Production of cheese from donkey milk as influenced by addition of transglutaminase.

Donkey milk is characterized by low contents of total solids, fat, and caseins, especially κ-casein, which results in formation of a very weak gel upon renneting. The objective of this study was to evaluate the effect of fortification of donkey milk with microbial transglutaminase (MTGase) for cheesemaking in relation to different enzyme addition protocols (patterns, PAT). Four independent trials were performed using MTGase (5.0 U/g of milk protein) according to the following experimental patterns: control (no MTGase addition); MTGase addition (40°C) 15 min before starter inoculation (PAT1); addition of MTGase to milk simultaneously with starter culture (40°C) (PAT2); and MTGase addition simultaneously with rennet (42°C) in acidified milk (pH 6.3) (PAT3). Evolution of pH during acidification, cheesemaking parameters, and proximal composition and color of cheese at 24 h were recorded. The protein fractions of cheese and whey were investigated by urea-PAGE and sodium dodecyl sulfate-PAGE. Addition of MTGase had no significant effect on moisture, protein, fat, or cheese yield. The addition of MTGase with rennet (PAT3) improved curd firmness compared with the control. Among the different patterns of MTGase addition, PAT3 reduced gel formation time, time between rennet addition and cheese molding, and weight loss of cheese at 24 h. The PAT3 treatment also resulted in the lowest lightness and highest yellowness color values of the cheese. Sodium dodecyl sulfate-PAGE of cheeses revealed that MTGase modified the protein pattern in the high-molecular-weight zone (range 37-75 kDa) compared with the control. Of the MTGase protocols, PAT3 showed better casein retention in cheese, as confirmed by the lanes of α- and ß-caseins in the electropherogram of the whey, which was subtler for this protocol. In conclusion, MTGase may be used in cheese production from donkey milk to improve curd firmness; MTGase should be added simultaneously with the rennet.

Dietary verbascoside supplementation in donkeys: effects on milk fatty acid profile during lactation, and serum biochemical parameters and oxidative markers.

Various uses of donkeys' milk have been recently proposed for human consumption on the basis of its nutritional characteristics. Improvements in milk fatty acid profile and animal oxidative status can be induced through dietary supplementation of phenolic compounds. The study aimed to evaluate in donkeys the effects of dietary supplementation with verbascoside (VB) on: (i) the fatty acid profile and vitamins A and E contents of milk during a whole lactation, and (ii) blood biochemical parameters and markers of oxidative status of the animals. At foaling, 12 lactating jennies were subdivided into two groups (n 6): control, without VB supplement; VB, receiving a lipid-encapsulated VB supplement. Gross composition, fatty acid profile and vitamins A and E contents in milk were assessed monthly over the 6 months of lactation. Serum total cholesterol, high-density lipoproteins cholesterol and low-density lipoproteins cholesterol, tryglicerides, non-esterified fatty acid, bilirubin, alanine aminotransferase (ALT), aspartate aminotransferase, reactive oxygen metabolites, thiobarbituric acid reactive substances (TBARs), vitamin A and vitamin E were evaluated at 8 days after foaling (D0) and then at D90, D105 and D120 of lactation. In milk, the VB supplementation decreased the saturated fatty acids (P<0.05) and increased the monounsaturated fatty acids (P<0.05), and vitamins A and E (P<0.01) values. On the serum parameters, the VB supplementation decreased total cholesterol (P<0.01), tryglicerides, bilirubin, ALT and TBARs, and increased (P<0.01) vitamin E. In conclusion, the VB dietary supplementation affects the nutritional quality of donkey's milk with a benefit on the oxidative status and serum lipidic profile of the animals.

Lactation curve and effects of milking regimen on milk yield and quality, and udder health in Martina Franca jennies (Equus asinus).

