560 kg for buffaloes and 176–448 kg for cattle. Right sides of all carcasses were jointed and dissected and the increase in the weight of ‘entire’ and ‘boneless’ cuts and cut groups (i.e. pistol; BLRC) relative to the ‘entire’ and ‘boneless’ side weights, respectively, were examined using covariance analyses.

Increasing distoproximal and dorsoventral growth gradients were found in both species. Most noticeably, the sticking was early developing in buffaloes and late developing in cattle, whereas the shortloin developed approximately at an average rate in buffaloes and at a lower rate in cattle. Statistically significant but relatively slight differences were recorded between buffaloes and cattle in the adjusted means of the ‘entire’ and ‘boneless’ hind shank, sirloin (favouring buffaloes) and brisket (favouring cattle). Buffaloes were superior to cattle in weight of pistol. At an equal side weight of 73 kg buffaloes had significantly higher weight of pistol (maximum difference = 1·4 kg). At a 115 kg side weight, the maximum difference in ‘entire’ and ‘boneless’ pistol reached 3·58 and 5·04 kg, respectively.     

Chemical composition of silages treated with some volatile fatty acids,with special reference to the changes in sugars

In eight separate experiments with laboratory silos, silages were prepared with 50 mmol caproic (nC₆), isocaproic (iC₆), valeric (nC₅) and isovaleric (iC₅) acid additions per kg Italian ryegrass or cocksfoot, and stored at 25°C for 70 days. In the nC₆ and iC⁶ treatments, fermentation was consistently inhibited, and also the contents of water-soluble carbohydrates (WSC) were considerably higher in the silages than in the grasses. This increase in WSC was partly explained by the increase in glucose but the difference between WSC and “glucose + fructose” was clearly larger in the silages than in the grasses. In the nC₅ and iC⁵ treatments, various results were obtained; in some cases, presumably due to high dry matter content, fermentation was inhibited and WSC increased, while, in one case, fermentation was improved with higher lactic acid and lower butyric acid production than in the control silage. According to the results of five experiments with bag silos, although the inhibition of fermentation was observed by the treatment with nC₆, little or no increase in WSC during ensilage was found.     

A micro-method for the estimation of oil content and fatty acid composition in seeds with special reference to cyclopropenoic acids

A micro-method is described for the routine estimation of oil content and fatty acid composition in seeds containing cyclopropenoic fatty acids (CPEFA) by determination of the total and component long-chain fatty acids. The oil was transmethylated without prior extraction using 1.17% sodium methoxide in methanol at 80°C for 45 min. The resultant fatty acid methyl esters were separated and measured by gas-liquid chromatography using a glass capillary column coated with Carbowax 20 M at 170°C. The method was shown to be applicable to a wide range of seeds including cottonseed (Gossypium hirsutum), kapok (Ceiba pentandra), paka (Urena lobata), baobab (Adansonia grandidieri and A. suarezensis). Individual seeds can be used with this method which needs only 50 to 150 mg for analysis. Results obtained with this micro-method were reproducible and good recoveries of oil and individual fatty acids were observed. The micro-method was compared for the determination of CPEFA (malvalic plus sterculic acids) to the nuclear magnetic resonance quantitation and gas-liquid chromography after derivatisation of CPEFA in more stable compounds.     

Association of MC4R gene variants with growth, fatness, carcass composition and meat and fat quality traits in heavy pigs

The melanocortin receptor 4 (MC4R) gene is implicated in the regulation of feeding behaviour and body weight in humans and mice. A missense mutation (Asp298Asn) located in a highly conserved region of this gene has clearly been associated with backfat depth, feed intake and growth rate in different porcine lines. In this work the complete coding region of the gene was sequenced in samples from six pigs of a commercial hybrid line and two polymorphisms were detected at positions 709 (C/T) and 1426 (G/A). The last one corresponds to the missense mutation, and has been genotyped in 333 animals with phenotypic records and 68 out of their 81 parents. An association study of these genotypes with several performance and quality traits was performed within the statistical animal model framework. The results confirmed the effect of the missense mutation on growth and fat deposition traits (live weight at 140d and backfat depth), and supported new effects on carcass composition (loin and shoulder weights) and traits related to fat and meat quality (profile of fatty acids; muscle Minolta L(*), a(*) and H(o) colour parameters). A transmission-disequilibrium test provided no evidence of spurious association due to population stratification.     

