Effects of Trifolium alexandrinum phytoestrogens on oestrous behaviour, ovarian activity and reproductive performance of ewes during the non-breeding season.

Phytoestrogens are classified as naturally occurring endocrine disrupting chemicals that may affect reproductive performance of farm animals. To investigate the effects of Berseem clover phytoestrogens on reproductive performance of seasonal anoestrus ewes, twenty four late pregnant Rahmani ewes were fed either Berseem clover or maize silage (n = 12/treatment). Treatment started 2 months prepartum and continued until oestrous induction (week 8 postpartum), using the CIDR-eCG based protocol, and early pregnancy. Throughout the 2-8 weeks postpartum, oestrous rate and ovarian activity were not affected by treatment. After oestrous induction, ewes in both groups expressed comparable oestrous rates; however feeding Berseem clover extended (P < 0.05) interval to oestrus (57.00 compared with 42.54 h) and shortened (P < 0.05) oestrous duration (20.0 compared with 34.90 h). Feeding Berseem clover did not affect follicular activity except the number of medium follicles, which was less (P < 0.05) on day of oestrus (Day 0). Feeding maize silage increased (P < 0.05) the total number of follicles and number of small and medium follicles the day before oestrus (Day -1). On Day 0, the greater total number of follicles was due to the greater (P < 0.05) number of medium follicles that was associated with less number of small follicles. Although, the number and diameter of corpora lutea (CLs) were not affected by treatment, serum P4 concentration was greater (P < 0.05) for ewes fed maize silage than for those fed Berseem clover. Fecundity and litter size tended to be greater (about 35%; P = 0.132 and 0.085, respectively) in the maize silage fed ewes. In conclusion, feeding Berseem clover throughout seasonal anoestrus disrupted aspects of behavioural oestrus and there was less luteal P4 synthesis and fecundity of ewes.

Effectiveness of controlled internal drug release device treatment to alleviate reproductive seasonality in anestrus lactating or dry Barki and Rahmani ewes during non-breeding season.

This study aimed to evaluate the effectiveness of hormonal treatments on ovarian activity and reproductive performance in Barki and Rahmani ewes during non-breeding season. Forty-eight multiparous ewes, 24 Barki and 24 Rahmani ewes were divided into two groups, 12 lactating and 12 dry ewes for each breed. Controlled internal drug release (CIDR) device was inserted in all ewes for 14 days in conjunction with intramuscular 500 IU equine chronic gonadotrophin (eCG) at day of CIDR removal. Data were analysed using PROC MIXED of SAS for repeated measures. Breed, physiological status and days were used as fixed effects and individual ewes as random effects. Barki ewes recorded higher (p < .05) total number of follicles, number of large follicles, serum estradiol concentration and estradiol: progesterone (E2 :P4 ) ratio compared to Rahmani ewes. Lactating ewes recorded higher (p < .05) number of small follicles and lower concentration of total antioxidant capacity (TAC) compared to dry ewes. Number and diameter of large follicles recorded the highest (p < .05) values accompanied with disappearance of corpora lutea at day of mating. Serum progesterone concentration recorded lower (p < .05) value at day of mating and the highest (p < .05) value at day 35 after mating. CIDR-eCG protocol induced 100% oestrous behaviour in both breeds, but Rahmani ewes recorded longer (p < .05) oestrous duration compared to Barki. Conception failure was higher (p < .05) in Barki compared to Rahmani ewes. In conclusion, CIDR-eCG protocol was more potent in improving ovarian activity in Barki compared to Rahmani ewes, but this protocol seems to induce hormonal imbalance in Barki ewes that resulted in increasing conception failure compared to Rahmani ewes.

Genetic screening of FecB, FecXG and FecXI mutations and their linkage with litter size in Barki and Rahmani sheep breeds.

Characterization of fecundity genes offers the opportunity to improve production efficiency, and the consequent increase in litter size in livestock industry, through utilizing them in breeding programs. The main objective of this study was to detect the BMPR-IB, BMP15 and GDF9 gene mutations and to investigate whether these mutations are associated with litter size in Egyptian sheep breeds. To achieve this goal, 73 adult ewes representing Barki (n = 33) and Rahmani (n = 40) breeds were used. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) screening approach was used to detect the presence of FecB, FecXG and FecXI mutations in the two selected breeds. Results of this study showed that the three different candidate gene mutations, namely FecB, FecXG and FecXI are not present among these selected populations of the Egyptian breeds. Further studies regarding other mutations and/or other genes, which may influence ovulation rate, should be carried out to determine the type and mode of inheritance of such genes in Egyptian sheep breeds.

