Molecular identification and relative abundance of microorganisms in douchi koji and salted egg white sufu during processing

A novel animal protein-based douchi koji-inoculated steamed salted egg white sufu (SEWS) has been developed. This study determined the relative abundance of microorganisms in the douchi koji and semi-finished (5-day fermentation) and finished (5-day fermentation and 14-day ripening) SEWS by using 16S and 18S ribosomal DNA and gene-cloning methods. The results revealed that Bacillus spp. and Aspergillus oryzae were dominant in the douchi koji. In the semi-finished SEWS, the percentages of Bacillus amyloliquefaciens and Bacillus subtilis were considerably lower, whereas those of Enterococcus and Staphylococcus were substantially higher. In the finished SEWS, Bacillus spp. became dominant again and A. oryzae was the only fungus detected. In conclusion, by using molecular techniques, microbial population dynamics in SEWS can be evaluated. During processing, the relative abundance of microorganisms in SEWS changed and Bacillus spp. and A. oryzae remained dominant. This study provides crucial information for designing starter cultures for producing SEWS.     

Effects of inoculants and environmental temperature on fermentation quality and bacterial diversity of alfalfa silage

To investigate the effects of inoculants and environmental temperature on fermentation quality and bacterial diversity of alfalfa silage, first‐cut alfalfa was ensiled with or without two screened lactic acid bacteria (LAB) strains, Lactobacillus plantarum, LP, and Lactobacillus casei, LC. Each treatment was divided into three parts and stored at 20°C, 30°C, 40°C, respectively. After 60 days ensiling, fermentation characteristics were measured and bacterial diversity was investigated by 16S ribosomal RNA gene sequencing using Illumina MiSeq platform. LP and LC decreased pH, coliform bacteria counts and increased lactic acid content at 20°C, and the two strains decreased pH, ammonia‐N concentration, coliform bacteria counts at 30°C. When the environmental temperature was 40°C, silage treated with LC showed lower LAB and coliform bacteria counts and higher lactic acid content than the untreated and LP treated silages. Butyric acid mainly appeared in silages stored at 40°C. The relative abundance of Lactobacillus in alfalfa silages stored at 20°C and 30°C was highest and increased after LP and LC were added. Garciella was another dominant genus in silages stored at 40°C. In conclusion, LP and LC improved fermentation quality of alfalfa silage by increasing Lactobacillus proportions at 20°C and 30°C; ensiling alfalfa at 40°C was difficult because of Garciella.     

Effects of bacterial strains on the development of the ripening flavor of cured pork loins

To determine the effect of bacteria on the development of the ripening flavor of cured meat, pork loins were cured with pickles containing 8 or 16% sodium chloride at 0 and 8°C. The bacterial flora, total free amino acid content and total free fatty acid content in the cured loins, sensory properties of cooked pork loins and the relationships between the proteolytic and lipolytic activities of isolates and curing conditions were investigated. Desirable bacteria, including salt‐tolerant bacteria and lactic acid bacteria, were predominant under the condition of 8% sodium chloride in the pickles and a curing temperature of 8°C. The total free amino acid content and total free fatty acid content at a curing temperature of 8°C were higher than those at 0°C. Cooked pork loins cured in pickles containing 8% sodium chloride at a temperature of 8°C for more than 7 days were preferred in terms of color, flavor and taste. Before the curing procedure, gram‐negative bacteria (Vibrio, Acinetobacter, Pseudomonas and Enterobacteriaceae) were predominant in the pork loins. During the curing period, the numbers of viable gram‐positive bacteria (Micrococcus, Staphylococcus and Pediococcus) increased and the numbers of viable gram‐negative bacteria decreased. Strains of Micrococcus and Staphylococcus with proteolytic and/or lipolytic activities in cured meat also increased during the curing period and were more predominant in the pork loins cured in pickles containing 8% sodium chloride and at a curing temperature of 8°C than in pork loins cured in pickles containing 16% sodium chloride and at a curing temperature of 0°C. The actions of these bacteria were thought to be important factors affecting the flavor of the cured pork. Micrococcus and Staphylococcus with proteolytic activity might contribute to the development of the ripening flavor of ham. The results of the present study together with the results of further investigations on the relationships of the enzyme activities of Micrococcus and Staphylococcus in cured meat with a preferable flavor would be useful for establishing a novel effective method for using bacteria to produce ham of a high quality.     

