Prediction of carcass traits in fattening Chios and Serres lambs using real-time ultrasonography and live body weight measurements pre-slaughter

The objective of this study was to assess the capability of predicting carcass traits and meat cuts weights, in fattening lambs of indigenous Greek dairy sheep breeds, using ultrasound measurements and live body weight measurements pre-slaughter. A total of 187 lambs of Chios and Serres breeds were involved in the study. Body condition score, live body weight (LBW), and ultrasound measurements of Longissimus lumborum muscle depth (LMD) and subcutaneous fat thickness (SFT) at the lumbar region were recorded pre-slaughter. After slaughter, the carcasses were classified using five-degree grading systems for muscle development and fat deposition, while hot (HCW) and cold carcass (CCW) and meat cuts weights were measured. The statistical analyses included descriptive statistics and linear regression models to estimate the fixed effects of sex and the covariances of LBW, BCS, and ultrasound measurements on the studied traits. High R2 values (0.60 ≤ R2 ≤ 0.92) were observed in the models predicting HCW, CCW, forequarter, leg chump on shank off, the short loin, the eye of the short loin, and foreshank weights. Among the models estimated LMD, SFT, and LBW as significant predictors, the ones predicting hot and cold carcass weights, the short loin, the eye of the short loin, and the eye of the rack weights were successfully validated. Other models including BCS, LBW, sex, and either one or none of the ultrasonography measurements as predictors were also validated and presented.

Predictability of carcass traits in live Tan sheep by real-time ultrasound technology with least-squares support vector machines

This study aimed to investigate the performance of least-squares support vector machines to predict carcass characteristics in Tan sheep using noninvasive in vivo measurements. A total of 80 six-month-old Tan sheep (37 rams and 43 ewes) were examined. Back fat thickness and eye muscle area between the 12th and 13th ribs were measured using real-time ultrasound in live Tan sheep. All carcasses were dissected to hind leg, longissimus dorsi muscle, lean meat, fat, and bone to determine carcass composition. Multiple linear regression (MLR), partial least squares regression (PLSR), and least-squares support vector machines (LSSVM) were applied to correlate the live Tan sheep characteristics with carcass composition. The results showed that the LSSVM model had a better efficacy for estimating carcass weight, longissimus dorsi muscle weight, lean meat weight, fat weight, lean meat, and fat percentage in live lambs (R = 0.94, RMSE = 0.62; R = 0.73, RMSE = 0.02; R = 0.86, RMSE = 0.47; R = 0.78, RMSE = 0.63; R = 0.73, RMSE = 0.02; R = 0.65, RMSE = 0.03, respectively). LSSVM algorithm was a potential alternative to the conventional MLR method. The results demonstrated that LSSVM model might have great potential to be applied to the evaluation of sheep with superior carcass traits by combining with real-time ultrasound technology.

Identification of polymorphisms in the MSTN and ADRB3 genes associated with growth and ultrasound carcass traits in Kajli sheep

The aim of this investigation was to find single nucleotide polymorphisms (SNPs) in the myostatin (MSTN) and the beta-3 adrenergic receptor (ADRB3) genes associated with growth and ultrasound carcass traits in Kajli sheep. The five growth traits were birth weight (BWT-EBV), 120-day weight (120DWT-EBV), 180-day weight (180DWT-EBV), 270-day weight (270DWT-EBV), and 365-day weight (365DWT-EBV). The three ultrasound carcass traits were width (WLD) and depth of longissimus dorsi (DLD) and back fat thickness (BFT). The analysis of the MSTN sequence revealed one non-synonymous substitution (c.197T > A) in exon 1, one single nucleotide substitution (c.373 + 18G > T) in intron 1, and one synonymous substitution (c.861T > A) in exon 3. However, there were four single nucleotide synonymous substitutions (c.130C > T, c.294C > G, c.579G > T, and c.654C > G) in exon 1 of the ADRB3 gene. All the SNPs in the MSTN gene, except for c.373 + 18G > T, were in Hardy-Weinberg Equilibrium (HWE). Conversely, none of the SNPs found in ADRB3 were in HWE. Two of the MSTN SNPs (c.197T > A and c.373 + 18G > T) had significant associations with all evaluated growth and ultrasound carcass traits. The SNPs c.130C > T and c.294C > G in ADRB3 were significantly associated with 180DWT-EBV. Collectively, these findings indicate that several SNPs in the studied genes were significantly related to growth and carcass traits in Kajli sheep.

