World Rabbit Science - Vol. 03 (3)-1995
Tabla de contenidos
- HETEROSIS, MATERNAL AND DIRECT GENETIC EFFECTS FOR LITTER PERFORMANCE AND REPRODUCTIVE INTERVALS IN RABBIT CROSSES
- USING SOME ANTIBIOTICS AND PROBIOTICS FOR ALLEVIATING HEAT STRESS ON GROWING AND DOE RABBITS IN EGYPT
- COPPER-PROTEIN NUTRITION OF NEW ZEALAND WHITE RABBITS UNDER EGYPTIAN CONDITIONS
- GENETIC AND NON-GENETIC FACTORS AFFECTING MILK PRODUCTION AND PREWEANING LITTER TRAITS OF NEW ZEALAND WHITE DOES UNDER EGYPTIAN CONDITIONS
- EFFECTS OF HEAT STRESS AND AGE ON GROWTH PERFORMANCE AND ENDOCRINE STATUS OF MALE RABBIT
- LA CUNICULTURE CHINOISE
- THE INFLUENCE OF FEEDING ON THE CHEMICAL COMPOSITION OF CARCASSES AND ON PELT QUALITY IN THE CASTOR REX RABBIT
URI permanente para esta colecciónhttps://riunet.upv.es/handle/10251/10377
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Item type: Artículo , Access status: Abierto , USING SOME ANTIBIOTICS AND PROBIOTICS FOR ALLEVIATING HEAT STRESS ON GROWING AND DOE RABBITS IN EGYPT(World Rabbit Science. ICTA. UPV, 1995) Abdel-Samee A.M.[EN] The influence was studied of different heat loads connected with the application of sorne antibiotics and probiotics on growth and reproductiva traits of 105 growing and 70 doe New Zealand White rabbits. The augmentation in environmental temperaturas increased the respiration rate and rectal temperatura significantly, while it significantly decreased daily body gain (24 %) and daily concentrate intake (18 %) in growing rabbits. Similarly,in does, litter size at birth and at weaning, viability percentage, young individual weight at birth and at weaning and gain from birth to weaning decreased significantly by 17, 31, 16, 27, 19 and 18% respectively. During summer, application of antibiotics: Avoparcin (AV), Flavomycin (FL) or Zinc bacitracin (ZB), or probiotics : e1ther Bospro (BS) or Lacto-Sacc (LS), had positiva effect on the physiological status of the arnmals and 1mproved significantly most of the growth and reproductiva traits studiea. This 1mprovements mclude thermoregulation (as observad by respiratory rate decreasing) and daíly body gain of fattening rabbits, conception rate (67 vs 57 %), litter size at weaning, young individual weight at birth and at weaning and body gam from birth to weaning of does. However, these improvements does not reach the levels observad in spring.Item type: Artículo , Access status: Abierto , THE INFLUENCE OF FEEDING ON THE CHEMICAL COMPOSITION OF CARCASSES AND ON PELT QUALITY IN THE CASTOR REX RABBIT(World Rabbit Science. ICTA. UPV, 1995) Petersen, A.[EN] The influence of feeding intensity on the chemical composition of skinned whole carcasses and on fur quality was examinad in 2 groups of Castor Rex rabbits, fed ad libitum (n = 8 ¿ and 8 <¡>¡ and 75 % of ad libitum (n = 8 ¿ and 8 <j>), respectively. The rabbits were born in June and pelted in December at 179 days of age. Feeding intensity strongly affected body weight at pelting (P<0.001). fat co. ntent (P<O.OOU, protein content (P<0.01 ), and water content (P<0.001 of the carcass, but did not affect the content of ash and resi ues. The restricted group had an 11 % lower body weight and the carcasses contained 4.1 % more water, O. 7 % more protein, and 4.9 % less fat than the group fed ad libitum. The females were significantly (P<0.05) fatter than the males (fat content 14.6 against 11.5 %). The restricted group had significantly (P<0.05) longer hair (point 3.8 against 2.9) and significantly (P<0.05) stiorter/smaller (5 %) skin length/skin size, whereas no significant differences were found in hair density, colour, quality and skin weight. The group fed ad libitum tended, however, to have the darkest skins and the restricted group the best hair density and quality and the lightest pelts (= dried skins).Item type: Artículo , Access status: Abierto , LA CUNICULTURE CHINOISE(World Rabbit Science. ICTA. UPV, 1995) Colin, M.