Reproductive and productive performance of rabbit does submitted to an oral glucose supplementation

In order to investigate the effect of different levels of oral glucose supplementation and/or reproductive method on productive and reproductive performance of New Zealand White (NZW) doe rabbits in the tropic, 36 bucks and 120 doe NZW rabbits were equally divided among four treatment groups (n = 9 bucks + 30 does). The treatments consisted of supplementing drinking water with 0 (control), 2.5, 5 and 10 g glucose/l, respectively. To study the effect of reproduction method (natural v. artificial), each group was divided into two sub-groups (naturally mated and artificially inseminated) with the same bucks of the same treatment group. Glucose supplementation at 5 or 10 g/l of water increased (P < 0.01) litter weight at birth and at weaning, and litter weight gain during the 4 weeks. However, glucose supplementation at 2.5 or 5.0 g/l water decreased (P < 0.01) feed consumption from 7 to 14 days after delivery. Glucose supplementation at 2.5 g/l water did not affect productive and reproductive performance of rabbits. Artificially inseminated does had higher daily litter weight gain between 21 and 28 days post partum. Artificially inseminated group had better milk conversion during the 1st and 4th week as compared to naturally mated groups. Compared with the control group, the economic efficiency and performance index of NZW rabbits was significantly improved by 5 g glucose supplementation under tropic condition.     

Controlled doe exposure as biostimulation of buck rabbits

Female exposure of males could be a low-cost biostimulation option that benefits AI in commercial rabbit operations by improving buck rabbits reproductive performance. The objective of the study was to evaluate exposure of buck rabbits to females as a biostimulation option to improve reproductive potential. Treatments were: exposure (biostimulated) or not (control) of bucks to does. Bucks were New Zealand White, 15-month-old, sexually experienced and fertile. Experimental design was completely random with nine replications, experimental unit was one buck. Doe exposure was permanent using replacement pubertal does housed in an adjacent wire-mesh cage and changed for new ones every other week. Semen collection lasted 14 weeks (late winter and early spring) twice a week with two ejaculates at each collection. Analyses of variance were under a mixed model: treatments, ejaculate number and season were fixed and rabbit random effects and buck weight at each collection as covariable. Biostimulated bucks showed greater (P<0.05) reproductive potential due to: 7% lesser reaction time (greater libido); and increased semen volume (40%), sperm motility (29%), sperm per ejaculate (31%), normal alive motile sperm (65%) and number of semen doses (64%). Semen characteristics differed by season in control bucks but not in doe exposed bucks (treatment × ejaculate number, P<0.05). Reproductive potential in spring was greater (P<0.05) than in winter in both treatments. Doe exposure is a biostimulation method that improves sexual drive and sperm production and quality of buck rabbits.     

Semen quality, testosterone, seminal plasma biochemical and antioxidant profiles of rabbit bucks fed diets supplemented with different concentrations of soybean lecithin

A total of 28 adult V-line rabbits were fed ad libitum a control diet or a diet supplemented with 0.5%, 1.0% and 1.5% soybean lecithin (SL) for 12 weeks. Bucks that received 0.5%, 1.0% or 1.5% dietary SL had a higher ejaculate volume, mass motility, sperm concentration, total sperm output and total motile sperm. Dietary SL reduced the percentage of dead sperm and increased the normal sperm, and this concurred with an increase in blood testosterone concentration. Blood and seminal plasma total lipid, acid phosphatase and seminal plasma alkaline phosphatase were significantly increased because of inclusion of SL. Interestingly, SL reduced blood and seminal plasma thiobarbituric acid-reactive substances while increasing blood and seminal plasma glutathione content, glutathione S-transferase, glutathione peroxidase and superoxide dismutase activity. Conception rate and litter size at birth and weaning were also significantly improved. Practically, it could be suggested that SL is a suitable supplement for improving semen quality, antioxidant status, reproductive traits and the economic efficiency of V-line rabbit bucks and 1% is an adequate concentration.     