Raised environmental temperature and food rationing as means of restricting growth of the replacement pullet

1. Four rearing temperature regimes (15, 20, 25, 30 °C) and three feeding schedules (ad libitum, restricting to the ad libitum intake of the 12th week and feeding 70% of this rate) were carried out with layer replacement pullets to 170 d of age. From this age, during lay, birds were kept at either 21 °C or on a 24‐h cycle of 21 for 18 h and 28 °C for the 6 h before lights out. Both a white and a brown egg‐laying strain were used.

2. Body weight at 169 d of age varied from, on average, 1409 g (15 °C, ad libitum) to 943 g (30 °C, 70% schedule) for the white strain and 1947 to 1250 g for the same treatments respectively for the brown strain. Sexual maturity was considerably delayed by the 70% feeding schedule, only slightly by rearing at 30 °C.

3. Rearing at 30 °C tended to depress subsequent egg output. The 70% feeding schedule at least maintained egg output compared with birds fed ad libitum in rearing.

4. There was a highly significant effect of temperature treatment during lay on food intake. The reduction in food intake due to the 21–28 °C cycle, however, appeared small.     

Evaluation of nutrient content,physicochemical and functional properties of desalted duck egg white by ultrafiltration as desalination

In this study, the effects of ultrafiltration technique on the desalination efficiency, nutrient content, physicochemical properties, functional properties, texture profile, and microstructure of salted duck egg white were evaluated. The results showed that ultrafiltration can remove 92.93% salt from salted duck egg white (SDEW) and final salt% of desalted duck egg white (DDEW) was 0.65%. The analysis of nutrient content and amino acid of SDEW and desalted duck egg white powder (DDEWP) sample was significantly lower than those of fresh duck egg white (FDEW). Although emulsifying capacity of SDEW, DDEW, and DDEWP exhibited significantly lower than that of FDEW, an excellent foaming ability was found in those samples. Moreover, the texture profiles (gel strength, hardness and elasticity) of SDEW, DDEW, and DDEWP samples presented lower value than FDEW. The observation of microstructure, DDEWP possessed smooth surface of protein globules with deep hole liked donuts and distribution of a few of salt crystals. While salted duck egg white powder (SDEWP) had a raisin‐like surface formation with salt formed cubic crystals. Overall, both liquid and dried material of desalted duck egg could be used as a good ingredient in baking food due to their excellent foaming capacity.     

The effect of cooling to different subzero temperatures on dog sperm cryosurvival

The objective was to assess the effect of cooling to different subzero temperatures around ice formation (?5°C) on dog sperm cryosurvival and plasma membrane fluidity. Semen was centrifuged, and sperm were resuspended in a Tris‐egg yolk medium (3% glycerol). Diluted sperm were cooled from 22 to 5°C, and then, a Tris‐egg yolk medium containing 7% glycerol was added (final concentration of 5% glycerol and 200 × 10⁶ cells/ml). Sperm were packaged in 0.5‐ml plastic straws, and equilibration was done 16 hr at 5°C before freezing. I. Straws (n = 47) at 5°C were exposed to nitrogen vapours to determine the freezing point. II. Other straws (from different ejaculates) processed as mentioned, were further cooled to ?3, ?5 or ?7°C and immediately rewarmed in a water bath at 37°C. Motility, plasma membrane functionality and acrosome integrity were assessed. III. Other straws (from different ejaculates) processed as mentioned were further cooled to ?3 or ?5°C, frozen over nitrogen vapours and stored in liquid nitrogen for one month. Straws were thawed in a water bath at 38°C for 30 s. Motility, plasma membrane functionality, plasma membrane integrity, acrosome integrity, capacitation status and plasma membrane fluidity were assessed. Ice nucleation temperature was ?14.3 ± 2.05°C (mean ± SD); cooling to +5, ?3, ?5 and ?7°C, without freezing, produces no differences on sperm quality between target temperatures; cooling to +5, ?3, and ?5°C produced no differences on sperm survival and plasma membrane fluidity after freeze–thawing. In conclusion, cooling of dog spermatozoa to different subzero temperatures did not improve sperm cryosurvival and had no effect on plasma membrane fluidity after thawing.     

