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7 Pág. Departamento de Tecnología de Alimentos​​, In recent years, concerns about fish welfare have increased in aquaculture, most pointedly regarding the slaughter process. Immersion in ice water (live chilling) is still commonly used as a stunning method in salmonids, but can have negative effects on the stress response and flesh quality. A valid alternative is electronarcosis, but the specific details of the intensity and frequency of the current applied depend on the species and size, and little is known about how that may affect fish welfare or product quality. In this study, adult rainbow trout (294 ± 8.44 g average weight) were subjected to three different stunning methods before slaughter: immersion in ice water and electronarcosis at two different current intensities (200 or 400 mA). Electronarcosis caused fish to lose consciousness faster than those live chilled. Plasma concentration of cortisol was lower in fish stunned with 400 mA (400 mA: 5.2 ± 0.67 vs. Ice: 9.1 ± 0.90; 200 mA: 9.3 ± 1.20 ng/ml). Creatine-phosphokinase enzyme levels were higher in ice stunned fish compared to electronarcosis (Ice: 168 ± 2.32 vs. 200 mA: 114 ± 0.89; 400 mA: 104 ± 0.62 U/l). Regarding flesh quality, initial muscle pH was lower in fish stunned by ice immersion than by electronarcosis (Ice: 6.49 ± 0.034 vs. 200 mA: 6.76 ± 0.050; 400 mA: 6.61 ± 0.04), presenting also an earlier onset of rigor mortis. Fish stunned with 400 mA electronarcosis also presented higher levels of muscle glycogen than those stunned with ice water (0.181 ± 0.029 vs. 0.101 ± 0.013 mg/g). In conclusion, electronarcosis is a stunning method that can produce an immediate loss of consciousness in rainbow trout, reducing stress response before slaughter and improving flesh quality (with higher benefits using a current intensity of 400 mA), in contrast to immersion in ice water., This project was financed by the Spanish Ministry of Economy and Competitiveness (MINECO), project AGL2013-45557-P.

In the present study, we investigated the effect of dietary supplementation with microalgae rich in DHA (C226n3) on the fatty acid composition of different fat deposits and muscles in light lambs. Two dietary treatments were studied control (CT) and microalgae (MT), containing 2% of DHA- rich microalgae. Dietary incorporation of microalgae modified fatty acid composition in all anatomical locations studied (intramuscular, subcutaneous and kidney knob and channel fat); however, intramuscular fat was the most affected deposit. Intramuscular fat of MT lambs had higher levels of DHA (3.35%) and total n3 fatty acids (5.71%), than that of CT lambs (0.25 and 1.23% respectively). Dietary supplementation with microalgae produced a greater proportion of DHA and total n3 in M. Infraspinatus (IM) (5.12 and 8.13% respectively) compared with M. Longissimus (LM) (3.35 and 5.71% respectively) and M. Psoas major (PM) (3.62 and 6.24% respectively). Dietary supplementation with microalgae enhanced the nutritional quality of lamb muscle with more favourable PUFA/SFA and n6/n3 ratios in conjunction with increased levels of DHA and total n3 fatty acids. © 2016 Elsevier Inc.

Fish normally undergo periods of food deprivation that are longer than non-hibernating mammals. In aquacultured rainbow trout (Oncorhynchus mykiss), it is unclear how fasting may affect their physiological adaptative response, especially when they are normally fed daily. In addition, that response may vary with temperature, making it necessary to express fasting duration in terms of degree days. In the current study, trout were fasted for 5, 10, and 20 days (55, 107, and 200 degree days (°C d), respectively). To assess the physiological response of fish to fasting, different biometric, blood, plasma, and metabolic parameters were measured, as well as liver fatty acid composition. The fish weight, condition factor, and the hepato-somatic index of 5-day fasted trout were not significantly different from those of control fish. Gastric pH increased as fasting progressed while plasma concentrations of glucose, triglycerides, and total proteins decreased significantly after 10 days of fasting, while the percentage of non-esterified fatty acids increased. There were no significant differences in plasma ions (sodium, potassium, and calcium), except for chloride ion which decreased after 5 days of fasting. Liver glycogen decreased after 5 days of fasting while glycogen concentration in muscle did not decrease until 20 days of fasting. Liver color presented a higher chroma after 5 days of fasting, suggesting a mobilization of reserves. Finally, acetylcholinesterase activity in the brain was not affected by food deprivation but increased after 10 days of fasting in liver and muscle, suggesting the mobilization of body reserves, but without severely affecting basal metabolism.

