Milk production of pseudopregnant multiparous does

The aim of the experiment was to evaluate the milk production of pseudopregnant does. In this experiment, data of multiparous, inseminated, pregnant (IP, n=15) does and two groups of presumably pseudopregnant multiparous does: inseminated, non-pregnant (INP, n=17) and induced to ovulation by GnRH (1.5 microgram per animal) at the day of insemination (11 d after parturition) (non-inseminated, ovulating: NIO, n=15) were analysed. The progesterone level was measured at the 12th d after treatment to determine if females were pseudopregnant. All IP and NIO does were pregnant and pseudopregnant, respectively. Within the INP group, 10 and 7 does were diagnosed as positive (INPO) or negative (INPNO) for pseudopregnancy. Two of the INPNO does perished during lactation. The average milk production of groups IP, INP and NIO was 212, 92 and 72 g/d, respectively (P160 g in the various groups were: IP=0, 0, 0, 0 and 100%, NIO=20, 13, 27, 40 and 0%, INP=15, 15, 15, 55 and 0%, respectively. The daily milk yield of the 5 INPNO does was 2, 6, 27, 84 and 139 g, respectively. These results demonstrated that multiparous empty does, pseudopregnant or non-pseudopregnant, can produce milk, but in lower quantities than multiparous does after kindling.Szendrö, Z.; Matics, Z.; Brecchia, G.; Theau-Clément, M.; Nagy, Z.; Princz, Z.; Biró-Németh, E.... (2010). Milk production of pseudopregnant multiparous does. World Rabbit Science. 18(2). doi:10.4995/WRS.2010.18.1018

Effect of group size and stocking density on productive, carcass, meat quality and aggression traits of growing rabbits

[EN] The aim of the experiment was to examine the effect of group size and stocking density on productive, carcass and meat quality traits. The trial was conducted using 230 Pannon white rabbits weaned at 5 weeks and reared until the age of 11 weeks. Seven groups were formed with different cage/pen sizes (group size) and stocking densities: SC16=small cage (0.12 m2), 16 rabbits/m2 (2 rabbits/cage); LC16=large cage (0.50 m2), 16 rabbits/m2 (8 rabbits/cage); LC12=large cage, 12 rabbits/m2 (6 rabbits/cage); SP16=small pen (0.86 m2), 16 rabbits/m2 (13 rabbits/cage); SP12=small pen, 12 rabbits/m2 (10 rabbits/cage); LP16=large pen (1.72 m2), 16 rabbits/m2 (26 rabbits/cage); LP12=large pen, 12 rabbits/m2 (20 rabbits/cage). Stocking density did not affect production significantly, as stocking densities lower than 16 rabbits/m2 had no effect on the growing rabbits¿ performance. Group size (size of the cage or pen) had an effect on certain growth, carcass and meat quality traits. Increasing group size resulted in lower values for weight gain (SC: 39.2>LC: 39.0> SP: 38.7> LP: 37.8 g/d; P=0.22) and body weight (SC: 2506>LC: 2498> SP: 2487> LP: 2446 g; P=0.35), similarly to other results in the literature, but the differences were not significant. Aggressive behaviour was observed to be more frequent in the larger group sizes. At the age of 11 weeks the proportion of rabbits with ear lesions in the SC, LC, SP and LP groups were 0.0, 7.1, 8.7, and 17.4%, respectively, demonstrating that larger group size increases the risk of ear lesions. The effect of group size on the ratio of the fore part to the reference carcass (SC: 28.5, LC: 28.2, LP: 29.0%; P=0.02) and on the amount of perirenal fat (SC: 21.3, LC: 18.0, LP: 13.7 g; P<0.001) was significant. Meat quality traits (dry matter, protein, fat and ash content, drip loss, pH, L*, a*, b* values) were not affected by group size (cage vs. pen), but successful discriminations were performed using the NIRS method.The authors gratefully acknowledge the financial assistance received from the GAK OMFB-01335/ALAP1- 00121 project.Szendrö, Z.; Princz, Z.; Romvári, R.; Locsmándi, L.; Szabó, A.; Bázár, G.; Radnai, I.... (2009). Effect of group size and stocking density on productive, carcass, meat quality and aggression traits of growing rabbits. World Rabbit Science. 17(3):153-162. https://doi.org/10.4995/wrs.2009.65515316217