Digestibility,productive performance,and egg quality of laying hens as affected by dried cassava pulp replacement with corn and enzyme supplementation

Two experiments were conducted to investigate the potential use of dried cassava pulp (DCP) supplemented with enzymes as an alternative feed ingredient in laying hen diets. In experiment 1, 45 laying hens (Isa Brown) aged 45 weeks were placed in individual cages to measure nutrient digestibility for 10 days. Nine dietary treatments were control and DCP as a replacement for corn at 20, 25, 30, and 35% supplemented with mixed enzymes (cellulase, glucanase, and xylanase) at 0.10 and 0.15%. Results showed that the use of DCP at 20–35% added with mixed enzymes had no negative effects on dry matter digestibility, while organic matter digestibility and nitrogen retention decreased with increased DCP up to 30–35% in diets. Both enzyme levels (0.10 and 0.15%) showed similar results on nutrient digestibility and retention. In experiment 2, a total of 336 laying hens aged 32 weeks were randomly allocated to seven dietary treatments (control and DCP-substituted diets at 20, 25, and 30%) supplemented with mixed enzymes (0.10 and 0.15%). Diets incorporated with 20–30% of DCP and supplemented with mixed enzymes at both levels had no significant effects on egg production, egg weight, feed intake, egg mass, feed conversion ratio, protein efficiency ratio, or egg quality, except for egg yolk color being decreased with an increase of DCP in diets (P?<?0.05). In conclusion, it is suggested that DCP supplemented with enzymes can be used as an energy source in laying hen diets up to 30% without showing negative effects on nutrient digestibility, productive performance, or egg quality.     

Successful Cryopreservation of Domestic Cat (Felis catus) Epididymal Sperm after Slow Equilibration to 15 or 10°C

To support conservation strategies in wild species, simple but highly reproducible procedures of sperm cryopreservation are required for an application under field conditions. We used epididymal sperm of the domestic cat to optimize a sperm freezing procedure for felid species, particularly questioning the demand for sperm cooling to 4°C. We equilibrated sperm during slow cooling to only 15 or 10°C in a Tes–Tris–fructose extender with final concentrations of 4.7% (v/v) glycerol and 10% (v/v) of the water‐soluble fraction of hen's egg yolk (low‐density lipoproteins). Subsequently, sperm were frozen over liquid nitrogen. Total and progressive motility (mean ± SD) after thawing was 60.7 ± 8.6% and 53.9 ± 9.6% in samples cooled to 15°C or 61.6 ± 9.5% and 55.3 ± 9.9% in samples cooled to 10°C. Therefore, a one‐step addition of glycerol to sperm at room temperature together with the freezing extender, the use of cryovials (loaded with diluted sperm aliquots of 300 μl), an equilibration period of 40 min comprising slow cooling to 15°C at a rate of approximately ?0.14 K/min before rapid freezing over liquid nitrogen, yielded satisfying results. Cooling, freezing and thawing rates were exactly characterized as a prerequisite for further optimization and to provide a repeatable protocol to other practitioners.     

