Body weight (BW), body mass index (BMI), body fat, serum leptin concentration and resting energy expenditure (REE) were fitted in a multiple linear regression model in a group of individuals with stable body weight. While serum leptin concentration was well related to BW, to BMI and to body fat, no correlations with the REE values were found. This suggests that serum leptin concentration would represent an index of adiposity and poorly reflects energy metabolism.

Reproduction Full-length research article Influence of age and weight of Girolando heifers on uterine and ovarian development ABSTRACT-The present study aimed to correlate the age and weight of Girolando heifers with uterine and ovarian development. Sixty heifers between 12 and 36 months old were weighed and subjected to ultrasound assessment to measure the diameters of each uterine horn and ovaries, monthly. These measures continued until their first ovulation. The animals were divided, for data analysis, according to their age into five groups: GI (12 to 14 months), GII (15 to 18 months), GIII (19 to 24 months), GIV (25 to 30 months), and GV (31 to 36 months). The dispersion diagram was used to assess the correlation between data collected monthly from uterus/ovaries and weight/age. An average daily growth of 0.0032 mm was recorded for the right ovary (RO) and 0.0051 mm for the left ovary (LO). The average size of the RO in GI was 17.58 mm and the LO was 15.28 mm; in GII, the RO was 16.72 mm and the LO was 15.89 mm; in GIII, the RO was 18.37 mm and the LO was 16.55 mm; in GIV, the RO was 19.09 mm and the LO was 17.49 mm; and in GV, the RO was 19.89 mm and the LO was 18.96 mm. The uterine horns showed an average daily growth of 0.0064 mm and 0.0071 mm for the right (RU) and left (LU) uterine horn, respectively. The average sizes of the uterine horns per group were:

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Bovine twin birth is associated with detriments including increased embryo/fetal losses, malpresentation and dystocia. Incidence of these is lessened in bilateral compared to unilateral twin pregnancy. This study was undertaken to assess use of follicular ablation by aspiration to create bilateral twin pregnancies in females with genetic potential for ~3.5 ovulations per cycle (Trio allele carriers). In Experiment 1, carriers (n=30) and non-carriers (n=10) were synchronized for ovulation and timed artificial insemination (TAI). Follicles (>5 mm) in excess of one per ovary were aspirated ~16h preceding TAI. Follicle count for females with follicles on only one ovary was reduced to two. Blood was sampled 2 weeks post-TAI to assess progesterone (P4) concentrations; embryo count was determined by ultrasound 6 weeks post-TAI. Circulating P4 concentration post-TAI was significantly (p& 0.001) associated with both genotype and subsequent pregnancy status (pregnant non-carriers, 7.06±0.68ng/mL; pregnant carriers, 5.54±0.55ng/mL; non-pregnant non-carriers 5.22±1.05ng/mL; non-pregnant carriers, 3.13±0.42ng/mL). Experiment 2 was undertaken to offset negative effects of follicular aspiration on subsequent P4 concentration observed in Experiment 1. Carriers (n=38) and non-carriers (n=32) were submitted to TAI and follicle ablation as described for Experiment 1. Additionally, accessory corpora lutea (CL) were induced in carriers by administration of human chorionic gonadotropin (carriers) at d6 post-TAI. Consequently, P4 concentration post-TAI was significantly (p& 0.05) associated with subsequent pregnancy status (pregnant, 8.48±0.61ng/mL; non-pregnant, 6.70±0.63 ng/mL) but not with genotype (carrier, 8.01±0.59 ng/mL; non-carrier, 7.17±0.64 ng/mL). Embryo number was greater in carriers (Exp1, 1.64±0.81; Exp2, 1.45±0.09) vs non-carriers (1.00±0.00, both Experiments). Single, twin, and triplet pregnancies occurred in carriers in Experiment 1 whereas multiples in Experiment 2 were limited to twin pregnancies. Genotype effects on pregnancy rate were not significant (p >0.10) in either experiment. Results suggest that follicular ablation to create bilateral twin pregnancies in Trio carriers is feasible but requires induction of accessory CL to offset the negative effects of follicular aspiration on subsequent P4 concentration and associated fertility outcomes.

Bovine twin birth is associated with detriments including increased embryo/fetal losses, malpresentation and dystocia. Incidence of these is lessened in bilateral versus unilateral twin pregnancy. This study was undertaken to assess use of follicular ablation by aspiration to create bilateral twin pregnancies in females with genetic potential for ~3.5 ovulations per cycle (Trio allele carriers). In Experiment 1, carriers (n = 30) and non-carriers (n = 10) were synchronized for ovulation and timed artificial insemination (TAI). Follicles (> 5 mm) in excess of one per ovary were aspirated ~16h preceding TAI. Follicle count for females with follicles on only one ovary was reduced to two. Blood was sampled 2 weeks post-TAI to assess progesterone (P4) concentrations; fetal count was determined by ultrasound 6 weeks post-TAI. P4 concentration post-TAI was significantly (P < 0.001) associated with both genotype and subsequent pregnancy status (pregnant non-carriers, 7.06 ± 0.68 ng/mL; pregnant carriers, 5.54 ± 0.55 ng/mL; non-pregnant non-carriers, 5.22 ± 1.05 ng/mL; non-pregnant carriers, 3.13 ± 0.42 ng/mL). Experiment 2 was undertaken to offset negative effects of follicular aspiration on subsequent P4 concentration observed in Experiment 1. Carriers (n = 38) and non-carriers (n = 32) were submitted to fixed-TAI and follicle ablation as described. Additionally, accessory corpora lutea were induced by administration of hCG (carriers) at d6 post-TAI. Consequently, P4 concentration post-TAI was significantly (P < 0.05) associated with subsequent pregnancy status (pregnant, 8.48 ± 0.61 ng/mL; non-pregnant, 6.70 ± 0.63 ng/mL) but not with genotype (carrier, 8.01 ± 0.59 ng/mL; non-carrier, 7.17 ± 0.64 ng/mL). Fetus number was greater in carriers (Exp1, 1.64 ± 0.81; Exp2, 1.45 ± 0.09) versus non-carriers (1.00 ± 0.00, both Experiments). Singles, twins, and triplets occurred in carriers in Experiment 1, whereas multiples in Experiment 2 were limited to twins. Genotype effects on pregnancy rate were not significant (P > 0.10) in either experiment. Results suggest follicular ablation to create bilateral twin pregnancies in Trio carriers is feasible but requires induction of accessory corpora lutea to offset the negative effects of follicular aspiration on subsequent P4 concentration.