Three experiments were conducted on Martina Franca jennies. Experiment 1 tested Wood's model for evaluating the lactation curve. Data from the entire lactation period of 12 jennies were used. The results showed that Wood's model was able to recognize the shape of the lactation curve from pooled data (r(2) = 0.11; P < 0.01), with the lactation peak occurring at 48 d. Individual curves showed wide variability. Experiment 2 aimed to evaluate the effects of the daily number of milkings (1, 3, or 6) and the interval between the separation of foals from dams and milking (2 or 3 h) on milk yield and udder health. Four groups of jennies (n = 5) were considered: 1 × 3H, milked once per day (1×) with a 3-h interval from the time of foal removal (3H) from the dams to mechanical milking (3-h interval); 3 × 3H, milked 3 times per day with 3-h intervals; 3 × 2H, milked 3 times per day with 2-h intervals; and 6 × 2H, milked 6 times per day with 2-h intervals. The milk somatic cell count (SCC) was monitored. Better efficiency was observed for 3 vs. 1 milking per day and for 3-h vs. 2-h intervals. The regimen of 6 daily milkings at 2-h intervals did not increase milk yield and was related to an increase in the SCC compared with 3 daily milkings. In Exp. 3, the effects of the interval from foal removal to milking (3, 5, or 8 h) on yield, gross chemical composition, organoleptic characteristics of the milk, and udder health of the jennies were evaluated. The effects of milking time were also evaluated. Twenty jennies milked twice daily (2×) were subdivided into 4 groups (n = 5): 2 × 3H, with milkings at 1200 h and 1900 h and an interval of 3 h; 2 × 5H, milked at 1200 h and 1900 h with a 5-h interval; 2 × 8H(1), milked at 1200 h and 2200 h with an 8-h interval; and 2 × 8H(2), milked at 0700 h and 1900 h with an 8-h interval. Milk yield was greater by 28.4% when an 8-h interval was used compared with a 3-h interval and at the morning vs. the evening milking. The milk yield per milking was greatest at 0700 h, indicating the existence of a circadian rhythm in milk secretion processes. Intervals of 5 and 8 h caused significant decreases in the fat and lactose content and organoleptic characteristics of the milk, whereas an 8-h interval led to an increase in the SCC. In conclusion, a milking regimen of twice-daily milking at 0700 h and 1900 h with an 8-h interval provided the maximum yield per day. In terms of milk quality, a 3-h interval yielded the best results.

Induction/synchronization of oestrus and ovulation in dairy goats with different short term treatments and fixed time intrauterine or exocervical insemination system.

Two experiments were carried out on Ionica dairy goats in order to test the efficiency of: (1) short term-5-day combined progestogen-PGF2α-GnRH treatments on induction/synchronization of oestrus and fertility after natural mating in lactating goats and during the transition period (Experiment 1); (2) short term-9-day FGA-PGF2α-eCG treatments on synchronizing oestrus and ovulation (Experiment 2.1) and artificial insemination (AI) fixed time system in synchronized does (Experiment 2.2), during the breeding season. In Experiment 1, four treatment groups (N=24) were considered: (1) FPe-11d - control, FGA intravaginal sponges (11 days)+PGF2α (9th d)+eCG (11th d); (2) FPe-5d, FGA (5 days)+PGF2α (5th d)+eCG (5th d); (3) PFe-5d, PGF2α (D0)+FGA (5 days)+eCG (5th d); (4) GPe-5d, GnRH (D0)+PGF2α (5th d)+eCG (5th d). Goats were checked for oestrus and naturally mated. The occurrence of oestrus was 75.0, 78.3, 86.4, and 58.3% for groups 1-4, respectively, with significant differences (P<0.05) between groups 3 and 4. Interval to oestrus was earlier (P<0.05) in GPE-5d than in FPe-11d control group. There were no differences between the groups (P>0.05) in fertility or in prolificacy. In Experiment 2.1, 22 goats were subdivided into two treatment groups (N=11): (T1) FPe-11d (control), FGA (11 days)+PGF2α (9th d)+eCG (11th d); (T2) FPe-9d, FGA (9 days)+PGF2α (7th d)+eCG (9th d). Oestrus and ovulation times were monitored every 4h; ovulation rate was also determined. The induction of oestrus ranged from 91 to 100% and all goats ovulated. Intervals to oestrus, from the onset of oestrus to ovulation, from sponge removal to ovulation, and ovulation rates were 28.2±4.9 and 26.0±4.0h, 25.3±9.2 and 28.9±7.4h, 53.5±7.6 and 54.9±7.1h, 3.7±1.6 and 2.4±1.4 corpora lutea (P<0.05) for T1 and T2, respectively. In T2 a great abnormal ovulatory response was observed. In Experiment 2.2, 48 goats were synchronized with FPe-9d treatment and subjected to AI, performed 50h after s.r. with frozen semen, and subdivided into 2 AI system groups (N=24): T3, exocervical AI (100×10(6)Spz/doe); T4, intrauterine AI (20×10(6)Spz/doe). Fertility rate was higher (P<0.05) in T4. It seems that short term-5-day combined progestogen-PGF2α-GnRH-eCG treatments need to be investigated for AI fixed time.