不同催熟浓度及贮藏温度对‘南天黄’香蕉果实后熟品质的影响

为明确‘南天黄’香蕉果实的催熟浓度、温度等条件,以期为生产上催熟提供技术参考。本研究以‘南天黄’香蕉果实为材料,研究1 g·L-1 、0.8 g·L-1 、0.5 g·L-1催熟浓度及14°C、18°C、22°C贮藏温度对果实后熟进程、果皮色度、果肉硬度和可溶性固形物含量等变化的影响。研究结果表明,随着催熟浓度及贮藏温度提高,香蕉果实色差H值及硬度下降速度和可溶性糖含量增加速度加快,后熟进程加快。并且贮藏温度对果实后熟品质的影响明显,在 14°C、18°C和22°C催熟的香蕉,转黄成熟级别分别在10、5和3 d达到可供上市的成熟度。另外,1 g·L-1乙烯利催熟的香蕉在18°C贮藏后再转入14°C贮藏能较好的保持果实品质13 d。综上所述,建议根据‘南天黄’果实上市计划长短的实际情况设置不同的催熟条件。     

Studies on the incorporation of 14 C-labelled amino acids into egg proteins

The incorporation of ¹⁴C‐labelled amino acids into egg white and yolk proteins has been studied. When the labelled amino acids were given intravenously as a hydrolysate of [U‐¹⁴C]‐protein from Chlorella, 10 per cent and 7 per cent of the ¹⁴G were recovered in the whites and yolks respectively of the first nine eggs laid. Differences in the specific activities of the conalbumin, the ovalbumins, ovomucoid, “postalbumins “ and lysozyme, isolated from the first active egg, were related to differences in amino acid composition. The specific activity of each amino acid prepared from the proteins was similar between different proteins, although within each protein specific activities of different amino acids varied widely. The proportionate rate of decrease of specific activity in the plasma of amino acids essential for egg production (except glycine) was constant or almost so, but it rapidly decreased for the non‐essential ones (except serine and proline). The specific activities of the amino acids, excepting aspartic and glutamic acids, in each protein were proportional to their mean specific activities in the plasma throughout the 24‐h period in which the egg white proteins were synthesised. It is concluded that these different proteins are synthesised from a shared amino acid pool, derived from plasma, at a rate which probably remains constant throughout the egg‐laying cycle and which is proportional to their content in the albumen.     

Moisture content and moisture quantity of sweated chicken eggs in 2 storage environments

There are instances where shell eggs may be moved from refrigeration into ambient temperature with high humidity, such as before wash and during transportation. Under these conditions, it is of concern that bacteria on wet eggs can grow and migrate through the shell pores into the egg. Objectives of this experiment were: 1) to compare 3 methods of quantifying condensate on eggs and 2) to quantify condensate on refrigerated shell eggs at 2 temperatures (22°C and 32°C). For objective 1, 270 fresh shell eggs (3 replications, 90 eggs per replication) were stored at 4°C, 60% relative humidity (RH), then placed at 22°C, 60% RH for 1 h. After this time, 30 pre-weighed eggs were randomly selected and weighed. Thirty eggs were thoroughly wiped with pre-weighed paper towels to collect condensate. Thirty eggs were evaluated with a pinless moisture meter for quantifying egg condensate, which was found to be an ineffective method. There was no difference in quantifying egg condensation by egg weight or weight of moisture absorbed on a paper towel (0.2% vs. 0.19% percentage gain mL condensation/egg surface area) (P > 0.05). For objective 2, 104 fresh eggs formed condensation at 2 temperatures (22°C and 32°C, 60% RH). Each egg weight was continuously recorded from the beginning of condensation formation to the point where the egg reached a constant weight. There was a difference found in the time it took for an egg to reach maximum condensation (11 min at 32°C, 17 min at 22°C), as well as completely dry (25 min at 32°C, 34 min at 22°C) between the 2 temperatures (P < 0.05).     

Divergent selection for shape of growth curve in Japanese quail. 6. Hatching time,hatchability and embryo mortality

1. Hatching time, hatchability of fertile eggs and embryo mortality under standard egg storage (1 or 5 days at 12?±?1°C and 55% relative humidity) and incubation conditions (37·5?±?0·2°C and 50% relative humidity) were analysed in lines long-term selected for high (HG) and low (LG) relative weight gain between 11 and 28?d of age, respectively, and constant body weight at 49?d of age.

2. Egg storage duration did not have an effect on average hatching time. LG quail, characterised by a fast postnatal growth rate immediately after hatching, hatched earlier than HG quail with a low early growth rate (about 391 vs. 406?h after egg setting, respectively).