Pre-slaughter fasting is a common practice in aquaculture to ensure emptying of the digestive tract, but little is known about how long fish should be fasted, in terms of degree days (°C days), to clear the gut without affecting their welfare or flesh quality. In this study, 180 rainbow trout (Oncorhynchus mykiss) were fasted for 3, 4, 5, 6, 7 and 9 days (17.2, 22.3, 28.6, 35.3, 41.8 and 55.3 °C days, respectively) and different morphometric, hematological and flesh quality parameters were measured. The slaughter weight, relative growth and hepato-somatic index did not decrease until after 7 days of fasting (41.8 °C days) and stomach content was similar and near zero after 4 days of fasting (22.3 °C days). Conversely, fasting time increased carcass yield. Plasma concentrations of cortisol, glucose and creatine phosphokinase enzyme were lower with increasing days of fasting. However, trout slaughtered after 5 days of fasting (28.6 °C days) had a higher flesh pH at 0 h post-mortem than 3 and 4 days fasted trout and, consequently, earlier establishment of rigor mortis. Furthermore, liver color could be useful as a stress indicator since its hue decreases after 5 days of fasting (28.6 °C days). In conclusion, a pre-slaughter fasting period from 17.2 °C days to 22.3 °C days makes possible to obtain a complete emptying of the digestive system in rainbow trout and simultaneously it can minimize the stress response with consequent better flesh quality. © 2017 Elsevier B.V.

Fasting is commonly used in aquaculture to empty the gut before slaughter, but little is known about how feeding frequency before fasting affects the stress response of trout. To find out more, 240 rainbow trout (Oncorhynchus mykiss) were separated into three groups with different feeding schedules during the final month of fattening, from 26 September to 28 October 2013 (daily, every two days or every four days) and two durations of pre-slaughter fasting (two days of fasting; 24.3 degree days, to nine days of fasting; 102 degree days). After slaughter, a number of stress-related parameters were measured, such as liver glycogen, skin/gill colour and haematological parameters (cortisol, glucose, lactate, triglycerides, lactate dehydrogenase and creatine phosphokinase). Trout given food every two days on the farm had lower levels of cortisol and higher levels of triglycerides and liver glycogen than the other treatments after two days of fasting; indicating that habituating trout to feed once every two days in the final month of fattening lowered their stress response to two days of fasting before slaughter. © 2016 Universities Federation for Animal Welfare.

To evaluate the effect of stocking density and transport time on physiological responses and meat quality, 72 male suckling lambs were transported by road to the slaughterhouse at three different stocking densities (0.12, 0.20 or 0.25 m2/lamb) and two transport times (5 h or 30 min). Blood samples were collected pre-transport at the farm and after unloading in the slaughterhouse to measure levels of cortisol, creatine kinase (CK) and lactate dehydrogenase (LDH). After slaughter, the weights of the hot carcass, liver and spleen were recorded and pH in Musculus longisimus thoracis et lumborum (L), Musculus semitendinosus (ST) and Musculus psoas major (PM) were determined. Colour, water-holding capacity (WHC), texture and thiobarbituric acid-reactive substances (TBARS) values were measured in samples of L, at 24 h post mortem and after 5 days of ageing. Cortisol and LDH were higher in suckling lambs transported for 30 min than those transported for 5 h. Stocking density did not affect blood parameters studied. Transport time significantly affected some carcass quality parameters, but stocking density had no significant effect. Suckling lambs transported for 5 h had lower liver weights and dressing percentages than those transported for 30 min. Transport time influenced pH values, with lambs subjected to the longer journey showing the lowest pH at 0 h in the three muscles studied, with the lowest final pH in L and PM. The PM lambs transported at high density (0.12 m2/lamb) had the lowest pH at 24 h. Transport time and stocking density did not greatly affect colour and texture parameters. The meat from lambs transported for 30 min had higher WHC than meat from lambs transported for 5 h. Animals transported for longer journeys showed higher lipid oxidation after 5 days of ageing than those transported for 30 min. Loading and initial transport caused significant stress response in suckling lambs, that stress response was reduced over the time course of the journey. © 2009 The Animal Consortium.

