Anatomy and Physiology of Reproduction in the Female Llama and Alpaca

Marcelo, A.

doi:10.1016/b978-1-4377-2352-6.00014-6

Cited by 8 publications

(12 citation statements)

References 51 publications

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“…Like in Old World camelids, the placenta of the alpaca is epitheliochorial, diffuse and of the non‐deciduate type (Arthur, A/Rahim, & Al Hindi, ; Brown, ; Jones, Skidmore, & Aplin, ; Smith, Peter, & Pugh, ; Steven, Burton, Sumar, & Nathanielsz, ), while it is also characterized as microcotyledonary (Aba, ; Abd‐Elnaeim et al, ; Brown, ; Pearson, Rodriguez, & Tibary, , ). It has some similarities with some of the aspects of the placenta found in horses, pigs and bush babies (Iturrizaga et al, ; Olivera, Zago, Leiser, Jones, & Bevilacqua, ).…”

Section: Introductionmentioning

confidence: 99%

“…It is translucent and covers the whole foetus and is attached at all mucocutaneous junctions (Figure 1). It is suggested that its function is to lubricate the foetus and thus facilitate its delivery (Aba, 2014;Brown, 2000;Merkt, Böer, Rath, & Schoon, 1988;Smith et al, 1994;Whitehead, 2009).…”

mentioning

confidence: 99%

“…According to the author, the allantois is adhered to the entire chorionic surface, and the amnion is adhered to the allantois at the level of the pregnant horn. The left horn is always the largest and pregnant horn (Aba, 2014;Brown, 2000;Skidmore, Billah, Binns, Short, & Allen, 1999).…”

mentioning

confidence: 99%

“…Common findings in the placenta of New World camelids are hippomanes in the allantoic cavity and small, firm pustules or plaques at the base of the umbilical cord, on the amniotic membrane (Morton, 1961;, 2014.…”

mentioning

confidence: 99%

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Macroscopic evaluation of the placenta of the alpaca (Vicugna pacos)

Meesters

Opsomer

Govaere

2019

Reprod Domestic Animals

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Macroscopic evaluation of the placenta is an essential post‐partum examination in the alpaca and can be of special interest in case of abortion, premature birth or stillbirth. Since there are not many reference values regarding macroscopic properties of normal alpaca placentas, a small descriptive study was conducted. Only placentae from normally foaling alpaca mares, giving birth to healthy crias, after a full‐term and uneventful gestation (±350 days; range 335–360 days) were taken into account (N = 11). Crias weighed (±SD) 7.7 ± 2.25 kg (range 5.5–10 kg), while the mean weight of the full‐term placentas was 0.8 ± 0.19 kg, that is 10% of the bodyweight of the crias. The weight of the allantoamnion and chorion was 0.2 ± 0.07 kg and 0.5 ± 0.13 kg, respectively. The umbilical cord length was 8.8 ± 2.84 cm, and the length of the pregnant and non‐pregnant uterine horns was 69.4 ± 12.77 cm and 54.5 ± 6.81 cm, respectively. The length of the corpus was 14.6 ± 4.68 cm, and the distance from the umbilicus to the corpus was 18.5 ± 6.13 cm. The tissue volume of the allantoamnion was 0.14 ± 0.079 L, and the chorionic volume was 0.37 ± 0.078 L. The surface area of the allantoamnion and the chorion was 87.6 ± 15.56 dm2 and 72.3 ± 9.28 dm2, respectively. All placentas had small calcifications either around the umbilical cord alone or around the umbilicus and blood vessels of the pregnant uterine horn. These measurements could be used to macroscopically evaluate alpaca placentas, although more research is needed to extend our knowledge of macroscopic evaluation of normal and abnormal placentas.