Gain and loss of subcutaneous and abdominal adipose tissue depot mass of German Holstein dairy cows with different body conditions during the transition period

Subcutaneous adipose tissue (SCAT) and abdominal adipose tissue (AAT) depots are mobilized during the fresh cow period (FCP) and early lactation period (ELP) to counteract the negative energy balance (NEB). Earlier studies suggested that fat depots contribute differently to lipomobilization and may vary in functionality. Differences between the adipose depots might influence the development of metabolic disorders. Thus, the gain and loss of subcutaneous and abdominal adipose depot masses in Holstein cows with lower and higher body condition (mean body condition scores: 3.48 and 3.87, respectively) were compared in the period from d -42 to d 70 relative to parturition in this study. Animals of the 2 experimental groups represented adequately conditioned and overconditioned cows. Estimated depot mass (eDM) of SCAT, AAT, retroperitoneal, omental, and mesenteric adipose depots of 31 pluriparous German Holstein cows were determined via ultrasonography at d -42, 7, 28, and 70 relative to parturition. The cows were grouped according to the eDM of SCAT on d -42 [low body condition (LBC) group: n = 16, mean eDM 8.6 kg; high body condition (HBC) group: n = 15, mean eDM 15.6 kg]. Average daily change (prepartum gain and postpartum loss) in depot masses during dry period (DP; from d -42 to d 7), FCP (d 7 to d 28), and ELP (d 28 to d 70) were calculated and daily dry matter intake and lactation performance recorded. Cows of this study stored about 2 to 3 times more fat in AAT than in SCAT depots. After parturition, on average more adipose tissue mass was lost from the AAT than the SCAT depot (0.23 kg/d vs. 0.14 kg/d). Cows with high compared with low body condition had similar gains in AAT (0.33 kg/d) and SCAT (0.14 kg/d) masses during the DP but mobilized significantly more adipose tissue mass from both depots after calving (AAT, HBC vs. LBC: 0.30 vs. 0.17 kg/d; SCAT, HBC vs. LBC: 0.19 vs. 0.10 kg/d). Correlation analysis indicated a functional disparity between AAT and SCAT. In the case of AAT (R² = 0.36), the higher the gain in adipose mass during DP, the higher the loss in FCP, but this was not the case for SCAT. During FCP, a greater NEB resulted in greater loss of mass from SCAT (R² = 0.18). In turn, greater mobilization of SCAT mass led to a higher calculated feed efficiency (R² = 0.18). However, AAT showed no such correlations. On the other hand, during ELP, loss of both SCAT and AAT mass correlated positively with feed efficiency (R² = 0.35 and 0.33, respectively). The results indicate that feed efficiency may not be an adequate criterion for performance evaluation in cows during NEB. Greater knowledge of functional disparities between AAT and SCAT depots may improve our understanding of excessive lipomobilization and its consequences for metabolic health and performance of dairy cows during the transition period.

Simultaneously prediction of sheep and goat carcass composition and body fat depots using in vivo ultrasound measurements and live weight

The present study established multiple linear regression models using two ultrasound in vivo measurements (at lumbar and sternal regions, with different real-time ultrasonography machines and probes) and live weight, to predict simultaneously carcass composition and body fat depots of different breeds of sheep and goat. This study is important for the small ruminant industry, considering the feasibility of using the ultrasound methodology in field conditions, as well as an online system of the carcass evaluation. The multiple linear regression models were obtained by selecting the best subset of variables between using the in vivo measurements (raw variables), their second degree and interactions, evaluated in terms of prediction performance using cross-validation "K-folds" and validated by a test group. Overall, high accuracy (adj R²) was obtained from the linear relationship between predicted and experimental values of the group test for each of the nine dependent variables, with values varying between adj R² 0.88 and 0.98.