Effect of different management methods on the nursing behaviour of rabbits

[EN] The aim of the experiments was to examine the nursing behaviour of does under different management methods. A continuous video recording with time lapse recorder (24 hours a day) was used. The experimental groups were: FF: Free nursing between parturition and day 16 (n=10 does); FC: Free nursing between parturition and day 9 and controlled nursing between day 10 and 16 (from 08:00 a.m. to 08:30 a.m., n=10); CF: Controlled nursing between parturition and day 9 and free nursing between day 10 and 16 (n=10); HF: The access to the nest box was free during an interval of 16 hours/ day (from 04:00 p.m. to 08:00 a.m.) between parturition and day 16 (n=8). All does were observed between the 1st and 9th day, 74.8 percent of the does nursed once a day and 25.2% nursed more then once a day. The same values were 78.4 and 21.6 percent between the 10th and 16th day. In the CF group, a higher frequency of more than once-a-day-nursing was observed (36.2% of all cases). Between 1st and 9th and 10th and 16th day in the FF group 74.5 and 84.6% of nursing events were in the period of darkness (between 09:00 p.m. and 05:00 a.m.). The corresponding figure in the CF group was 39.3 because of the high frequency of double nursing. It seems that the change from controlled nursing to free has a significant effect on the increased frequency of double nursing. The interval between the evening and morning nursing events of twice-a-day-nursing does was 8 hours and 42 minutes. The duration of daily nursing was decreased during the period of observation. The duration of once a day nursing was significantly shorter than that of the first or the second nursing event of does that nursed twice a day. When changed from free to controlled nursing (Group FC) the behavioural patterns of the doe become nervous (head contact, scraping, wire biting) as can be frequently observed several hours before the nest box is opened. Does tend to adapt to the new nursing method within a few days.Matics, Z.; Szendrõ, Z.; Hoy, S.; Nagy, I.; Radnai, I.; Biró-Németh, E.; Gyovai, M. (2004). Effect of different management methods on the nursing behaviour of rabbits. World Rabbit Science. 12(2):95-108. doi:10.4995/wrs.2004.578SWORD9510812

Preparation of Chitosan Particles Suitable for Enzyme Immobilization

Macro-, micro- and nanosized chitosan particles suitable as immobilization carriers were prepared by precipitation, emulsion cross-linking and ionic gelation methods, respectively. Effects of particle preparation parameters on particle size were investigated. Activities of β-galactosidase covalently attached to differently sized particles have been evaluated and compared. The highest activity was shown by the biocatalyst immobilized on nanoparticles obtained by means of the ionotropic gelation method with sodium sulphate as gelation agent. β-Galactosidase fixed on macro- and microspheres exhibited excellent storage stability in aqueous solution, with no more than 5% loss of activity after 3 weeks storage at 4 °C and pH 7.0

