This study evaluated the effect of dietary supplementation with Amaranthus dubius on carcass characteristics and meat quality of fattening rabbits. One hundred and six New Zealand White rabbits, weaned at 35 d of age, were assigned to three experimental diets including 0%, 16% and 32% of A. dubius (A0, A16 and A32), and were fed ad libitum until their slaughter at 87 d of age.

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Abstract:The effects on performance and digestibility in growing rabbits were studied by comparing 3 diets containing increasing inclusion rates of amaranth (Amaranthus dubius Mart. ex Thell.): 0 (A0), 160 (A16) and 320 g/kg (A32 diet). Diets were formulated isoproteic and isocaloric to meet the nutrient requirements of growing rabbits. One hundred and thirteen weaned New Zealand White rabbits (mean±standard deviation weight: 760±102 g), individually caged, were randomly assigned to one of the 3 experimental diets. Rabbits were fed ad libitum from 35 to 87 d of age, and health status and performance traits were monitored. The coefficients of total tract apparent digestibility of the diets were measured between 42 and 46 d of age in 12 rabbits per treatment. Amaranthus dubius contained 209 g/kg dry matter (DM) of crude protein and 398 g/kg DM of neutral detergent fibre. There were no significant differences between treatments in weight gain (mean 21.6 g/d) and live weight at the end of the fattening period (mean 1883 g). Daily feed intake was higher (P<0.05) in A0 than in A16 and A32 diets (85.4 vs. 73.7 and 69.9 g/d, respectively), and feed conversion rate improved with increased inclusion of A. dubius in the diet (from 3.84 to 3.28 for A0 and A32 diets, respectively; P<0.05). Health status was not affected by the amaranth inclusion rate. Total tract apparent digestibility showed high values, with no differences among diets except for ether extract. Thus, A. dubius could be considered as an alternative source of protein and fibre for rabbit feeding in tropical and subtropical regions.

Two experiments were carried out with pregnant (experiment 1) and lactating ewes (experiment 2), to compare dry-matter (DM) intake, and total tract apparent digestibility, digesta kinetics and weight of digestive tract contents of Lacaune and Manchega sheep, with the aim of explaining possible differences between the breeds in voluntary food intake. In experiment 1, 20 3-year-old single-bearing pregnant ewes, 10 Manchega and 10 Lacaune, were permanently housed for the last 10 weeks of pregnancy. The diet used consisted of lucerne hay, offered ad libitum, supplemented with 0·3 kg/day of concentrate. DM and digestible DM intake per kg M0·75 were higher (P < 0·01) in Lacaune than in Manchega sheep. Breed did not affect total tract apparent digestibility, fractional rates of passage, transit time, total mean retention time, or weight of digestive tract contents. Changes in body weight and body condition score were similar between breeds. In contrast, Lacaune lambs tended (P = 0·09) to weigh less than Manchega lambs, suggesting genetic differences in the energy utilization between breeds in late pregnancy. Higher DM intake observed in Lacaune sheep may have been related to a higher energy demand for mammary development. In experiment 2, 32 3-year-old lactating multiparous ewes, 16 Manchega and 16 Lacaune, were permanently housed during the first 12 weeks of lactation. The experimental diet used was based on a mixture of maize silage and dehydrated lucerne (10: 1, fresh weight basis), offered ad libitum, and supplemented with 0·8 kg/day of concentrate. Milk, fat and protein yield as well as DM and digestible DM intake in Lacaune ewes was higher (P < 0·01) than in Manchega ewes. DM intake was constant in Lacaune sheep with advancing lactation, while in Manchega sheep DM intake decreased. Throughout this period Lacaune ewes lost 0·5 kg of body weight while Manchega gained 4·4 kg. Breed did not affect either apparent digestibility of DM, organic matter and neutral-detergent fibre, or fractional rates of passage, transit time and total mean retention time. The weight of total tract digestive contents was greater (P < 0·05) in Lacaune than in Manchega sheep, particularly in the reticulo-rumen. Results suggest that the scheme of selection in Lacaune dairy sheep has increased milk yield together with voluntary food intake, the latter being associated with an increase in the rumen fill capacity. The higher milk yield of Lacaune ewes cannot be attributed to the higher DM intake only; other factors, i.e. mobilization of fat reserves, are required to support this higher milk output.

