One hundred and thirty-two young rabbits were divided into two groups at weaning and given ad libitum a control diet (C), or an experimental diet (M) in which lucerne hay was substituted by mulberry leaves in order to examine their effects on fattening rabbit performance, carcass characteristics and meat quality.Digestibility coefficients of dry matter (DM), crude protein and gross energy were similar in both groups but digestibility of crude fibre in the experimental diet was higher in line with a lower food intake in this group of animals, while ether extract digestibility of mulberry leaves was very low.Food conversion ratio was similar in the two groups (3.1 g DM per g gain) but rabbits given the experimental diet had lower food intake (102 v. 144 g/day) and impaired live-weight gain. The rate of mortality was similar in the two groups. The substitution of lucerne with mulberry in the diet may have induced a higher retention time of digesta, as seems to be indicated by a higher weight of digestive tract contents recorded at slaughter (proportionately 0.32 more) in mulberry group. Live weight at slaughter of animals in control group was higher (2680 v. 2211 g) and also skin weight was proportionately 0.5 higher and its carcasses were proportionately 0.41 heavier than those of animals in experimental group (dressing yield 587 v. 503 g/kg). At constant carcass weight, the carcasses of rabbits of the mulberry group were longer than the lucerne group, but lumbar circumference tended also to be higher (P = 0.09) and no differences were found in the length: circumference ratio. No differences were found in the weights of kidneys or thoracic viscera, but livers of rabbits of the lucerne group were heavier (proportionately 0.3 heavier). The more remarkable difference was that carcasses of rabbits given the experimental diet had markedly less fat in scapular (5.8 v. 10.0 g) and perirenal fat (9.0 v. 22.3 g) deposits.No differences in cooking losses or water-holding capacity of the meat were found and also the colour was similar, but the b* parameter was a little lower for meat of the M group rabbits.The proportion of protein in the meat was the same for rabbits of the two groups, but rabbits given the experimental diet which had leaner carcasses also had leaner meat (19 v. 37 g lipids per kg meat) and a little more moisture (755 v. 736 g/kg meat). Intra and intermuscular fat of hindleg meat from rabbits of group M was less saturated and more unsaturated than that of the conventional rabbits mainly due to its higher proportion of polyunsaturated fatty acids, ω6 (37·3 v. 29·1 g/100 g lipids) and ω3 (3·4 v. 2·2 g/ 100 g lipids). Polyunsaturated: saturated ratio was higher in the mulberry group than in the lucerne group (1·15 v. 0·85) indicating a more desirable value in rabbits given the experimental diet, so meat of these rabbits could be considered preferable for human nutrition from this point of view.

Seven diets were formulated in order to determine the nutritive value of whole maize plant at three stages of maturity by substitution of a control diet (C) with 20% and 40% whole maize plant at early dough, mid-dent and mature stages of grain. A digestibility trial was performed with 74 rabbits. Digestible protein and energy values of whole maize plant at different maturity stages were calculated by substitution and regression procedures. A fattening experiment was carried out with 200 rabbits from weaning (28 days of age) giving ad libitum either diet C or 20% mature whole maize plant. One hundred and forty-three rabbits were slaughtered at 63 days of age and some carcass traits were measured.The crude protein and fibre content of whole maize plant decreases as the kernel matures (CP: 8.3, 8.1 and 7.6% DM; CF: 15.8, 12.6 and 13.4% DM; NDF: 45.3, 38.0 and 38.0% DM; ADF: 19.1, 15.0 and 16.1% DM for early dough, mid-dent and mature stages, respectively). The digestible energy concentration, calculated by regression, of whole maize plant increased (P<0.01) with maturity stage (8.5, 9.5 and 10.4 MJ/kg DM, respectively) but the digestible protein value was higher (P<0.01) at the intermediate maturity stage (3.7, 4.5 and 3.2% DM). Rabbits given the diet with 20% plant maize at the maturity stage had similar feed intake (101 vs. 99 g DM/d) and live weight gain (44 vs. 45 g/d) but a worse feed conversion index than C rabbits (2.29 vs. 2.21, P=0.03). No differences were found at slaughter in live weight, carcass characteristics and dressing percentage of rabbits fed the two experimental diets.

