Carcass characteristics of Criollo Cordobés kid goats under an extensive management system: Effects of gender and liveweight at slaughter

Evaluation of carcass traits, meat quality and the expression of lipid metabolism-related genes in different slaughter ages and muscles of Taihang black goats

OBJECTIVE

This study was conducted to investigate the effect of slaughter age on carcass traits, meat quality, and the relative mRNA levels of lipid metabolism-related genes in different muscles of Taihang black goats.

METHODS

In this study, the triceps brachii (TB), longissimus dorsi (LD) and gluteus (GL) muscles of 15 grazing Taihang black goats slaughtered at the age of 2, 3, and 4 (designated as 2-year-old, 3-year-old, and 4-year-old, respectively) were collected. The differences in carcass shape, meat quality, amino acid composition and lipid metabolism gene expression among Taihang black goats of different ages and from different plant parts were compared.

RESULTS

Compared with goats at other ages, goats slaughtered at the age of 4 had greater live and carcass weights, meat weights, bone weights and skin areas (p<0.05). LD in the 4-years-old had the lowest cooking loss and moisture content. The crude protein content in the LD of 2-year-old was significantly greater than that in the other age group, and at the age of 2, the LD had the highest crude protein content than TB and GL. The highest fat content was in LD, followed by TB, for goats slaughtered at the age of 4. Eight out of 9 essential amino acids had higher content in the TB compared with other muscles, regardless of age. The total essential amino acid content was highest in the 4-year-old and lowest in the GL muscle at the age of 3. The sterol regulatory element-binding protein-1c (SREBP-1c) and adipose triglyceride lipase (ATGL) genes were significantly more abundant in the TB muscle than in the other muscles for goats slaughtered at the age of 2. At the age of 4, the ATGL and peroxisome proliferator-activated receptor γ (PPARγ) genes were significantly more abundant in the GL than in the LD, while the fatty acid synthase (FAS) genes were significantly less abundant in the GL than in the other muscles. Similarly, compared with those in goats of other ages, the relative mRNA expression levels of the FAS and heart-type fatty acid binding protein (H-FABP) genes in goats slaughtered at the age of 4 were the highest, and the relative mRNA expression of the PPARγ gene was the lowest (p<0.05). The relative mRNA expression of the H-FABP and FAS genes was positively correlated with the intramuscular fat (IMF) content, while the relative mRNA expression levels of the PPARγ and ATGL genes was negatively correlated with the IMF content.

CONCLUSION

Overall, a better nutritional value was obtained for TB from 4-year-old goats, in which the total essential amino acid and fat contents were greater than those of other muscles. The comprehensive action of lipid metabolism genes was consistent with that of the IMF content, among which the FAS, H-FABP, PPARγ, and ATGL genes had positive and negative effects on the process of IMF deposition in Taihang black goats.

Terminal Crossbreeding of Murciano-Granadina Goats with Boer Bucks: Characteristics of the Carcass and the Meat

After verifying productive improvements from the crossbreeding (MB) of Boer males with females of the Murciano-Granadina (MG) breed, the aim of this work was to determine its consequences on the carcass and meat characteristics of suckling kids (9 kg of weight at slaughter) of both sexes. A total of 94 kids (25 purebred MG males, 19 purebred MG females, 25 crossed MB males and 25 crossed MB females) were used. It was found that MB kids reached slaughter weight at a younger age (44 ± 1 vs. 63 ± 1 days, p < 0.001). For carcass yield, the interaction genotype x sex was observed, where MB females presented a higher value (51.71 ± 0.34%) than the rest of the animals (MB males 50.53 ± 0.34, p < 0.05; MG males 50.60 ± 0.34, p < 0.05; MG females 49.62 ± 0.39, p < 0.001). MB kids had greater leg compactness, (36.28 ± 0.27 vs. 34.71 ± 0.29 g/cm, p < 0.001), slightly improved expensive carcass cuts (75.93 ± 0.31 vs. 74.77 ± 0.34%, p = 0.014) and higher muscle/bone (2.93 ± 0.03 vs. 2.76 ± 0.03, p < 0.001) and meat/bone ratios (3.56 ± 0.04 vs. 3.36 ± 0.04, p < 0.001) than MG kids. They also showed a somewhat more intense red colour (8.57 ± 0.25 vs. 7.74 ± 0.27, p = 0.027), higher colour saturation (9.06 ± 0.24 vs. 8.20 ± 0.26, p = 0.016) and less meat firmness (1.95 ± 0.08 vs. 2.23 ± 0.081 kg/cm2, p = 0.021). On the other hand, males had a slightly improved proportion of expensive cuts (75.98 ± 0.31 vs. 74.73 ± 0.34, p = 0.008), but their carcass contained a higher proportion of bone (22.16 ± 0.21 vs. 21.17 ± 0.17%; p < 0.001), a lower proportion of intermuscular fat (9.54 ± 0.24 vs. 10.93 ± 0.24, p < 0.001), a higher muscle/fat ratio (5.01 ± 0.10 vs. 4.41 ± 0.10, p < 0.001) and lower muscle/bone (2.80 ± 0.03 vs. 2.89 ± 0.03%, p = 0.016) and meat/bone ratios (3.36 ± 0.04 vs. 3.56 ± 0.04%, p < 0.001) than females. There were no sensory differences in any case. It is concluded that this crossbreeding strategy also improves the carcass and meat characteristics, making it a valid alternative to improve the productive results of MG dairy goat herds.