Fertility of fresh and frozen rabbit semen inseminated at different times is indicative of male differences in capacitation time

Some reports indicate that sperm from different males differ in capacitation time, and other reports suggest that freezing sperm may affect their capacitation time. These two variables were specifically studied in rabbits in a fertility trial with 96 does inseminated with approximately 1.6 million motile fresh or frozen sperm from three different bucks at 15, 10, 5, and 0 h before expected ovulation. Fresh semen averaged 84% live (unstained) sperm and 88% had normal acrosomes; corresponding values for frozen sperm were 44% and 54%. On the basis of does that became pregnant, average litter size with fresh semen was 5.5 and with frozen semen was 4.8 (p greater than 0.05), but overall, does bred with frozen semen produced fewer young (p less than 0.05). On the basis of total does and total semen, average litter size from insemination at 15, 10, 5, and 0 h was 2.8, 4.2, 3.8, and 1.7, and average litter size for the three bucks was 4.0, 1.8, and 3.6. There was no interaction of type of semen (fresh or frozen) with the other variables in the model (p greater than 0.05). Bucks and time of insemination affected both the proportion of does that were pregnant and litter size (p less than 0.01). A major interaction between buck and time of insemination (p less than 0.01) was due apparently to both differential sperm survival and probable capacitation time among bucks. This major interaction should be considered in designing in vitro and in vivo fertility studies, and for selecting males for use in artificial insemination.     

Sociality, time and space in a sparse population of rabbits (Oryctolagus cuniculus)

This 10-year study describes a sparse population of rabbits ( Oryctolagus cuniculus ) living in small, semi-isolated groups on river flats with some scrub in an otherwise forested valley. The rabbits lived above ground in the scrub by day and fed in the open at night. They bred in isolated 'stops' dug in the shingle often far from suitable grazing for the young. Many stops collapsed, killing the young. Home ranges were recorded by radio telemetry. Bucks had larger ranges than does and spent less time in the scrub. Adults of both sexes were sedentary for life. Some bucks travelled > 500 m at night. Most ranges were too large to be defended strictly; night feeding grounds were often communal. In the evening, adult rabbits spent 44% of the time feeding and 33% inactive. Social interactions were frequent. At all seasons, in the evening most adult rabbits were seen singly or as pairs. Pairs seldom remained intact for > 12 months even when both partners were alive. The buck of the pair was usually older than the doe because bucks outlived does. The adult survival rate was about 0.80 for bucks, 0.55 for does. Four bucks lived for > 7 years. Few young survived for long after leaving the nest; many were killed by predators. Dungheaps, used for 60% of the droppings, were concentrated near the scrub where rabbits congregated in the evening. The behaviour of these rabbits differed in many ways from that of rabbits in enclosures or at higher density in the wild.     

Is caprine arthritis encephalitis virus (CAEV) transmitted vertically to early embryo development stages (morulae or blastocyst) via in vitro infected frozen semen?

The aim of this study was to determine, in vivo, whether in vitro infected cryopreserved caprine sperm is capable of transmitting caprine arthritis-encephalitis virus (CAEV) vertically to early embryo development stages via artificial insemination with in vitro infected semen. Sperm was collected from CAEV-free bucks by electroejaculation. Half of each ejaculate was inoculated with CAEV-pBSCA at a viral concentration of 10⁴ TCID₅₀/mL. The second half of each ejaculate was used as a negative control. The semen was then frozen. On Day 13 of superovulation treatment, 14 CAEV-free does were inseminated directly into the uterus under endoscopic control with thawed infected semen. Six CAEV-free does, used as a negative control, were inseminated intrauterine with thawed CAEV-free sperm, and eight CAEV-free does were mated with naturally infected bucks. Polymerase chain reaction (PCR) was used to detect CAEV proviral-DNA in the embryos at the D7 stage, in the embryo washing media, and in the uterine secretions of recipient does. At Day 7, all the harvested embryos were PCR-negative for CAEV proviral-DNA; however, CAEV proviral-DNA was detected in 8/14 uterine smears, and 9/14 flushing media taken from does inseminated with infected sperm, and in 1/8 uterine swabs taken from the does mated with infected bucks. The results of this study confirm that (i) artificial insemination with infected semen or mating with infected bucks may result in the transmission of CAEV to the does genital tack seven days after insemination, and (ii) irrespective of the medical status of the semen or the recipient doe, it is possible to obtain CAEV-free early embryos usable for embryo transfer.     