The effect of dietary vitamin E supplementation on lamb during vacuum-packed storage was studied. Thirty-six weaned male Manchego breed lambs were offered four dietary treatments (20, 270, 520 and 1020 mg vitamin E kg−1 feed). Lambs were fed the vitamin E-supplemented diet from 13 until 26 kg live weight. Pieces of M. longissimus dorsi were stored under vacuum at 2 ± 1 °C in the dark and meat quality was assessed after 5, 14 and 28 days of storage. Dietary supplementation significantly increased the α-tocopherol concentration in the muscle (P < 0.001). Initially, lipid oxidation, meat colour and bacterial load were similar in all groups. In meat of non-supplemented lambs the thiobarbituric acid reactive substance value increased throughout storage, whereas in meat of supplemented lambs it did not increase. Meat pigments and discolouration proportion were significantly affected by storage time (P < 0.001). The bacterial load was low initially, but after 28 days of storage it was close to 7 log10 colony-forming units (cfu) cm−2 and Enterobacteriaceae surpassed the limit of acceptability of 2.5 log10 cfu cm−2, making the lamb unsuitable for human consumption. Meat of supplemented lambs displayed less lipid oxidation than that of their non-supplemented counterparts, while meat colour and bacterial load were not affected by supplementation. Copyright © 2007 Society of Chemical Industry

Pre-slaughter fasting, usually measured in days, helps to empty the digestive system but less is known about its effect on fish welfare or flesh quality. We evaluated the combined effects of fasting (measured in degree-days, °C. d), preceded by intermittent feeding in the last month of production, on the flesh quality rainbow trout (Oncorhynchus mykiss). Trout (n. = 240) were fed the same total amount of food either daily (D), once every two days (2D) or once every four days (4D) for one month, and then fasted for 24.3. °C. d (2. days) or 102. °C. d (9. days). There was a significant interaction between the effects of intermittent feeding and pre-slaughter fasting for most of the parameters measured. Slaughter weight was higher in 2D and 4D trout after two days of fasting, probably since they had more feed in their stomachs. Muscle glycogen and the hepato-somatic index were also higher in 2D trout after 2. days of fasting, suggesting higher energy reserves. There was no interaction between the effects of intermittent feeding and fasting on final muscle pH which was higher after 9. days of fasting, indicating poorer flesh quality. Overall, the results suggest that trout that received a skip-a-day feeding schedule one month before slaughter, adapt better to a two day fast than trout fed daily or once every four days. © 2015 Elsevier B.V..

Body composition was evaluated in 49 males and females suckling lambs of the Manchego breed slaughtered at 10, 12 and 14 kg. Lambs slaughtered at 14 kg had a greater proportion of loin-rib than those slaughtered at 10 kg. Male lambs exhibited a larger forequarter (neck, anterior rib and shoulder) while females had larger loin-rib. Slaughter weight affected the distribution of fat, and proportion of fat in loin-rib increased with slaughter weight. Males at 10 kg had more muscle in shoulder and neck than females. Significant slaughter weight × gender interaction was observed for total fat proportion in leg, loin-rib, anterior rib and flank. These proportions increased with slaughter weight in male lambs while in female lambs remained constant. The carcass composition of the suckling lamb showed significant correlations with muscle, fat and bone of the individual cuts, mainly leg and loin-rib. As expected, the proportion of muscle in the carcass was highly correlated with muscle in loin-rib, leg and shoulder. In conclusion, carcass composition may be predicted from the composition of leg and loin-rib. © 2005 Elsevier B.V. All rights reserved.