Carryover effect of direct-fed microbial supplementation and early weaning on the growth performance and carcass characteristics of growing Najdi lambs

Growing Najdi lambs were randomly selected from lambs weaned at 30, 45, and 60 days old which were treated with 3 doses of direct-fed microbial (DFM) at 5, 10, and 15 days old to investigate the carryover effect of early weaning and DFM supplementation on their growth performance and carcass characteristics. Ten lambs from each group were transferred to individual pens for a feeding trial using the total mixed ration (Wafi). Lambs treated with DFM and weaned at 60 days old showed numerically higher body weight and average daily gains compared to other groups. Concerning the carcass and meat quality, there were significant differences between all groups in all carcass and tissue measurements, except for the back-fat and body wall thickness. In conclusion, treatment did not have any significant negative effect on body weight, feed intake, and conversion ratio compared with the control, but positively affected Zn and Cu absorption. DFM also played an important role in fat metabolism, which affects fat deposits in carcasses. The most important finding was that early weaning can be performed using DFM supplementation without any negative effect on the lambs’ performance during growth.

Mesquite pod (Prosopis juliflora) meal on meat quality of pasture-finishing lambs

This study was carried out to validate the inclusion of up to 750 g/kg of mesquite pod (Prosopis juliflora) meal in the diet and evaluate the effects on carcass characteristics and meat quality for lambs finished in pasture. Forty male, non-castrated, crossbred Santa Inês lambs, with an initial body weight (24.2 ± 3.1 kg), and approximately 120 days old were used. The animals were kept in a total area of 4 ha, divided in four paddocks of 0.62 ha each (10 animals/paddocks), on pastures of Massai (Panicum maximum cv. Massai) with drinkers and feeders during the finishing phase. Dietary treatments based on mesquite pod meal inclusion levels (g/kg of dry matter): CON, without mesquite pod meal; MPM25, 250 g/kg of mesquite pod meal; MPM50, 500 g/kg of mesquite pod meal; and MPM75, 750 g/kg of mesquite pod meal. No treatment effect were detected (P > 0.05) for carcass measures, carcass characteristics, chemical composition of longissimus thoracis muscle, tissue composition, and lipid oxidation. Lamb meat color values, such as lightness (L*) and yellowness (b*), were not affected (P > 0.05) by mesquite pod meal inclusion on the diets, whereas for redness (a*), HUE-angle, and chroma were influenced (P < 0.05). Palmitic acid had a quadratic effect, while oleic acid, eicosatrienoic acid, saturated fatty acids, monounsaturated fatty acids, and PUFA:SFA had a linear course (P < 0.05). In conclusion, the mesquite pod meal can be used as an energy feed source up to 750 g/kg of dry matter in the diet, without changing the carcass characteristics and meat quality of lambs finished in pasture.

Growth performance, nutrient digestibility and carcass characteristics of pigs fed diets containing amarula (Sclerocarya birrea A. Rich) nut cake as replacement to soybean meal

This experiment evaluated varying levels of Amarula (Sclerocarya birrea A. Rich) nut cake (ANC) on growth performance, nutrient digestibility and carcass characteristics in pigs. Thirty Large White × Landrace (LW × LR) pigs were stratified by weight (average live weight of 20 ± 5 kg) and randomly allocated to the five experimental diets that contained 0 (control), 50, 100, 150 and 200 g ANC/kg DM. Each pig served as a replicate unit, housed individually. The pigs were fed the experimental diets ad-lib once in the morning, allowing a 10% of feed refusal, and had free access to water. Bodyweight, feed intake, average daily gain (ADG) and feed conversion ratio (FCR) were recorded weekly throughout the 56-day trial period. On completion of the growth trial, following a 3-day adaptation, a nutrient digestibility study was conducted over 5 days. Thereafter, pigs were fasted for 12 h, weighed, slaughtered, and carcass samples were collected for analysis. Data on the effects of treatments on growth performance, nutrient digestibility and carcass characteristics were analysed using a two-way ANOVA in randomised blocks and were compared using Student's t-LSD. Feed intake was not affected by dietary treatment, but ADGs were reduced at ANC levels > 150 g/kg, resulting in poor FCR. Protein digestibility was reduced at ANC levels > 150 g/kg, while ether extract and fibre levels increased. Warm and cold carcass weights were lower at ANC levels > 150 g/kg, with improved meat redness and lightness. It was concluded that ANC could replace SBM in the diet of growing pigs at less than 150 g/kg inclusion level.