SUMMARYIn the present review article, a recapitulation of recent research made with the purpose of decreasing the negative effect produced by the insects Hypsipyla grandella and Hypsipyla robusta (shoot borers) on seedlings of the Meliaceae family is presented, highlighting the mahogany (Swietenia macrophylla) and the cedar (Cedrela odorata) that are considered of high commercial importance due to the structure and quality of their wood in the forestry industry. Hypsipyla spp. has been identified as a potential plague and of commercial interest, as it attacks plants in their first life stages. This attack induces excessive branching, deformation of the stem and in the worst cases the death of the affected seedlings in monospecific plantations. The use of chemical agents (insecticides and pheromones), shade regulation on plantations, implementation of good forestry practices, biological control and the combination of plants with allelopathic principles against the plague in forestry cultures are some of the alternatives evaluated in situ and ex situ for the control or extermination of this plague that for many years has been the object of study of researchers.Key words: Cedrela odorata, commercial importance, monospecific plantations, pests, Swietenia macrophylla. RESUMENEn el presente artículo de revisión se hace una recapitulación de investigaciones recientes que se han realizado con el propósito de disminuir el efecto negativo producido por los insectos Hypsipyla grandella e Hypsipyla robusta (taladrador de los brotes tiernos) en plántulas pertenecientes a la familia de las meliáceas, destacando la caoba (Swietenia macrophylla) y el cedro (Cedrela odorata), consideradas de suma importancia comercial por su estructura y calidad de la madera en la industria forestal, se ha identificado a Hypsipyla spp. como una plaga potencial y de interés comercial por atacar a las plantas en los primeros estadios de vida, puesto que el ataque induce a la formación excesiva de ramas, malformación de fustes y, en el peor de los casos, la muerte de las plántulas afectadas en plantaciones monoespecíficas, desde el uso de agentes químicos (insecticida y feromonas), manejo de la sombra en plantaciones, implementación de buenas prácticas silviculturales, control biológico y la combinación de plantas con principios alelopáticos hacia la plaga en cultivos forestales, son algunas de las alternativas evaluadas in situ y ex situ a fin de controlar o erradicar la plaga que por muchos años ha sido objeto de estudio por investigadores.Palabras clave: Cedrela odorata, importancia comercial, plagas, plantaciones monoespecíficas, Swietenia macrophylla. INTRODUCCIÓNLos taladradores Hypsipyla grandella [Zeller, 1848] e Hypsipyla robusta [Moore, 1886] (Lepidoptera: Pyralidae) son plagas potenciales y económicamente importantes porque atacan los brotes tiernos terminales y en algunas ocasiones el fuste de los individuos arbóreos pertenecientes a la familia de las meliáceas (importantes en los mercados madereros a nivel mundial) como la caoba (Sw...

Objective: Determine if prewean steer and heifer calves given two phytogenic starter supplements containing caraway, licorice, oak bark and vanilla which is soluble in milk (PM) or phytogenic supplement containing caraway, licorice, oak bark and vanilla (PC) or no phytogenic supplement, control (C), at a commercial calf ranch increases starter intake, weight gain or rumen development.Materials and Methods: Holstein calves (124) were randomly assigned to 1 of 3 treatments, C, PM or PC, at 2 d of age. Supplements PM or PC were added to individual feed buckets at each feeding at the rate of 0.25g / kg starter at AM and PM feedings. Calves were weighed at enrollment and at weaning, and blood samples were collected from a subset of 13 calves per treatment to assess rumen development. Weekly average DMI, milk intake, Glu and BHB were analyzed using the Mixed procedure of SAS (v. 9.4) Results and Discussion: Weekly average DMI (P < 0.01), BHB (P < 0.01) and Glu (P < 0.01) were different by week but not by treatment. Product PC group was numerically greater in total DMI, gain, ADG and had faster rumen development indicated by overall higher BHB values but were not different among treatments.Implications and Applications: Addition of PM or PC to starter feed did not increase DMI, rumen development or body weight gain. But, the dose may have been too small or not fed long enough to elicit a response during the pre wean period.

Three hundred young rabbits were divided into three groups at weaning and given ad libitum a control diet (C), or an experimental diet in which 0·20 of control diet was substituted by maize ear (E) or by whole maize plant (P) in order to examine their effects on fattening rabbits performance, carcass characteristics and meat quality. No significant differences were found in live-weight gain (45 g/day) or in food intake between diets but food conversion ratio was higher in the P group (2·4 g dry matter (DM) per g gain) than in E group (2·2 g DM per g gain). The rate of mortality was similar in the three groups. No differences between groups on live weight (2152 g) or in the digestive tract weight (437 g) were found and the dressing yield was similar in the three groups. At constant carcass weight, the carcasses of rabbits of the P group had lesser lumbar circumference and higher length to circumference ratio (P<0·0001) than of the C or E groups. No differences were found in the weights of liver or thoracic viscera, but kidneys of rabbits of P group were lighter than of the C or E groups. No differences between groups were found in the weights of scapular fat, perirenal fat, forelegs or thoracic cage, but the loin of rabbits of P group was heavier (291 v. 286 g) than in the other groups. Meat of rabbits P had higher L* and b* parameters of colour and higher water-holding capacity (P=0·003) but the meat of rabbits of the control group had less lipids (31 v. 36 g/kg meat) and more moisture (739 v. 735 g/kg meat) than of the experimental groups. The proportion of protein was higher in E group than in P group. Intra and intermuscular fat of hind leg meat from rabbits ‘maize’ substituted was more monounsaturated than control rabbits (34·2 v. 32·5 g·100 g lipids) and had lesser saturated: monounsaturated ratio (1·2 v. 1·3) indicating a more desirable meat from a nutritional point of view, but had less n-3 fatty acid content. Loin meat of the rabbits given E and P diets seems more tender than one fed conventionally (10·4 v. 11·4 kg) and meat of the rabbits ‘whole maize plant’ had more grass flavour (P=0·009) which is a positive factor for acceptability of consumers.