Quality characteristics of pork with special reference to Pietrain, Pietrain X Landrace and Landrace pigs at different weights

Summary. The meat quality of Pietrain, Pietrain x Landrace and Landrace hogs and gilts at four finishing weights was studied with respect to post-mortem glycolytic rates, colour, wateriness and toughness.
The rate of post-mortem glycolysis was found to be indicative of the subsequent meat quality in the three breeds.
The longissimus dorsi of the Pietrain carcasses exhibited those characteristics associated with paleness, wetness and toughness. The Pietrain x Landrace were intermediate between the parent breeds, but more closely resembled the Landrace.
Muscle brightness was significantly related to the pH of the muscle measured at 45 min post mortem (pH₁) and also pigment concentration.
Significant correlations were found between pH₁, and protein solubility, compressibility and tenderness values; and also between compressibility ratios and tenderness values.
The light coloured part of the semitendinosus was significantly paler in the Pietrain than in the Landrace and Pietrain x Landrace, while the dark part became darker with increasing weight.
With increasing weight, the inner layer of subcutaneous fat became less pink and increased in brightness for gilts.     

Association of the melanocortin-4 receptor (MC4R) with feed intake,growth, fatness and carcass composition in pigs raised in Poland

The melanocortin-4 receptor (MC4R) is involved in feed intake regulation. A missense mutation G/A in position 1426, which causes Asp-Asn substitution at position 298 in the MC4R gene has been associated with feed intake, fatness and growth, however published results of its effect are inconsistent. In our study we evaluated an effect of missense mutations on carcass composition, growth traits and meat quality in 1191 gilts of five breeds: Polish Large White, Polish Landrace, Pu?awska, Pietrain and Duroc. G/A 1426 MC4R mutations were genotyped using a 7500 Real-Time PCR System (Applied Biosystem). Our observations confirm that the G allele is frequent in breeds selected for lean meat content (Pietrain – 92.4%) and rare in breed with a fat carcass (Duroc – 31.5%), which has been previously reported. Our study revealed that the A allele was associated with increased daily feed intake (AA – 2.51 kg; GG – 2.31 kg in the Pu?awska breed, P < 0.05), daily gain and backfat thickness (AA – 1.67 cm, GG – 1.52 cm in PL, P < 0.01) and decreased lean meat content (total weight of ham was 0.5 kg greater in G/G than in A/A Pu?awska animals). We obtained an unexpected result for IMF: higher percentage of IMF was observed in the G/G genotype.     

The effect of cooking on the chemical composition of meat products with special reference to fat loss

The chemical composition and energy content of four product categories (sausages, restructured steaks, burgers and minced beef) were determined before and after cooking. Two cooking methods were used for each product category: sausages and burgers were fried or grilled, restructured steaks were grilled or cooked in an oven whilst mince was either boiled or lightly fried and then boiled to simulate domestic practice. Based on an initial 100 g of product and excluding the low fat products included in the survey, the average weights after cooking were 78, 73, 72 and 70 g for the sausages, restructured steaks, burgers and minced beef, respectively; average fat contents before and after cooking were 22 and 17 g for the sausages, 17 and 14 g for the restructured steaks, 25 and 16 g for the beef burgers, and 19 and 7 g for the mince; and average energy contents before and after cooking were 1215 and 1016 kJ for the sausages, 958 and 815 kJ for the restructured steaks, 1244 and 906 kJ for the burgers and 1009 and 544 kJ for the mince. For a given product type, cooking method was relatively unimportant; the cooking loss, fat loss and energy content of the cooked product being more dependent on product formulation and manufacturing process. The survey included a low fat sausage, a low fat burger, a lean mince and an extra lean mince with fat contents of 8.7, 7.5, 12.4 and 5.2%, respectively. Overall weight losses during cooking were similar to standard products, though low fat products lost proportionally more water and less fat. Frying resulted in a slight gain in fat content for the low fat sausages and burgers, based on an initial 100 g of product, though fried low fat products still had lower fat and energy contents than standard products. It is argued that national consumption figures should take into account the losses that occur during cooking to avoid overestimating fat and energy intake levels.     

