The Effects of Sample Size on the Outcome of Ovarian Tissue Cryopreservation

Cryopreservation of ovarian tissue is known to affect follicular survival. Several variables may be responsible for this. Little attention has focused on the effect of the size of the fragment to be cryopreserved. This study was conducted to assess the effect of the size of the tissue on follicular histology after freezing with 1,2-propanediol. Histological evaluations were performed of control and cryopreserved tissue. Fragments were cut 10 × 3 × 2 mm³ (2 mm group) or 10 × 3 × 4 mm³ (4 mm group). Percentages of normal follicles in control fragments cut into 2 and 4 mm slices were 56% and 34%, respectively. The relative risks to obtain normal follicles in the 2 mm and the 4 mm fragments after cryopreservation were 0.63 and 0.47, respectively. Freezing reduced follicle survival to a significantly greater extent in the larger tissue fragments. There is an increased risk of damage to primary and primordial follicles, when the tissue slices are cut with all dimensions larger than 2 mm.     

Association with TGF‐β1 Gene Polymorphisms and Reproductive Performance of Large White Pig

As a multifunctional cytokine, transforming growth factor‐beta1 (TGF‐β1) was detected in the utero‐placental interface during early pregnancy in the pig and believed to enhance trophoblast attachment to the endometrium. In this experiment, we selected TGF‐β1 as the candidate gene affecting litter size in pigs. Four polymorphic loci of TGF‐β1 gene were found by PCR‐SSCP (single‐strand conformation polymorphism) in Large white sows (n = 567): C→T mutation at 33nt in the intron 4; G→A mutation at 179nt in the intron 6; C→T mutation at 1043nt in the intron 6; GG→AA linkage mutations at 2490nt and 2494nt respectively. We haplotyped these SNPs as: CGCAA (denote as P) and TATGG (denote as K). The effects of three haplotypic combinations (HCs) of PP, PK and KK on litter sizes were investigated by a linear model. It was found that for the first parity litters, the least squares mean for total number born (TNB) of KK was 1.02 piglets/litter, higher than that of PK (p < 0.05), 0.49 piglets/litter higher than that of PP (p > 0.1). There were no significant differences between HCs on the second parity. The result indicated that KK HCs was significantly associated with pig litter size.     

The Influence of Powdered Coconut Water (ACP‐318®) in In Vitro Maturation of Canine Oocytes

The objective of this study was to determine the influence of powdered coconut water (ACP‐318^®) diluted in high glucose (11.0 mm ) TCM199 in the achievement of nuclear in vitro maturation (IVM) of canine oocytes. Cumulus oocyte complexes (COCs) (n = 632) were randomly allocated into three experimental groups named as group 1 (control group), group 2 (5% powdered coconut water) and group 3 (10% powdered coconut water). The percentage of meiotic resumption (MR) (GVBD to MII) was 39.1% (81/207), 50.2% (108/215) and 46.6% (98/210) for groups 1, 2 and 3 respectively (p < 0.05). There were no differences in MR rates among groups 2 and 3. The medium with ACP‐318^® slightly enhanced the nuclear maturation of canine oocytes when a comparison was established with rates of maturation exhibited by oocytes in the experimental group 1 without ACP‐318^® (p < 0.05). The results suggest that oocytes’ nuclear morphology integrity and meiosis achievement were positively influenced when exposed to high glucose TCM199 supplemented with 5% powdered coconut water. Further investigation must be performed for a better understanding of powdered coconut water influence in cellular events during IVM of dog oocytes.     

Comparison of the omp I gene of Chlamydia psittaci between isolates in Victorian koalas and other animal species

Objective The objective of this study is to compare the strain of chlamydia causing genital infection in koalas from Victoria with isolates from other animal species.
Design Polymerase chain reaction and restriction enzyme analysis has been used to compare various Chlamydia psittaci isolates from a range of animals and disease syndromes. The isolates used in this study include isolates from three birds, three from aborted sheep, one from polyarthritis, one from bovine abortion, one from feline pneumonitis, three porcine isolates from faeces, polyarthritis and abortion, and three urogenital isolates from Victorian koalas.
Procedure Two polymerase chain reactions were performed, each amplifying a different region of the omp I gene. The first polymerase chain reaction amplified a 144 bp segment of the gene which was then digested with the restriction enzyme Eco R I. The second polymerase chain reaction amplified a larger 1070 bp region of the omp I gene which was digested with two restriction enzymes Alu I and Nde II.
Results and conclusions The results obtained have confirmed that variation in DNA sequence of various animal chlamydia isolates does occur. They have also shown that it is possible to classify isolates, based on their restriction enzyme profiles, into distinct groups.     

In vitro Capacitation and Acrosome Reaction of Dog Spermatozoa can be Feasibly Attained in a Defined Medium Without Glucose

Incubation of dog spermatozoa in a medium without glucose and in the presence of lactate and pyruvate (l-CCM) for 4 h at 38.5 degrees C in a 5% CO(2) atmosphere induced in vitro capacitation of these cells. This was verified after the combined specific capacitation-like changes in percentages of viability and altered acrosomes, motility characteristics, sperm location of reactivity against Pisum sativum, Arachis hypogaea and Helix pomatia lectins and the tyrosine phosphorylation pattern. Furthermore, a feasible acrosome reaction (AR) was induced when spermatozoa incubated in l-CCM for 4 h were further co-incubated for 1 h with canine oocytes. This was demonstrated by AR-like changes in percentages of viability, altered acrosomes, motility characteristics and sperm location of reactivity against P. sativum, A. hypogaea and H. pomatia lectins. All these results clearly indicate that in vitro capacitation, and subsequent AR, can be feasibly achieved without the presence of sugars. This ability can be related to the specific characteristics of energy-metabolism regulation reported in dog spermatozoa.     

