Effect of chronic infusion of leptin and nutrition on sexual maturation of zebu heifers1

Carvalho, Marina Vieira de; Diniz-Magalhães, Juliane; Pereira, A. S. C.; Santos, Marcos Veiga dos; Silva, Luís Felipe Prada e

doi:10.2527/jas.2012-5918

Cited by 7 publications

(5 citation statements)

References 38 publications

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“…Furthermore, administration of recombinant ovine leptin stimulated secretion of GnRH and LH in undernourished heifers, but was not capable of accelerating puberty onset in well-nourished heifers Zieba et al, 2004). However recent findings show that although exogenous administration of leptin temporarily enhanced the rate of follicular growth, it does not accelerate puberty (Carvalho et al, 2013). Collectively these data indicate that while leptin plays an important role as a signal linking nutritional status to the central reproductive axis in cattle, other factors are also involved.…”

Section: Suckling-maternal Bondmentioning

confidence: 66%

Optimising reproductive performance of beef cows and replacement heifers

Diskin

Kenny

2014

Animal

102

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A reproductively efficient beef cow herd is fundamental to meeting the protein and specifically, red meat demand of an ever increasing global population. However, attaining a high level of reproductive efficiency is underpinned by producers being cognisant of and achieving many key targets throughout the production cycle and requires significant technical competency. The lifetime productivity of the beef bred female commences from the onset of puberty and will be dictated by subsequent critical events including age at first calving, duration of the postpartum interval for each successive calving, conception and pregnancy rate and ultimately manifested as length of intercalving intervals and number of calves weaned over her lifetime. Puberty in heifers is a consequence of the interactive effects of genetics and both pre-and post-weaning nutrition. Early onset of puberty is essential to achieving the first main reproductive target for beef cow herds; first calving at 2 years of age. In calved heifers and mature cows, the onset of ovarian activity, postpartum is a key event dictating the calving interval. Again, this will be the product mainly of prepartum nutrition, manifested through body condition and the strength of the maternal bond between cow and calf, though there is increasing evidence of a modest genetic influence on this trait. Following the initiation of postpartum ovarian cyclicity, conception and subsequent pregnancy rate is generally a function of bull fertility in natural service herds and heat detection and timing of insemination in herds bred through artificial insemination. Cows and heifers should be maintained on a steady plane of nutrition during the breeding season, but the contribution of significant excesses or deficiencies of nutrients including protein and trace elements is likely to be minor where adequate pasture is available. While, increased efforts are being made internationally to genetically identify and select for more reproductively efficient beef cows, this is a more long-term strategy and will not replace the need for a high level of technical efficiency and management practice at farm level.

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Section: Suckling-maternal Bondmentioning

confidence: 66%

Optimising reproductive performance of beef cows and replacement heifers

Diskin

Kenny

2014

Animal

102

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“…Leptin can inhibit NPY expression (Gamba et al 2006), modulate the expression of kisspeptin receptors (Stephens et al 2015), and then hasten puberty. However, although chronic administration of recombinant leptin increased leptin concentration, it did not increase the frequency of LH pulses nor anticipated puberty in beef heifers (Maciel et al 2004;Carvalho et al 2013). Therefore, it is assumed that leptin is not responsible for puberty triggers, but acts as a permissive signal for puberty (Maciel et al 2004;Barb et al 2004).…”

Section: Discussionmentioning

confidence: 89%

Effect of growth rates on hormonal and pubertal status in Nellore heifers early weaned