A review on grain and nut deterioration and design of the dryers for safe storage with special reference to Turkish hazelnuts

Turkey produces about 80% of the total hazelnut crop of the world. About 75% of the production are exported. In Turkey hazelnuts are traditionally sun dried, and may be subject to mold growth and subsequent mycotoxin formation due to prolonged drying time under humid and rainy weather conditions. Drying hazelnuts in a reasonable time after harvest is necessary for mycotoxin-free, high-quality products. In general, nuts and cereals contaminated by the toxins pose a potential hazard not only to the people of the producer countries, but also to people of the importing countries, if they should be regarded as safe by inefficient sampling plans, therefore preventing toxin formation actually benefits very large populations. Deterioration and health hazards associated with toxin contaminated hazelnuts and other nuts and cereals have similar causes and consequences; therefore, deterioration of the nuts and cereals in storage has been reviewed by considering as many grains and nuts as possible, then special reference was made to hazelnuts. Proper preharvest practices followed by proper drying and safe storage reduces the hazards associated with contamination by the toxins. This article reviews the pre- and post-harvest practices, and the grain- and nut-drying systems required for toxin-free products. Because drying is the major unit operation involving this process, the drying systems and the mathematical models required for their design is also discussed.     

The determination of polychlorinated biphenyl residues: a review with special reference to foods

The determination of polychlorinated biphenyls presents several unique analytical problems, not least of which is the need to identify and quantify 209 possible analytes. Moreover, congener-specific analysis is essential because of structure-activity effects on toxicity and environmental stability. Although significant advances have been achieved in identification/quantification procedures with the aid of highly efficient, inert open tubular chromatography columns and coupled GC-MS, sampling and extraction procedures have not developed to the same extent. The primary focus of this review is the determination of polychlorinated biphenyls in foods. However, the problems of separation and identification overshadow the importance of the sample matrix, and relevant data from other areas of analysis are quoted.     

From bud to berry, with special reference to inflorescence and bunch morphology in Vitis vinifera L.

A brief review of the reproductive system of the grapevine is presented. Phases discussed include floral induction and initiation during early spring, inflorescence primordium growth during summer to dormancy, flower formation at budburst in the subsequent growing season, and finally flowering and berry development. Difficulties in clearly defining and describing some of these developmental stages will be outlined, especially the complex bud system, the morphology of buds at budburst, and the course of flowering. The course of floral development during dormancy and at the time of budburst requires further attention, especially the reported effect that low temperature at budburst leads to increased numbers of flowers. Also, the recent finding that 'intercarpellar' floral organs can be induced by applying auxin is of particular interest and will be described. Case studies from Burgundy vineyards with Chardonnay, Pinot Noir and Gamay ovaries and berries will be included.
A detailed analysis of what constitutes a grape bunch will be presented from observations of Chardonnay inflorescences and bunches collected at random after set and at harvest in two seasons from spur-pruned, cane-pruned and hedged vines growing on two sites varying in climate and productivity (Adelaide Hills and Southern Vales of South Australia). This analysis covered variability in numbers of branches and flowers and in per cent berry set, as well as relationships between branch numbers and flower numbers. Relationships between flower numbers and per cent set, per cent set and berry size along the inflorescence, and berry size and seed complement are outlined. Likely implications of inter-bunch and intra-bunch variability for bunch compactness, berry composition and yield components are discussed.     

