Mimicking the cauda epididymal plasma-like osmolality in extender improves liquid preservation of ram semen at 3–5°C

Figures & data

Table 1. Physicochemical properties of ram cauda epididymal plasma.

Biophysical property	Mean	Range	Previous report^#
pH	6.32 ± 0.01	6.2–6.4	6.2–6.7^a
Osmolality (mOsmol/kg)	375.45 ± 6.44	336–421	365–395^a
Na^+ (mmol)	34.73 ± 1.06	28–45	40 (22–57)^b
K^+ (mmol)	29.15 ± 0.74	26–36	29 (24–39)^b

Data represents mean ± S.E.M. of 20 samples.

^# Data was compiled from the following sources:

^aTamayo-Canul et al. (2011)

^bJones (1978)

Table 2. Effect of pre-incubation in hyperosmotic solution on mass motility, hypoosmotic swelling response and sperm viability after the hypoosmotic swelling test.

Sperm attributes	Sodium citrate-fructose solution (mOsmol/kg)
	360	390	450
Mass motility (0–5 scale)	4.3 ± 0.2^b	4.1 ± 0.3^ab	3.5 ± 0.2^a
Functional membrane Integrity (%)	52.1 ± 2.1^b	35.3 ± 4.1^a	30.4 ± 3.2^a
Viability after HOST (%)	72.1 ± 2.3	71.4 ± 3.5	62.2 ± 1.7

Pooled semen sample was diluted 1/3 in each of the sodium citrate – fructose solutions, pH 7.3 and incubated at 37°C in a water bath for 30 min prior to analysis. HOST: hypoosmotic swelling test; Number of replicates (n); 8, means bearing different superscript letters (a, b, c) within a row differ significantly (P < 0.05).

Table 3. Effect of cauda epididymal plasma-like osmolality of extender on sperm kinematics following liquid preservation of ram semen in soya lecithin-Tris-fructose extender at 3–5°C.

Sperm Attributes	Soya lecithin-Tris-fructose extender, pH 6.8 (mOsmol/kg)		Storage period (h)
	360	390	0	24	48	72
LIN (%)	39.5 ± 0.9^a	47.4 ± 0.4^b	45.4 ± 0.9	45.6 ± 0.5	42.9 ± 0.7	39.7 ± 1.9
STR (%)	74.0 ± 0.5^a	79.7 ± 0.5^b	77.4 ± 0.8	78.1 ± 0.6	76.1 ± 1.0	75.8 ± 0.9
VCL (µm/s)	175.1 ± 5.8^b	163.2 ± 6.3^a	211.0 ± 7.9^c	173.9 ± 5.4^b	149.4 ± 3.4^a	142.2 ± 4.3^a
VAP(µm/s)	94.9 ± 3.3	95.4 ± 3.6	119.8 ± 3.2^c	99.6 ± 2.8^b	82.7 ± 2.1^a	78.4 ± 2.4^a
VSL(µm/s)	71.3 ± 2.7^a	77.8 ± 3.1^b	94.8 ± 2.8^c	79.3 ± 2.4^b	64.2 ± 2.5^a	59.9 ± 2.1^a
ALH (µm)	8.0 ± 0.1^b	7.1 ± 0.1^a	8.3 ± 0.3^b	7.6 ± 0.1^a	7.2 ± 0.1^a	7.1 ± 0.1^a
BCF (Hz)	26.0 ± 0.5^a	28.6 ± 0.8^b	31.1 ± 0.5^c	27.4 ± 1.1^b	26.5 ± 0.6^ba	24.2 ± 0.8^a

Note: Interaction between extender osmolality and storage period was significant (P < 0.05) in TM and PROG. The interactions in the rest of the sperm attributes were non-significant. Values represent the mean ± S.E.M. of seven replicates. TM: total motility; PROG: progressive motility; LIN: linearity; STR: straightness; VCL: curvilinear velocity; VAP: average path velocity; VSL: straight-line velocity; ALH: amplitude of lateral head displacement; BCF: beat cross frequency. Means bearing different superscripts (a, b, c) within a row and factor differ significantly (P < 0.05).

Table 4. Effect of interaction between the extender and period of storage on sperm motility following liquid preservation of ram semen in soya lecithin-Tris-fructose extender at 3–5°C.

Treatment		TM (%)	PROG (%)
Soya lecithin-Tris-fructose extender, pH 6.8 (SLTF, mOsmol/kg)
	360	82.6 ± 1.3	55.9 ± 2.1
	390	82.6 ± 1.4	57.0 ± 1.9
	Overall	82.6 ± 1.3	56.4 ± 2.0
Storage period (h) SLTF Extender, pH 6.8 (mOsmol/kg)
0	360	89.2 ± 2.5	76.0 ± 2.3
	390	87.4 ± 2.7	75.1 ± 2.3
	Overall†	88.3 ± 1.8	75.8 ± 1.5
24	360	86.5 ± 2.1	69.0 ± 1.6
	390	87.3 ± 3.1	64.4 ± 2.7
	Overall	86.9 ± 1.8	67.6 ± 1.5
48	360	75.4 ± 1.5^a	39.5 ± 1.9^a
	390	83.3 ± 1.8^b	51.7 ± 2.3^b
	Overall	79.5 ± 1.3	45.6 ± 1.7
72	360	77.5 ± 2.1	37.4 ± 3.2
	390	70.3 ± 1.5	34.8 ± 1.9
	Overall	75.0 ± 1.5	36.1 ± 1.8

†Overall mean value at a given period of storage. TM: total motility; PROG: progressive motility. Means bearing different superscripts within a column and storage time differ significantly (P < 0.05).