Aminopeptidase activity in seminal plasma and effect of dilution rate on rabbit reproductive performance after insemination with an extender supplemented with buserelin acetate

Ovulation induction in artificially inseminated rabbits by adding GnRH synthetic analogues in the seminal doses is a welfare-orientated method to induce ovulation in rabbits and could have some advantages in field practice. This study was conducted to determine the effect of male genotype on the aminopeptidase activity in rabbit seminal plasma and the effects of dilution rate of semen on availability and reproductive performance when buserelin acetate is added to the seminal dose. To study the aminopeptidase activity, 12 mature bucks belonging to a paternal line and 12 from a maternal line were used. The bucks from the paternal line were used to study the effect of dilution rate on the availability of buserelin acetate after 2 hours of dilution and on the reproductive performance of the doses after artificial insemination of 389 commercial crossbreed does. Aminopeptidase activity in seminal plasma is dependent on the male genotype. The paternal line resulted 27% more aminopeptidase activity than the maternal line (P < 0.05). On the other hand, semen diluted 1:20 exhibited a marked increase in the availability of buserelin acetate and the fertility in this group was significantly higher than females from dilution rate 1:5 group, which showed similar results to that of the negative control group (does inseminated with semen diluted 1:20 in non–GnRH-supplemented extender). We conclude that the bioavailability of buserelin acetate when added to the seminal dose appears to be determined by the activity of the existing aminopeptidases and is consequently affected by the dilution rate used to prepare the artificial insemination doses.     

The effect of seminal sperm concentration on sperm transport in the reproductive tract of female rabbits treated with progesterone or diethylstilbestrol

Forty-two mature Baladi female rabbits were used in a randomized 3x2 factorial experiment to determine the effects of three treatments (control, progesterone injection: 2 mg/doe and DES injection: 0.1 mg/doe) and two semen sperm cell concentrations (1x10(6) and 60x10(6) sperm/0.25 ml semen on sperm transport and distribution in the female reproductive tract. The injections were given for three consecutive days after which rabbits were injected with 5 IU HCG and inseminated with 0.25 ml semen. The does were sacrificed 10 hrs after insemination and the sperm were recovered and counted from the oviducts, uterine horns, cervices and vagina. Total spermatozoa recovered was high when rabbits were inseminated with 60x10(6) sperm as compared to those inseminated with 1x10(6) sperm. When rabbits were injected with progesterone or DES, the number of sperm recovered relative to the total number of sperm inseminated was high in rabbits inseminated with 1x10(6) sperm, in comparison to those inseminated with 6x10(6) sperm. The number of sperm recovered was highest from cervix which was followed by vagina, uterus and oviducts. DES increased the number of the total sperm recovered while progesterone decreased the number as compared to control. This trend was also observed within the different segments of the reproductive tract and with groups inseminated with 1x10(6) or 60x10(6) sperm/0.25 ml semen. The effect of DES was more obvious with does inseminated with low sperm numbers. Significant correlation coefficients were found between the sperm numbers recovered in the uterus and oviducts and in the cervix and uterus of all groups of rabbits.     

Influence of supplemental dietary sprouted wheat on reproduction in artificially inseminated doe rabbits

The sprouted wheat contains great amounts of 6-methoxybenzoxazolinone (6-MBOA) a phenol compound that stimulates reproduction in certain small wild herbivorous mammals. The objective of the present study was to evaluate the effect of dietary sprouted wheat as supplement on reproduction in artificially inseminated doe rabbits. Two-month-old New Zealand White doe rabbits (n = 48) were randomly allocated to one of two treatments: (1) pelleted diet plus sprouted wheat for 6 consecutive days prior to service, (2) pelleted diet only (control). First insemination occurred when does reach 3200g body weight and bred 6 days after parturition across 6 months period during summer and autumn. Records from 41 does completing the experiment accounted for 192 inseminations and 142 kindlings equivalent to 4.6 +/- 0.15 and 3.5 +/- 0.15 litters per doe, respectively. Mean daily intake of sprouted wheat on wet and dry matter bases were 196.1 +/- 7.5 and 75.4 +/- 2.9g, respectively. The number of young born produced per doe during the trail was significantly (P = 0.02) greater in does fed sprouted wheat (28.1 +/- 1.2 versus 23.6 +/ -1.3 control). Does fed sprouted wheat had 0.65 +/- 0.06 receptivity rate at AI over 28 per cent greater (P = 0.001) than does in the control treatment. Sexual receptivity was not influenced by physiological status of does and season (P > 0.05). Diet and season had no effect (P>0.05) on kindling rate. However, physiological status had an effect (P = 0.002) on this variable. Kindling rates for nulliparous, lactating and non-lactating does were 0.95 +/- 0.08, 0.63 +/- 0.04 and 0.78 +/ -0.11, respectively. Sexually receptive does had a greater (P = 0.0001) kindling rate (0.95 +/- 0.05) than non-receptive females (0.63 +/-0.05). Does fed sprouted wheat produced larger (P = 0.02) litters than those in the control group: 7.7 +/- 0.30 and 6.8 +/- 0.32, respectively. There was an effect of season (P = 0.04) on the size of the litter at birth. Largest litters were born during autumn (7.9 +/- 0.37) than during summer (6.6 +/- 0.41). Receptive does had more (P = 0.002) young in the litter (7.9 +/- 0.28) than non-receptive (6.6 +/- 0.35). Feeding sprouted wheat as a source of biological 6-MBOA enhanced sexual receptivity and prolificacy in artificially inseminated doe rabbits bred in summer and autumn.     

