Effect of photoperiod on follicular IGF-1 and oocyte quality independently of metabolic status in buffalo heifers

Figures & data

Table 1. Blood concentrations (mean ± SEM) of metabolic substrates in buffalo heifers (n = 6) during periods of decreasing and increasing day length.

	Day length		p value
	Decreasing	Increasing
Total cholesterol, mg/dL	69.0 ± 2.1	58.0 ± 2.9	.01
HDL cholesterol, mg/dL	44.3 ± 1.8	50.0 ± 5.1	.20
Glucose, mg/mL	81.5 ± 2.4	73.8 ± 1.7	.07
Tryglicerides, mg/dL	19.6 ± 2.3	18.0 ± 3.3	.73
NEFA, mmoL/L	0.4 ± 0.0	0.6 ± 0.1	.07

HDL: high-density lipoprotein; NEFA: non-esterified fatty acids

Table 2. Blood concentrations (mean ± SEM) of metabolic hormones in buffalo heifers (n = 6) during periods of decreasing and increasing day length.

	Day length		p value
	Decreasing	Increasing
Insulin, mmol/L	4.0 ± 0.3	3.5 ± 0.3	.41
Glucagon, pg/mL	358.5 ± 19.0	432.8 ± 19.0	.04
Leptin, ng/mL	2.1 ± 0.1	1.6 ± 0.1	<.01
IGF-1, ng/mL	84.7 ± 4.5	78.5 ± 3.4	.27
GH, pg/mL	5.9 ± 0.6	4.5 ± 1.2	.28
T3, ng/mL	163.3 ± 11.2	187.0 ± 42.0	.46
T4, µg/mL	4.6 ± 0.3	4.7 ± 0.5	.77
TSH, µg/mL	0.2 ± 0.1	0.3 ± 0.2	.64

IGF-1: Insulin-like growth factor 1; GH: Growth hormone; T3: triiodothyronine; T4: thyroxine; TSH: Thyroid-stimulating hormone

Table 3. Hormone concentrations (mean ± SEM) in plasma and follicular fluid of buffalo heifers (n = 6) during periods of decreasing and increasing day length.

	Day length		p value
	Decreasing	Increasing
Plasma
Oestradiol, pg/mL	9.2 ± 0.5	3.9 ± 0.4	<.001
P4, ng/mL	1.9 ± 0.2	2.2 ± 0.3	.470
Follicular fluid
Oestradiol, ng/mL	109.1 ± 25.8	49.7 ± 12.9	.050
P4, ng/mL	123.5 ± 27.9	68.3 ± 15.5	.100
IGF-1, ng/mL	58.5 ± 3.9	45.5 ± 4.0	.020

P4: Progesterone; IGF-1: Insulin-like growth factor 1

Table 4. Ovarian features (mean ± SEM) of buffalo heifers (n = 6) during periods of decreasing and increasing day length.

	Day length		p value
	Decreasing	Increasing
Ovarian size, cm^2	3.4 ± 0.1	3.3 ± 0.1	.600
Follicular fluid, mL	1.5 ± 0.1	1.4 ± 0.0	.010
Total follicles, n	11.9 ± 0.6	8.4 ± 0.5	<.001
Small follicles, n	10.8 ± 0.6	5.3 ± 0.5	<.001
Medium follicles, n	1.0 ± 0.3	2.7 ± 0.3	<.001
Large follicles, n	0.2 ± 0.1	0.3 ± 0.1	.120
Total COCs, n	4.3 ± 0.5	2.2 ± 0.3	<.001
Recovery rate, %	36.2 ± 4.0	31.5 ± 6.6	.530
Grade A COCs (n), %	0.2 ± 0.1 (4.1 ± 1.6)	0.02 ± 0.0 (1.5 ± 1.5)	.040 .352
Grade B COCs (n), %	0.9 ± 0.2 (21.4 ± 4.0)	0.2 ± 0.1 (12.7 ± 4.8)	.004 .044
Grade C COCs (n), %	2.1 ± 0.3 (49.6 ± 4.9)	0.6 ± 0.2 (26.1 ± 5.8)	<.001 .003
Grade D COCs (n), %	0.5 ± 0.2 (12.4 ± 3.7)	1.1 ± 0.2 (52.1 ± 6.8)	.008 <.001
Grade E COCs (n), %	0.5 ± 0.1 (12.6 ± 3.5)	0.2 ± 0.1 (7.6 ± 2.9)	.182 .345
Grade A + B (n), %	1.1 ± 0.2 (25.5 ± 4.2)	0.2 ± 0.1 (14.2 ± 4.9)	.002 .030
Grade A + B + C (n), %	3.2 ± 0.4 (75.1 ± 5.1)	0.9 ± 0.2 (40.3 ± 6.8)	<.001 < .001

COCs: Cumulus oocyte complexes