Advances in Sheep and Goat Meat Products Research

The main goal of this chapter was to review the state of the art in the recent advances in sheep and goat meat products research. Research and innovation have been playing an important role in sheep and goat meat production and meat processing as well as food safety. Special emphasis will be placed on the imaging and spectroscopic methods for predicting body composition, carcass and meat quality. The physicochemical and sensory quality as well as food safety will be referenced to the new sheep and goat meat products. Finally, the future trends in sheep and goat meat products research will be pointed out.

The use of ultrasound to measure muscle depth and area in postmortem Holstein dairy calves

Monitoring growth of neonatal dairy calves is a useful management tool to assist producers in achieving goals for reproduction and performance. The goal of this study was to examine ultrasound as an in vivo tool to quantify longissimus dorsi muscle (ribeye) linear depth and extensor carpi radialis (ECR) and semitendinosus (ST) muscle cross-sectional areas in postmortem preweaned Holstein calves. Postmortem preweaned calves (n = 137, age 13.1 d ± 15.5 SD, body weight 36.5 kg ± 7.2 SD) were obtained from two California calf ranches between April and July 2013. Two operators collected ultrasound images of the ribeye, ECR, and ST muscles using an Aloka 500V equipped with a 5-cm 7.5-MHz linear transducer. Ultrasound ribeye linear depth and ECR and ST cross-sectional areas were calculated using the Ultrasound Image Capture System. Ultrasound measurements were compared to dissected (carcass) measures. Carcass ribeye linear depth was estimated using a ruler. Dissected ECR and ST muscle cross-sectional areas were estimated by tracing muscle cross sections onto transparency paper and then photocopying, cutting out, and weighing individual paper muscle tracings. Weights of the tracings were then converted to areas using the known area of a standard 8.5 × 11 inch paper. Data were analyzed by regressing carcass estimates on observed ultrasound measurements. The coefficient of determination (R²) indicated that ultrasound measurements were most closely associated with carcass measurements for the ST muscle (R² = 0.60, 0.62 for operator 1 and 2, respectively) when compared to the ribeye and ECR muscles (R² = 0.27, 0.41 for ribeye and 0.43, 0.32 for ECR for operator 1 and 2, respectively). The mean bias showed consistent underestimation by the ultrasound measurements when predicting carcass measurements for all three muscles and for both operators (ribeye bias = 0.15, 0.40; ECR bias = 0.95, 1.15; and ST bias = 0.73, 0.27 for operator 1 and 2, respectively). Operator contributed significantly in explaining a proportion of the variation in the regression equation for the ST muscle only, whereas calf body weight contributed significantly in explaining a proportion of the variation in the regression equation for all three muscles. The results of this study demonstrated that ultrasound measurements of the ST were the most accurate for quantifying the cross-sectional area when compared to both the ECR and ribeye in postmortem Holstein calves.

Relationships between body condition score and ultrasound skin-associated subcutaneous fat depth in equids

Background

In equids, health and welfare depend on body composition. A growing number of equids are now used as leisure and companion animals, and often found overfeed. The need for a close monitoring of body fatness led to the search for tools allowing a rapid and non-invasive estimation of fatness. This study intends to assess real-time ultrasonography (RTU) usefulness in establishing a relationship between ultrasound measures of subcutaneous fat–plus–skin thickness (SF-Skin) and body condition score (BCS) in horses and donkeys. Forty-three healthy animals (16 donkeys and 27 horses) were used in this study to generate 95 records (RTU and BCS pairs), in multiple RTU sessions for 2 years. Using visual appraisal and palpation, BCS was graded in a 1–9 points scale. Real-time ultrasonography images were taken using a 7.5 MHz linear transducer, placed perpendicular to the backbone, over the 3rd lumbar vertebra. ImageJ was used to measure the SF-Skin on RTU images. The relation between BCS and SF-Skin measurements was tested by linear and polynomial regression analysis.

