Using dried orange pulp in the diet of dairy goats: effects on milk yield and composition and blood parameters of dams and growth performance and carcass quality of kids.

Although dried orange pulp (DOP) may conveniently replace cereals in ruminant diets, few studies have considered similar diet substitution for goats. We hypothesised that DOP could replace cereal-based concentrate in goat diets without detrimental effects on growth performance and carcass quality of suckling kids and milk performance and blood biochemical parameters of dams in early lactation. We also hypothesised that DOP substitution may increase the levels of antioxidants, such as phenolic compounds and vitamin E, in milk and improve its total antioxidant capacity (TAC). Therefore, 44 primiparous Payoya dairy goats were allocated to three experimental groups, each fed a different diet: control (CD, n = 14) based on a commercial concentrate with alfalfa hay as forage; and DOP40 (n = 16) in which 40% and DOP80 (n = 14) in which 80% of the cereal in the concentrate were replaced by DOP. The experiment lasted from the final month of pregnancy to 55 days postpartum. The DOP diets did not affect suckling kids' carcass quality, but at 28 days, led to improvement in live weight (LW) and average daily gain (ADG) from birth, although no differences were found between DOP40 and DOP80 (for CD, DOP40 and DOP80, LW at 28 days was 8.00, 8.58 and 8.34 kg and ADG was 184, 199 and 195 g/day, respectively). Diet had no significant effect on milk yield (average daily milk yield and total yield at 55 days were 1.66 l/day and 90.6 l, respectively) and commercial and fatty acid composition. Nevertheless, α-tocopherol, total phenolic compound (TPC) and TAC concentration in milk increased with substitution of cereals by DOP (for CD, DOP40 and DOP80, concentration of α-tocopherol was 21.7, 32.8 and 42.3 µg/100 g, TPCs was 63.5, 84.1 and 102 mg gallic acid equivalents/l, and TAC was 6.63, 11.1 and 12.8 µmol Trolox equivalents/ml, respectively). Every plasma biochemistry parameter considered was within reference values for healthy goats; therefore, no pathological effect was detected for these variables due to dietary treatment. However, DOP diets caused a reduction in plasmatic creatine kinase and aspartate aminotransferase, implying reduced oxidative damage to muscles. In conclusion, DOP may be an interesting alternative to cereals in early lactation goat diets for increasing farmers' income and the healthy antioxidant capacity of milk.

Authentication of Iberian pork official quality categories using a portable near infrared spectroscopy (NIRS) instrument.

A portable near infrared spectroscopy (NIRS) instrument was evaluated for the discrimination of individual Iberian pig carcasses into the four official quality categories (defined by a combination of genotype and feeding regime). Spectra were obtained scanning four anatomical locations (live animal skin, carcass surface, fresh meat and subcutaneous fat samples) at a commercial abattoir, using a handheld micro electro mechanical system instrument. The best assignments into official quality categories with the NIRS measurements in the carcass surface and subcutaneous fat were able to correctly classify 75.9% and 73.8% of the carcasses, respectively. Moreover, 93.2% and 93.4% of carcasses were correctly classified according to feeding regimes by using the spectra from fresh meat and subcutaneous fat samples. The results suggest that, using subcutaneous fat samples, a portable NIRS could be used in commercial abattoirs as a tool to support the control of official quality category assignment in Iberian pig carcasses.

Association between functional candidate genes and organoleptic meat traits in intensively-fed beef.

The aim of this study was to assess the associations between the single nucleotide polymorphisms in CAPN1, CAST, DGAT1, FABP4, LEP, RORC and SCD1 genes and the sensory meat quality in an intensively fed commercial population (Charolais, Limousin and Retinta breed). This work carried out analyses on a common Spanish population and evaluated the association between the markers and sensory traits. A total of 161 bulls were allocated to two different feedlots with two different finishing diets. Steaks aged for 7 and 21 days were assessed by both untrained and trained sensory panels. A significant association and allelic substitution effect were observed for markers UoG-CAST, LEP: g.73C>T and SCD1: g.878T>C on different descriptors evaluated by a consumer panel (tenderness and overall acceptability). There are no precedents of these kinds of association studies in a Spanish commercial population. The study suggested that CAST, LEP and SCD1 genes have a potential effect on the different measurements of sensory meat quality.

Association study between a SNP in bovine SCD1 gene with fatty acid composition in a Spanish commercial population fed with two different diets.