[EN] The exact origins of rabbit domestication in China are still not very well known, and different hypotheses regarding them have been formulated. Globally, the Chinese rabbit production is mainly angora wool production orientad. This represents a value 2,5 times higher than meat and an important part of the meat comes from young angora rabbits. Nevertheless, a high number of meat proauct1on orientad rabbit farms exist in China. From a geographic point of view, the rabbit is developed mainly in Sichuan and near the coast. Globally, more than 90 % of the rabbit production comes from little farms with only few does even if sorne big rabbits farms also exist. Rabbit meat production is very popular in certain areas as in Sichuan, but appears to practically unknown in many other regions. The main market for Chinese rabbit meat is export from which the amount is about 40 000 tons/year sold mainly in the EEC. The angora wool exports are very important also and China is the absoluta leader of this market. China produces a total of 120 000 tons/year of rabbit meat and 6 000 tons/year of angora wool ; consequently, the rabbit sector is very important for Chinese economy and besides its contribution to increase meat and fibre availability within the country, it provides hard currency incomes of about 2 billions dollars/year.Item type: Artículo , Access status: Abierto , HETEROSIS, MATERNAL AND DIRECT GENETIC EFFECTS FOR LITTER PERFORMANCE AND REPRODUCTIVE INTERVALS IN RABBIT CROSSES(World Rabbit Science. ICTA. UPV, 1995) KHALIL, M.H.; AFIFI, E.A.; YOUSSEF, Y.M.K.; KHADR, A.F.[EN] A crossbreedin~ experiment was carried out in Egypt involving a local breed Baladi Red, BR) and an exotic one (New Zealand White, N ) to estimate direct heterosis, maternal additive effects and direct additive effects on sorne litter traits and reproductive intervals in doe rabbits. Litter traits included litter size and weight and mean young weight (at birth, 21 days and at weaning), number born alive and preweaning litter gain and mortalitv, while reproductive mtervals included days open (intervaí from kindling to next conception) and kindling interval (period between two consecutive parturitions). Data were analysed using a linear mixed model. Winter kindlings recorded the largest litter size and the heaviest weight and gain of litter weight up to weaning along with the lowest preweaning mortality compared to autumn and spring kindlings. Heterosis was found at weaning on litter size and weight at weaning and on sorne interval traits but not on litter size at birtn, where negativa values are found. Crossbred litters obtained from mating BR bucks with NZ does were generally associated with superiority comparad to those litters obtained from the reverse mating. Maternal additive effects on all litter traits were in favour of NZ bread, although the differences between the two breeds were not significant. In terms of reproductiva intervals, BR-mothered litters recordad shorter intervals comparad to NZ-mothered litters. For all litter traits and reproductive intervals, the direct additive effect was not significant. NZ-sired litters had higher direct additive effects comparad to BR-sired litters, while BR-sired litters recordad shorter reproductiva intervals relativa to NZ-sired litters.Item type: Artículo , Access status: Abierto , EFFECTS OF HEAT STRESS AND AGE ON GROWTH PERFORMANCE AND ENDOCRINE STATUS OF MALE RABBIT(World Rabbit Science. ICTA. UPV, 1995) Chiericato, G.M.; Boiti, C.; Canali, C.; Rizzi, C.; Ravarotto, L.; Consiglio Nazionale delle Ricerche, Italia[EN] The effect of environmental temperature and age on plasma hormonal concentrations of testosterone (Tl, dihydrotestosterone (DHT}, cortisol (C), triiodothyronine (T3) and thyroxine (T4) were evaluated in 40 male Grimaud rabbits. Twenty animals were reared at 20ºC (TNT = Thermic Neutrality Temperature) and the other 20 at 27ºC (HST = Heat Stress Temperature). Far both treatments relative humidity levels averaged 77 % and the photoperiod was 8D:16L with a light intensity of about 40 lux. The animals were fed ad libitum with a commercial pelleted feed. Blood samples were collected from each ammal by intracardiac puncture at 71 and 85 days of age. No interaction effect between temperature and age was found. With regard to effect of temperature, the HST animals hada lower (P<0.01) final body weight (2325 vs 2555 g), daily gain (32. 7 vs 38.1 g) and feed intake (106 vs 126 g/d). The HST treatment significantlr (P<0.05) decreased plasma levels ot T (1.01 vs 1.96 ng/ml , DHT (0.42 vs 0.73 ng/ml) and T + DHT (1.43 vs 2.66 ng/ml , but not the T/DHT ratio (2.69). TNT animals had higher (P<0.01) plasma levels of T3 (1.30 vs 1.01 ng/ml) and a lower (P<0.01) T 4/T3 ratio (32. 