磷酸泰乐菌素颗粒剂生物效价测定方法的建立及验证

建立了磷酸泰乐菌素颗粒剂的生物效价测定方法，并对新建立的测定方法进行了验证，验证内容包括：方法对照试验、精密度试验、线性及线性范围试验、回收率试验。验证结果证明新方法能准确测定磷酸泰乐菌素颗粒剂的效价单位。     

Influence of Staining Method on the Values of Avian Sperm Head Morphometric Variables

Computer‐assisted systems for the assessment of sperm morphometry (ASMA systems) have been used successfully with several mammalian species. Unfortunately, they have so far been of little use for assessing bird semen, a consequence of the filiform shape of avian spermatozoa. This study compares two staining techniques (Hemacolor^® and aniline blue staining) for the morphometric analysis of rooster and red‐legged partridge spermatozoa as part of a computer‐assisted light microscopy method. For both species, Hemacolor^® staining provided a significantly higher percentage of measurable cells (93.7 ± 11.7% in roosters and 71.9 ± 15.3% in red‐legged partridges). Hemacolor^® also showed greater repeatability (lower coefficients of variation) for length and area in roosters' sperm and for width in the case of red‐legged partridge's sperm. In the roosters, the Hemacolor^® technique returned significantly (p < 0.05) larger sperm head width and area values than did the aniline blue technique, while the latter resulted in greater sperm head length values (p < 0.05). In the red‐legged partridge, no differences were seen in the results for sperm head width and area provided by the two techniques, but aniline blue staining was associated with longer length measurements. In conclusion, the morphometric values recorded differed depending on the staining method and species. However, the Hemacolor^® technique might be deemed the more appropriate for computerized sperm assessment systems as it provides larger percentages of measureable cells and shows greater repeatability.     

Effect of the Interaction Between Cryoprotectant Concentration and Cryopreservation Method on Frozen/Thawed Chicken Sperm Variables

This work examines the effect of the interaction between different concentrations of two cryoprotectants – glycerol (GLY) and dimethylacetamide (DMA) – and two methods of cryopreservation – pellets produced by plunging into liquid nitrogen and gradual in‐straw freezing – on frozen/thawed chicken sperm variables. Sperm was cryopreserved using: (i) 6% DMA, following the in‐straw and the pellet methods (ii) 11% GLY, following the in‐straw and the pellet methods; and (iii) 8% GLY in the in‐straw method and 3% DMA in the pellet method (i.e. reduced cryoprotectant concentrations). When 6% DMA was used as the cryoprotectant, no differences were seen between the in‐straw and pellet methods in terms of frozen/thawed sperm variables or fertility (10.8% and 12.8%, respectively). The viability and motility variables of the frozen/thawed sperm produced using the in‐straw method with 11% GLY were higher (p < 0.05) than those recorded for the sperm preserved using the same cryoprotectant and concentration in the pellet method. However, fertility was extremely low in both groups (2.1% and 4.2% for the in‐straw and pellet methods, respectively). Finally, the use of 8% GLY in the in‐straw method returned higher sperm viability, intact acrosome and motility values than the use of 3% DMA in the pellet method (p < 0.01). No differences were seen, however, in the fertility results obtained (28.8% and 25.0%, respectively). These results suggest that cryoprotectant concentrations can be reduced and still provide acceptable fertility rates.     

A Pilot Study to Compare Oxidative Status between Organically and Conventionally Managed Dairy Cattle During the Transition Period

The aim of this study was to assess the redox balance of organically managed dairy cattle (OMC; n = 40) during the transition period and to compare this with conventionally managed cattle (CMC; n = 22). Serum samples of dairy cows from two organic and one conventional farm were taken. Markers of oxidants production [reactive oxygen species] and total serum antioxidant capacity were measured in four different production stages: (i) far‐off dry (2 to 1 months before calving; 44 samples in CMC and 48 in OMC); (ii) close‐up dry (1 month until 3 days before calving; 44 CMC; 54 OMC); (iii) fresh (3 days to +1 month after calving; 44 CMC; 49 OMC); and (iv) peak of lactation (+1 to +3 months; 71 CMC; 78 OMC). Values were compared between production stages and against a metabolic baseline status (4th–5th month of pregnancy; 40 CMC; 30 OMC). Our results indicated that throughout the periparturient period, OMC had lower concentrations of reactive oxygen species, but also a lower antioxidant capacity than CMC. Indeed, when the two components of the redox balance were assessed together through the Oxidative Stress index, the values of this parameter were higher for OMC than for CMC, thereby implying a higher risk of oxidative stress. Therefore, further larger studies are needed to confirm the current observations, as organically reared animals might be exposed to a lack of antioxidants supply.