1,721,066 research outputs found
Su alcuni aspetti ormonali del determinismo del parto della pecora e della capra e sulle relative possibilità di controllo
No full textEmbryo transfer negli ovini e nei caprini II - Tecniche di trapianto degli embrioni e fattori che influenzano il successo dell'embryo transfer
No full textInfluence of milking number and frequency on milk production in Martina Franca breed asses
No full textEvaluation of seasonal variations of semen freezability in Leccese ram
No full textThe experiment was carried out in Southern Italy (41degreesN 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 100 x 10(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 3 h incubation (37degreesC) 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
Post-thaw survival and acrosome integrity of spermatozoa of Leccese rams frozen in different seasons with a milk-egg yolk extender
No full textThe influence of the period of semen collection on post-thawing survival, motility and acrosome integrity of spermatozoa in Leccese rams was studied throughout an entire year. The year was divided into the seasons: winter and spring (first semester) and summer and autumn (second semester). Semen from 5 adult rams was collected every two weeks by artificial vagina and frozen according to a freezing system based on milk-lactose egg yolk to constitute semen doses of 400 x 10(6) spermatozoa. At thawing, survival and acrosomal status of cells were assessed and the motility of the sperm and their kinetic rating (scale 0 to 5 score) were determined at thawing (0 h), and after 1 and 3 h incubation (37 degrees C). Semen collected during the first semester (winter - spring) of the year showed the highest (P<0.01) proportion of post-thaw live spermatozoa, with the maximum value in winter (P<0.01), and the best acrosomal status of spermatozoa, considered as both total proportion of spermatozoa with acrosome break down and spermatozoa without acrosomes. Acrosome integrity was positively correlated (r = 0.32; P<0.01) with post-thaw sperm viability.
Motility of spermatozoa at thawing was not influenced by the period of semen collection. However, after 3 h incubation sperm motility was higher (P<0.01) during the first semester of the year, without a difference between winter and spring.
A marked individual ram effect was found on freezability of semen.
The results provide evidence that the period of semen collection can influence freezability of spermatozoa in Leccese rams. The best characteristics of spermatozoa were observed during the first semester of the year, corresponding to the sexual hypoactivity season for this breed
LACTATION CURVE AND EFFECTS OF NUMBER, INTERVAL AND TIME OF MILKINGS ON MILK YIELD AND QUALITY AND UDDER HEALTH IN MARTINA FRANCA ASSES
No full textThree 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 (r2 = 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 × 8H1, milked at 1200 h and 2200 h with an 8-h interval; and 2 × 8H2, 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
Progress in nutritional and health profile of milk and dairy products: a novel drug target
No full textThere is an increasing focus on diet as a tool to maintain human health and prevent disease. Milk and milk products of ruminants are important source of fat and saturated fatty acids, which are not considered to be very favourable to human health, but are valuable sources of nutrients including bioactive fatty acids (FA), vitamins, and minerals, which can promote positive health effects. The nutritional characteristics of milk and dairy products are related to their composition, which depends on the source species, and varies due to numerous factors, among which the animal diet is the most important. An improvement in milk FA composition and other micronutrients can be reached through an animal feeding strategy. Natural pasture-based farming systems increase microconstituents that are beneficial to human health (CLA, PUFAs, n-3 FAs, antioxidants, vitamins A and E, and Se) and volatile compounds (flavour, and terpenes) in milk and cheese. There are still uncertainties about the health benefits of various milk FAs and other compounds; deep and extensive long-term clinical studies with humans are needed. The contamination of milk and dairy products by heavy metals or dioxins has dramatic negative consequences for human and livestock health and necessitates very urgent consideration and intervention
Efficiency of FSH/LH treatments for in vivo production of embryos and their cryopreservation by different methods in goats
No full textThe effectiveness of FSH/LH in superovulatory treatment and embryo cryopreservation by
different methods was studied in goats. Forty-five goats were synchronized for oestrus and
subdivided into three superovulatory treatment groups (N 15) with p-FSH (250 IU, over
3 days), corresponding to different doses of purified FSH and LH giving FSH/LH ratios of:
(A) control, FSH/LH = 1:1, constant during the treatment; (B) FSH/LH = 2:1, constant; (C)
FSH/LH = 2:1, decreasing in the three days of the treatment (FSH/LH = 3.4:1.7:0.8, respectively).
Embryo production was assessed at 7th d after oestrus. Mean number of transferable
embryos of Group C (6.9) was similar to Group A (8.2) and higher (P < 0.05) than in Group
B (3.8). On the produced morulae (N 113) and blastocysts (N 144), four freezing methods
were evaluated: CF1, slow-freezing in 1.5 M ethylene glycol (EG); CF2, slow-freezing in
3.0 M methanol; QF, quick-freezing in EG 3.0 M, exposure at N2 vapor and plunging into
liquid N2; V3, vitrification in three-step-process at increasing GLY and EG concentrations
and direct plunging in liquid N2. At thawing, the morphological viability rates of embryos
with V3, and QF, methods were significantly higher (P < 0.05) than with CF1 and CF2. Survival
rates of blastocysts through Day 45 of pregnancy were 70% (7/10), 66.7% (6/9), 44.4%
(4/9) and 28.6% (2/7), for embryos cryopreserved with V3, QF, CF1 and CF2, respectively
(P > 0.05). In conclusion, a satisfactory superovulatory response occurs using treatment A.
QF and V3 methods resulted more suitable for the cryopreservation of embryos in goats
Influenza della presenza dell'ariete sulle manifestazioni estrali di pecore cicliche di differenti età sottoposte a sincronizzazione degli estri
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