Breed and experience effect on the sexual behaviors of Damascus and Egyptian-Nubian goat bucks

This study compares the sexual behaviors of bucks from two pure breeds of goats, Damascus and Egyptian-Nubian (Zaraibi), and assesses their relationships with the pregnancy and kidding rates of their inseminated does. Twenty-three bucks (12 Damascus and 11 Egyptian-Nubian bucks) were used in this study. These bucks were either in their first season of service (N =12, with an average age of 1.51 years) or had been previously used in service for several seasons (N = 11, with an average age of 3.34 years). Buck service behaviors toward estrous does were continuously recorded for 30 minutes from the moment of appearance of the doe. Egyptian-Nubian bucks were highly sexually active with estrous does in comparison with Damascus bucks. They required less time to mount and ejaculate for the first (P < 0.04) and second times (P < 0.0002) and tended to sniff, nudge and vocalize more frequently than Damascus bucks. In addition, Egyptian-Nubian bucks had more ejaculations and a higher mating efficiency (27.48% vs. 10.21%, P < 0.001), and their inseminated does had a higher pregnancy rate and larger litter sizes. Regarding the effect of experience, the data revealed a limited influence. No significant differences in sexual behavior were recorded between younger and older bucks. Conversely, pregnancy, kidding rates, and litter size were not influenced by the total number of ejaculations. From these results, it can be concluded that there were sexual behavior differences as a function of breed between Damascus and Egyptian-Nubian bucks and that experience had little impact in this study.     

Pre-mating plasma prolactin profile affects California doe rabbit reproductive performance

Ovulation failure was associated with a reduction in pre-mating concentrations of oestradiol-17β and prolactin (PRL). The present study aimed to evaluate whether pre-mating PRL levels have a role in the reproductive efficiency of doe rabbits. A total of 78 multiparous California does (2nd parity) were divided, according to plasma pre-mating PRL, into five categories, >20–25, >25–30, >30–35, >35–40, and >40–45 ng/ml. Does in all categories were naturally mated and kindled, then their reproductive measurements and progesterone (P4) levels were determined. Results show that pre-mating PRL averaged 23.60 ± 0.78, 28.00 ± 0.83, 33.46 ± 0.43, 38.17 ± 0.49 and 41.98 ± 0.68 ng/ml in five categories (p < 0.05), respectively, representing the highest distribution (38.5%) in the 3rd-category. Live body weight of doe rabbits, at mating, pregnancy, and parturition increased (p < 0.05) with increasing pre-mating PRL level. The number of services, litter size, and pregnancy rate increased (p < 0.05) by increasing PRL levels. Reproductive traits and P4 level at mid-pregnancy of does, and the average weight of kits at birth increased (p < 0.05) by increasing PRL levels. The pre-mating PRL profile is important for the identification of reproductive performance in doe rabbits.     

Effect of the buck on number of services per conception,service period and litter size at birth in Bauscat rabbits

A non-significant buck effect on the number of services per conception, service period and litter size at birth in Bauscat rabbits was found using 66 bucks. The within-buck repeatability of number of services per conception and service period of 0.027 ± 0.028 and 0.035 ± 0.029, respectively, were non-significant. The same parameter for litter size at birth could not be obtained because of the negative buck component of variance observed. For this population of rabbits it appeared that no difference in these traits existed among bucks and, as a result, improvement in these traits could not be made by selection of bucks based on their own performance.     