Effect of GnRH treatment on ovarian activity and reproductive performance of low-prolific Rahmani ewes.

This study was designed to evaluate the effect of GnRH treatment during different times of the reproductive cycle on ovarian activity, progesterone (P4) concentration, and subsequent fertility of low-prolific, subtropical, Rahmani ewes during breeding season. Forty-five ewes were synchronized for estrus using a double injection of 0.5 mL of PGF2α agonist (125-µg cloprostenol), 11 days apart. Ewes showing estrus (Day 0) were treated with 1 mL of GnRH agonist (4-µg buserelin) on the day of estrus (GnRH0, n = 12) or 7 days post-mating (GnRH7, n = 10) or on both days (GnRH0+7, n = 11) or not (control, n = 12). Ovarian response to the treatment and diagnosis of pregnancy were ultrasonographically monitored. Also, serum P4 concentration was determined weekly throughout 28 days post-mating. Results showed that neither total number of follicles nor their populations were changed on Day 0 or 7 days post-mating by the GnRH treatment. GnRH treatment on Day 0 or Day 7 post-mating or both days did not enhance ovulation rate compared with the control. The mean numbers of accessory CL increased (P < 0.05) in the GnRH7 group than those in the control and GnRH0 groups, whereas it was intermediate in the GnRH0+7 group. The greatest (P < 0.05) overall mean of serum P4 concentration was for the GnRH7 and GnRH0+7 groups, followed by the GnRH0 and control groups. Serum P4 concentration increased (P < 0.05) on Day 14 post-mating and continued higher (P < 0.05) until Day 28 post-mating in the GnRH7 and GnRH0+7 groups compared with the control. Regardless of the time of GnRH administration, GnRH treatment reduced (P < 0.05) pregnancy loss from Day 40 post-mating to parturition and tended to enhance (P < 0.20) lambing rate compared with the control. In conclusion, a single dose of GnRH at the time of estrus or 7 days post-mating could be used as an effective protocol to decrease pregnancy loss from Day 40 after mating to parturition in low-prolific Rahmani ewes.

Molecular approach of gossypol-induced reproductive toxicity in male rabbits. Changes in seminal plasma amino acids and fatty acids.

This study was done to evaluate the effects of two sublethal doses of gossypol (4 and 20 mg/kg of BW, every other day) on some amino and fatty acid concentrations in male rabbit seminal plasma. Rabbits were chosen as an experimental animal owing to the fact that they are excellent model for reproductive toxicological effects. The experiment lasted 16 weeks and included two periods: a treatment period (first 8 weeks) where the animals were given the tested product, and a recovery period (second 8 weeks) where all drugs were withdrawn. Results showed that total amino acids (TAA), total essential amino acids (EAA), total non-essential amino acids (non-EAA) and EAA/non-EAA ratio were decreased in a dose-dependent manner during gossypol treatment. The deleterious effect on TAA concentrations was mainly due to the reduction in total EAA. However, these concentrations regained their normal values after gossypol cessation. Basic, acidic, neutral amino acids and basic/acidic amino acids ratio decreased in a dose-dependent manner by gossypol treatment. Additionally, gossypol administration caused decreases in total unsaturated fatty acids (USFA) and increases in total saturated fatty acids (SFA) and the SFA/USFA ratio in a dose-dependent manner. During the recovery period, total SFA and USFA showed significant reduction and significant increase, respectively, after gossypol withdrawal. In conclusion, gossypol administration affected rabbit seminal plasma concentrations of amino and fatty acids in a dose-dependant manner. Gossypol reduced TAA, total EAA and total non-EAA. Additionally, gossypol caused decreases in total USFA and increases in total SFA. These deleterious effects were associated with poor-quality semen observed in our previous studies.

Influence of ascorbic acid supplementation on the haematological and clinical biochemistry parameters of male rabbits exposed to aflatoxin B1.