Stearoyl-CoA desaturase (SCD1 gene) is an enzyme responsible for the endogenous conversion of saturated fatty acid into monounsaturated fatty acids. The objective of this study was to assess the association of a single nucleotide polymorphism (SNP) in the SCD1 gene with the fatty acid composition of beef intramuscular fat of a Spanish commercial bull population (n = 155) finished with two different diets. The results suggested that the marker could be used as a candidate gene to obtain a healthier final product.

Use of serial ultrasound measures in the study of growth- and breed-related changes of ultrasonic measurements and relationship with carcass measurements in lean cattle breeds.

The growth and breed-related changes of rib and rump characteristics in lean beef cattle and the ability of ultrasound to predict carcass traits were investigated. Three hundred bulls from three breeds were scanned monthly (6-7 times) using real-time ultrasound with final scans taken <7 days prior to harvest. The rib and rump ultrasound measurements, except intramuscular fat content, increased (P<0.05) with live weight. Breed affected most of traits. The 12th rib ultrasound measurements showed a weak to high positive correlation (0.131 to 0.976, P>0.05 to P<0.001) with 12th rib measurements in the carcass. Regression equations developed with the ultrasound measurements, explained 97% of the variation in longissimus muscle area, 88% of the variation in fat thickness and 57% of the variation in intramuscular fat content. When last ultrasound scan measurements were excluded from prediction equations, the R(2) significantly decreased. Ultrasound measures "in vivo" are viable options for assessing carcass attributes of lean cattle.

Marbling in the longissimus thoracis muscle from lean cattle breeds. Computer image analysis of fresh versus stained meat samples.

One hundred eighty ribeye steaks from Charolais, Limousin and Retinta bulls were used to describe and compare the marbling fat between fresh and stained samples. Image analysis overestimated the intramuscular fat content (P<0.05) in relation to chemical analysis. Staining had a significant effect (P<0.05) on most of the marbling fleck traits, showing an increase in the number of marbling flecks and the proportion of marbling fleck area in the whole and in the ventral half of the longissimus m., and a decrease in the size, length and width of marbling flecks. Breed had a significant influence (P<0.05) on some quantity traits of marbling, but not in the distribution and structure of marbling flecks (P>0.05). Retinta breed was leaner than French breeds and showed fewer and smaller marbling flecks (P<0.05). The results showed a positive correlation (r=0.183 to 0.465) between USDA marbling score, and intramuscular fat by image and chemical analysis.

Use of image analysis of cross-sectional cuts to estimate the composition of the 10th-11th-12th rib-cut of European lean beef bulls.

Data from 180 bulls from Charolais, Limousine and Retinta breeds were used to evaluate image analysis of cross-sections as method of predicting the physical composition of the 10th-11th-12th rib-cut. The site along the longissimus thoracis muscle (between either the 9th and10th ribs or the 12th and 13th ribs), and the breed had significant influence on most of the variables analyzed. The correlation coefficients between the rib composition obtained by image analysis and by dissection were low to moderate (r=0.18-0.59, P<0.01-P<0.001). The R(2) values of the composition components of the 12th-13th rib cross-section to 10th-11th-12th rib-cut composition were higher than those recorded from the 9th-10th rib cross-section (R(2)=0.535 to 0.759 vs. 0.148 to 0.502). The accuracy of the predictions of lean, longissimus thoracis m. and bone percentages improved significantly with the addition of carcass weight. Results indicate that image analysis can predict rib composition in lean cattle with moderate accuracy and precision.

Effect of slaughter weight and breed on instrumental and sensory meat quality of suckling kids.

The effects of breed and slaughter weight on chemical composition, fatty acid groups, texture, and sensory characteristics of meat of 141 suckling male kids from 5 Spanish breeds were studied. There was a decrease in texture and lightness and hue angle with the increase of the slaughter weight. Fatty acid composition was correlated with the intramuscular fat content. All the breeds except MO had values of n-6/n-3 ratio below 4, which is the healthy limit recommended, and a low atherogenic index as well as a low intramuscular fat content. A multivariate analysis discriminated light kid, which had the most tender and juicy meat, from heavy kid which had more intense kid and milk odours. Blanca Andaluza and Pirenaica had most tender and juicy meat. The effect of slaughter weight on meat traits should be considered separately for each breed to find the most appropriate meat according to consumers preferences.

Fatty acid profile of three adipose depots in seven Spanish breeds of suckling kids.