Ferraz

Santos

Oliveira

et al. 2023

Trop Anim Health Prod

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This study aimed to determine the effect of growth rates on the hormonal status and puberty onset. Forty-eight Nellore heifers weaned at 3.0 ± 0.1 months old were blocked according to BW at weaning (84 ± 2 kg) and randomly assigned to treatments. The treatments were arranged in 2 x 2 factorial according to the feeding program. The rst program was high (H; 0.79 kg/day) or control (C; 0.45 kg/day) ADG from 3rd to 7th month of age (growing phase I). The second program was also high (H; 0.70 kg/day) or control (C; 0.50 kg/day) ADG from the 7th month until puberty (growing phase II), resulting in four treatments: HH (n = 13), HC (n = 10), CH (n = 13) and CC (n = 12). To achieve desired gains, heifers in high ADG program were fed ad libitum dry matter intake (DMI), and the control group was offered around 50% of ad libitum DMI of high group. All heifers received a diet with similar composition. Puberty was assessed weekly by ultrasound examination, and the largest follicle diameter was evaluated every month. Blood samples were collected monthly to quantify leptin, IGF1, and LH.At 7 months of age, heifers in high ADG were 35 kg heavier than the control. Heifers in the HH had greater DMI compared with CH in phase II. The puberty rate at 19 months old was greater in the HH treatment (84%) than in the CC (23%), but there was no difference between HC (60%) and CH (50%) treatments. Heifers from HH treatment had greater serum leptin concentration than others at 13 months old, and serum leptin was greater in HH compared with CH and CC at 18 months old. High heifers in phase I had greater serum IGF1 concentration than the control. In addition, HH heifers had a greater diameter of the largest follicle than CC. There was no interaction between phases and age in any variable relative to the luteinizing hormone (LH) pro le. However, the heifers` age was the main factor that increased the frequency of LH pulse. In conclusion, increasing ADG was associated with greater ADG, serum leptin and IGF-1 concentration, and puberty onset; however, LH concentration was affected mainly by age of the animal. The increasing growth rate at younger age made heifers more e cient.

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“…Leptin administration restores normal LH pulses in fasted animals (Amstalden et al, 2000). Carvalho et al (2013) reported higher expression of the leptin gene on adipose tissue in heifers fed high-energy diets; therefore, heifers with more adipose tissue can synthetize more leptin.…”

Section: Discussionmentioning

confidence: 99%

Effect of high energy intake on carcass composition and hypothalamic gene expression in Bos indicus heifers

et al. 2017

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-The objective of this study was to evaluate the effect of high or low energy intake on carcass composition and expression of hypothalamic genes related to the onset of puberty. Twenty-four prepubertal Nellore heifers, 18-20-months-old, with 275.3±18.0 kg body weight (BW), and 4.9±0.2 (1-9 scale) body condition score (BCS) were randomly assigned to two treatments: high-energy diet (HE) and low-energy diet (LE). Heifers were housed in two collective pens and fed diets formulated to promote average daily gain of 0.4 (LE) or 1.2 kg (HE) BW/day. Eight heifers from each treatment were slaughtered after the first corpus luteum detection -considered as age of puberty. The 9-10-11th rib section was taken and prepared for carcass composition analyses. Samples from hypothalamus were collected, frozen in liquid nitrogen, and stored at −80 °C. Specific primers for targets (NPY, NPY1R, NPY4R, SOCS3, OXT, ARRB1, and IGFPB2) and control (RPL19 and RN18S1) genes were designed for real-time PCR and then the relative quantification of target gene expression was performed. High-energy diets increased body condition score, cold carcass weight, and Longissimus lumborum muscle area and decreased age at slaughter. High-energy diets decreased the expression of NPY1R and ARRB1 at 4.4-fold and 1.5-fold, respectively. In conclusion, the hastening of puberty with high energy intake is related with greater body fatness and lesser hypothalamic expression of NPY1 receptor and of β-arrestin1, suggesting a less sensitive hypothalamus to the negative effects of NPY signaling.Key Words: cattle, energy supplementation, neuropeptides, puberty, reproduction Revista Brasileira de Zootecnia

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Effect of chronic infusion of leptin and nutrition on sexual maturation of zebu heifers1

Cited by 7 publications

References 38 publications

Optimising reproductive performance of beef cows and replacement heifers

Optimising reproductive performance of beef cows and replacement heifers

Effect of growth rates on hormonal and pubertal status in Nellore heifers early weaned

Effect of high energy intake on carcass composition and hypothalamic gene expression in Bos indicus heifers

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