Forty-nine Manchega breed suckling lambs were used. Carcass weight was less than 13 kg, and lambs were slaughtered at 10, 12 and 14 kg liveweight. Carcasses were classified by three assessors on colour photographs, by several classification methods the European Union scale for light lambs carcasses (EU), Colomer-Rocher methods for fatness (CF) and conformation (CC), and the new scale for suckling lambs (SL) developed by our research group. Carcasses were also assessed using these scales divided into 0.25 point-intervals (EU-25, CF-25, CC-25 and SL-25). A correlation analysis was made between assessors score and tissue composition in the carcass and in three joints (leg, best end of neck and loin, and shoulder). For all the methods studied 0.25 point scales were best correlated to tissue composition than 1.0 points-interval scales. When 1.0 point-interval scales were used the SL scale was best correlated to tissue composition. When 0.25 point-scales were used, the EU scale gave the best correlations. Conformation scale (CC) was useful to predict carcass composition, specially kidney knob and channel fat content. © 2003 Elsevier Ltd. All rights reserved.

This study involved 53 Talaverana-breed lambs fattened until reaching a slaughter weight of 28 kg. After weaning at 45 days of age, the lambs were divided into four study groups. The lambs of two of the groups were fattened at pasture, while those of the other two groups were kept on a drylot. One group at pasture and another on the drylot received a commercial fattening concentrate. The other two groups received whole barley with a protein supplement. Drylot lambs displayed better carcass dressing, greater carcass fatness, higher carcass conformation values and a superior refriger- ated carcass weight than lambs fattened at pasture. Lambs fattened with concentrate displayed better carcass dressing, higher carcass compactness and less digestive tract development (due to a lower proportion of stomach and digestive content) than those fed barley. The fat colour of lambs fattened at pasture was lighter (greater L*) than that of the drylot lambs, and the lambs fed concentrate exhibited a higher redness index (a*) than those fed barley. The longissimus dorsi (LD) muscle was used to evaluate meat quality. The lambs fattened at pasture displayed a lower lightness value, lower cooking losses and greater pleasantness scores in the sensorial analysis than drylot lambs. The lambs fattened at pasture presented lower values of fatty acids with an odd number of carbon atoms and monounsaturated fatty acids and higher linolenic acid (C18:3) levels than drylot lambs in both the in- tramuscular fat of the LD muscle and in subcutaneous fat. The lambs fed barley exhibited a higher proportion of fatty acids with an odd number of carbon atoms and lower C18:3 values than the lambs given the concentrate.

Forty-five Talaverana breed sucking lambs of both sexes were slaughtered at 10 and 12 kg live weight in order to study the effect of gender and slaughter weight on carcass, meat and fat traits. Carcass dressing proportions and fatness (by various measures) were higher in females and heavier lambs, which also showed better conformation. Lightness (L*) of the carcass fat was higher in males and heavier lambs. Females and heavier lambs also displayed a greater proportion of fat on dissection, primarily due to a higher percentage of subcutaneous fat tissue. Water-holding capacity was greater in males and in lower-weight lambs. Males presented higher total collagen and lower soluble collagen values than females. In general, a high percentage of short-chain (C12:0 and C14:0) fatty acids, as well as of palmitic acid (C16:0), was observed in the intramuscular fat of the longissimus dorsi muscle, corresponding with an exclusively milk diet.

In many studies in which the relationship between blood pressure and blood lead level has been examined, investigators have found significant--but small--associations. There was only one previous report of a significant association of blood lead with blood pressure in pregnant women. We measured blood lead level and sitting blood pressure of 1,627 women in their third trimester of pregnancy. We eliminated subjects with known causes of hypertension. Most women (98.4%) were normotensive. We controlled for body mass index, age, and stress--among other factors--and constructed multiple-regression models of lead association with diastolic and systolic blood pressures. Immigrants (73% of total) had significantly higher blood lead levels and different blood pressures than nonimmigrants, suggesting that analysis be stratified by "immigrant, nonimmigrant" status. Positive relationships between blood lead level and blood pressure were found only for immigrants (por = .001). From the 5th to 95th blood-lead percentiles (0.9-6.2 microg/dl) in immigrants, systolic blood pressure increased 2.8 mm Hg, and diastolic blood pressure increased 2.4 mm Hg. Higher prior lead exposure of immigrants (97.7% from Latin countries) than nonimmigrants might explain the differential effect of these low levels of blood lead on blood pressure in nonimmigrants. Perhaps some immigrants are at higher risk than nonimmigrants for lead-associated elevated blood pressure during pregnancy, despite blood lead levels within the currently considered acceptable range.