Carcass characteristics and meat quality of lambs fed with cassava foliage hay and spineless cactus

The objective of this study was to evaluate the influence of the total or partial replacement of Tifton 85 hay (TH) by cassava foliage hay (CH) and/or spineless cactus (SC) on the carcass characteristics and meat quality of confined lambs. Thirty-five Dorper x Santa Inês crossbred lambs were used, with an initial average weight of 16.0 ± 1.9 kg, fed with five treatment diets: 70% TH, 70% CH, 35% TH + 35% CH, 35% TH + 35% SC, and 35% CH + 35% SC. After 90 days of confinement, the animals were slaughtered and the carcass and meat data were compared using the Tukey test at 5%. The partial replacement of TH by SC increased the cold carcass weight by 3.9 kg (p < .05). The proportion of fat (%) increased (p < .05) when TH was replaced by CH + SC. The intensity of red (a*) was lower (p < .05) in the meat of animals fed with CH or CH + SC. It is recommended to partially replace TH with SC, or to replace totally with CH in association with SC.

Predicting the Digestive Tract Development and Growth Performance of Goat Kids Using Sigmoidal Models

The transition from monogastric to rumination stage is crucial in ruminants' growth to avoid stressors-weaning and neonatal mortalities. Poor growth of the digestive tract could adversely affect the performance of the animal. Modeling informative growth curves is of great importance for a better understanding of the effective development pattern, in order to optimize feeding management system, and to achieve more production efficiency. However, little is known about the digestive tract growth curves. For this reason, one big goat farm of Laiwu black breed was chosen as a basis of this study. Forty-eight kids belonging to eight-time points (1, 7, 14, 28, 42, 56, 70, and 84 d; 6 kids for each) were selected and slaughtered. The body weight, body size indices, rumen pH, and stomach parts were determined and fitted to the polynomial and sigmoidal models. In terms of goodness of fit criteria, the Gompertz model was the best model for body weight, body oblique length, tube, and rumen weight. Moreover, the Logistic model was the best model for carcass weight, body height, and chest circumference. In addition, the Quadratic model showed the best fit for dressing percentage, omasum weight, abomasum weight, and rumen volume. Moreover, the cubic model best fitted the ruminal pH and reticulum percentage. The Weibull model was the best model for the reticulum weight and omasum percentage, while the MMF model was the best model describing the growth of chest depth, rumen percentage, and abomasum percentage. The model parameters, R squared, inflection points, area under curve varied among the different dependent variables. The Pearson correlation showed that the digestive tract development was more correlated with age than body weight, but the other variables were more correlated with body weight than age. The study demonstrated the use of empirical sigmoidal and polynomial models to predict growth rates of the digestive tract at relevant age efficiently.

Meat production traits of Angora goat 1: fattening, slaughter, and carcass characteristics of intact and castrated kids

Fattening performance, slaughter, and carcass traits of intact and castrated Angora goat kids slaughtered at different slaughter weights were examined. A total of 96 (48 intact, I-kids, and 48 castrated, C-kids) single Angora kids were fattened, and 48 of them (24 I-kids and 24 C-kids) were slaughtered at slaughter weights (SW) of 20, 25, and 30 kg. Castration negatively affected fattening performance, and the kids showed rising daily weight gain with increasing SW. While dressing percentages were not affected by castration, it caused a tendency for a decrease in offal. However, with the increase in SW, dressing percentages increased, and offal decreased. Castration increased non-carcass fat percentages and back fat depth. The proportions of individual cuts did not generally vary because of castration but changed with SW; foreleg percentages decreased (P < 0.001) while neck percentages increased (P < 0.05). Carcass composition was affected by castration; the percentages of carcass lean (P < 0.001) and bone (P < 0.01) dropped, and total fat (P < 0.001) increased. SW had an impact on carcass composition; the percentages of carcass bone (P < 0.001) declined, and lean (P < 0.001) and total fat (P < 0.001) raised as SW increased. The lean/fat ratio was affected by castration (P < 0.001) and increasing SW (P < 0.05). Castration reduced the lean percentage in all cuts. The leg showed the highest lean percentage, whereas the greatest fat ratio was found in the breast+flank in all SW groups. Consequently, castration of Angora male kids negatively affected fattening performance and altered the carcass composition, while the increase in slaughter weight improved fattening performance and slaughter and carcass characteristics.