Synchronization of oestrus and ovulation by short time combined FGA, PGF(2α), GnRH, eCG treatments for natural service or AI fixed-time.

Two experiments were conducted in ewes in order to develop an oestrus-ovulation short time synchronization protocol based on combined FGA, PGF(2α), GnRH, eCG treatments, for use in dairy sheep before natural service (Experiment 1) or for fixed-time artificial insemination (Experiment 2), during the breeding season. In Experiment 1 seventy-five non-lactating dairy ewes were subdivided into 5 treatment groups (N=15): (1) Group Fe - control, which received FGA vaginal sponges (14 days)+eCG (Day 14); (2) Group FPe, FGA (5 days)+PGF(2α) (Day 5)+eCG (Day 5); (3) Group PFe, PGF(2α) (Day 0)+FGA (5 days)+eCG (Day 5); (4) Group PFG, PGF(2α) (Day 0)+FGA (5 days)+GnRH (30h after sponge removal, s.r.); (5) Group GPe, GnRH (Day 0)+PGF(2α) (Day 5)+eCG (Day 5). Ewes were checked for oestrus and hand-mated. Time of ovulation was recorded by laparoscopy for 10 animals from each treatment. The percentages of female in oestrus and the interval to oestrus (h after treatment), fertility and prolificacy rate were recorded. There were no treatment differences in the percentage of females in oestrus. The interval to oestrus was earlier in Fe Group and delayed in FPe Group (P<0.01). Ovulation time was earlier in GPe Group compared to FPe Group (P<0.05). Fertility rates were significantly different (P<0.05) between the PFe and the FPeG Groups compared with the PFG Group. No significant differences were observed in prolificacy among the treatments. In Experiment 2, sixty dry ewes were subdivided (N=20) into the following three experimental treatment groups: (1) Group FP, FGA (5 days)+PGF(2α) (Day 5); (2) Group FPG, FGA (5 days)+PGF(2α) (Day 5)+GnRH (30hs.r.); (3) Group FPeG, FGA (5 days)+PGF(2α) (Day 5)+eCG (Day 5)+GnRH (30hs.r.). These were further subdivided into two groups (N=10) corresponding to 52 and 60hs.r. fixed-time insemination. Laparoscopic intrauterine insemination was performed with frozen semen (80×10(6)spermatozoa/dose) and ovulation time was recorded in a subgroup (N=10). GnRH resulted in an earlier ovulation time (P<0.05) in FPG and FPeG Groups (53.0h vs 61.6h). Fertility rate was higher in FPeG treated ewes inseminated at 60hs.r. (60%, 6/10). In FP and FPG Groups fertility rates were higher following insemination at 52hs.r. (50.0 and 40.0%).

Donkey and goat milk intake and modulation of the human aged immune response.