Table 5. Effect of cauda epididymal plasma-like osmolality of extender on sperm membrane attributes following liquid preservation of ram semen in soya lecithin-Tris-fructose extender at 3–5°C.

Treatment	Viability (%)	Acrosomal integrity (%)	Functional membrane integrity (%)
Soya lecithin-Tris-fructose extender, pH 6.8 (mOsmol/kg)
360	94.5 ± 1.2	91.9 ± 0.9	75.4 ± 1.1^b
390	88.9 ± 1.7	90.1 ± 1.3	65.7 ± 1.5^a
Storage period (h)
0	95.3 ± 1.24^b	94.4 ± 0.83^b	75.7 ± 2.02
24	88.3 ± 1.25^a	90.7 ± 0.88^ab	70.6 ± 1.66
48	86.7 ± 2.00^a	90.2 ± 1.48^ab	70.6 ± 2.26
72	86.2 ± 2.29^a	88.3 ± 2.37^a	65.5 ± 2.00

Note: The interaction between the extender and storage period was non-significant (P > 0.05). Values are mean ± S.E.M. of seven replicates; means bearing different superscript letters (a, b, c) within a column and treatment differ significantly at P < 0.05.

Table 6. Effect of cauda epididymal plasma-like pH of extender on sperm membrane attributes following liquid preservation of ram semen in soya lecithin-Tris-fructose extender at 3–5°C.

Treatment	Viability (%)	Acrosomal Integrity (%)	Functional membrane integrity (%)
Soya lecithin-Tris-fructose extender, 390 mOsmol (pH)
6.5	88.30 ± 1.61	62.70 ± 1.55	90.50 ± 1.19
6.8	88.90 ± 1.69	65.70 ± 1.48	90.10 ± 1.34
Storage period (h)
0	94.8 ± 1.46^b	94.1 ± 1.18^b	72.7 ± 1.73^b
24	90.0 ± 2.38^ab	91.0 ± 1.14^ab	66.5 ± 1.86^ab
48	84.7 ± 1.82^a	89.4 ± 1.44^ab	61.4 ± 2.43^ab
72	82.5 ± 1.92^a	85.7 ± 2.30^a	55.7 ± 1.36^a

Note: The interaction between the pH of extender and storage period was non-significant (P > 0.05). Values are mean ± S.E.M. of seven replicates; means bearing different superscript letters (a, b, c) within a column and treatment differ significantly at P < 0.05.

Table 7. Effect of cauda epididymal plasma-like pH of extender on sperm motility and kinematics following liquid preservation of ram semen in soya lecithin-Tris-fructose extender at 3–5°C.

Sperm Attributes	Soya lecithin-Tris-fructose Extender,390 mOsmol (pH)		Storage period (h)
	6.5	6.8	0	24	48	72
TM (%)	81.2 ± 1.4	79.4 ± 1.3	88.5 ± 1.5^c	80.9 ± 1.0^b	80.9 ± 1.5^b	68.9 ± 0.9^a
PROG (%)	57.2 ± 2.4	55.7 ± 2.5	76.5 ± 1.1^c	65.5 ± 0.7^b	59.8 ± 1.9^b	26.6 ± 1.6^a
LIN (%)	44.7 ± 0.5	45.0 ± 0.5	46.2 ± 0.4	44.8 ± 0.4	43.3 ± 0.8	45.0 ± 1.0
STR (%)	72.0 ± 0.6	73.0 ± 0.7	74.2 ± 0.7	71.4 ± 0.5	69.5 ± 1.0	74.3 ± 1.2
VCL (µm/s)	185.9 ± 10.0	187.0 ± 10.3	257.1 ± 4.8^c	188.9 ± 2.9^b	181.7 ± 8.1^b	118.2 ± 4.1^a
VAP(µm/s)	110.3 ± 5.9	110.7 ± 6.2	152.4 ± 3.0^c	112.6 ± 2.5^b	107.6 ± 4.0^b	69.3 ± 2.5^a
VSL(µm/s)	81.1 ± 4.6	81.5 ± 4.6	114.9 ± 2.1^c	81.9 ± 2.4^b	75.5 ± 2.4^b	52.7 ± 2.8^a
ALH (µm)	7.0 ± 0.2	7.3 ± 0.2	8.5 ± 0.1^c	6.8 ± 0.1^b	6.7 ± 0.2^b	6.3 ± 0.2^a
BCF (Hz)	15.3 ± 0.6	14.8 ± 0.8	17.3 ± 0.6^b	12.3 ± 0.8^a	12.7 ± 0.4^a	17.9 ± 1.0^b

Values represent the mean ± S.E.M. of seven replicates. TM: total motility; PROG: progressive motility; LIN: linearity; STR: straightness; VCL: curvilinear velocity; VAP: average path velocity; VSL: straight-line velocity. Means bearing different superscripts (a, b, c) within a row and factor differ significantly (P < 0.05).

Tamayo-Canul J, Alvarez M, Lopez-Uruena E, Nicolas M, Martinez-Pastor F, Anel E, de Paz P. 2011. Undiluted or extended storage of ram epididymal spermatozoa as alternatives to refrigerating the whole epididymis. Anim Reprod Sci. 126:76–82.

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Jones R. 1978. Comparative biochemistry of mammalian epididymal plasma. Comp Biochem Physiol. 61:365–370.

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