This study was undertaken to evaluate the effectiveness of L-ascorbic acid (AA) in alleviating the toxicity of aflatoxin B1 (AFB1) in male New-Zealand white rabbits. Five rabbits (6 months of age and mean body weight 3.12 kg) per group were assigned to 1 of 6 treatment groups: 0 mg AA and 0 mg AFB1/kg BW (control); 20 mg AA/kg BW; 15 microg AFB1/kg BW; 15 microg AFB1 plus 20 mg AA/kg BW; 30 pg AFB1/kg BW; 30 pg AFB1 plus 20 mg AA/kg BW. Rabbits were orally administered their respective doses every other day for 9 weeks, followed by a 9-week recovery period where all drugs were withdrawn. Evaluations were made for hemato-biochemical parameters and enzymatic activities. Results showed that AFB1 significantly (p < 0.05) decreased hemoglobin (Hb), total erythrocytic count (TEC) and packed cell volume (PCV), in a dose-dependent manner, and these effects were continued during the recovery period. Ascorbic acid caused an increase in these parameters, and alleviated the negative effect of AFB1 during the treatment period. Additionally, serum concentrations of total protein, albumin and glucose were significantly (P < 0.05) declined by treatment with the high dose of aflatoxin and these effects were continued during the recovery period. Ascorbic acid caused non-significant increases in these parameters and alleviated the harmful effect of AFB1. On the other hand, aflatoxin treatment caused significant increases (P < 0.05) in the activities of serum aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (AlP) during the treatment period in a dose dependent manner, and this effect was continued during the recovery period, especially with the high dose. Also, treatment with the high dose of aflatoxin caused significant increases (P<0.05) in cholesterol and total bilirubin. Ascorbic acid caused significant decreases in these parameters and alleviated the harmful effects of AFB1. Whereas, Total leukocyte count (TLC), urea and creatinine were not significantly affected by aflatoxin-treatment. Generally, it is interesting feature that the treatment with AA alone had no negative effects on most of the previous parameters. Also, the presence of AA could diminished the adverse effects of AFB1 on most of hematological and biochemical values, and enzymatic activities in rabbits.

Hyperhomocysteinaemia and risk of thrombosis in systemic lupus erythematosus patients.

Hyperhomocysteinaemia is strongly associated with increased relative risk of occlusive vascular disease, mainly of the carotid and coronary arteries. The aim of our study was to assess whether raised plasma homocysteine is a risk factor for thrombotic events in patients with systemic lupus erythematosus (SLE), a condition known to be associated with premature atherothrombotic complications. The study included 34 consecutive consenting SLE patients who were seen in the Rheumatology Unit of Al-Amiri hospital, one of the main teaching hospitals in Kuwait. Twenty consenting healthy subjects were included in the control group. Twenty-four patients were grouped as SLE without thrombosis and 10 had different types of thromboses. Vitamin B(12), folate, anticardiolipin antibodies (IgG and IgM), activated partial thromboplastin time (APTT) and total homocysteine level were measured for both patients and controls. A raised homocysteine concentration was defined as plasma homocysteine level above 9.4 mmol/l. Hyperhomocysteinaemia was found in 21 (61.8%) SLE patients. Low levels of folate and vitamin B(12) were significantly associated with high concentrations of plasma homocysteine (r = -0.35 and -0.39, respectively, P<0.01). SLE patients with elevated homocysteine concentration have a threefold increase in odds ratio of thrombotic events after adjusting for other risk factors (male sex, shortened APTT, treatment with prednisone, low folate and vitamin B(12) levels). We concluded that homocysteine is an independent risk factor for thrombosis in patients with SLE and is potentially modifiable.

Protective role of ascorbic acid to enhance semen quality of rabbits treated with sublethal doses of aflatoxin B(1).

Aflatoxins are toxic to a wide variety of animals, including man. The antioxidant ascorbic acid (AA) plays an important role in various physiological processes in the body including detoxification of different toxic compounds. The objective of this study was to evaluate the effects of AA on productive and reproductive characteristics of mature male rabbits given two sublethal doses (15 or 30 microg/kg of body weight; every other day) of aflatoxin B(1) (AFB(1)). The experiment lasted 18 weeks and included two periods: a treatment period (first 9 weeks) where the animals were given the tested materials, and a recovery period (second 9 weeks) where all the drugs were withdrawn. Results showed that live body weight (LBW), dry matter intake (DMI), relative testes weight (RTW), and serum testosterone were significantly reduced (P<0.05) by treatment with AFB(1) in a dose-dependent manner, and these effects continued during the recovery period. Aflatoxin treatment also decreased (P<0.05) ejaculate volume, sperm concentration, total sperm output, sperm motility index, and semen initial fructose concentration. The negative effects of aflatoxin on semen characteristics were dose-dependent and continued during the recovery period. Treatment with AA increased (P<0.05) LBW, DMI, RTW, serum testosterone concentration, improved semen characteristics, and alleviated the negative effects of AFB(1). Aflatoxin treatment increased (P<0.05) the numbers of abnormal and dead sperms in a dose-dependent manner, and this effect continued during the recovery period. Treatment with AA alleviated the negative effects of AFB1 during treatment and recovery periods. Results demonstrated the beneficial influences of AA in reducing the negative effects of AFB(1) on production and reproduction of male rabbits.