3. In contrast to hatching time, the hatchability of fertile eggs was influenced by line as well as egg storage duration. Extended storage decreased hatching success in both lines. However, LG eggs exhibited a higher hatchability than HG eggs (1?d storage: 96·0 vs. 82·5%; 5?d storage: 88·7 vs. 72·7%, respectively).

4. Lower hatchability resulted mostly from a higher frequency of embryo death during early (up to d 7) and late (d 14 and later) phases of incubation.

5. An inadequate nutrient supply to embryos in consequence of developmental delay seems to be a key factor decreasing viability of embryos during incubation.     

Characteristics of isolated lactic acid bacteria and their effectiveness to improve stylo (Stylosanthes guianensis Sw.) silage quality at various temperatures

Two lactic acid bacteria (LAB) strains, Pediococcus pentosaceus SC1 and Lactobacillus paraplantarum SC2 isolated from king grass silage, were characterized and their effectiveness to improve the silage fermentation quality of stylo (Stylosanthes guianensis Sw.) was studied. Strain SC1 was able to grow at a high temperature of 45°C, while SC2 did not. SC2 normally grew at a low pH of 4.0, while SC1 could not. These two strains and a commercial inoculant of LAB (L. plantarum, LP) were used as additives to stylo silage preparation at various temperatures (20°C, 30°C and 40°C). All LAB inoculants significantly (P < 0.05) reduced the pH value and ammonia-N content, and increased the ratio of lactic acid to acetic acid and quality score compared with the control. In addition, inoculating LAB strains markedly (P < 0.05) reduced butyric acid content at the temperatures of 30°C and 40°C. Compared to SC2 and LP strains, strain SC1 was the most effective for improving stylo silage quality at 20°C, indicated by the increase in lactic acid, ratio of lactic acid to acetic acid and quality score. At 30°C and 40°C, there were no significant differences among SC1, SC2 and LP treatments in pH values, contents of acetic acid, butyric acid and ammonia-N (P > 0.05).     

In vitro Evaluation of in vivo Fertilizing Ability of Frozen Rabbit Semen

The present work studied different spermatozoa parameters and the ability of frozen rabbit spermatozoa to fertilize, in vitro, in vivo‐matured oocytes, as a test to predict their in vivo fertility and prolificacy. Semen from rabbit bucks was frozen using two freezing protocols [in a freezer at ?30°C or in liquid nitrogen vapour (LNV)]. For the in vivo trial, females were inseminated with frozen‐thawed spermatozoa. Oocytes used for in vitro testing were recovered 14 h after ovulation induction from donors and co‐incubated with 2 × 10⁶ frozen‐thawed spermatozoa during 4 h at 37°C in Tyrode's medium under an atmosphere of 5% CO₂ in air with maximal humidity. After co‐incubation period, presumptive zygotes were cultured in TCM199 supplemented with 20% foetal bovine serum (FBS), under the same conditions described above. Although no statistical differences were observed between freezing protocols in seminal parameters [motility rate: 40 and 35%, VCL: 35 and 46 μm/s, amplitude of lateral head displacement (ALH): 1.7 and 2.4 μm, for semen frozen at ?30°C and in LNV, respectively], significant differences were noted in the fertilizing ability in vivo and in vitro. Semen frozen at ?30°C showed the highest fertilizing ability in vitro (26.7% vs 6.2 and 8.7% for semen frozen at ?30°C, in LNV and fresh semen, respectively) and the lowest fertility rate in vivo (21.7% vs 64.2% and 70.6% for semen frozen at ?30°C, in LNV and fresh semen, respectively). Sperm frozen at ?30°C seemed to be more capacitated.     