Effect of deoxynivalenol (DON) on growing pigs and its modification by modified yeast cell wall or modified yeast cell wall and bentonite

The study examined effect of two adsorbents on the toxicity of Deoxynivalenol (DON) in growing pigs in a feeding trial. 24 male growing pigs (average initial body weight 11.5 kg) were assigned to one of six dietary treatments: control (uncontaminated diet); control + 0.5% adsorbent I; DON contaminated diet (1.73 mg/kg); DON contaminated diet + 0.5% adsorbent I; control + 0.5% adsorbent II and DON contaminated diet + 0.5% adsorbent II. Two digestibility trials were conducted on the second and fourth week of the feeding period with a sampling period of 7 days to determine the digestibility of the nutrients and the amounts of DON in faeces and urine. At the end of the experiments, the pigs were slaughtered, followed by blood haematology and biochemi analys. These data suggest that the addition of 0.5% modified yeast cell wall or a combination of modified yeast cell wall and bentonite to the naturally DON — contaminated diets reduce the effect of DON on the immune system of pigs but do not play an significant role in detoxification of DON in growing pigs.     

Potential protective effect of HSCAS and bentonite against dietary aflatoxicosis in rat: with special reference to chromosomal aberrations.

Bentonite and hydrated sodium calcium aluminsilicate (HSCAS) were added at a level of 0.5% (w/w) to the diets containing 2.5 mg aflatoxins (AF) per kg diet and fed to male mature rats for 15 successive days. Aflatoxin alone significantly decreased feed intake and altered serum biochemical parameters of liver and kidney functions. Aflatoxin caused chromosomal aberrations in bone marrow cells. Bentonite or HSCAS did not alter any of the parameters measured. The addition of bentonite or HSCAS to the AF-contaminated diet diminished most of the deleterious effects of the aflatoxin. Pathological examinations of liver and kidney proved that both bentonite and HSCAS were hepatonephroprotective agents against aflatoxicosis. The cytogenetic findings demonstrated that the addition of bentonite or HSCAS to AF-contaminated diet suppressed chromosomal aberrations. These findings indicated that bentonite and HSCAS could diminished many of the adverse effect of dietary AF in rats.     

The reproductive response to the male effect of 7- or 10-month-old female goats is improved when photostimulated males are used

The exposure of adult, female, Mediterranean goats during anoestrus to males with induced sexual activity via photostimulation, induces a very high percentage of ovulations. The present work examines the ability of photostimulated bucks to improve the male effect-induced reproductive response of young does over that induced by non-stimulated bucks. A 2×2 factorial experiment was designed, consisting of doe age and buck photoperiod treatments. During seasonal anoestrus, 41 does aged 7 (n=19) or 10 (n=22) months were subjected to the male effect on 10 April; half of each group was exposed to males rendered sexually active by prior exposure to 3 months of long days (16 h of light/day) from 31 October (PHOTO bucks), and half to males maintained under the natural photoperiod (CONTROL bucks). Oestrous activity was recorded daily by direct visual observation of the marks left by male-worn marking harnesses over the 32 days following the bringing of the sexes together (introduction). Doe body weight and body condition were determined weekly. Ovulation was detected by measuring plasma progesterone concentrations twice per week over the 3 weeks after introduction. The ovulation rate was assessed by transrectal ultrasonography. Fecundity, fertility, prolificacy and productivity were also determined. The interaction doe age × buck photoperiod treatment had no effect on any outcome. The percentage of females showing ovulation or oestrus was higher in the does exposed to PHOTO bucks (85% v. 43% for those exposed to CONTROL bucks) they also showed higher fertility (75% v. 43%) and productivity (1.05±0.17 v. 0.57±0.16 kids born per doe serviced) (all P values at least P<0.05). The 10-month-old group showed higher percentage of females showing ovulation, oestrus, fertility and productivity than the 7-month-old does after the male effect (females showing ovulation: 82% v. 42%; showing oestrus: 73% v. 42%; fertility: 73% v. 42% and productivity: 1.09±0.17 v. 0.47±0.14 goat kids born per doe serviced; respectively, all P values at least P<0.05). The present results show that the use of photostimulated males improves the reproductive performance of 7- and 10-month-old does, and may contribute towards increasing their productivity and lifetime reproductive performance.     