SUMMARYIn this work, the canonical biplot (CB) method (Vicente-Villardón, 1992;Gower and Hand, 1996) is used to determine the origin, distribution, conservation and pollution state of the different types of stones used in the construction and restoration of monuments of great historical interest. The stone materials (sandstones) used in the Cathedral of Ciudad Rodrigo (Salamanca, Spain) have been used to assess the usefulness of the method. The age of this monument (eight centuries), together with the surrounding environmental conditions, have especially contributed to the pollution of the stone masonries, in comparison to the same stones identified in the original quarries. The CB method has allowed us to: (a) identify the sandstone varieties used in the construction; (b) locate the original quarries of these sandstones; (c) locate these materials in the building, and (d) detect the pollution and deterioration affecting the stones in the monument, in comparison to the stones of the original quarries.

Amaranthus dubius is an alternative source of fibre and protein for the feed formulation for growing rabbits, although its effects on their health status are yet unknown. Therefore, this study aimed to evaluate the effects of three dietary levels (0, 160 and 320 g/kg) of A. dubius on haematological, serum biochemical and histopathological parameters of fattening rabbits. One hundred and thirteen New Zealand White rabbits were fed ad libitum from weaning (35 days) to slaughter (87 days). The health status of the animals was monitored, and mortality was recorded. Before slaughtering, 30 rabbits were randomly selected for haematological and serum biochemical analysis. During slaughter, 18 rabbits were randomly selected for histopathological study in heart, liver, lung and small intestine. The health status of rabbits was good, with no differences among treatments in mortality. Diet and sex did not affect the values of most haematological and serum biochemical parameters. Fibrinogen, glucose and high-density lipoprotein values increased significantly from 0 to 320 g/kg A. dubius diets. The white blood cell count and glutamic oxaloacetic transaminase values decreased significantly from 0 to 320 g/kg A. dubius diets. The organs showed histologically well-structured tissues. However, in all experimental groups several samples with lesions were observed, always highly focalized in small tissue areas. The main lesions observed, probably related to conditions of thermal stress affecting the rabbits, were cholesterolosis (heart), steatosis (liver), inflammatory lymphoplasmacytic infiltrate (lung) and chronic inflammatory tissue damage (small intestine). In conclusion, the inclusion of up to 320 g/kg A. dubius in diet did not jeopardize the health status of growing rabbits. Therefore, A. dubius can become an alternative raw material for the formulation of feeds in tropical and subtropical countries where this plant is widespread.

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Este meta-análisis evaluó el efecto de los taninos condensados (TC) (polifenoles formados a partir de monómeros flavan-3-ol) sobre los resultados productivos, la composición de ácidos grasos y el color de la carne de cordero, a partir de los resultados de 41 publicaciones (años 1998-2019) que permitieron realizar hasta 67 comparaciones entre lotes de corderos experimentales comparados con un lote control dentro del mismo ensayo. Estos lotes se dividieron en dos grupos, según la diferencia de contenido de TC entre el lote control y el experimental (nivel medio, 16 g/kg MS o alto, 25 g/kg MS). Se calculó la diferencia de medias entre cada lote experimental y su lote control para ganancia media diaria, consumo medio de alimento, índice de conversión, grasa intramuscular, perfil de ácidos grasos y coordenadas cromáticas de color de la carne. No se han observado diferencias significativas en los resultados productivos por la inclusión de TC en la dieta, siendo de mayor importancia el efecto de otros nutrientes de la dieta, como la proteína bruta y la grasa bruta. Se ha observado una reducción consistente de la ratio ácidos grasos saturados/ácidos grasos poliinsaturados y el contenido de ácido ruménico de la carne al incluir TC en la dieta. Sin embargo, la inclusión de TC en la dieta no mejoró significativamente los atributos de color de la carne respecto al lote control.