Does the length of time dried distillers' grain with solubles substitution for soybean meal affect physiological indicators and meat quality in finishing lambs?

This study examined how inclusion of dried distillers' grains with solubles (DDGS) in finishing lamb diets for different periods affects some physiological indicators and meat quality. A total of 40 male lambs were divided into four groups according to feeding regimen during the 120-day finishing period as follows: C120: no DDGS included in diet for 120 days; D120: DDGS included in diet for 120 days; D75: no DDGS included in diet for 45 days + DDGS included in diet for 75 days; D45: no DDGS included in diet for 75 days + DDGS included in diet for 45 days. Dietary inclusion rate of DDGS was 27.5%. Fattening performance and rumen parameters were not affected by treatment. Feeding regimens had no significant effect on meat quality except the instrumental tenderness and juiciness score. DDGS fed lambs had higher level of total trans fatty acids and n-6/n-3 ratio in meat. 10t-C18:1, 11t-C18:1 and 9c,11t conjugated linoleic acid contents of adipose tissue were higher in all the DDGS groups compared with C120 lambs (p < .001). These results suggest that soybean meal can be replaced with corn DDGS in lamb diets for up to 120 days during the finishing period with no adverse effects on some physiological response feedlot performance and meat quality.

Dietary enzyme addition on the growth performance and carcass characteristics of pigs fed diets containing avocado oil cake silage

Avocado oil cake (AOC) was mixed with dried grape pomace and sugarcane molasses and ensiled for 90 days. A total mixed ration containing 5% AOC silage was formulated and top dressed with Axtra® XB enzyme at 0, 2.5 and 5%. The experimental diets were fed to 24 (8 pigs/diet) Large White × Landrace (LW × LR) cross pigs (± 22-kg live weight). Growth performance data was recorded for 60 days, after which the pigs were adapted to chromic oxide mixed diet for 3 days, whereby faeces were collected for 5 days after to determine nutrient digestion. Following nutrient digestion, pigs were fasted for 12 h, weighed and slaughtered. Carcass samples were collected and analysed for meat quality. Dietary addition of enzyme increased (P < 0.05) dry matter intake and nutrient digestibility, but did not affected (P > 0.05) feed conversion ratio and average daily gain. Carcass characteristics were not affected (P > 0.05); however, small and large intestine weight and length were increased (P < 0.05) with enzyme inclusion in feed. Dietary treatments did not affect (P > 0.05) the colour and cooking quality of the meat. Enzyme addition was worth in the growth performance and nutrient digestion but did not affect the carcass characteristics and meat quality of pigs.

Influence of the Use of Milk Replacers and pH on the Texture Profiles of Raw and Cooked Meat of Suckling Kids

The aim of this work was to study the texture profile of fresh and cooked longissimusthoracis et lumborum muscle from suckling kids raised with natural milk or milk replacers. Suckling male kids from eight goat breeds (Florida, FL; Cabra del Guadarrama, GU; Majorera, MA; Palmera, PL; Payoya, PY; Retinta, RE; Tinerfeña, TI; Verata, VE), all of single parturition, were raised with milk replacers (MR) or with natural milk from the dams (NM). The meat pH, Warner-Bratzler shear force, texture profile analysis and chemical composition were determined. Kids were clustered based on their pH by k-means clustering. The effect of the rearing system on the textural profile was strongly modulated by breed. The values of Warner-Bratzler shear force and hardness found in these breeds under both rearing systems were very low. Hence, the toughness of very light suckling kids should not be a determining factor in choosing a breed or rearing system. Nevertheless, the use of milk replacers increased the presence of meat with high pH, which modified the textural parameters, decreasing the shear force but increasing cohesiveness and adhesiveness. Consequently, depending on the commercial strategy of the farm, the election of the breed and rearing system must be considered together.

Comparison of the decision tree, artificial neural network and multiple regression methods for prediction of carcass tissues composition of goat kids

The aim of this study was to predict carcass tissue composition of goat kids using the decision tree with CHAID algorithm (DT) and artificial neural network (ANN) method in comparison with classical step-wise regression (SWR) analyse. Data were obtained from 57 goat kids of Gokceada breed. Predictor variables were pre-slaughter weight, several carcass measurements and indices, weights of different carcass joints and dressing percentage. R² values ranging from 0.212 to 0.371 indicating low to moderate accuracy were obtained for predicting muscle proportion. DT and ANN yielded similar R² values for predicting bone proportion. DT was the best prediction method for estimating proportions of subcutaneous fat (R² = 0.828) and intermuscular fat (R² = 0.789). According to DT analyses, cold carcass weight was the most important factor influencing bone proportion, while kidney knob and channel fat weight was the predominant factor influencing subcutaneous, intermuscular and total fat proportions. Consequently, the use of DT method can be considered to predict carcass fat proportions.