Los resultados de las últimas excavaciones en Tel Hatsor permiten asignar definitivamente al periodo salomónico la puerta de seis cámaras y la muralla acasamatada, así como un edificio civil y una calle de ronda empredada. Por otra parte, un gran palacio cananeo del Bronce Último, con influencias arquitectónicas sirias, está siendo descubierto en la acrópolis de Hatsor. Este descubrimiento es de máxima importancia, ya que es prácticamente el único edificio claramente palacial de este período descubierto hasta ahora en la zona.

To evaluate the effect of journey duration and space allowance on behavioural and physiological responses, 72 male suckling lambs were transported by road to the slaughterhouse using two transport times - short (around 40min) or long (around 4.75h) - and three different space allowances 0.12 (LSA), 0.20 (MSA) and 0.25 (HSA)m 2/lamb. Lamb behaviour was recorded continuously during the entire journey. A heart rate monitor was used to determine the heart rate during transport, and blood samples were collected two days prior to transport and after unloading at the slaughterhouse to measure the concentrations of various stress-related variables. Immediately after slaughter, and 24h thereafter, samples of Musculus longissimus were collected to determine muscle glycogen concentrations and inosine monophosphate (IMP)/adenosine triphosphate (ATP) ratio. The highest number of lambs was standing for both short and long journeys, whereas the lowest number was walking. However, the number of lambs performing each behaviour was found to differ with journey time, with significant differences in the behaviour shown by lambs transported at different space allowances. The heart rate increased during loading with respect to the values recorded during the resting period on the farm for both journey times in lambs transported at LSA and MSA, and remained high throughout the transportation period for these two space allowances. Cortisol, LDH, glucose, albumin and osmolality were higher in suckling lambs transported for a short time than for those transported for longer periods. Space allowance did not affect any of the blood parameters studied except for albumin and plasma total protein concentration, both of which were lower for MSA group (0.20m 2/lamb). In addition, liver glycogen concentration was higher for lambs after the long journey. Our results suggest that short journey produce higher stress response in suckling lambs than long journey, due to mainly to loading and initial transport which were similar handling and transport to first part of long journey. Nevertheless, this initial stress response decreases during the journey, although the heart rate remains high throughout mainly as space allowance decrease. © 2012 Elsevier B.V.

Fatty acid content and sensory characteristics of meat from light lambs fed three diets supplemented with different sources of n −3 fatty acids (fish oil, extruded linseed and extruded linseed plus microalgae) and a control diet during refrigerated storage have been studied. The meat from lambs fed linseed diets had the highest levels of C18:3 n −3, while animals fed fish oil had the highest long-chain n −3 polyunsaturated fatty acids (PUFA). Thus, 100 g of meat from lamb fed the fish oil diet provided 183 mg of long-chain n −3 PUFA, representing 40% of the daily recommended intake. The levels of n −3, n −6 and long-chain n −3 PUFA decreased during a 7-day storage period. The meat from lambs fed the fish oil diet had high scores of fish odour and flavour and rancid odour and flavour and the lowest overall liking. Rancid odour and flavour increased after storage, mainly in supplemented groups.

The aim of this study was to evaluate the fatty acid composition of intramuscular fat and the vitamin E content of beef from different production systems. Four cattle production systems were used cattle reared under intensive conditions and fed concentrate (INT1) from Spain, cattle raised at pasture and supplemented with concentrate (SUP1) from the United Kingdom, cattle raised at pasture and on corn silage (SUP2) from Germany and cattle reared under extensive conditions slaughtered at two and three years old (EXT2 and EXT3) from Uruguay. The highest proportion and content (mg per 100 g of muscle) of linoleic acid (C182n-6) and arachidonic acid (C204n-6) and the lowest saturated fatty acids (SFA) was found in INT1 beef. In contrast, beef reared under extensive conditions showed the highest proportion and content of linolenic acid (C183n-3), docosapentaenoic acid (DPA, C225n-3) and eicosapentaenoic acid (EPA, C205n-3), and SUP1 and SUP2 beef showed the highest level of palmitic acid (C160) and SFA. Beef from intensive system (INT1) had the lowest P/S (PUFA/SFA) ratio, whereas beef from extensive system (EXT2 and EXT3) had the lowest n-6/n-3 ratio. The results of the PCA (principal components analysis) of fatty acid composition showed that beef from intensive system (INT1) was clearly differentiated from the other meats and was located with the C18:2n-6 and C20:4n-6 and the n-6/n-3 ratio. EXT2 and EXT3 beef were located with C18:3n-3 and long chain fatty acids. Beef from extensive systems had the highest concentration of vitamin E (3.91 mg α-tocopherol/kg muscle). © 2009.