The effect of lactating rabbit does on the development of the caecal microbial community in the pups they nurture

AIMS: To study the effect of microbial community of the rabbit does as influenced by dietary factors, on the development of the gut microbiota of their litters. METHODS AND RESULTS: Twenty-four lactating does were given a diet unsupplemented (NAB) or with 100 ppm of bacitracin (BAC) or tiamulin (TIA) to modify their digestive microbiota. Litters were adjusted to six pups. In Trial 1, four does per diet milked their own six pups. In Trial 2, two does per diet nursed three of their pups and three fostered from the doe given the same diet. In Trial 3, two does on each diet nursed three of their pups and three fostered from another doe fed on another diet. Denaturing gradient gel electrophoresis (DGGE) analyses of the litter microbiota showed that the effect of the milking mother was greater than the influence of the biological mother. TIA had a strong effect on the bacterial profile even prevailing over that of the milking mother, in contrast to BAC. CONCLUSIONS: Nursing mother microbiota plays an important role over that of the litter. Caecal colonization that occurs during the lactation process prevailed over that during the partum. SIGNIFICANCE AND IMPACT OF THE STUDY: Manipulation of the mother's microbiota may help for adaptation of the litter microbial community against pathologic digestive processes.     

Effect of number of motile sperms inseminated on reproductive performance of rabbit does

The relationship between the number of motile sperms inseminated and fertility rate and litter size at birth in rabbits was investigated. A total of 651 artificial inseminations on multiparous rabbit does in different physiological states (lactating or not; sexually receptive or not) were inseminated with a number of motile cells/dose varying from about 1-20 x 10(6). The statistical model computed the following traits: maximum expected value (a), rate of approach to this value (b) and number of motile spermatozoa/dose needed to obtain threshold level (95% of the maximum). The physiological condition of the doe affected the reproductive performance. The sexual receptivity had significant effect during lactation: non-receptive does had the lowest fertility (a: 43.70%; P < 0.05) while no significant differences were found in non-lactating ones (73.80 vs. 89.11%). Also the rate of approach to this maximum was different: non-receptive does showed a higher dependence on spermatozoa number than receptive females (b: 0.69 and 0.58, respectively, in lactating and non-lactating does) and consequently more spermatozoa (13.1 and 11.1 x 10(6) motile/dose) were needed to reach the threshold value. The physiological state of the does did not affect litter size and only 4.1 x 10(6) of motile spermatozoa/dose are needed to reach the threshold value.     

Genetic evaluation for semen characteristics in a crossbreeding project involving Saudi and Spanish V-line rabbits

Two parallel schemes of crosses were practised involving the Spanish maternal line called V-line (V) and Saudi Gabali (S) rabbits. The first scheme began by crossing Saudi Gabali bucks with V-line does to get the F₁ cross (½S½V), then does of this F₁ were backcrossed with bucks of V-line to get ¾V¼S, then the progenies of the backcross were inter se mated to get (¾V¼S)², followed by two more generations of inter se mating of (¾V¼S)² to get a new synthetic maternal line named Saudi 2. The second scheme began by crossing V-line bucks with Saudi does to get the F₁ cross (½V½S), then does of this F₁ cross were backcrossed with Saudi bucks to get ½S½V, then progeny of this backcross were inter se mated to get (¾S¼V)², followed by two generations of inter se mating of (¾S¼V)² to form a new synthetic paternal line named Saudi 3. A generalised least-square procedure was used to estimate differences between lines in direct and maternal additive effects, direct and maternal heterosis, and direct recombination losses. A total number of 2497 ejaculates of 642 bucks were evaluated for ejaculate volume (VE), pH of semen, sperm concentration (SC), percentage of motile spermatozoa (MS), percentage of spermatozoa with abnormal form (AS), percentage of dead spermatozoa (DS) and libido score (LS). The estimates of direct additive effect for DS (14.2%), SC (12.4%) and AS (12.0%) were moderate and favourable to Saudi rabbits. Maternal additive effects for VE (11.7%) were in favour of genes of V-line carried by the dams of bucks, while these estimates were in favour of Saudi genes for DS (18.6%), AS (13.2%), MS (10.8%) and SC (10.0%). Positive estimates of direct heterosis recorded for SC (13.5%), VE (10.6%) and MS (10.5%) and the negative estimates recorded for AS (−21.5%) and DS (−20.3%) were moderate and well disposed to semen parameters of crossbred bucks. Positive estimates of maternal heterosis for VE (24.0%), MS (21.8%), SC (10.3%) and LS (10.2%) of bucks, and the negative estimates for percentage of DS (−14.7%) and AS (−9.6%) were also significantly favourable. Estimates of direct recombination losses for the majority of semen traits were always not significant.     