Effect of the rearing system on the color of four muscles of suckling kids

Most suckling kids are raised on farms for cheese production, and many goat farmers rear kids with milk replacers. The aim of this work was to study the influence of the use of milk replacers on the color of four muscles. A total of 246 suckling kids of eight breeds were slaughtered to achieve carcasses of 5 kg. The color of the biceps femoris, semimembranosus, semitendinosus, and longissimus thoracis muscles was measured with a spectrophotometer, and CIELab coordinates were registered. In addition, the pH of longissimus thoracis was measured. The effect of the rearing system (RS) on the color of the studied muscles is strongly modulated by breed. In general terms, there are two groups of kids according to the color of meat. The first group has great lightness and hue angle including Malagueña, Palmera, and Tinerfeña fed natural and artificial milk. The second group with great redness includes Retinta, Payoya, and Verata fed natural and artificial milk together with Florida fed natural milk and Cabra del Guadarrama fed milk replacers. Hence, farms should consider selecting a breed and RS together. Most of the kid meat with high pH comes from kids raised on milk replacers. Because artificial RSs use very early weaning, which might induce a high pH and dark meat, two artificial rearing strategies can be proposed. The first strategy is to choose less sensitive breeds that produce meat with a normal pH. The second strategy is to restrict suckling of natural milk but minimize separation from the mother.

Enhanced oxidative stability of meat by including tannin-rich leaves of woody plants in goat diet

Objective

The aim of this study was to evaluate the effect of dietary incorporation of tannin-rich woody species on meat oxidative stability, carcass traits and meat quality in goats.

Methods

Two tannin-rich species were tested using a three-treatments feeding trial, where treatments consisted of: Larrea divaricata and Acacia aroma both at 12.5% in dry matter basis of the diet and a control diet (alfalfa hay). All feeding diets were iso-protein and iso-energy. Carcass conformation, carcass compactness, carcass fatness and subcutaneous fat deposition were evaluated. Intake, liveweigh, Longissimus thoracis et lumborum muscles of goats were analyzed in order to evaluate quality parameters such as pH value, instrumental color evaluation, water holding capacity, total phenolic content, antioxidant activity, meat oxidative stability and fatty acid profiles in meat.

Results

Feed intake, liveweight gain, carcass and meat traits did not differ among treatments. Changes in meat lipid profile among treatments were observed for oleic and elaidic acid contents. Meat total phenolic content and antioxidant activity did not differ among treatments; although, meat oxidative status after storage at room temperature, as well as under refrigerated and frozen conditions were different between control and both supplemented groups.

Conclusion

The inclusion of Acacia aroma and Larrea divaricata leaves in goat diet enhanced meat oxidative stability. Modulation of the ruminal biohydrogenation of fatty acids produced by condensed tannins of these plant species need to be further investigated.

Effects of pre-slaughter ascorbic acid administration on some physiological stress response and meat quality traits of lambs and kids subjected to road transport

The present study determined the effects of pre-slaughter ascorbic acid administration on some physiological indicators and meat quality traits of road transport-stressed lambs and kids. Eighteen lambs and 18 kids were divided into the following three groups: no transportation (T0), 3-h transportation (T3), and ascorbid acid administered at 125 mg/kg before 3-h transportation (T3+C). The liveweight loss and rectal temperature were similar, while there were significant differences among groups for some biochemical parameters in both lambs and kids. Glucose concentrations significantly increased after transportation in lambs (P = 0.005) and kids (P &lt; 0.001). Ascorbic acid had significant effects on serum glucose of lambs. T3 lambs had higher glucose concentrations than did T0 lambs (P &lt; 0.001), while T0 and T3+C lambs were found to have similar concentrations. Oxidative status in lambs and kids, as determined by serum malondialdehyde concentration, did not differ among groups. However, some meat quality traits were negatively influenced by transportation. T3 lambs had a significantly lower muscle glycogen concentration than did T0 and T3+C lambs (P = 0.018), while ultimate pH was similar among groups. Muscle glycogen concentration was significantly lower (P = 0.008) and ultimate pH was higher in T3 and T3+C kids (P = 0.028). T3 and T3+C groups had darker meat (L*) than did T0 groups both in lambs and kids, whereas a*, cooking loss and water-holding capacity were similar among groups. The effect of ascorbic acid on meat toughness was significant and shear force value in T0 lambs was lower than that in T3 lambs (P = 0.009), while T0 and T3+C lambs were found to have similar shear force values. Overall, the administration of ascorbic acid to lambs before transportation could partly reduce the adverse effects of road transportation stress, whereas its effects on kids were found to be insignificant.