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Section: Introductionmentioning

confidence: 99%

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confidence: 99%

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confidence: 99%

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confidence: 99%

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Macroscopic evaluation of the placenta of the alpaca (Vicugna pacos)

Meesters

Opsomer

Govaere

2019

Reprod Domestic Animals

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“…CL diameter in the Control group was significantly greater than that of the Restricted group. Indeed, CL diameter in the Restricted group was smaller than mean values (12-14 mm) reported in another study conducted in camelids (49). Corpus luteum formation involves the luteinization of granulosa and theca cells, increment of the ovarian blood flow, and the stimulation of a proliferation and differentiation process of endothelial and steroidogenic cells (50,51).…”

Section: Discussionmentioning

confidence: 82%

Effect of Different Levels of Energy Diet Restriction on Energy Balance, Leptin and CL Development, Vascularization, and Function in South American Camelids

et al. 2020

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The objective was to determine the effect of energy diet restriction on energy balance, systemic leptin and corpus luteum (CL) vascularization, development, and function in South American camelids. In experiment 1, adult llamas were randomly assigned to receive a diet of 70% of their maintenance energy requirements (MER) (Restricted group, n = 7) or fed ad libitum (Control group, n = 7) during 28 days. Body live weight (BLW) and body condition score (BCS) were recorded, blood samples were collected every 2 weeks to measure plasma leptin concentrations, and energy metabolites were quantified. In experiment 2, adult alpacas were randomly assigned to receive a diet of 40% MER for 21 days (Restricted group, n = 7) or fed ad libitum (Control group, n = 7). Then, ovulation was induced with gonadorelin acetate (day = 0), and trans-rectal ultrasonography (7.5 MHz) was performed using B and Doppler mode to record the diameter of the pre-ovulatory follicle, ovulation, CL diameter, and vascularization from Days 0 to 13. Blood samples were collected every 48 h from Days 1 to 13 to quantify plasma leptin and progesterone concentrations. In experiment 1, energy diet restriction of 70% MER did not affect plasma leptin concentration and metabolic parameters of the Restricted group. In experiment 2, the Restricted group had a lower BCS (p < 0.001), a smaller diameter of the CL on Days 5 and 7 (p < 0.05), and a smaller maximum diameter of the CL (10.2 ± 0.6 mm) than the Control group (12.1 ± 0.6 mm; p = 0.04). Low energy restriction of 70% MER for 28 days did not affect the energy balance of llamas (Experiment 1). Moderate energy restriction of 40% MER for 21 days negatively affected energy balance (BCS), and CL development but not its vascularization, leptin, and progesterone concentrations. These species must be submitted to longer periods or a higher level of energy restriction to impair ovarian function.

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Intra-horn Penile Intromission in the AlpacaVicugna pacosand Consequences to Genital Morphology

Sterett

DiBuono

Granados

et al. 2021

Integrative and Comparative Biology

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Copulatory behavior and genital morphology interact to deliver sperm more effectively during mating, but the nature of this interaction has not been explored in depth in most vertebrates. Alpacas have unusually long copulations lasting 15-20 minutes, and a unique copulatory behavior, where the penis intromits all the way past the cervix, into the uterine horns. Here we describe the morphology of male and female genitalia and report unique morphological characteristics that may be associated with this unusual insemination mode. Vaginal shape is highly variable, and seemingly not associated with age or parity. The cranial vagina varies between bulbous and cylindrical, while the caudal vagina is typically narrower and always cylindrical. The cervix consists of a series of 2-3 spirals or rings, and it is often found in a relaxed state that may prevent damage caused by the cartilaginous penis tip as it pushes through the cervix to reach the uterine horns. The uterus and uterine horns have a complex shape with multiple constrictions. The cartilaginous penis tip has a sharp urethral process that may help to push against these constrictions. The diameter of the vaginal lumen is much greater than the diameter of the penis suggesting that there is little direct interaction between them, and that female vaginal shape is not under strong copulatory selection. In effect, the entire female reproductive tract of the female is interacting with the penis during copulation.

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Anatomy and Physiology of Reproduction in the Female Llama and Alpaca

Cited by 8 publications

References 51 publications

Macroscopic evaluation of the placenta of the alpaca (Vicugna pacos)

Macroscopic evaluation of the placenta of the alpaca (Vicugna pacos)

Effect of Different Levels of Energy Diet Restriction on Energy Balance, Leptin and CL Development, Vascularization, and Function in South American Camelids

Intra-horn Penile Intromission in the AlpacaVicugna pacosand Consequences to Genital Morphology

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