In a group of 14 healthy aged subjects, donkey and goat milk was administered respectively, for a period of one month. Cytokine profile [interleukin (IL)-12, IL-10, IL-1beta, IL-8, IL-6 and Tumor Necrosis Factor (TNF)-alpha] was assessed before and after milk intake by means of a cytometric bead array test. Data demonstrated that IL-12 was undetectable, while IL-10, IL-1beta and TNF-alpha were released in very low amounts. Quite interestingly, IL-8 was increased by donkey milk administration, while same cytokine was dramatically decreased following goat milk intake. Same pattern of response was noted with IL-6 even if levels of these cytokine were lower than those detectable in the case of IL-8. Taken together, these findings indicate that administration of donkey milk in the aged host is able to upregulate the immune response, while goat milk seems to reduce the exaggerated acute phase response in elderly.

Ability of goat milk to modulate healthy human peripheral blood lymphomonocyte and polymorphonuclear cell function: in vitro effects and clinical implications.

The in vitro effects of goat's milk from different sources (Jonica, Saanen, and Priska breeds plus a commercial preparation) on healthy human peripheral blood mononuclear cells (PBMCs) were evaluated in terms of nitric oxide (NO) and cytokine release. According to the incubation time (24 h or 48 h) used all milks could induce release of NO from monocytes. In this context, however, in the presence of a commercial milk preparation inhibition of lypopolysaccharide (LPS)-induce NO generation was evident. Also polymorphonuclear cells stimulated with the various milks released detectable amounts of NO. In the case of Priska milk inhibition of LPS-mediated NO generation was observed. Despite a broad array of cytokines tested [Interleukin (IL)-4, IL-5, IL-6, IL-10, IL-12, IL-13, IL-17, Tumor Necrosis Factor (TNF)-alpha, Transforming Growth Factor-beta and Granulocyte Colony Stimulating Factor] only IL-10, TNF-alpha, and IL-6 were released by PBMCs upon stimulation with various milks. Taken together, these data indicate that goat's milk for its capacity to produce NO may exert a cardioprotective and anti-atherogenic effect in consumers. Moreover, induction of proinflammatory (TNF-alpha and IL-6) and anti-inflammatory (IL-10) cytokines suggests the ability of this milk to maintain immune homeostasis in the immunocompromised host (e.g., aged people).

Immunological properties of donkey's milk: its potential use in the prevention of atherosclerosis.

Donkey's milk is the best substitute of human milk for its content in lactose, proteins, minerals, and omega-3 fatty acids. Here, we have evaluated the effects of colostrum and milk from donkeys (Martina Franca breed) on the function of human peripheral blood mononuclear cells (PBMCs) at different intervals from lactation. Colostrum induced more IgA responses, while milk induced predominantly more IgG responses. Both milk and colostrum induced expression of CD25 and CD69 on PBMCs. The ability to induce release of interleukins (IL) (IL-12, IL-1 beta and IL-10) and tumor necrosis factor-alpha was confined only to milk, while colostrum was devoid of this capacity. Finally, both colostrum and milk induced nitric oxide (NO) release from PBMCs but milk exhibited a greater capacity than colostrum in NO generation. Taken together, these immunological activities exerted by both colostrum and milk from donkeys may be useful in the treatment of human immune-related diseases. In particular, NO induction by donkey's milk may be very useful in the prevention of atherosclerosis, being a strong vasodilator and an effective antimicrobial agent since pathogens and/or their products may play a proatherogenic role.

How the FSH/LH ratio and dose numbers in the p-FSH administration treatment regimen, and insemination schedule affect superovulatory response in ewes.