A sensitive sperm-motility test for the assessment of cytotoxic effect of pesticides.

A sensitive sperm-motility test for the evaluation of cytotoxic effects of carbofuran and glyphosate in a defined protein-free culture medium is described. The sperm motility was compared to that obtained with a protein-containing medium. The use of protein-free medium considerably increased the sensitivity of sperm cells from rabbit and human to the toxic effects of the pesticide. The respective IC50 values (the concentration needed to cause 50% inhibition of sperm motility) in protein-free medium of carbofuran and glyphosate were 321 and 48.2 microM with human sperm, and 116 and 23.5 microM with rabbit sperm. Whereas, the corresponding values in protein-containing medium were 920 and 740 microM, and 910 and 500 microM with human and rabbit sperm, respectively. Our results show that testing human and rabbit sperm in protein-free medium proves to be a more sensitive method than that in protein-containing medium. Additionally, the use of rabbit sperm is a more sensitive test system than human sperm. This study suggests that the rabbit sperm test appears to have a potential for the assessment of toxicity on human reproduction.

Toxic effects of carbofuran and glyphosate on semen characteristics in rabbits.

The present study was undertaken to investigate the effect of chronic treatment with two sublethal doses of Carbofuran (carbamate insecticide) and Glyphosate (organophosphorus herbicide) on body weight and semen characteristics in mature male New Zealand white rabbits. Pesticide treatment resulted in a decline in body weight, libido, ejaculate volume, sperm concentration, semen initial fructose and semen osmolality. This was accompanied with increases in the abnormal and dead sperm and semen methylene blue reduction time. The hazardous effect of these pesticides on semen quality continued during the recovery period, and was dose-dependent. These effects on sperm quality may be due to the direct cytotoxic effects of these pesticides on spermatogenesis and/or indirectly via hypothalami-pituitary-testis axis which control the reproductive efficiency.

Effect of cyclic AMP on fructose utilization, progressive motility and protein synthesis by ram spermatozoa.

Ejaculated washed ram spermatozoa showed consistent increases in the intracellular concentration of cyclic 3', 5'-adenosine monophosphate (cAMP) after incubation for 15 minutes with the phosphodiesterase (PDE)-inhibitors, theophylline and caffeine. In vitro addition of cAMP or PDE-inhibitors to ram semen also stimulated and maintained sperm motility and enhanced the rate of fructose utilization. The same doses of cAMP or theophylline significantly stimulated the rate of protein synthesis by the washed spermatozoa, while the PDE-stimulator, imidazole, inhibited protein synthesis significantly. The stimulatory effect of cAMP on sperm protein synthesis was not affected by cycloheximide, but was abolished by the mitochondrial inhibitor, chloramphenicol. The present results indicate a positive correlation between the intracellular concentration of cAMP and the rates of progressive motility, fructose utilization, and protein synthesis by ram spermatozoa. The results suggest that the effect of cAMP is associated with the synthesis of mitochndrial proteins which may be involved with the observed enhancement of sperm motility and metabolism. The data also indicate that cAMP map act either as a first or a second messenger in mature spermatoza.

Effect of cyclic AMP, imidazole and triiodothyronine on the rate of RNA synthesis by ejaculated ram spermatozoa.

The effects of cyclic AMP (cAMP) and of triiodothyronine (T(3)) on the enhancement of sperm motility and metabolism are well documented, and the present study was undertaken to investigate the mechanisms underlying these effects in terms of their influence on sperm RNA synthesis in vitro. Washed ram sperm were diluted to 1 40 (v/v) with incubation buffer that contained 100 mug/ml penicillin-G and 400 mg% glucose, followed by incubation at 37 degrees C for a period of 4 h. Washed ram spermatozoa incubated with graded doses of cAMP (10(-8), 10(-6) and 10(-4) M) showed significant enhancements of the rate of (3)H-uridine incorporation into RNA, with maximal effect occurring at 10(-8) M. The presence of 3.75, 7.50 or 15.00 muM T(3) also stimulated the rate of RNA synthesis by the washed ram sperm, with maximal effect occurring at 7.50 muM. On the contrary, imidazole (a compound known to stimulate phosphodiesterase activity and consequently to decrease the intracellular cAMP levels in many tissues) was found to cause consistent inhibition of spermatozoal RNA synthesis. The inhibition was 47, 90 and 92% of control for 10, 50 and 100 mM imidazole, respectively. The results obtained indicate that cAMP may act either as a first or a second messenger in the mature sperm. The data also indicate that T(3) (possibly mediated by cAMP) may act on the ram sperm by the induction of enzymes, which are required for the well-known effects of this hormone in enhancing the sperm metabolic activity.