Milk and cheese fatty acid composition in sheep fed Mediterranean forages with reference to conjugated linoleic acid cis-9,trans-11

Two experiments were undertaken to evaluate the effect on milk and cheese fatty acid composition of feeding different fresh forages to dairy sheep both in winter (experiment 1, growing stage of the forages, early lactating ewes) and in spring (experiment 2, reproduction stage of the forages, midlactating ewes). Four forage species were compared: annual ryegrass (RY, Lolium rigidum Gaudin), sulla (SU, Hedysarum coronarium L.), burr medic (BM, Medicago polymorpha L.), and a daisy forb (CH, Chrysanthemum coronarium L.). The forages were cut twice daily and offered ad libitum to 4 replicate groups of Sarda dairy sheep (groups RY, SU, BM, and CH). The CH forage was particularly rich in linoleic acid in both periods, whereas BM and SU forages were rich in linolenic acid in winter and spring, respectively. Milk fatty acid composition was affected by the forage in both experiments. Milk conjugated linoleic acid and vaccenic acid contents were higher in CH and BM groups (winter) and CH group (spring) than in the other groups. No differences were observed when comparing fatty acid profile between milk, 1-d-old cheeses, and 60-d-old cheeses within experimental groups, suggesting that the fatty acid recovery rates during cheese making and ripening were not affected by the feeding regimens. After stepwise discriminant analyses of the pooled data, the milks and cheeses sourced in the different feeding regimens differed among them. Based on these results, we conclude that it is possible to manipulate the fatty acid profile of sheep dairy produce to maximize the content of beneficial fatty acids by the use of appropriate fresh forage-based regimens.     

Copper, chromium, manganese, nickel and zinc in kidneys of cattle, pigs and sheep and in chicken livers in The Netherlands

Kidneys of cattle, pigs and sheep and chicken livers have been analyzed for contents of copper, chromium, manganese, nickel and zinc. Mean levels found for copper, manganese and zinc correspond well with results of earlier studies as well as with literature data. Contents measured for chromium and nickel are very low: for nickel in porcine kidneys and sheep kidneys median values of 0.045 and 0.022 mg/kg were found. Average contents for nickel in the other tissues and for chromium in all tissues investigated are below 0.01 mg/kg fresh mass. These results for chromium and nickel correspond well with recent results from Sweden, but are lower than most published values.     

Copper, chromium, manganese, nickel and zinc in kidneys of cattle, pigs and sheep and in chicken livers in The Netherlands

Summary Kidneys of cattle, pigs and sheep and chicken livers have been analyzed for contents of copper, chromium, manganese, nickel and zinc. Mean levels found for copper, manganese and zinc correspond well with results of earlier studies as well as with literature data. Contents measured for chromium and nickel are very low: for nickel in porcine kidneys and sheep kidneys median values of 0.045 and 0.022 mg/kg were found. Average contents for nickel in the other tissues and for chromium in all tissues investigated are below 0.01 mg/kg fresh mass. These results for chromium and nickel correspond well with recent results from Sweden, but are lower than most published values.

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Kupfer, Chrom, Mangan, Nickel und Zink in Nieren von Rindern, Schweinen und Schafen und in Hühnerlebern in den Niederlanden

Zusammenfassung Nieren von Rindern, Schweinen und Schafen und Hühnerlebern wurden auf den Gehalt an Kupfer, Chrom, Mangan, Nickel und Zink untersucht. Die Durchschnittswerte für Kupfer, Mangan und Zink stimmen gut mit Ergebnissen früherer Untersuchungen und mit Literaturwerten überein. Die gemessenen Werte für Chrom und Nickel sind sehr niedrig; für Nickel in Schweine- und Schafnieren wurden mediane Gehalte von 0,045 und 0,022 mg/kg gefunden. Durchschnittswerte für Nickel in den übrigen Geweben und für Chrom in allen untersuchten Geweben liegen unterhalb 0,01 mg/kg Frischsubstanz. Diese Werte für Chrom und Nickel stimmen gut mit neueren Daten aus Schweden überein, aber sie sind niedriger als die meisten Literaturdaten.

