Non-invasive methods to quantify the carcass parameters of sheep: Interaction between thermal environment and residual feed intake.

The thermal environment is important in unit production because the perception of thermal stress can reduce fertility, and productive performance, therefore its management is necessary. The use of non-invasive methods, such as infrared thermography and real-time ultrasonography, are widely used to evaluate indicators in animal production, without the need to slaughter the animals. Thus, we aimed to assess the effect of the thermal environment on the physiological parameters and carcass characteristics of Dorper sheep with positive and negative residual feed intake (RFI) using infrared thermography and real-time ultrasonography techniques. Twenty uncastrated male Dorper sheep (17.8 ± 2.4 kg) were confined for 40 days for RFI classification. Sheep were separated into positive RFI (n = 10) and negative RFI (n = 10). The experimental design was in randomized blocks, in a 2 × 2 factorial arrangement, with 2 thermal environments (full sun or shade) and two feed efficiency groups (positive RFI or negative RFI), with 5 replications. The sheep remained in confinement for 60 days. The animals were slaughtered at the end of the experiment and the carcasses dissected for tissue separation. Rectal temperature (RT) and respiratory rate (RR) were measured at two times (14:00 h and 18:00 h) for periods of 5 days. The RR was determined by indirect auscultation of heart sounds at the level of the laryngotracheal region. The RT was measured introduced a digital clinical thermometer into the animal's rectum. Surface temperature (ST) was obtained using a thermographic infrared camera, collecting the temperatures of the eyeball and skin surface in the regions of the head, ribs, rump, flank and shin. Sheep confined in full sun showed higher RR (P = 0.0001), ST ribs (P = 0.0020), ST rumb (P = 0.0055), ST flank (P = 0.0001) and heat tolerance coefficient (HTC) (P = 0.0010). For sheep confined in full sun, a strong correlation was observed between the RR and the mean ST (MST; r = 0.6826; P = 0.0236) and between the final loin eye area (LEAf) with the real LEA (LEAr) (r = 0.9263; P = 0.0001) and slaughter body weight (SBW) (r = 0.7532; P = 0.0325). For negative RFI sheep, a positive correlation was observed between the RR and the ST rump (r = 0.7343; P = 0.0025) and ST ribs (r = 0.6560; P = 0.0178) and the MST (r = 0.7435; P = 0.0001), between the MST and the LEAr (r = 0.6837; P = 0.0025) and the final LEA (r = 0.6771; P = 0.0144), and between the final LEA and LEAr (r = 0.9942; P = 0.0001), BW (r = 0.8415; P = 0.0277) and MST (r = 0.6771; P = 0.0045). Positive RFI sheep confined to shade showed a high correlation between final LEA and LEAr (r = 0.9372; P = 0.0001). The use of shading in confined Dorper sheep, regardless of the RFI classification, reduces the effects of heat stress on physiological parameters.

Effect of sex on carcass yield and meat quality of guinea pig.

The aim of this study was to evaluate the effect of sex on carcass yield and meat quality of guinea pig (Cavia porcellus). Twenty animals (10 males and 10 females) Criollos, with initial body weight of 286 ± 4.26 g and 2 months of age were distributed in a completely randomized design. The guinea pigs fed a diet based on vegetables and concentrate in a roughage:concentrate ratio of 80:20. After 60 days, animals were slaughtered and their carcasses and meat were evaluated. Males had higher slaughter weight, total weight gain, hot carcass weight, cold carcass weight, cold carcass yield, meat weight, meat yield, leg weight, loin + flank weight and front weight (P < 0.05). Females showed higher carcass chilling loss, liver yield, cooking loss and protein and ash content in meat (P < 0.05). The use of male guinea pigs for meat production provides higher yields of carcasses, meat and commercial cuts, and lower losses during carcass chilling and meat cooking.

Differences in Beef Quality between Angus (Bos taurus taurus) and Nellore (Bos taurus indicus) Cattle through a Proteomic and Phosphoproteomic Approach.