Carcass and meat quality traits of Saanen goat kids reared under natural and artificial systems and slaughtered at different ages

Production of high-quality carcass and meat from goat kids may contribute to an increase in goat farming profitability. The aim was to compare carcass and meat quality traits of Saanen goat kids raised under natural (NR) and artificial (AR) rearing systems and slaughtered at 80 days and 120 days of age. The AR kids were separated from their dams immediately after birth and were fed with a commercial milk replacer, while the NR kids suckled their mothers. The rearing type did not affect the average daily gain, slaughter weight, hot carcass weight, empty body weight, commercial dressing percentage, subjective conformation and fatness scores. In parallel with the increase in slaughter age, the slaughter weight, hot carcass weight, empty body weight and subjective carcass conformation score increased. The rearing type had no effect on instrumental meat quality traits, except for meat Lightness (L*) and Hue values. Meat from NR kids had higher L* and Hue values 1 h and 24 h after cutting than those of AR kids. Warner-Bratzler shear force value increased with the slaughter age, but the meat lightness decreased. The ultimate pH was generally high in all groups, ranging between 5.94 and 6.10. The panellists evaluated the meat from NR kids to be more tender and juicy and also gave the highest tenderness scores to the meat obtained from the kids slaughtered at 80 days of age. As a conclusion, the slaughter age may be more determinant than the rearing type in the occurrence of carcass and meat quality characteristics.

Consumer visual appraisal and shelf life of leg chops from suckling kids raised with natural milk or milk replacer

BACKGROUND

The use of milk replacers to feed suckling kids could affect the shelf life and appearance of the meat. Leg chops were evaluated by consumers and the instrumental color was measured. A machine learning algorithm was used to relate them. The aim of this experiment was to study the shelf life of the meat of kids reared with dam's milk or milk replacers and to ascertain which illuminant and instrumental color variables are used by consumers as criteria to evaluate that visual appraisal.

RESULTS

Meat from kids reared with milk replacers was more valuable and had a longer shelf life than meat from kids reared with natural milk. Consumers used the color of the whole surface of the leg chop to assess the appearance of meat. Lightness and hue angle were the prime cues used to evaluate the appearance of meat.

CONCLUSION

Illuminant D65 was more useful for relating the visual appraisal with the instrumental color using a machine learning algorithm. The machine learning algorithms showed that the underlying rules used by consumers to evaluate the appearance of suckling kid meat are not at all linear and can be computationally schematized into a simple algorithm. © 2017 Society of Chemical Industry.

The ontogenetic allometry of body morphology and chemical composition in dairy goat wethers

We studied the ontogenetic growth of goat wethers (castrated male goats) of the Saanen and Swiss Alpine breeds based on a large range of intraspecific body mass (BM). The body parts and the chemical constituents of the empty body were described by the allometric function by using BM and the empty body mass (EBM) as the predictors for morphological traits and chemical composition, respectively. We fitted the allometric scaling function by applying the SAS NLMIXED procedure, but to evaluate assumptions regarding variances in morphological and compositional traits, we combined the scaling function with homoscedastic (MOD1), and the heteroscedastic exponential (MOD2) and power-of-the-mean (MOD3) variance functions. We also predicted the ontogenetic growth by using the traditional log-log transformation and back-transformed results into the arithmetic scale (MOD4). We obtained predictions from MOD4 in the arithmetic scale by a two-step process, and evaluated MOD1, MOD2 and MOD3 by a model selection framework, and compared MOD4 with MOD1, MOD2 and MOD3 based on goodness-of-fit measures. Based on information criteria for model selection, heterogeneous variance functions were more likely to describe 10 over 36 traits with a low level of model selection uncertainty. One trait was predicted by averaging the MOD1 and MOD2 variance functions; and nine traits were better described by averaging the MOD2 and MOD3 variance functions. The predictions for other 16 traits were averaged from MOD1, MOD2 and MOD3. However, MOD4 better described 11 traits according to the goodness-of-fit measures. Depending on the variable being analyzed, the body parts and the chemical amounts exhibited the three types of allometric behavior with respect to BM and EBM, that is, positive, negative and isometric ontogenetic growth. Reference BMs, that is, 20, 27, 35 and 45 kg, were used to compute the net protein and energy requirements based on the first derivative of the scaling function, and the results were presented in reference to the EBM and EBM0.75. Both the net protein and energy requirements scaled to EBM0.75 increased from 20 to 45 kg of BM.