EFFECT OF BIRTH WEIGHT AND LITTER SIZE ON GROWTH AND MORTALITY IN RABBITS

[EN] Two experiments were performed with Pannon White rabbits. In the first experiment 50 litters were formed with 6, 8 or 1 O rabbits of different birth weight in equal ratios (n = 380, between 39 and 70g). In the second experiment 60 litters of 6, 8 or 1 O rabbits were formed (n = 456), each litter consisting of rabbits of a single weight group only (small: 39 to 43g; medium: 53 to 56 g; large: 63 to 70 g). With increasing birth weight and decreasing litter size, mortality in the suckling rabbits decreased and daily weight gain of kits and weight of rabbits up to 1 O weeks of age increased significantly. These effects were weaker in experiment 2. In the extreme groups used in the experiments (1 O small kits and 6 large kits) the following results were obtained : mortality between birth and 21 days was 35.3 and 8.1 % in experiment 1 and 18.0 and 5.6 % in experiment 2, daily weight gain of kits between birth and 21 days was 9.2 and 18.5 g in experiment 1 and 10.8 and 16. 7 g in experiment 2, and body weight at 1 O weeks of age was 1.90 and 2.58 kg in experiment 1 and 2.11 and 2.45 kg in experiment 2. In conclusion, intra-litter homogenisation of birth weight markedly reduced mortality in small rabbits and standard deviation in live weight within litters.[FR] Des lapins de souche Pannon White ont été utilisés pour deux expérimentations consécutives. Dans la premiére, il a été constitué 50 portées comprenant 6, 8 ou 1 O lapereaux de poids différents a la naissance mais en proportions égales (380 lapereaux au total, pesan! a la naissance entre 39 et 70g). Dans la seconde expérimentation, 60 portées ont été constituées (n = 456 lapereaux) comprenant toujours 6, 8 ou 1 O lapins, mais chaque portée n'était constituée que de lapins du méme groupe de poids ( petit : 39 a 43 g ; moyen : 53 a 56g et gros : 63 a 70g). L'accroissement du poids a la naissance et la diminution de la taille de la portée sont associés a une réduction de la mortalité chez les lapereaux allaités et a un accroissement significatif de la vitesse de croissance des lapins et de leur poids vif jusqu'a 1 O semaines. Ces effets son! atténués dans la deuxiéme expérimentation. Dans les groupes extrémes ("petits" dans des portées de 1 O lapereaux et "gros" dans des portées de 6) les résultats suivant ont été obtenus : mortalité entre la naissance et 21 jours : 35,3 et 8, 1 % da ns l'expérimentation 1 , mais 18,0 et 5,6% dans la 2 ; gain de poids journalier de la naissance a 21 jours : 9,2 et 18,5g pour l'exp. 1, mais 10,8 et 16,7 pour l'exp. 2 ; le poids vif a 1 O semaines a été de 1 ,90 et 2,58kg pour l'exp. 1 , mais de 2, 11 et 2,45kg pour l'exp. 2. En conclusion, l'homogénéisation des portées selon le poids a la naissance réduit considérablement la mortalité pour les lapereaux les plus légers a la naissance et l'écart de poids entre les portées.Poigner, J.; Szendrõ, Z.; Lévai, A.; Radnai, I.; Biró-Németh, E. (2000). EFFECT OF BIRTH WEIGHT AND LITTER SIZE ON GROWTH AND MORTALITY IN RABBITS. World Rabbit Science. doi:10.4995/wrs.2000.413SWORD08

Three-step experimental design to determine the effect of process parameters on the size of chitosan microspheres

Investigation was carried out to elucidate the influence of process parameters on the mean particle size of chitosan microspheres produced by water-in-oil (w/o) emulsion crosslinking method. The aqueous chitosan solution was dispersed in the oil phase composed of 40% (v/v) sunflower oil and 60% (v/v) n-hexadecane in the presence of Tween 80 surfactant. The droplets were solidified and hardened by glutaraldehyde crosslinking agent. The particle size of the obtained microspheres was influenced by four independent process variables, such as stirring rate, and the concentrations of chitosan, Tween 80 and glutaraldehyde. To study these effects, 4-factorial 3-level Box-Behnken type experimental design and statistical analysis of the experimental results were carried out in three consecutive steps. First, the 4 independent factors at 3 levels were taken into consideration without repetitions, resulting in 27 scheduled experiments. Second, the design was completed by further experiments to check the effects of some of the variables at five levels both inside and outside the original factor intervals used in the first step. In addition, five repeated experiments at the central points of the four factors were also involved in the second step to determine the pure error. In order to elucidate the effects of process variables on the mean particle size, non-linear multidimensional regression was determined. Third, the less significant effects were neglected resulting in a simplified model equation that proved to be suitable for the prediction of the mean particle size as a function of the studied process parameters. (c) 2008 Elsevier B.V. All rights reserved