The fatty acid composition of commercial lambs from different production systems of Spain, Germany, United Kingdom and of two types of Uruguayan lambs (heavy and light) was studied. Concentrate fed lambs, as Spanish lambs, displayed the highest proportions of linoleic acid (C182), while Uruguayan lambs, reared under extensive grazing conditions, showed the highest proportions of linolenic acid (C183), due to the great concentration of this fatty acid in grass. German and British lambs, which were fed grass and concentrate, displayed intermediate proportions of linolenic acid (C183). Heavy Uruguayan lambs had higher intramuscular fat content (5.92%) than German (4.25%) and British (4.32%) lambs, and this content was twofold higher than light lambs (Spanish (2.41%) and light Uruguayan (3.05%)). Heavy Uruguayan, German and British lambs had a low polyunsaturated/saturated (P/S) ratio due to their high saturated fatty acid (SFA) content and proportion. Principal component analysis was performed to study the relationship between fatty acids. Spanish lambs were clearly separated from the other types and were situated close to the proportions of short chain and n - 6 fatty acids and n - 6/n - 3 ratio in the data plot for fatty acid proportions. Light Uruguayan lambs were located close to long chain fatty acids, and heavy Uruguayan and British lambs were placed near the antithrombotic potential (ATT), stearic acid (C180), SFA and conjugated linoleic acid (CLA) proportions. German lambs were located between Spanish lambs and the other types. © 2005 Elsevier Ltd. All rights reserved.

Eighty-seven Manchego sucking lambs raised exclusively on maternal milk were slaughtered. The carcasses were weighed immediately after dressing and classified according to hot carcass weight (HCW): low HCW (P< 0.001) as carcasses became heavier. With regard to the joints, leg (P< 0.001) and shoulder (P< 0.05) proportions decreased as carcass weight increased, whereas loin-rib (P< 0.001) and flank (P< 0.001) proportions increased. The proportion of fat in the leg clearly increased in the heavier carcasses (P< 0.001), while that of bone decreased (P< 0.001) and that of muscle was not affected. pH at 24 h in them. longissimusdorsi andm. semitendinosusdecreased as carcass weight increased. The only meat colour parameter affected by carcass weight was the yellowness index; lighter-weight carcasses displayed lower index (P< 0.05). Cooking losses were unaffected as carcass weight increased, whereas with regard to tenderness, the shear force value tended to be higher in the low carcass weight group. No differences between carcass weight groups were found in the sensory analysis. Fatty acid composition did not show any significant effect due to carcass weight except in stearic fatty acid (C18:0); C18:0 proportion decreased (P< 0.01) as carcasses became heavier. Carcass weight affected carcass quality (all carcass quality parameters studied were higher in the heavier carcasses), whereas meat quality varied little as a result the small variation between carcass weights in sucking lambs.

Correlations and regression between fatness and carcass conformation measurements and carcass tissue composition has been studied for both sexes in suckling lambs, with slaughter weights between 9 and 15 kg. Objective fat measurements showed higher correlations than subjective fat measurements, mainly with carcass fat. Conformation measurements presented greater correlations with tissues weight than with tissues proportion (r ≤ 0.50). CCW was highly correlated with total muscle in the carcass (R2 = 0.961). Two fatness measurements (KKCF proportion and dorsal fat thickness) were included for the prediction of the muscle proportion. Furthermore, the model included other measurements, such as fore cannon bone weight and internal carcass length although they displayed very low correlation coefficients. This equation explained 64.1% of the variation of carcass muscle proportion (r.s.d. = 1.532). CCW was included in the prediction equations of tissue weights, although in the fat tissue equation it appeared in the form of the carcass compactness index (CCW/L). CCW was a good predictor of the weight of carcass tissues in suckling lambs, especially for muscle. Prediction equations for tissue composition in grams were more accurate (R2 ≥ 0.91) than those for tissue proportion. When gender was included in all models it did not improve either accuracy or precision of the prediction. © 2003 Elsevier Ltd. All rights reserved.