Some hormonal characteristics of high and low yielding Holstein cows and water buffaloes located in temperate and subtropical environments.

The present study was carried out on 18 Holstein cows located in Missouri, USA (Holstein-M), 32 Holstein cows located in Egypt (Holstein-E), and 32 Egyptian water buffaloes (Buffaloes-E). Half of each group was high yielders and the other half was low with a mean daily milk yield of 32.2 and 18.6 kg for Holstein-M, 14.6 and 6.7 kg for Holstein-E, and 7.2 and 1.8 kg for Buffaloes-E, respectively. Blood samples were collected after the morning milking. Mean plasma thyroxine and triiodothyronine concentrations were significantly higher in Holstein-M than those in Holstein-E or Buffaloes-E. In all animal groups, the high yielders generally had lower plasma thyroxine and antidiuretic hormone but higher plasma triiodothyronine contents than the low yielders. Buffaloes had lower plasma cortisol and 9-fold higher plasma antidiuretic hormone as compared with the two Holstein groups.

In vitro effect of profenofos, fenvalerate and dimilin on protein and RNA biosynthesis by rabbit liver and muscle tissues.

The present study was carried out to investigate the effect of Curacron (profenofos), Sumicidin (fenvalerate) and Dimilin (difluobenzuron) on the in vitro rate of protein and RNA synthesis by rabbit liver and muscle tissues. The synthesis of protein and RNA were significantly stimulated in the liver and inhibited in the muscle by graded doses of these insecticides. Profenofos showed maximum effect on protein synthesis in both tissues at a dose of 0.2 microgram/mL, while the maximum effect on RNA synthesis occurred at 0.2 microgram/mL, while the maximum effect on RNA synthesis occurred at 0.2 microgram mL in the liver and at 2 micrograms/mL in the muscle. Fenvalerate caused maximum stimulation in both liver protein and RNA synthesis at a dose of 2 micrograms/mL, and maximum inhibition in the muscle at 10 and 0.2 micrograms/mL for protein and RNA synthesis respectively. The maximum effect of Dimilin on both tissues was reached at 5 micrograms/mL for protein synthesis and at 0.2 microgram/mL for RNA synthesis. The effect of Dimilin on RNA synthesis was more pronounced in both tissues than its effect on protein synthesis, but this trend was reversed in the case of profenofos and fenvalerate. Present data also showed antagonism between these insecticides on the rate of protein and RNA synthesis.

Effect of incubation conditions, inhibitors, 2-mercaptoethanol and testosterone on RNA synthesis in ram spermatozoa.

In vitro studies on RNA synthesis using washed ram spermatozoa were carried out by measuring the incorporation of (3)H-uridine into RNA. Penicillin-G (100 mug/ml medium) was added to prevent contamination by microorganisms. Spermatozoa were quickly separated from seminal plasma by washing twice in Tris-HCl buffer (at pH 7.2) and centrifuged at 1,000 g for 5 min. Washed spermatozoa were then diluted to 1 10 , 1 20 or 1 40 (v/v) by the same buffer system (containing 400 mg% glucose) and were incubated in air at 37 degrees C for 1, 2 and 4 h. Results indicated that the rate of RNA synthesis was maximal at 1 40 semenbuffer dilution (5-8 x 10(7) spermatozoa/ml) and increased linearly up to 4 h of incubation. The rate of RNA synthesis at 1 40 dilution also increased linearly as the dose of exogenous glucose substrate was increased up to 400 mg%. Denaturation of the ram spermatozoa by 1% HgCl(2) caused almost complete inhibition of RNA synthesis that amounted to 97% of the control samples. Incubation of spermatozoa with 50, 100 or 200 mug/ml chloramphenicol also inhibited uridine incorporation by 86 to 94%, while equivalent doses of cycloheximide did not. On the other hand, the incorporation of (3)H-uridine into the RNA of ram spermatozoa was significantly enhanced by graded doses of 2-mercaptoethanol (0.2, 0.4 and 0.8 muM) and of testosterone (15 and 30 mug/ml). The results of this study indicate RNA synthesis, mainly of mitochondrial origin, by mature ram sperm. The data also suggest a role for intracellular cyclic adenosine monophosphate in the regulation of sperm RNA synthesis.