Effects of pre-slaughter diet/management system and fasting period on physiological indicators and meat quality traits of lambs

This study determined the effects of pre-slaughter diet/management system on blood and rumen parameters and meat-quality traits of Norduz lambs. Eighty lambs were divided into two groups according to diet (AH: alfalfa hay; BAH: alfalfa supplemented with 500 g/head barley) for 21 days. Following this period, lambs from each group were distributed among four groups according to pre-slaughter fasting period as 0, 12, 24 or 48 h. Cortisol concentrations were found to be significantly higher in the 24 h and 48 h groups when compared to the 0 h group (p<0.01). Diet and fasting period had limited effect on muscle glycogen content and ultimate pH·L*, WHC and moisture decreased in line with increases in the fasting period (p<0.01). In conclusion, carcass conformation and some meat quality traits were better in BAH lambs. Fasting had a negative effect on some meat quality parameters, with significant increases in some physiological stress indicators after fasting periods of 24 h or longer.

Growth, feed intake and carcass characteristics of indigenous goats fed local resources in Tunisian arid land

Native genetic resource of goats is a pivotal source for meat and milk in southern Tunisia. Feeding is one of the most important activities of goat husbandry. Perceptions on the role of native feed resources for growth and carcass characteristics have not been well studied. Therefore, the present study was designed to help understand and to compare the influences of local forage resources (grass hay, dried olive leaves, Stipa tenacissima and oat hay) on growth performance and carcass characteristics of kids. The kids with the age of 4 months (average live bodyweight of 15 ± 58 kg) were selected for the study. The three study groups in the 90-day trial were as follows: Group C, where animals received oat hay only (control), Group OL, where animals received olive leaves (dried) + S. tenacissima and Group GH, where animals received grass hay. A daily allowance of commercially available concentrate (305 g DM/day) was offered to all groups (making about half of the total DM intake). At the end of the experiment, all animals were slaughtered. Statistical analysis showed that total DM intake was lower (P < 0.001) in C group (490.77 g) than the other two groups having similar DM intake (619.22 and 589.28 g for OL and GH, respectively). Average daily gain was comparable for the three groups (38.33, 40.71 g and 39.52, respectively, for C, OL and GH), with similar final liveweights. Cold carcass weight and carcass yield were not affected by diet treatment. Diet had no significant effect on individual organ weights and carcass composition. The use of the local forage resources evaluated in this trial could be used for the local goat population without loss of productivity when they make up about half of the diet along with a concentrate feed.

Carcass and non-carcass component yields of crossbred Boer and Brazilian semiarid indigenous goats subjected to different feeding levels

The effect of different feeding levels (ad libitum, 25 and 50 % restriction) and genotypes (½ Boer × ½ nondescript breed goats, Canindé, and Moxotó) on carcass quantitative characteristics and non-carcass components (NCC) were evaluated. Forty-five intact male goats were distributed in a 3 × 3 factorial design with five replicates. There was no effect of genotype on carcass weights and yields and retail cuts weights and yields (P > 0.05). Compared to Moxotó, ½ Boer presented better carcass conformation and higher weights (P < 0.01) and yields of viscera from gastrointestinal tract (P < 0.05), and compared to the other genotypes (P < 0.01), ½ Boer presented larger carcass compactness. Carcass weights and yields, retail cuts weights and NCC, and soft tissues yields were higher (P < 0.01) in goats fed ad libitum. The two restriction levels did not differ (P > 0.05) for these variables. There were interactions of genotype and feeding level. At ad libitum feeding, ½ Boer had higher weights of breast and shank, leg, soft tissues, and gastrointestinal viscera compared to the Moxotó (P < 0.05). The crossing of nondescript breed goats with Boer may be a strategy for increasing the efficiency of goat meat production in the Brazilian semiarid. Moreover, in times of feed scarcity, farmers may use higher feed restriction levels to keep animals, since for most of the parameters evaluated, there were no differences between the restriction levels.