Forty-nine Manchego-breed lambs raised exclusively on their dams' milk until slaughter were used in this study. The effects of gender and slaughter weight (10, 12 and 14 kg) on carcass fatness, meat quality and the fatty acid composition of their fat were studied. Fatness, and in particular dorsal-fat thickness (P ≤0.01), increased with live weight. The effect of gender was even greater (P ≤0.001), as female lambs presented the highest fatness values for all parameters studied. The smallest drop in m. longissimus pH values was seen in the lowest-weight (10 kg) Iambs. These same lambs displayed the highest L* value and thus the lightest colour. Fatty acid composition, which was not influenced by live weight, was affected by gender. The subcutaneous fat of female lambs contained more linolenic acid (C183) (P ≤0.01) and a greater proportion of polyunsaturated fatty acids than that of male lambs (P ≤0.001). Likewise, the intramuscular fat of female lambs displayed a greater proportion of monounsaturated fatty acids (P ≤ 0.001) than that of male lambs. © 2003 Elsevier Ltd. All rights reserved.

Forty-eight sucking lambs (26 males and 22 females) of the Manchega breed were used in this work. Lambs were slaughtered at 10, 12 and 14 kg live weight. Carcass degree of fatness was assessed by three assessors from colour photographs of the carcasses, using the European Union scale for light lambs (EU), the Colomer-Rocher method (CF) and another new scale developed by our group (sucking lambs scale, SL). Carcass conformation was assessed according to the Colomer-Rocher method (CC). Fatness and conformation scales were divided to give 0·25 points in each interval. Left half-carcasses were jointed and dissected into lean, fat and bone. Muscle proportion, bone proportion and whole fat proportion (obtained by addition of every fat depot: subcutaneous fat, intermuscular fat, inguinal fat and kidney knob and channel fat) were determined. Male and female carcasses showed a very different tissue composition: both groups had statistically significant differences (P < 0·05) in 20 out of 25 tissue composition variates. Males showed a higher number of variates that were well correlated with assessors’ scoring than females. Correlation coefficients between most of the tissue composition variates and assessors’ scores were higher in males. Furthermore, the number of variates that were significantly correlated with assessors’ scores was lower in females. Therefore, subjective methods for the estimation of carcass degree of fatness and of carcass conformation are poor predictors of tissue composition in female sucking lamb carcasses.

Two production systems, pasture and sheepfold based on lambs fed concentrates ad libitum was evaluated for carcass and meat quality of lambs slaughtered at body weights of 24 and 28 kg. There was no effect of production system on growth rate of lambs. In sheepfold, commercial carcass dressing values of slaughter lambs were heavier than in those raised at pasture with more dorsal fat thickness (1.6 mm vs. 1.1 mm), kidney knob and channel fat (1.6% vs. 1.2%) and a greater percentage of leg fat (8.5% vs. 6.6%). Lambs at heavier weights had more fat. Meat quality, pH, water-holding capacity and collagen content parameters were not affected by the production systems. The color of the longissimus dorsi muscle was somewhat darker in lambs fattened at pasture, but no color differences were seen in the rectus abdominis muscle. In both subcutaneous and intramuscular fat of the two cuts studied (leg and loin), sheepfold lambs presented a lower percentage of stearic acid (C180) and a higher proportion of palmitic (C160) and linoleic (C182) acids, and thus a lower percentage of SFA and a higher one of TUFA, while a better (n - 6)/(n - 3) ratio was observed in lambs raised at pasture. Lambs at heavier weights displayed a lower percentage of PUFA and PUFA/SFA ratio in the intramuscular fat of the longissimus dorsi muscle and higher levels of oleic (C181) and palmitic (C160) fatty acids and a lower one of myristic acid (C140) in both depots. © 2002 Elsevier Science B.V. All rights reserved.