Effect of organophosphorus (dimethoate) and pyrethroid (deltamethrin) pesticides on semen characteristics in rabbits.

The present study was undertaken to determine the effect of chronic treatment with two sublethal doses of Dimethoate (organo-phosphorus) or Deltamethrin (pyrethroid) on body weight and semen characteristics in adult male rabbits. Pesticide treatment resulted in a decline in body weight, libido, ejaculate volume, sperm concentration and semen initial fructose; and an increase in abnormal and dead sperm and methylene blue reduction time. In this regard Dimethoate showed greater effects than Deltamethrin. The hazardous effect of these pesticides on semen quality continued during the post-treatment period, and was dose-dependent. This deleterious effect on sperm formation together with the decline in libido suggest a decrease in testosterone secretion by pesticide treatment.

In vitro effect of aflatoxin B1 on the transcriptional activity of DNA template, chromatin and soluble DNA-dependent RNA polymerases in buffalo liver.

The effect of aflatoxin B1 on the DNA template and DNA-dependent RNA polymerases in buffalo liver was studied. Aflatoxin B1 inhibited both Mg2+- and Mn2+-activated RNA polymerases in a dose-dependent manner. At 10 micrograms the inhibition of both enzymes was almost complete. The inhibitory effect on the solubilized enzymes was higher than the chromatin-bound, suggesting a direct effect at the enzyme level. On the other hand, incubating DNA or deoxyribonucleoprotein (DNP) with 2 micrograms aflatoxin reduces its transcriptional capacity with a greater effect on the Mg2+-activated RNA polymerase than the Mn2+-activated enzyme. These results suggest that aflatoxin B1 inhibits in vitro transcription in buffalo liver at both enzyme and template levels.

Isolation, purification and characterization of enzyme(s) responsible for conversion of sterigmatocystin to aflatoxin B1.

The cell-free extract prepared from Aspergillus flavus ATCC 5517/A 228 showed activity in converting sterigmatocystin to aflatoxin B1. The extract was purified on Ultrogel AcA-54 and resulted in ten protein peaks, one of which (peak VI) showed activity in sterigmatocystin conversion. The protein in this peak gave one protein band using polyacrylamide gel (PAG)-disc electrophoresis. For further purification, protein(s) in peak VI were applied on DEAE-Sephadex A-50 and two protein peaks were detected. Only one peak showed enzyme activity which showed homogeneity as one band on PAGE and sodium dodecyl sulphate (SDS)-PAGE. The optimum temperature for the enzyme activity was 28 degrees C and the optimum pH was 8. The maximum conversion resulted from the action of 0.6 mg enzyme protein on 48 X 10(-8) mol sterigmatocystin. Zn2+, Co2+ and Mn2+ enhanced the enzyme activity, while ethylenediaminetetraacetic acid, parahydroxymercuric benzoate and phenylmethylsulphonic fluoride inhibited the enzyme activity in a dose-dependent manner. Amino-acid analysis showed the presence of 22 amino acids, three of which are unknown. The enzyme has a molecular weight of 64,000 daltons (by gel filtration) and 70,000 daltons (by SDS-PAGE).

The effect of exposure to direct solar radiation on the semen characteristics of the male rabbit.

Three groups of cross-bred bucks (Baladi X standard breeds) were exposed to solar radiation for three hours per day during an 8-week experimental period in June and July and were compared with a control subgroup of the same age. Each subgroup (experimental and control) comprised 10 bucks, totalling 60 bucks. The effects were determined and assessed during the 28-week period following the experiment. The exposure to solar radiation at 5 or 12 weeks of age caused a delay in the onset of puberty. In all three groups, the concentration of sperms and the fructose content were decreased. There was a marked increase in the proportion of abnormal or dead sperms and in the methylene blue reduction time. The young animals were most affected by the exposure.

Relationship between milk production and some blood constituents in Egyptian Baladi goats.

Under the conditions of a high ambient temperature and the lack of green fodder goats are very important for milk production. During 16 weeks of lactation period, the milk yield of 10 Baladi goats was 55 kg. The amount of milk exhibited a positive relation to the globulin and glucose content of the blood. There was a highly negative correlation with the albumin content and the number of leucocytes.