Effectiveness of sodium bentonite and two commercial products as aflatoxin absorbents in diets for broiler chickens

Three hundred day-old commercial broiler chicks were reared in 10 groups to examine the effects of indigenous sodium bentonite (SB) as a sodium bentonite simple, sodium bentonite + gention violet and sodium bentonite + acetic acid on two levels 0.5 and 1% of feed, along with two market products Sorbatox and Klinofeed on two levels of aflatoxin 0 and 100 mcg/kg. Each group was replicated three times. The aflatoxins (AF) were incorporated in a standard commercial broiler ration and fed to chicks for 6 week. Body weight and feed consumption was recorded weekly. At the end of the experiment two birds from each group were slaughtered to note the relative weight of heart, liver, gizzard and dressing percentage. Titre against Newcastle disease (ND) was monitored at day 21st, 28th, 35th and 42nd of the experiment.Statistical analysis indicated that aflatoxin in diet negatively affected (P<0.05) all the parameters. Chicks receiving aflatoxin-contaminated diet had suppressed body weight, feed consumption and FCR value, which was significantly improved with the addition of 0.5% simple sodium bentonite. The relative weight of liver (5.34%), heart (0.72%), gizzard (2.05%) and mortality (40%) increased significantly with the addition of 100 mcg/kg aflatoxin and were restored to 3.57, 0.57, 1.43 and 16.6%, respectively, with the dietary inclusion of 0.5% simple sodium bentonite. However, dressing percentage significantly decreased (51.7%) when diet (B) was supplemented with 100 mcg/kg aflatoxin as compared to the diet where no aflatoxin was added (diet A). The titre against Newcastle disease (ND) also showed poorest results by addition of aflatoxin which also improved by inclusion of 0.5% simple sodium bentonite. Addition of indigenous sodium bentonite gave overall better results than the market products and between two levels of indigenous sodium bentonite, 0.5% level gave better results than 1%.     

Fertility of fresh and frozen-thawed goat semen during the nonbreeding season

A total of 4109 does of a local Greek breed (Capra prisca) were synchronized with intravaginal MPA-sponges and PMSG, and 24 bucks of Alpine (n = 8), Saanen (n = 8) and Damascus (n = 8) breeds were used for studying the fertility of nonfrozen and frozen-thawed semen during the nonbreeding season (June to August). Artificial insemination (AI) was performed once (50 to 55 h after sponge withdrawal) or twice (36 and 60 h after sponge withdrawals with fresh semen (collected during the nonbreeding season, stored at 16 degrees C and inseminated within 6 h) or frozen semen (prepared from the same bucks during the preceding breeding season). The induction of estrus was successful, varying between 91.0 and 95.0%. The form of semen (fresh or frozen-thawed used for inseminating the synchronized does affected their fertility: the overall kidding rate with fresh semen (65.5%) was higher (P < 0.05) than that with frozen-thawed semen (53.4%). The fertility level was also affected by the number of inseminations performed: the overall kidding rate was significantly higher (P < 0.001) in the does inseminated twice with fresh or frozen-thawed semen (70.4 and 59. 1%, respectively) than in those inseminated only once (48.9 and 44.9%, respectively). Finally, the breed of the buck used for preparing the fresh or the frozen-thawed semen affected the fertility level of the does. The kidding rate was higher in does inseminated with fresh semen prepared from bucks of the Damascus breed than from bucks of Saanen or Alpine breed. However, when frozen-thawed semen was used the kidding rate was lower in does inseminated with semen prepared from bucks of the Damascus breed than from bucks of the Alpine or Saanen breed. It is concluded that the fresh semen of Alpine, Saanen and Damascus breed bucks, born and raised under the climate conditions prevailing in Greece (34 degrees to 41 degrees N), can be used successfully during the nonbreeding season (June to August) for inseminating does.