Intramuscular, subcutaneous and kidney knob fat depot fatty acid profiles were studied in 104 male suckling kids from seven Spanish breeds: Blanca Andaluza, Blanca Celtibérica, Moncaína, Negra Serrana-Castiza, Pirenaica, Malagueña and Murciano-Granadina. Kids were raised in the traditional production system on mother's milk and slaughtered at around 7kg live weight. Differences were observed between dairy (Malagueña) and meat breeds (Blanca Andaluza, Blanca Celtibérica, Moncaína, Negra Serrana-Castiza, and Pirenaica). Malagueña showed higher monounsaturated and conjugated linoleic fatty acid levels than the other breeds. Highest percentages of saturated fatty acids were observed in meat breeds. For intramuscular fat depot, the range for desirable fatty acids was 66.16-72.27% was. The influence of breed on fatty acid profiles of intramuscular, subcutaneous and kidney knob fat depots studied was evident. Intramuscular fat depot is proposed as a differentiating factor between dairy and meat breed goat kids, but not between meat breed kids.

Suckling kid breed and slaughter weight discrimination using muscle colour and visible reflectance.

Meat colour was evaluated in 141 male suckling kids from five Spanish breeds: Blanca Andaluza (BA), Blanca Celtibérica (BC), Moncaína (MO), Negra Serrana-Castiza (NE) and Pirenaica (PI). Kids were slaughtered at 7.5 and 11.5 kg. pH and colour were measured in the longissimus thoracis et lumborum muscle. pH values did not differ significantly among breeds. Lightness tended to decrease and redness to increase as weight increased. BC and NE at light weight and BC and BA at heavy weight were characterized by greater lightness, chroma and hue. At both weights MO and PI were darker and showed lower values for chroma and hue. BA at light weight and NE at heavy weight were characterized by values that were between those of the former groups for all variables. Discriminant analysis based on colour and pH correctly classified 48.9% of the kids into their breed and slaughter weight.

Meat and fat quality of unweaned lambs as affected by slaughter weight and breed.

Sixty-four male lambs of two Southern Spanish breeds, a dairy breed (Grazalema Merino) and a meat breed (Churra Lebrijana), were used to study the effects of slaughter weight and breed on meat traits and intramuscular and subcutaneous fat composition. Lambs were reared following a traditional production system without weaning and slaughtered when live weight reached 12kg (suckling) or 20kg (light). Meat from suckling lambs of both breeds had lower fat and myoglobin contents, and was more tender and had higher scores for sustained juiciness in the sensory analysis. Fat from light lambs had lower C12:0 and C14:0 levels than fat from suckling lambs. Grazalema Merino meat had higher fat and ash contents, and its fat had higher conjugated linoleic acid content than Churra Lebrijana meat.

Estimation of factors influencing fatty acid profiles in light lambs.

Fatty acid composition of intramuscular, intermuscular, subcutaneous, omental and kidney knob fat depots of eighty male light lambs (±21kg live weight) from five Spanish sheep breeds was analysed. Fat depot, anatomical depot location (internal, external and intramuscular), breed (Spanish Merino, Grazalema Merino, Churra Lebrijana, Segureña and Montesina), weaning type (weaning at 45 days after birth or no weaning) and subcutaneous fat thickness factors were analyzed using a statistical model to quantify their contribution to the variation of each fatty acid. Production system was the main factor to explain variations in overall fatty acid profiles (34.68%). However, for several fatty acids and indices (arachidonic, linoleic, PUFA, n-3/n-6) anatomical depot location was the most significant factor. Feeding system explained 65.49% of CLA variance, indicating a strong influence of suckling period length on CLA deposition in lambs' fat. Moreover, due to the lack of interaction between anatomical depot location or depot and breed type or weaning system for total CLA, for future research only one depot would be enough to study the effect of those factors on CLA levels.

Southern Spain lamb types discrimination by using visible spectroscopy and basic physicochemical traits.

The potential for using visible spectroscopy (400-700nm) to classify six types (breed×production system) of lamb meat was investigated. Seven wavelengths namely 400, 410, 420, 450, 510, 610 and 670nm were retained for the discriminant analysis. The basic meat physicochemical traits of Longissimus dorsi were also studied and a model including that information together with the spectra was developed to compare both accuracies. Then, Myoglobin content, water holding capacity, pH, a(∗), 670 and 610nm wavelengths, protein percentage, L(∗), ash content, 450 and 420nm wavelengths and moisture percentage were selected as variables for the development of the discriminant function. The data analysis showed that it was possible to discriminate the lamb types with accuracy around 83% using visible spectroscopy. However these results improved to 95% when using the reflectance together with basic physicochemical traits (12% better than using only the spectra).