We wished to evaluate the effects of FSH/LH ratio and number of doses of p-FSH during a superovulatory treatment on ovulation rate and embryo production (Experiment I). In Experiment II, we studied the efficacy of fertilization after various insemination schedules in superovulated donors. In Experiment I estrus was synchronized in 40 ewes (FGA, for 9 days plus PGF2alpha on Day 7) and the ewes were randomly assigned to four treatment groups as follows (n = 10 ewes each): Group A: four p-FSH doses with the FSH/LH ratio held constant (1.6); Group B: four p-FSH doses with the FSH/LH ratio decreasing (FSH/LH 1.6-1.0-0.6-0.3); Group C: eight p-FSH doses with the FSH/LH ratio held constant (1.6); Group D: eight p-FSH doses and FSH/LH ratio decreasing (1.6-1.6, 1.0-1.0, 0.6-0.6, 0.3-0.3). p-FSH administrations were performed twice daily 12 h apart. The ewes were mated at the onset of estrus and again after 12 and 24 h; then, one ram per four ewes was maintained with the ewes for two additional days. Ovarian response and embryo production were assessed on Day 7 after estrus. Experiment II. Three groups (n = 10 each) of superovulated ewes were inseminated as follows: Group M: mated at onset of estrus; Group AI: artificial insemination 30 h after onset of estrus; M + AI) mating at onset of estrus and intrauterine AI performed 30 h from estrus with fresh semen. Results of Experiment I showed that treatment (D) improved (P < 0.05) ovulatory response in comparison to Groups (C) and (A). The fertilization rate was lower (P < 0.01) in Group D) than Group (A). Also the proportion of transferable embryos was lower in Group (D) in comparison to all the other treatments (P < 0.01). Group A gave the best production of embryos (7.3/ewe; 89.0% transferable). In Experiment II, combined mating plus AI improved fertilization rate (80.3%) compared to both mating (P < 0.01) and AI (P < 0.02) alone.

Evaluation of seasonal variations of semen freezability in Leccese ram.

The experiment was carried out in Southern Italy (41 degrees N latitude) to examine the effects of seasonal variations of semen freezability in Leccese ram. Semen from five rams, collected every 2 weeks for a whole year, was frozen in straws, using a system based on Tris-fructose egg yolk as extender to constitute semen doses of 100x10(6) spermatozoa. Post-thaw survival and acrosomal status of cells were assessed by dual staining by Hoechst 33258 and FITC-PSA. Three different forms of fluorescence distribution were displayed indicating sperm without acrosome (unstained cells), sperm with damaged acrosome (cells with incomplete fluorescence over the head), sperm with widespread fluorescence (cells completely fluorescent). Motility and kinetic rating at thawing and after 1 and 3h incubation (37 degrees C) were also assessed. Semen frozen in summer and autumn, corresponding to the breeding season, showed the highest (P<0.01) post-thaw survival of spermatozoa (41.7%) and the lowest (P<0.01) incidence of spermatozoa with damaged acrosome. The positive influence of the summer-autumn period was expressed also on motility and kinetic rating of spermatozoa at thawing. The integrity of the acrosomal membrane was positively correlated (P<0.01) with sperm viability before processing (r=0.32) and after thawing (r=0.51). In conclusion, the results show that season exerts a significant influence on semen freezability in Leccese ram, with the best performance occurring the summer and autumn period, corresponding to the reproductive season in temperate zones.

Superovulation in ewes by a single injection of pFSH dissolved in polyvinylpyrrolidone (PVP): effects of PVP molecular weight, concentration and schedule of treatment.