Proteins are the major constituents of muscle and are key molecules regulating the metabolic changes during conversion of muscle to meat. Brazil is one of the largest exporters of beef and most Brazilian cattle are composed by zebu (Nellore) genotype. Bos indicus beef is generally leaner and tougher than Bos taurus such as Angus. The aim of this study was to compare the muscle proteomic and phosphoproteomic profile of Angus and Nellore. Seven animals of each breed previously subjected the same growth management were confined for 84 days. Proteins were extracted from Longissimus lumborum samples collected immediately after slaughter and separated by two-dimensional electrophoresis. Pro-Q Diamond stain was used in phosphoproteomics. Proteins identification was performed using matrix assisted laser desorption/ionization time-of-flight mass spectrometry. Tropomyosin alpha-1 chain, troponin-T, myosin light chain-1 fragment, cytoplasmic malate dehydrogenase, alpha-enolase and 78 kDa glucose-regulated protein were more abundant in Nellore, while myosin light chain 3, prohibitin, mitochondrial stress-70 protein and heat shock 70 kDa protein 6 were more abundant in Angus (P<0.05). Nellore had higher phosphorylation of myosin regulatory light chain-2, alpha actin-1, triosephosphate isomerase and 14-3-3 protein epsilon. However, Angus had greater phosphorylation of phosphoglucomutase-1 and troponin-T (P<0.05). Therefore, proteins involved in contraction and muscle organization, myofilaments expressed in fast or slow-twitch fibers and heat shock proteins localized in mitochondria or sarcoplasmic reticulum and involved in cell flux of calcium and apoptosis might be associated with differences in beef quality between Angus and Nellore. Furthermore, prohibitin appears to be a potential biomarker of intramuscular fat in cattle. Additionally, differences in phosphorylation of myofilaments and glycolytic enzymes could be involved with differences in muscle contraction force, susceptibility to calpain, apoptosis and postmortem glycolysis, which might also be related to differences in beef quality among Angus and Nellore.

Energy and protein requirements of non-descript breed hair lambs of different sex classes in the semiarid region of Brazil.

The aim of this study was to determine the energy and protein requirements of non-descript breed hair lambs (NDB) reared under Brazilian semiarid conditions. Sixty animals from three sex classes (20 intact males, 20 castrated males, and 20 females) with an average initial body weight of 18.1 ± 0.4 kg and an average age of 5 months were used. The nutritional requirements were estimated using the comparative slaughter. The animals in the final slaughter group were distributed in a completely randomized design with a 3 × 3 factorial scheme (three sex classes and three feeding levels: ad libitum feeding (positive energy balance), 70% feed restriction (maintenance level), and 80% feed restriction (negative energy balance)). The net energy requirement for maintenance (NEm) did not differ between sex classes (P > 0.05) and it was 68 kcal/kg of metabolic empty body weight (EBW(0.75))/day (P < 0.05). The coefficients for the nonlinear regression of retained energy (RE) on the empty body weight gain (EBWG) were not different among the different sex classes (P > 0.05). The net energy requirement for weight gain (NEg) was estimated by NEg (Mcal/day) = 0.29 × EBW(0.75) × EBWG(0.86) for all sex classes (P < 0.05). The net protein requirement for weight gain (NPg) was estimated by NPg (g/day) = 224.45 × EBWG - 0.025 × RE for all sex classes (P < 0.05). The NEg increased and the NPg decreased with the increase in body weight of NDB lambs.

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.

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.

Biometria da cabeça e da cavidade craniana de ovinos deslanados sem raça definida (Ovis aries LINNAEUS, 1758) em Petrolina/Pernambuco, Brasil / Biometry of head and cranial cavity of wooless mongrel sheep (Ovis aries LINNAEUS, 1758) in Petrolina/Pernambuco, Brazil

A espécie ovina é largamente utilizada na região Nordeste do Brasil por apresentar alta rusticidade. No entanto, sua anatomia ainda é pouco estudada. Assim, crescem os estudos para gerar subsídios técnico-científicos àqueles profissionais que trabalham com as áreas aplicadas da Medicina Veterinária e afins. O objetivo do presente estudo foi estabelecer correlações entre as dimensões da cabeça e da cavidade craniana, utilizando 80 ovinos, 40 machos e 40 fêmeas, com média de peso entre 27,0 e 33,0 kg. Em fêmeas, foi observada correlação entre a massa corpórea e o comprimento da cabeça; entre a massa corpórea e largura da cabeça; entre o comprimento da cabeça e sua respectiva largura; entre comprimento da cabeça e o comprimento da cavidade craniana e entre a altura da cabeça e o comprimento da cavidade craniana. As demais dimensões, nas fêmeas, não tiveram correlação estatisticamente significativa. Já em animais do sexo masculino, foi possível evidenciar correlação apenas entre a altura da cabeça e altura da cavidade craniana. Desta forma, é possível concluir que, quanto maiores forem as proporções da cabeça, maiores serão as dimensões e volume intracranianos.

The sheep is a commonly used species in Northeast region of Brazil because of its high rusticity. Yet, very little is known about the anatomy of these species. Therefore, the number of studies in this field is increasing to stimulate technical and scientific subsidies to professionals in Veterinary Medicine. The aim of this study was to establish correlations between the head and cranial cavity dimensions, using 80 sheep, 40 males and 40 females, with a medium weight of 27,0 to 33,0 kg. In females, it was observed correlation between corporal weight and length of the head; corporal weight and width of the head; length of the head and its respective width; length of the head and length of the cranial cavity; height of the head and length of the cranial cavity. The other dimensions, in females, had non-significant correlation. In males, the only correlation established was between height of the head and height of the cranial cavity. Thus, it was possible to conclude that the larger the proportions of the cranium are, the larger will be the dimensions and the intracranial volume.