Colour differences among carcasses graded with similar score for conformation and fatness.

In a population of 268 yearling bulls, those carcasses graded as U-, U0 or U+ for beef carcass conformation (n = 240) and those graded as 2-, 20 or 2+ for beef carcass fatness (n = 213) were selected to study the efficiency of carcass weight, carcass dimensions and instrumental colour of latissimus dorsi, rectus abdominis and subcutaneous fat, to discriminate among these carcass grades, in a population of high-muscled and very lean carcasses from young bulls. The increase in conformation grade meant an increase in carcass weight and perimeter of the leg. Classifiers use attributes characterizing muscular development and carcass profiles from a general impression of the whole carcass. There were no significant differences for carcass weight or carcass dimensions, among the carcasses classified according to the three fat classes. The a* and b* coordinate values for the latissimus dorsi muscle were observed to decrease significantly as the carcass conformation score increased (P < 0.05). However, muscle and subcutaneous fat of fatter carcasses showed higher a*, b* colour coordinates and chroma (C*) values than leaner carcasses. The CIE (Commission International de l'Éclairage) L*, a* and b* colour coordinate measurements taken on the carcasses 45 min post mortem varied significantly from the readings taken after hanging for 24 h (P < 0,001). The higher a* and b* values on the carcasses chilled for 24 h could be caused by oxygenation of both subcutaneous fat, and latissimus dorsi and rectus abdominis muscles in the time elapsing after slaughter and after carcass exposition to circulating air in the cooler for 24 h. Lightness of the latissimus dorsi muscle underwent a decrease, compared with an increase in the rectus abdominis muscle. Hardening of the subcutaneous fat during cold storage may exert an influence on the decrease in lightness observed. These differences in carcass colour during chilling storage would suggest that the relationship between carcass colour and conformation grades was higher shortly after slaughter. Both L* colour coordinate of fat colour (P < 0.01) and a*, b* and C* colour coordinates of latissimus dorsi muscle (P < 0.05) were related to conformation classification. Colour was more efficient to differentiate conformation than fat cover classes. Sixty-two percent of carcasses were correctly classified for conformation by colour differences but only 37% of carcasses were correctly classified for fatness by colour.

Characteristics of Lacha and Rasa Aragonesa lambs slaughtered at three live weights.

A study was made of differences in the quality of meat from Lacha (L) and Rasa Aragonesa (RA) lambs slaughtered at 12, 24, or 36 kg live weight. Lambs from both breeds were weaned at 25 to 57 d, approximately 11.5 to 18.5 kg live weight, and fed concentrate and barley straw until slaughter at 24 and 36 kg live weight. Hot carcass weight, cold carcass weight, conformation, color, firmness, and thickness of backfat and color of rectus abdominis muscle were recorded on the carcass. Final pH (pHu), instrumental color (L*, a*, b*), myoglobin concentration, chemical composition, and water-holding capacity (WHC) of the longissimus muscle, shear force of the biceps femoris muscle, and iodine values and fatty acid composition of the i.m. and s.c. fat depots were determined. The percentage of fat in the longissimus muscle increased with live weight, and values for RA lambs were higher than those for L lambs. The WHC of meat from RA lambs was lower at 24 kg than at 12 or 36 kg slaughter weight. Live weight and breed had no effect on the shear force of the biceps femoris muscle. There was an increase in myoglobin concentration in the longissimus muscle with increased live weight in both breeds. The fatty acid content of s.c. and i.m. fat, which was not affected by breed, declined with the increase in slaughter weight. The polyunsaturated fatty acid content of the s.c. fat depot increased, whereas that of the i.m. fat depot decreased, with the increase in slaughter weight in both breeds. Subcutaneous fat had a higher content of heptadecanoic acid (17:0) than i.m. fat, and this increased with the increase in slaughter weight. In both depots, there was an increase in oleic acid (18:1) at 12 kg in RA lambs and at 24 kg in L lambs. In the s.c. fat depot, there was a progressive increase in linoleic acid (18:2) content with the increase in live weight in both breeds. There was a higher degree of unsaturation in the s.c. fat of RA lambs than in that of L lambs, which was reflected in the iodine value.