Muscle growth affects the metabolome of the pectoralis major muscle in red-winged tinamou (Rhynchotus rufescens).

The aim of the present study was to identify and quantify the metabolites (metabolome analysis) of the pectoralis major muscle in male red-winged tinamou (Rhynchotus rufescens) selected for growth traits. A selection index was developed for females [body weight (BW), chest circumference (CC), and thigh circumference (TC)] and males [BW, CC, TC, semen volume, and sperm concentration] in order to divide the animals into 2 experimental groups: selection group with a higher index (TinamouS) and commercial group with a lower index (TinamouC). Twenty male offspring of the 2 groups (TinamouS, n = 10; TinamouC, n = 10) were confined for 350 d. The birds were slaughtered and pectoralis major muscle samples were collected, subjected to polar and apolar metabolites extractions and analyzed by proton nuclear magnetic resonance (1H NMR) spectroscopy. Analysis of the polar metabolomic profile identified 65 metabolites; 29 of them were differentially expressed between the experimental groups (P < 0.05). The TinamouS groups exhibited significantly higher concentrations (P < 0.05) of 25 metabolites, including anserine, aspartate, betaine, carnosine, creatine, glutamate, threonine, 3-methylhistidine, NAD+, pyruvate, and taurine. Significantly higher concentrations of cysteine, beta-alanine, lactose, and choline were observed in the TinamouC group (P < 0.05). The metabolites identified in the muscle provided information about the main metabolic pathways (higher impact value and P < 0.05), for example, phenylalanine, tyrosine and tryptophan biosynthesis; alanine, aspartate and glutamate metabolism; D-glutamine and D-glutamate metabolism; ß-alanine metabolism; glycine, serine and threonine metabolism; taurine and hypotaurine metabolism; histidine metabolism; phenylalanine metabolism. The NMR spectra of apolar fraction showed 8 classes of chemical compounds. The metabolome analysis shows that the selection index resulted in the upregulation of polyunsaturated fatty acids, unsaturated fatty acids, phosphocholines, phosphoethanolamines, triacylglycerols, and glycerophospholipids. The present study suggests that, despite few generations, the selection based on muscle growth traits promoted changes in metabolite concentrations in red-winged tinamou.

Carcass and meat quality of red-winged tinamou (Rhynchotus rufescens) selected for muscle growth.

The aim of the present study was to evaluate the efficiency of selection for body growth and its association with carcass and meat quality traits in the red-winged tinamou. Two experimental groups were selected based on the selection index: selection group with a higher index (TinamouS) and commercial group with a lower index (TinamouC). Weight at 180 days and slaughter weight were significantly higher (p < 0.05) in the TinamouS group, as were hot carcass weight, skinless breast weight, wing weight, and thigh and drumstick weight. The meat quality traits or sensory attributes did not differ significantly (p > 0.05) between groups. A significant positive correlation (0.59; p < 0.05) was found between shear force and chewability and a significant negative correlation (- 0.59; p < 0.05) between aroma intensity and strange aroma. The present study suggests that the selection index promotes greater body growth and preserves meat quality and sensory traits in red-winged tinamou.

Experimental ethology of intensively reared lowland pacas (Cuniculus paca).

The objective of this study was to evaluate and to describe the main behaviors of family groups of lowland pacas (Cuniculus paca) raised in a commercial breeding facility. We used 24 adult pacas, 16 females and 8 males, with a mean live weight of 8.2 kg and age ranging from 2 to 4 years. The animals were kept in groups of two females and one male per enclosure. Cameras were used to monitor the animals. The behaviors identified were divided into five categories (maintenance, exploratory, social interaction, reproductive, and environmental interaction). A completely randomized design in a split-split plot arrangement with three treatment factors was used: sex, period of the day, and season. The frequencies of the maintenance and environmental interaction behavioral categories were significantly higher during the day compared to the nocturnal period (P < 0.05). The duration of each behavioral category differed significantly (P < 0.05) between day and night. The frequencies of the maintenance and reproductive behavioral categories were significantly higher during the dry season compared to the rainy season (P < 0.05) and the relative duration of behaviors of the environmental interaction category was shorter during the dry season (P < 0.05). Females exhibited a significantly higher frequency of maintenance and environmental interaction than males (P < 0.05) and the duration of environmental interaction was shorter (P < 0.05) in females. The present results add to the existing knowledge on the behavior of lowland pacas raised in captivity for production of this wild species which is in the stage of domestication.