Three weaning treatments (weaning at 45 days of age, at 65 days of age, unweaned) and two slaughter weights (24 and 28 kg) were compared in lambs raised at pasture, and their effect on carcass and meat traits were studied. Unweaned lambs displayed a greater growth rate, lower concentrate consumption, greater dorsal fat thickness, more kidney knob and channel fat and greater total fat levels, measured through dissection of the hind limb. Total collagen concentration was lower in unweaned lambs and the intramuscular fat of these same animals exhibited a greater proportion of saturated fatty acids and a lower n-6/n-3 fatty acid ratio. Slaughter weight influenced scored carcass fatness, which was greater in heavier lambs, meat colour, which displayed greater lightness in lower-weight lambs, and water-holding capacity, which was lower in lambs with the lower slaughter weight. The heavier lambs displayed lower soluble collagen values, and the intramuscular fat of thelongissimus dorsimuscle of these same lambs contained higher levels of monounsaturated and lower levels of polyunsaturated fatty acids.

Forty-nine male Talaverana-breed suckling lambs slaughtered at 14 kg live weight were used to study the fatty acid composition of adipose depots of lambs raised under different management systems (pasture or drylot) and diets (maternal milk with or without a concentrate supplement). Drylot lambs displayed a higher fatness score, in addition to greater dorsal fat thickness; these parameters corresponded with a greater percentage of total fat at dissection. Addition of concentrate to the diet did not modify carcass fatness. Drylot lambs presented higher proportions of oleic acid (C181) and monounsaturated fatty acids (MUFA) and lower linolenic acid (C183) values in subcutaneous and intramuscular fat (muscle longissimus thoracis). The subcutaneous fat of these lambs thus displayed a higher n-6/n-3 PUFA ratio (C182/C183) than that of pasture-raised ones. Concentrate in the diet of both pasture and drylot lambs resulted in higher linoleic fatty acid (C182) and PUFA values and a greater PUFA/SFA ratio in intramuscular fat than the corresponding values of lambs which consumed maternal milk alone. Loin displayed a higher percentage of subcutaneous and intramuscular chemical fat than leg. Compared with intramuscular leg fat (muscle quadriceps femoris), intramuscular loin fat (muscle longissimus thoracis) had lower oleic acid (C181) and MUFA values, higher PUFA values and a higher PUFA/SFA ratio, due to greater linolenic acid (C183) levels. © 2001 Elsevier Science Ltd.

Twenty-five years of public health efforts produced a striking reduction in lead exposure; the blood lead average in the United States has decreased to less than 20% of levels measured in the 1970s. However, poor minority groups that live in large urban centers are still at high risk for elevated lead levels. In this study, our data showed that pregnant immigrants (n = 1,428) who live in South Central Los Angeles--one of the most economically depressed regions of California--have significantly higher (p.0001) blood lead levels (geometric mean = 2.3 microg/dl [0.11 micromol/l]) than 504 pregnant nonimmigrants (geometric mean = 1.9 microg/dl [0.09 micromol/l]). The most important factors associated with lower blood lead levels in both groups were younger age; more-recent date of blood sampling (i.e., decreasing secular trend); and blood sampling in mid-autumn, instead of mid-spring (i.e., seasonal trend). Blood lead levels of immigrants were strongly dependent on time elapsed since immigration to the United States; each natural log increase in years of residence was associated with an approximately 19% decrease in blood lead levels. Although blood lead means for both groups were almost the same as the estimated national average, 25 of the 30 cases of elevated blood lead (i.e.,or = 10 microg/dl [0.48 micromol/l) occurred in the immigrant group. The odds ratio (95% confidence intervals within parentheses) for having elevated blood lead levels (a) was 9.3 (1.9, 45.8) if the immigrant engaged in pica; (b) was 3.8 (1.4, 10.5) if the immigrant had low dietary calcium intake during pregnancy; and (c) was .65 (.43, .98) for every natural log unit increase of years of residence in the United States. The control of pica and dietary calcium intake may offer a means of reducing lead exposure in immigrants.