EFFECTS OF THE TIME OF INSEMINATION AND LITTER SIZE ON THE GESTATION LENGTH OF RABBITS

[EN] Pannon White nulliparous and multiparous does were divided into two groups and inseminated at 8:00 a.m. (n = 587) or at 8:00 p.m. (n = 548). On the basis of 390 and 346 kindlings respectively, it was established that the 12-hour time difference between inseminations had no effect on the length of gestation (31.73 and 31.67 days, respectively). The time of parturition was also influenced by the time of day. Does most often kindled between 22:00 and 04:00 and least often during the day (between 10:00 and 16:00). Parity significantly influenced gestation length (first parity: 31.42 days, 8th -10th parities: 32.15 days, P < 0.05). Litter size at insemination had no effect but litter size at birth exerted a significant effect on gestation length: with the increase of litter size the gestation length shortened (litters of 1 and 2 young: 32.42 - 32.46 days, litters of 9 -14 young: 31.32-31.50 days, P < 0.05).Rashwan, A.; Szendrõ, Z.; Matics, Z.; Szalai, A.; Biró-Németh, E.; Szendrõ, E.; Nagy, I. (2003). EFFECTS OF THE TIME OF INSEMINATION AND LITTER SIZE ON THE GESTATION LENGTH OF RABBITS. World Rabbit Science. 11(2):75-85. doi:10.4995/wrs.2003.499SWORD758511

A study of the carcass traits of different rabbit genotypes

[EN] The aim of this experiment was to study the carcass traits of rabbits when the same maternal stocks were mated with bucks of two well-known hybrids selected for growth traits or with Pannon White bucks selected for carcass traits by CT (computerised tomography). Three experiments were carried out at the same time. Experiment 1: Pannon White (P) or Hycole terminal (H) males were crossed with Pannon White (P) does (n=PP: 60, HP:59). Experiment 2: Pannon White (P), Hycole terminal (H) or Zika terminal (Z) bucks were crossed with Hycole (H) parent does (n=PH: 60, HH:52 and ZH:58). Experiment 3: Pannon White (P) or Zika terminal (Z) males were crossed with a Maternal line (M) stock (n=PM: 60, ZM:58). In all the experiments, hybrid males increased their body weight. Mating the same maternal stock with hybrid or Pannon White bucks, the body weight of the offspring of hybrid males was higher than that of the offspring of Pannon White bucks (Experiment 1: PP and HP:2644 and 2758 g, P<0.001; Experiment 2: PH, HH and ZH:2611, 2671 and 2890g, P<0.001; Experiment 3: PM and ZM:2534 and 2677 g, P<0.001). The most important carcass traits differences were found in rabbits originated from Pannon White males. Genetic origin influenced the dressing out percentage, which was 0.5% higher in PP rabbits compared to the HP group in Experiment 1 (60.6 and 60.1%, resp.; P=0.092); 1% higher in PH and ZH genotypes compared to HH animals in Experiment 2 (in PH, ZH and HH:59.6, 59.7 and 58.7%; P=0.008), and 1.5% higher in PM than in ZM rabbits in Experiment 3 (61.0 and 59.5%, resp.; P<0.001). The ratio of the m. Longissimus dorsi to reference carcass weight was also higher in rabbits derived from P males in Experiments 2 and 3 (Experiment 2: PH:11.2, HH:10.8, ZH:10.5%, P<0.001; Experiment 3: PM:11.5, ZM:10.6%, P<0.001), while it did not differ in Experiment 1. Significant difference in fat deposit was found only in Experiment 3, progeny of Pannon White males had higher weight (22.3 vs. 16.6g, P=0.002) and ratio of perirenal fat (1.65 vs. 1.25%, P=0.003) compared to offspring of Z males. Results of the dressing out percentage and the ratio of m. Longissimus dorsi proved that the selection based on CT (Pannon White genotype) was successful.The authors wish to acknowledge the support received from the NKFP 4/034/2001 ProjectMetzger, S.; Odermatt, M.; Szendro, Z.; Mohaupt, M.; Romvári, R.; Makai, A.; Biró-Németh, E.... (2006). A study of the carcass traits of different rabbit genotypes. World Rabbit Science. 14(2). https://doi.org/10.4995/wrs.2006.550SWORD14