The utilization of 15N-labeled urea by the laying hen. 3. Incorporation of labeled nitrogen into the amino acids of the white and egg yolk

In an experiment with 3 colostomized laying hens the incorporation of heavy nitrogen from urea into the amino acids of the 21 eggs laid during the 8-day experiment was ascertained. In these eggs the content of 15 amino acids was ascertained separately in the whites and yolks of the eggs and their atom-% 15N-excess (15N') was determined. The heavy nitrogen could be detected in all amino acids investigated. The incorporation of 15N' into the essential amino acids of the white and yolk of eggs is very low. Of the applied 15N'-amount of the urea 0.18% could be detected in the 9 essential amino acids of the white of egg and 0.12% in those of the yolk. For the 6 analysed nonessential amino acids the rediscovery quota of 15N' in the white of egg was 0.50% and in the yolk 0.81%. The conclusion from these results is that the NPN-source urea is insignificant for egg protein synthesis.     

Tropical legume supplementation influences microbial protein synthesis and rumen ecology

Four rumen‐fistulated male swamp buffaloes, 5‐year‐old with initiated live weight at 360 ± 12 kg, were randomly assigned according to a 4 × 4 Latin square design to investigate the effect of feeding high level of dried Leucaena leaf (DLL) on feed intake, fermentation efficiency and microbial protein synthesis. The dietary treatments were the feeding levels of DLL at 0, 2, 4 and 6 kg/head/day. All buffaloes were supplemented with concentrate mixtures at 0.1% of body weight, and rice straw was fed ad libitum with the availability of water and mineral block at all time. The results revealed that the total feed intake and nutrient digestibility were significantly improved with the increasing levels of DLL feeding, and the highest was in the buffaloes consuming DLL at 6 kg/head/day. Feeding high levels of DLL did not affect on ruminal pH and temperature, while ammonia nitrogen, blood urea nitrogen and volatile fatty acid concentration were significantly enhanced. Moreover, methane production was dramatically reduced by increasing levels of DLL feeding. Total direct counts of the micro‐organism population were increased with the increasing levels of DLL feeding. According to the application of quantitative PCR to quantity cellulolytic bacteria (16S rRNA) targets, it was found that the population of total bacteria and Fibrobactor succinogenes was affected by treatments, while Ruminococcus flavefaciens and methanogen population were significantly decreased as buffaloes were fed with DLL. The nitrogen balance and microbial nitrogen supply were remarkably improved with the increasing levels of DLL feeding. Based on this study, it could be concluded that high levels of DLL feeding at 6 kg/head/day could enhance feed intake, nutrient digestibility, rumen fermentation efficiency and microbial protein synthesis in swamp buffaloes fed on rice straw without any adverse effect.     

The microclimate of the canine coat: the effects of heating on coat and skin temperature and relative humidity

The coat of seven ‘Landseer’ Newfoundland dogs was irradiated using an infra-red source for 25 min. In each dog, at a site of each colour (black and white), skin and coat temperatures were monitored, and coat air humidity measured with a specially designed instrument. Almost no differences were noted at sites with differing coat colour. Skin temperature rose from 35 °C to a plateau at 39 °C, whilst coat temperature rose from 30 °C to 41 °C. Relative humidity of coat air initially rose, then fell significantly (P < 0.001). The absolute humidity initially almost doubled (P < 0.001), but then fell, although remaining significantly higher than that of ambient air. It was concluded that an initial burst of sweating was followed by lower but continuing secretion. This was not, however, of great importance in cooling. In a separate study the skin temperature of black coated dogs exposed to bright sunshine was explored. The mean temperature was almost identical to that of the plateau skin temperature noted in Newfoundland dogs.     

ORIGINAL ARTICLE: Ileal endogenous amino acid flow of broiler chickens under high ambient temperature

High environmental temperature has detrimental effects on the gastrointestinal tract of poultry. An experiment was conducted to determine the effect of acute heat stress on endogenous amino acid (EAA) flow in broiler chickens. A total of 90, day‐old broiler chicks were housed in battery cages in an environmentally controlled chamber. Chicks were fed a nitrogen‐free diet on day 42 following either no heat exposure (no‐heat) or 2 weeks exposure to 35 ± 1 °C for 3 h from days 28 to 42 (2‐week heat) or 1 week exposure to 35 ± 1 °C for 3 h from days 35 to 42 (1 week heat). The most abundant amino acid in the ileal flow was glutamic acid, followed by aspartic acid, serine and threonine in non‐heat stressed group. The EAA flow in 1‐week heat and 2‐week heat birds were significantly (p < 0.05) higher than those under no heat exposure (14682, 11161 and 9597 mg/kg of dry matter intake respectively). Moreover, the EAA flow of 2‐week heat group was less than 1‐week heat group by approximately 36%. These observations suggest that the effect of heat stress on EAA flow is mostly quantitative; however, heat stress may also alter the content of EAA flow qualitatively.     