Características de carcaça de cabritos criados em dois sistemas de terminação

Avaliaram-se as características da carcaça de cabritos Saanen confinados, Saanen e 7/8 Boer - 1/8 Saanen semiconfinados, bem como a influência de grupo genético e sistema de terminação sobre o rendimento comercial, índice de compacidade, não constituintes, área de olho de lombo, força de cisalhamento, gordura, teor de umidade e teor de extrato etéreo. Utilizaram-se 31 machos inteiros, com aproximadamente 128 dias de idade e 22,9±2,4kg de peso vivo. Destes, 22 eram da raça Saanen e nove animais eram mestiços 7/8 Boer - 1/8 Saanen. Os animais da raça Saanen foram divididos em dois grupos de 11 animais, sendo um grupo mantido em confinamento e outro em semiconfinamento, enquanto os mestiços foram mantidos em semiconfinamento. Compararam-se os sistemas de terminação na raça Saanen, e os grupos genéticos no sistema semiconfinado. Os animais confinados receberam 3,5% do PV em ração completa peletizada; os semiconfinados tiveram acesso à pastagem e suplementação de 1,5% do PV em ração concentrada peletizada. Aos 47 dias de terminação, os animais foram abatidos e as características de carcaça determinadas por meio de uma amostra de lombo dissecado. Foram observadas diferenças entre sistemas de terminação para rendimento comercial de carcaça, índice de compacidade da carcaça, não constituintes de carcaça, área de olho de lombo, força de cisalhamento, gordura, teor de umidade e de extrato etéreo. Entre os grupos genéticos, foram observadas diferenças para área de olho de lombo, espessura de gordura e matéria mineral. O sistema de terminação exerceu influência sobre as características de carcaça avaliadas. A raça Saanen pode ser utilizada para a produção de carne quando submetida ao confinamento.

Chemical composition and meat quality attributes of indigenous sheep and goats from traditional production system in Tanzania

The aim of the study was to compare chemical composition and quality attributes of meat between male long fat tailed sheep (n = 17) and Small East African goats (n = 17) existing in Tanzania. Animals of 1.5 to 2 yrs in age and live body weight of 22.59±0.50 kg were purchased from livestock auction markets. Animals were fasted for 18 h and slaughtered according to standard halal procedure. Left carcasses were dissected into muscles, fat and bone and the muscle and fat were mixed together and chemically analysed. Meat quality attributes were measured based on Muscle longissimus thoracis et lumborum excised from right sides of carcasses. Goat carcasses had significant higher (p = 0.0302) moisture content (70.65% vs 66.96%) and lower (p = 0.0027) ether extract (2.49% vs 5.82%) than sheep but there was no significant species differences in protein and ash content. Sheep had lower (p = 0.0157) ultimate pH (5.74 vs 5.88) and higher (p = 0.0307) temperature (3.77°C vs 3.15°C) than goat carcasses. Sheep meat had lower (p = 0.0021) shear force values (29.83 N vs 34.07 N) than goat. Within species, at day 9 of ageing, meat tenderness improved (p = 0.0001) by 44.63% and 34.18% for sheep and goat. Pooled data showed that at d 9 of ageing, meat tenderness improved (p = 0.0001) by 39.25% (from 39.54 N to 24.02 N) compared to tenderness of meat which was not aged at day one of slaughter. The present study demonstrated the differences in chemical composition and quality attributes of meat existing between sheep and goats originated from East Africa.

Preliminary evaluation of slaughter value and carcass composition of indigenous sheep and goats from traditional production system in Tanzania

The aim of the pilot study was to evaluate slaughter characteristics and carcass composition of indigenous long fat tailed sheep and Small East African goats purchased from the auction markets slaughtered at 1.5 to 2 yrs of age and 20 kg to 25 kg live weight. The animals were slaughtered according to halal standard procedures. The left half carcasses were jointed into eight wholesale joints, and dissected into muscles, fat and bone, which were weighed separately. Sheep had greater (p<0.05) slaughter BW (22.29 kg vs 20.50 kg) and empty BW (20.17 kg vs 18.67 kg) than goats (p<0.05). Dressing percentages were lower (p<0.001) in sheep than goats when carcass weight was expressed as percentage of slaughter BW (42.31% and 47.15%) and empty BW (46.75% and 51.79%). Sheep carcasses had lower (p<0.001) proportion (66.18% vs 71.64%) of muscles and higher (p<0.001) proportion of fat (7.41% vs 3.44%) than goat carcasses. Sheep had proportionally lighter (p<0.001) shoulder (18.89% vs 22.68%) and heavier (p<0.05) proportion of chump (7.916% vs 6.76%) and main rib (8.12% vs 7.07%). Sheep had more (p<0.001) muscles in the leg (28.83% vs 27.08%) and main rib (7.62% vs 6.36%) than goats. Sheep had less (p<0.001) muscles (20.28% vs 23.56%) in shoulder joints when expressed as percentage of total muscle of carcasses. It is concluded that there are differences in sheep and goat both in terms of carcass and joint yields and composition. The present study also implies that there is need to consider setting different meat cuts and prices for these cuts when one takes into account the differences in muscle distribution within joints in sheep and goats.