Three experiments were carried out to evaluate induction in ewes of superovulation and embryo production by a single injection of a porcine pituitary extract (pFSH) dissolved in polyvinylpyrrolidone (PVP), investigating the effects of PVP molecular weight and its concentration (Experiment I), time and method of treatment (Experiments II and III). All ewes were synchronized for estrus by vaginal sponges impregnated with fluorogestone acetate (FGA; 30 mg, 9 days) plus PGF(2alpha) (Cloprostenol, 50 microg, 48h before sponge removal - s.r.), and superovulated by 250 IU pFSH. In Experiment I, 60 Gentile di Puglia ewes were subdivided into five experimental groups (n = 12): Group A, the control, received six decreasing intramuscular (i.m.) doses of pFSH, 12 h apart, beginning 48h before s.r.; Groups B and C were given 48 h before s.r. a single i.m. injection of pFSH dissolved in PVP with MW = 10,000, respectively, at concentrations of 15 and 30% w/v; Groups D and E received the same treatments as for B and C using PVP with MW = 40,000. None of the pFSH-PVP treatments were effective in inducing superovulation. In Experiment II, 22 Leccese ewes were subdivided into two groups (n = 11): Group A, control received i.m. four decreasing doses of pFSH, beginning 24 h before s.r., 12h apart; Group B was given a single i.m. injection of pFSH dissolved in PVP (MW = 40,000 at 30% w/v), 24 h before s.r. The pFSH-PVP treatment provided an ovulation rate similar to the control and tended to enhance embryo yield (4.4 versus 2.4, P>0.05). In Experiment III, 60 Leccese ewes were subdivided into six treatment groups (n = 10). Groups A and D served as controls and received i.m. 12 h apart, six doses (from 48 h before s.r.) and four doses (from 24h before s.r.) of pFSH, respectively. Groups B and C were treated by a single injection of pFSH in PVP (MW = 10,000; 30% w/v) 48 h before s.r., respectively by i.m. or subcutaneous (s.c.) administration. Groups E and F received the same treatments as for B and C 24 h before s.r. Intramuscular pFSH-PVP administration 24 h before s.r. provided an ovulation rate (8.1), mean numbers of ova recovered (5.6) and fertilized (4.2) comparable to the six or four dose treatments and significantly higher (P <0.01) compared to the pFSH-PVP treatment carried out i.m. 48 h before s.r. These results show that a single injection of pFSH dissolved in PVP at 30% w/v, performed i.m. 24 h before s.r., is able to induce a superovulatory response comparable to that following multiple injection treatment, regardless of PVP molecular weight.

Active immunization with a synthetic fragment of pig inhibin alpha-subunit increases ovulation rate and embryo production in superovulated ewes but season affects its efficiency.

Two experiments were designed to determine the effects of active immunization against one of two synthetic peptides from humans (inhibin-like peptide) or pigs (inhibin alpha-subunit) on antibody titres, ovulation rate and embryo production in ewes superovulated with 16 U ovine FSH. In Expt 1, during the breeding season, 30 ewes were subdivided into three groups: group I served as the non-immunized control; group II was immunized against inhibin-like peptide (100 micrograms inhibin-like peptide equivalent, followed by three booster injections); group III was immunized against pig inhibin alpha-subunit conjugated to human serum albumin (96 micrograms for the primary administration and 46 micrograms for the booster). In Expt 2, the efficiency of immunization against pig inhibin alpha-subunit on ovarian response and embryo production was evaluated during the non-breeding season in two groups of ewes (n = 12): group IV was a non-immunized control; Group V was immunized against pig inhibin alpha-subunit. During the breeding season, the ewes immunized against pig inhibin alpha-subunit showed higher antibody titres compared with the group immunized against inhibin-like peptide (P < 0.01) and a significant increase in ovulation rate (12.1) compared with both the control (5.0; P < 0.05) and the inhibin-like peptide-immunized group (3.1; P < 0.01). Immunization against pig inhibin alpha-subunit increased transferable embryo yield 4.5-fold (6.7 versus 1.5; P < 0.01) and improved embryo quality (94.6 versus 40.6%; P < 0.01). During the non-breeding season, immunization against pig inhibin alpha-subunit enhanced ovulation rate from 2.6 in the controls to 9.4 (P < 0.01) but did not affect transferable embryo production (3.9 versus 2.1; P > 0.05) and significantly lowered their quality (54.1 versus 100%; P < 0.01). In conclusion, active immunization against pig inhibin alpha-subunit can improve superovulatory response during the breeding season, while it appears to be unable to increase embryo yield during the seasonal anoestrus.

Some effects of adding p-LH in defined amounts to purified p-FSH to modify FSH/LH ratios during the superovulatory treatment of anestrous ewes.