     

Reactions of nitrate and nitrite in foods with special reference to the determination of N-nitroso compounds.

The stabilities of nitrate and nitrite in food systems and their reactions in such matrices are reviewed. Particular reference is made to reactions with haem proteins, smoke components and amines in foods, and the chemistry of formation of N-nitroso compounds from food components is discussed. Finally, the methodology available for determination of both volatile and non-volatile N-nitroso compounds is addressed.     

Nitrogenous constituents in the urine of cattle,sheep and goats

Ten samples of urine from dairy cows, five from sheep and four from goats were analysed to assess the distribution of urinary nitrogen (N) among various chemical constituents in order to gain a better understanding of the reactions undergone by urinary N in soil. Total N in the cow urine ranged from 6.8 to 21.6 g N litre^?1, of which an average of 69% was present as urea, 7.3% as allantoin, 5.8% as hippuric acid, 3.7% as creatinine, 2.5% as creatine, 1.3% as uric acid, 0.5% as xanthine plus hypoxanthine, 1.3% as free amino acid N and 2.8% as ammonia. In the sheep urine, total N ranged from 3.0 to 13.7 g litre^?1 of which an average of 83 % was present as urea; creatine accounted for 5.3% of the N; hippuric acid and allantoin both accounted for 4.3%, while each of the other constituents amounted to less than 1% of the total N. The goat urine was similar to the sheep urine but with a lower ratio of creatine to creatinine and a somewhat higher proportion (2.0 %) of the total N as amino acid.     

Invited review: Current production trends,farm structures,and economics of the dairy sheep and goat sectors

Dairy small ruminants account for approximately 21% of all sheep and goats in the world, produce around 3.5% of the world's milk, and are mainly located in subtropical-temperate areas of Asia, Europe, and Africa. Dairy sheep are concentrated around the Mediterranean and Black Sea regions, where their dairy products are typical ingredients of the human diet. Dairy goats are concentrated in low-income, food-deficit countries of the Indian subcontinent, where their products are a key food source, but are also present in high-income, technologically developed countries. This review evaluates the status of the dairy sheep and goat sectors in the world, with special focus on the commercially and technically developed industries in France, Greece, Italy, and Spain (FGIS). Dairy small ruminants account for a minor part of the total agricultural output in France, Italy, and Spain (0.9 to 1.8%) and a larger part in Greece (8.8%). In FGIS, the dairy sheep industry is based on local breeds and crossbreeds raised under semi-intensive and intensive systems and is concentrated in a few regions in these countries. Average flock size varies from small to medium (140 to 333 ewes/farm), and milk yield from low to medium (85 to 216 L/ewe), showing substantial room for improvement. Most sheep milk is sold to industries and processed into traditional cheese types, many of which are Protected Denomination of Origin (PDO) cheeses for gourmet and export markets (e.g., Pecorino, Manchego, and Roquefort). By comparing break-even milk price among FGIS countries, we observed the following: (1) most Greek and French dairy sheep farms were unprofitable, with the exception of the intensive Chios farms of Greece; (2) milk price was aligned with cost of production in Italy; and (3) profitable farms coexisted with unprofitable farms in Spain. In FGIS, dairy goat production is based on local breeds raised under more extensive systems than sheep. Compared with sheep, average dairy goat herds are smaller (36 to 190 does/farm) but milk yield is greater (153 to 589 L/doe), showing room for improvement. Goat milk is mainly processed on-farm into dairy products for national markets, but some PDO goat milk cheeses (e.g., Murcia al Vino) are exported. Processed goat milk is sold for local human consumption or dehydrated for export. Mixed sheep-goat (e.g., Feta) and cow-sheep-goat milk cheeses are common in many countries. Strategies to improve the dairy sheep and goat sectors in these 4 countries are proposed and discussed.