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.

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.

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.