Early resynchronization of follicular wave emergence among Nelore cattle using injectable and intravaginal progesterone for three timed artificial inseminations

The aim of this study was to evaluate ovarian antral follicle populations (OAFP) of Nelore and Girolando breed heifers (12–18 months old) and cows (24–60 months old). Animals were assigned to four groups: (1) Nelore cows (n = 18), (2) Girolando cows (n = 20), (3) Nelore heifers (n = 7), and (4) Girolando heifers (n = 7). Cows were treated to synchronize follicular wave emergence by implantation of an intravaginal device containing 1.9 g of progesterone, as well as intramuscular administration of 2 mg of estradiol benzoate and 25 mg of dinoprost. This synchronization treatment was administered at a random day of the estrous cycle of each cow, designated D0. Intravaginal devices were removed on D7, and on D11, OAFP counts were performed by transvaginal ovarian ultrasound. For each cow, all follicles ?3 mm in diameter were counted in both ovaries and counts were performed three times at 35-day intervals. Counts were also obtained from heifers, but these animals were not treated for synchronization of follicular wave emergence. Analysis of variance (ANOVA) with Tukey’s test and Pearson’s correlation test were used to compare mean OAFPs between counts as well as mean OAFPs between breed and age groups. No differences were observed in mean OAFPs between Nelore and Girolando cows (30.9 vs. 26.7, respectively; P > 0.05) or heifers (16.2 vs. 18.1, respectively; P > 0.05). However, within each breed, there were differences in mean OAFPs between heifers and cows (for Nelore cattle: 16.2 and 30.9, respectively; for Girolando cattle: 18.1 and 26.7, respectively; both P < 0.05). In conclusion, OAFPs were similar between Nelore and Girolando breeds and were influenced by age. Furthermore, we observed a high correlation for individual animals between the mean numbers of follicles counted in both ovaries and total number of follicles counted in either the right or left ovary, indicating that the evaluation of a single ovary is sufficient to estimate the OAFP of an individual.

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Estimates of genetic correlations between days to calving and reproductive and weight traits in Nelore cattle

Journal of Animal Science ◽

10.2527/2005.8371511x ◽

2005 ◽

Vol 83 (7) ◽

pp. 1511 ◽

Cited By ~ 41

Author(s):

S. Forni ◽

L. G. Albuquerque

Keyword(s):

Genetic Correlations ◽

Nelore Cattle

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PSIV-B-28 Late-Breaking: Performance and carcass quality of Nelore bull’s progenies with contrasting traits for precocity, growth and muscularity

Journal of Animal Science ◽

10.1093/jas/skz258.644 ◽

2019 ◽

Vol 97 (Supplement_3) ◽

pp. 319-321

Author(s):

Taiane S Martins ◽

Juliana Silva ◽

Lenise Mueller ◽

Tamyres Amorim ◽

Annelise Aila G Lobo ◽

...

Keyword(s):

Feed Efficiency ◽

Average Daily Gain ◽

Backfat Thickness ◽

Longissimus Muscle ◽

Muscle Area ◽

Final Body Weight ◽

Fat Thickness ◽

Nelore Cattle ◽

Daily Gain

Abstract The goal of this study was to evaluate the performance and the carcass traits of Nelore cattle progenies from bulls selected by contrasting traits for precocity, growth and muscularity, through the Expected Progeny Difference (EPD). One hundred and five Nelore bulls (initial weight of 350kg±15kg) and 20 months of age were confined and fed with same diet (73% of concentrate). Thirty-two animals were selected to create the contrasting groups for precocity, growth and muscularity (16 animals assigned as a low EPD group - LEPD and 16 animals assigned as a high EPD group - HEPD), based on the EPD of their parents. The ribeye area and backfat thickness were performed by ultrasonography of 12–13th rib fat thickness and longissimus muscle area (LMA), as well as rump fat thickness (RF) measurements. Animals were harvested after 100 days and during the deboning, meat cuts were weight for cutting yield. The animals selected for the HEPD group had greater average daily gain (P = 0.006), which can be explained by the higher feed intake (P = 0.006). However, there are no difference between groups for the final body weight (P = 0.254) and feed efficiency (P = 0.715). The LEPD group presented higher dressing percentage (P = 0.028). Although the groups evaluated did not presented difference in LMA (P = 0.329) and weight of longissimus muscle (P = 0.480), the weight of rump displayed heaviest in the HEPD (P = 0.037). There was no difference between groups for RF (P = 0.086). Nevertheless, backfat thickness was higher in HEPD group (P = 0.006). The present study indicates that Nelore cattle progenies, with parents displaying higher potential for precocity, growth, and muscularity, show greater backfat thickness and weightiest of rump than the other genetic backgrounds. Thanks to FAPESP for the scholarship (Grant # 2017/02349–1).

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Transcriptome profiling of muscle in Nelore cattle phenotypically divergent for the ribeye muscle area

Genomics ◽

10.1016/j.ygeno.2019.07.012 ◽

2020 ◽

Vol 112 (2) ◽

pp. 1257-1263 ◽

Cited By ~ 1

Author(s):

Danielly Beraldo dos Santos Silva ◽

Larissa Fernanda Simielli Fonseca ◽

Ana Fabrícia Braga Magalhães ◽

Maria Malane Magalhães Muniz ◽

Fernando Baldi ◽

...

Keyword(s):

Transcriptome Profiling ◽

Muscle Area ◽

Nelore Cattle

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The use of a ‘first-wave’ model to study the effect of nutrition on ovarian follicular dynamics and ovulation rate in the sheep

Reproduction ◽

10.1530/rep-10-0196 ◽

2010 ◽

Vol 140 (6) ◽

pp. 865-874 ◽

Cited By ~ 27

Author(s):

C Viñoles ◽

B Paganoni ◽

K M M Glover ◽

J T B Milton ◽

D Blache ◽

...

Keyword(s):

Body Condition ◽

Wave Model ◽

Ovulation Rate ◽

Short Term ◽

Metabolic Hormones ◽

Follicular Waves ◽

Follicular Wave ◽

The Third ◽

High Concentrations ◽

Follicular Dynamics

We have developed an experimental model in which groups of ewes are simultaneously experiencing the first ovarian follicular wave of their oestrous cycle. We used this ‘first-wave model’ in a 2×2 factorial experiment (ten ewes per group) to study the effect of body condition (BC) and a short-term supplement on follicular dynamics and ovulation rate. The ‘first-wave’ was established by giving ewes three injections of prostaglandin (PG), 7 days apart. The 6-day supplement (lupin grain) began 2 days after the second PG injection and continued until the third. Follicles were studied by ultrasound, and blood was sampled to measure glucose and hormones. The supplement increased (P<0.01) the concentrations of glucose, insulin and leptin, decreased FSH concentrations (P<0.01) and tended to increase oestradiol concentrations (P=0.06). The supplement tended to increase the number of 3 mm follicles (P=0.06). Compared with low-BC ewes, high-BC ewes had more follicular waves (P<0.05), higher concentrations of insulin, leptin and IGF1 (P<0.05) and tended to have higher FSH concentrations (P=0.09). Leptin and insulin concentrations remained high until the end of supplementation in high-BC ewes, whereas they decreased after the third day of supplementation in low-BC ewes. In conclusion, high concentrations of metabolic hormones in fat ewes are associated with the development of more follicular waves. When a supplement is superimposed on this situation, changes in glucose and metabolic hormones allow more follicles to be selected to ovulate.

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