7 vs 41.3). The concentrations of C (18.9 ng/ml} and r 4 (41.0 ng/ml) resulted unchanged. The effect of age in the older rabbits was a significantly higher (P<0.01) final body weight (2698 vs 2181 g) daily intake (123 vs 109 g) and feed/gain ratio (3.44 vs 3.12 g/g). No significant difference was observed in plasma concentrations of T (1.48 ng/ml), DHT (0.58 ng/ml), T/DHT (2.69) and T + DHI (2.05 ng/ml} in 71 and 85 days old rabbits. Age had no effect on C levels, which averaged 19.0 ng/ml. In blood samples of younger and older rabb1ts there was no difference in T3 (1.16 ng/ml}, T4 (41.0 ng/ml} values and T4/T3 ratio (37.0). Correlations and linear regression equations were also calculated far daily gain (DG), digestible energy intake per unit of metabolic body weight (DET/MBW) and each hormone plasma level. Only the thyroid hormones showed significant correlations : T3 was positively (P<0.01) correlated with DG (r = 0.624) and DEl/MBW (r = 0.749), whereas the T4/T3 ratio was negatively influenced (P<O.Oi) by DG (r = - 0.563) and DEl/MBW (r = - 0.654).Item type: Artículo , Access status: Abierto , COPPER-PROTEIN NUTRITION OF NEW ZEALAND WHITE RABBITS UNDER EGYPTIAN CONDITIONS(World Rabbit Science. ICTA. UPV, 1995) AYYAT, M.S.; MARAI, I.F.M.; ALAZAB, A.M.[EN] One hundred and twenty male New Zealand White (NZW) rabbits of 35 days of age were randomly allotted to twelve groups. Rabbits of six groups were fed a low protein diet (f6.44 % crude protein) and the other six were fed a high protein diet (18.5 % crude protein). Within each dietary protein level, three groups were supplemented with copper sulfate to supply e1ther O, 100 or 200 ppm copper/kg diet, while the other three were supplemented with copper cflloride to supply the same levels of copper. Most of the studied traits were affected positively with the increase in each of protein and copper levels in the diets of NZW rabbits without interaction. The affected traits were : live body weight and daily gain ( Protein high vs low : 28.2 vs 23.4 g/d ; Cu 0- 100-200 ppm : 22.1-25.9-29.2 g/d ; P<0.001), feed conversion, protein efficiency, nutrient digestibility and final margin, as well as, concentration of serum protem, albumin (Protein high : + 12 % vs low ; Cu 100 and 200 ppm : 8 % and 17 % vs O ppm ; P<0.001), urea, creatinine (P<0.01) and SGOT (P<0.05). Feed cost, serum globulin level, SGPi and sorne carcass and non-carcass components were insignificantly affected by levels of either protein or copper. Dressing percentage increased slightly with the increase of dietary protein and copper levels, while empty gut percentage (relatively to live body weight) decreased w1th addition of copper in rabbit diets. The effects of copper source and the interaction between protein level and each of copper level and source on the traits studied, did not show any significance.Item type: Artículo , Access status: Abierto , GENETIC AND NON-GENETIC FACTORS AFFECTING MILK PRODUCTION AND PREWEANING LITTER TRAITS OF NEW ZEALAND WHITE DOES UNDER EGYPTIAN CONDITIONS(World Rabbit Science. ICTA. UPV, 1995) AYYAT, M.S.; MARAI, I.F.M.; EL-SAYIAD, GH.A.[EN] To study the genetic and non genetic factors affecting doe milk production and preweaning litter performance, 519 litters of New Zealand White raboit were used. Sire significantly (P<0.05) affected milk yield of the first week only, while doe afl'ected siQnificantly (P<0.01) milk yield of most of the experimental penods except the fourth week which was insignificantly affected. Milk yield was the highest in the second parity. Season of kindling affected significantly (P<0.01) milk yield in most of the weeks of the study, except the fourth which was insignificantly affected and showed the lowest yield at summer. Litter size at birth affected significantly (P<0.01) milk yield which increased by the increase of the number of young at birth. The peak of milk production was 155.3 g/day at the third week of lactation. Sire affected insignificantly most of preweaning performances traits studied except litter size at birtfl (P<0.05). Doe affected significantly (P<0.01) litter size and weight at birth and weaning. Parity affected significantly (P<0.01) each of litter size and weight at weaning as well as preweaning mortality. Season of kindling affected rnsignificantly litter size and weight at birth and significantly (P<0.01) at weaning. Days open (from kindling to fertile mating) showed highly s1gnificant (P<0.01) effects on all preweaning litter traits studied. Each of heritability and repeatability estimates for milk yield and litter performance traits studied were, in general, low.