Nonlactating Leccese ewes (n = 61) were used during seasonal anestrus to investigate the effects on ovarian response and embryo production of adding defined amounts of p-LH to purified p-FSH as well as decreasing the FSH/LH ratio during treatment. The ewes were synchronized with FGA-impregnated intravaginal pessaries for 9 days and prostaglandin F2 alpha (Cloprostenol) injected on the seventh day. They were divided into six treatment groups in a 3 x 2 factorial design: three amounts of purified p-LH (100, 50 or 25% equivalent to 525, 262 or 131 IU p-LH) x 2 regimen of p-FSH and p-LH administration (constant or decreasing FSH/LH ratio). Each ewe received a total of 525 IU p-FSH at a decreasing dose, twice daily over a 3-day period. Group I (n = 11), Group II (n = 10) and Group III (n = 10) were treated with p-FSH supplemented with p-LH at 100%, 50% and 25%, respectively, of p-FSH dose and a constant FSH/LH ratio throughout the treatment period. Group IV (n = 10), Group V (n = 10) and Group VI (n = 10) were treated with p-FSH supplemented with p-LH at 100%, 50% and 25%, respectively, of p-FSH dose but with a decreasing FSH/LH ratio over the 3 days of the treatment: 1.7-0.86-0.43 for Group IV; 3.4-1.7-0.86 for Group V; 6-3-1.5 for Group VI. Embryos were flushed surgically on Day 6 after estrus. The ovulation rate did not differ among the groups (8-12.8). Superovulation with 100% p-LH and decreasing the FSH/LH ratio (Group IV) resulted in: (i) the highest ova recovery (9.8 +/- 1.7), and this was significantly different (P < 0.05) from the 25% p-LH treated group (Group VI; 5.0 +/- 1.7), (ii) the highest fertilization rate (90.6 +/- 9.2%), with a significant (P < 0.01) difference compared with the constant ratio regimen (Group I; 62.6 +/- 8.3%); (iii) the highest transferable embryo yield (6.4 +/- 1.1), differing significantly (P < 0.01) from Group VI (2.2 +/- 1.1) and Group I (2.7 +/- 1.0). It is concluded that decreasing the amount of p-LH added to purified p-FSH did not improve the superovulatory response of ewes during the anestrous period. Transferable embryo production was significantly improved when ewes were treated with p-LH equivalent to 100% p-FSH, with the FSH/LH ratio decreasing during treatment.

Embryo production and endocrine response in ewes superovulated with PMSG, with or without monoclonal anti-PMSG administered at different times.

Mature nonlactating Altamurana ewes (n = 168) were synchronized in the seasonal anestrus period with FGA-impregnated intravaginal pessaries for 12 d. In Experiment 1, 48 ewes were divided into a 3 x 4 factorial design for anti-PMSG monoclonal antibody (AP) bioassay test. Concomitant injections of PMSG (1000, 1500, 2000 IU) and AP (0, 1, 2, 3 microl/IU PMSG) were given, and ovarian response was evaluated by laparoscopy. In Experiment 2, 120 ewes were divided into 8 experimental groups (n = 15 per group). The ewes treated with 1000 or 1500 IU PMSG at -24 h from sponge removal were given AP intravenously at 50 h after pessary withdrawal, 12 or 24 h after the onset of estrus, while the controls did not receive AP. Blood samples were collected from ewes (n = 6) treated with 1500 IU PMSG with or without anti-PMSG. Ovarian response and embryo production were evaluated on Day 7 after sponge removal upon laparotomy. It was found that 1 microl AP was effective in neutralizing 1 IU PMSG. No significant differences in serum concentrations of progesterone were observed among the groups of superovulated ewes. Estradiol-17 beta levels were reduced following AP treatment 12 h after the onset of estrus. At a lower dosage of superovulatory treatment (1000 IU PMSG), AP injected at 12 or 24 h after the onset of estrus significantly lowered large follicles (P < 0.01) and increased the rate of ovulation (P < 0.05). Moreover, embryo production showed a more than two-fold increase (P < 0.01) of viable embryos following AP injection at 12 or 24 h after the onset of estrus (3.2 to 3.3 vs 1.3, with vs without anti-PMSG). It is concluded that superovulatory treatment with 1000 IU PMSG plus AP administered at a fixed time after the onset of estrus may improve ovarian response and the yield of viable embryos in ewes.