Effect of urea in the diet on ovarian follicular dynamics and plasma progesterone concentration in Alpine goats

Abstract

-To evaluate the effect of using urea in the diet on ovarian follicular dynamics and plasma urea and progesterone concentration, an experiment was carried out with 29 Alpine goats randomly distributed into four diets, each one containing 0%; 0.73%; 1.46% or 2.24% of urea on total dry matter. The follicular dynamics was monitored daily by ultrasonography. The estrous cycles were characterized by occurrence of two, three, four or five follicular waves. The emergence day of the first follicular wave in cycles with two waves, the length of the third wave and the maximum diameter of the largest follicle of the third wave in cycles with three waves presented a quadratic behavior according to the percentage of urea in the diets. In cycles with four waves, the urea intake did not influence the follicular dynamics. The interestrus and interovulatory periods and the luteal and follicular phases length did not differ among treatments. The plasma urea concentration did not differ among diets neither among collection weeks. Plasma progesterone concentration on the estrus day and on the 11 th day after estrus presented quadratic behavior, and on the 15 th day after estrus, it linearly reduced acording to the percentage of urea in the diets. The supply of urea in diets at levels up to 2.24% in dietary dry matter did not influence the dry matter intake and the urea plasma concentration. For goats, the emergence day and the length of the waves, the follicular diameter and the plasma progesterone concentration on the estrus day and in the latter stages of diestrus were altered when there was supply of urea in the diet.

Estrous Signs and Progesterone Profile of Ongole Grade Cows Synchronized at Different Ages Fed Different Level of Dietary Crude Protein

“…Furthermore, the concentrations of progesterone reached the highest levels on d 17 and experienced a non-substantial decrease thereafter until day 21, which was maintained and decreased at a particular degree due to pregnancy. The dynamic of progesterone levels showed a quadratic trend during estrous, diestrous, and proestrus following the physiological reproduction during this period in which the concentration reached the highest levels during days 11 to 17 after estrous (Alves et al, 2011). Adequate circulating concentrations of progesterone during diestrous are required to stimulate endometrial secretions, which are essential for embryonic implantation, development and survival, maternal recognition, and maintenance of pregnancy (Spencer et al, 2016).…”

“…As previously performed by Hankele et al (2020), concentrations of all progesterone metabolites were low during the estrous period and increased following quadratic patterns in response to fertilization and follicle growth. Supporting this reason, Alves et al (2011) suggested that high estrogen concentration during the follicular phase promotes a low level of progesterone. On the day 5, progesterone concentrations increased at 2 ng/mL on all groups.…”

Plasma urea nitrogen and progesterone concentrations and follicular dynamics in ewes fed proteins of different degradability

“…High-energy diets stimulate follicular development (Armstrong et al, 2001;Webb et al, 2004). However, there is still controversy on the effects of diets rich in crude protein (CP), rumen-degradable protein (RDP) and non-protein nitrogen (NNP) on ovarian follicular dynamics (GarciaBojalil et al, 1998;Laven et al, 2004;Alves et al, 2011).…”

Postpartum Concentrations of Estradiol and Progesterone in Three Genotype of Sheep Fed Varying Levels of Protein

“…Hileman et al (2011) added that interval from parturition until the first ovulation is greatly influenced by season. Though, there is still controversy on the effects of diets rich in protein, rumendegradable protein and non-protein nitrogen on ovarian follicular dynamics (Laven et al, 2004;Alves et al, 2011). In his research, Webb et al (2004) emphasized that high energy diets stimulate follicular development.…”

“…Khanum et al (2008) reported that at estrus period, the concentration of estrogen reaches the highest value of 7.70±1.70pg/ml whereas progesterone begins to rise from the basal 0.010±0.6ng/ml on day 0 up to 3.00±0.90ng/ml on day 6 of estrus cycle and reaches peak value of 7.70±0.60ng/ml on day 12. High energy diets stimulate follicular development (Webb et al, 2004), however, there is still controversy on the effects of diets rich in protein, rumen-degradable protein and non-protein nitrogen on ovarian follicular dynamics (Laven et al, 2004;Alves et al, 2011). The effect of dietary protein on reproduction is complex (Surai, 1999), prolonged inadequate protein intake has been reported to reduce reproductive performance.…”