Effect of concentration and addition method of glycerol on the quality of cryopreserved mithun (Bos frontalis) spermatozoa

The effect of concentration and addition method of glycerol on the quality of cryopreserved mithun (Bos frontalis) spermatozoa was investigated. Semen samples were collected from five healthy mithun bulls through rectal massage method and cryopreserved in liquid nitrogen. The samples were diluted in Tris–egg yolk–glycerol extender, equilibrated for 4 h at 4 °C and loaded into 0.50‐ml straws. The straws were then frozen in liquid nitrogen vapour for 10 min and finally plunged into liquid nitrogen for storage. The required amount of glycerol was added into the diluted samples either in a single dose (3%, 4%, 5%, 6% or 7%; added at 37 °C immediately before equilibration) or in split doses (5%, 6% or 7%; the total amount was divided into four equal parts, and a part was added at 37 °C immediately before equilibration, and the remaining parts were added subsequently at 1, 2 and 3 h of equilibration at 4 °C). In the single‐dose addition method, following freeze‐thawing, greater (p < 0.05) motility (%) and proportion of live spermatozoa with intact acrosome (LSIA, %) in 5% glycerol (40.6 ± 1.7 and 43.4 ± 1.8 respectively) and lesser (p < 0.05) total morphological abnormalities (%) in 5% (14.1 ± 0.8) and 6% (13.7 ± 1.0) glycerol were observed compared to the other glycerol concentrations. In the split‐dose addition method, following freeze‐thawing, greater (p < 0.05) motility (%) and LSIA proportion (%) were found in 5% (50.2 ± 1.9 and 53.3 ± 1.8 respectively) compared to 6% or 7% glycerol, but the total morphological abnormalities were not different among the glycerol concentrations. In addition, in all the glycerol concentrations, better (p < 0.05) post‐freeze‐thaw motility and LSIA proportions were observed when glycerol was added in split doses compared to a single dose. In conclusion, Tris–egg yolk extender with 5% glycerol added in split doses was found most suitable for cryopreserving mithun sperm.     

Zur Problematik der Klimaempfindlichkeit bei Haustieren*

In a group of 6 young German Black and White bulls it was investigated whether the jollowing criteria of the ejaculate volume density total number of sperms per trial day mass motion (total) forward motion local motion proportion of morphologically alterated sperms pH value pH alteration in 5 hours can be influenced individually by thermal loading. The loadings were performed in a climatic stall over 9 days at + 30’C during daytime and + 25° C at night, and at + 35°C and + 30° C respectively. Before and after the loading periods there were normal control periods at+15°C during daytime and+12°C at night. An analysis of variance was done regarding the stress periods, the individual animals and the interactions animals to periods. Regarding the alterations by the thermal loading periods the first (weaker) one at + 30°/+ 25°C hardly proved any effect on the variables mentioned. But the second (stronger) period at + 35°/+ 30° C alterated nearly all the variables at a high degree and partially in such a manner that the starting values of the control period could not in all cases be normalized again up to 10 weaks after the loading period. Considering the intensity and duration of the reactions of the individuals there were distinct differences. Especially 2 animals in the test population were reacting outstandingly, one in a positive manner, the other particularly negatively. 12¹/₂ weeks after the loading periods, at the end of the observations the latter was still unable to regain normal values. The question whether this was a permanent defect unfortunately could not be pursued. The reaction of the other 4 animals was intermediary to the two extremes. On the basis of these and previous results it is supposed that there is a variation in the thermosensibility also within the German Black and White cattle, a factor which might be accessible as a criterion of selection.