Results

The BCS values were similar in horses (5.50; from 3 to 8 points) and donkeys (5.14; from 3 to 7 points). The SF-Skin measures show a similar trend (a mean of 7.1 and 7.7 mm in horses and donkeys, respectively). A polynomial regression among BCS and SF-Skin explained 92 and 77 % of the variation in donkeys and horses respectively. The coefficient of determination was considerably higher for the regression developed for donkeys compared with that of horses (R2 = 0.92 vs. 0.77, respectively), which reduced the accuracy of the method in horses. Both the linear and polynomial models tested show a strong relationship among BCS and SF-Skin for donkeys (R2 > 0.91; P < 0.01) and horses (R2 > 0.74; P < 0.01), despite that the extremes for BCS did not existed in our sample.

Conclusions

Our results showed the potential RTU usefulness to monitor body fat in equids. Using a high-frequency transducer and RTU together with image analysis allowed the identification of small SF-skin variations. This report will support further studies on the relationships between SF-Skin and BCS, particularly in extreme BCS scores.

Indirect methods for predicting body composition of Boer crossbreds and indigenous goats from the Brazilian semiarid

The aim of this study was to evaluate the correlation and to develop regression equations between the body composition obtained by the comparative slaughter and the neck composition and the ultrasound ribeye area (REAu) in goats from the Brazilian semiarid region. Forty-five intact male goats from three genetic groups were used: 15 Canindé, 15 Moxotó, and 15 F1 Boer x non-descript breed. Animals were randomly assigned to three feeding levels (ad libitum, 25 and 50% restriction) aimed to result in different slaughter weights and body composition, to fit the regression equations. The REAu was assessed between the 12th and 13th ribs with a 7.5 MHz linear transducer. The values of crude protein, ether extract, and water in the empty body showed high positive correlation (P < 0.01) with REAu and with the same values measured in the neck for all genetic groups. In addition, body composition was well predicted (R(2) > 0.80) from the REAu and from the neck composition.

Backfat thickness and longissimus dorsi real-time ultrasound measurements in light lambs

The aim of this study was to assess the accuracy of ultrasound measurements for predicting carcass traits in 124 Spanish pascual-type lambs (13 to 16 kg carcass weight). Ultrasound images were taken transversal and longitudinal to the vertebral column and at thoracic (TV; between 12th and 13th ribs) and lumbar (LV; between first and second lumbar vertebrae) locations. Skin thickness, subcutaneous backfat thickness (BFT), and depth (DLD), width (WLD), and area (ALD) of longissimus dorsi were obtained with ImageJ 1.42q software. After slaughter, BFT (TV, 2.30 ± 0.06 mm; LV, 2.46 ± 0.06 mm), DLD (TV, 2.47 ± 0.03 cm; LV, 2.48 ± 0.03 cm), WLD (TV, 4.50 ± 0.04 cm; LV, 4.60 ± 0.04 cm), and ALD (TV, 9.96 ± 0.12 cm(2); LV, 10.19 ± 0.13 cm(2)) were directly measured on the lamb carcass. Correlations between ultrasound and direct carcass measurements were greater than 0.61 for DLD, WLD, and ALD (P < 0.05) whereas they fluctuated between 0.32 and 0.60 for BFT (P < 0.05); moreover, correlations were significantly (P < 0.05) greater for transversal than for longitudinal views. In a similar way, linear regression analyses suggested a moderate underestimation for BFT and lumbar DLD when using real-time ultrasound technologies whereas WLD, ALD, and thoracic DLD suffered from under- and overestimation for small and large values of carcass traits, respectively. After decomposing the mean square prediction error (MSPE) for the different ultrasound measurements, we found that the error due to disturbance contributed most to the MSPE followed by the error of central tendency and the error due to regression. The SE of prediction (SEP) was also calculated as an additional precision indicator, obtaining estimates less than that in previous studies with larger lambs. In conclusion, transversal ultrasound measurements at the thoracic and lumbar levels could be a useful tool for predicting DLD, WLD, and ALD in light lambs, perhaps suffering from worse prediction properties when focusing on BFT. This information could be of special relevance for light lamb producers worldwide, with a special emphasis in the Mediterranean basin where this kind of production system accounts for a large percentage of the sheep industry.