Peiró Rosa, Argente María-José, García María-Luz
Instituto de Conservación y Mejora de la Agrodiversidad Valenciana (COMAV), Universitat Politècnica de València, Camino de Vera s/n, 46022 Valencia, Spain.
Centro de Investigación e Innovación Agroalimentaria y Agroambiental (CIAGRO-UMH), Universidad Miguel Hernández de Elche, Ctra. Beniel km 3.2, 03312 Alicante, Spain.
Animals (Basel). 2023 Oct 14;13(20):3213. doi: 10.3390/ani13203213.
The aim of this work is to study changes in body weight, perirenal fat thickness (PFT), and non-esterified fatty acid (NEFA) and leptin concentrations throughout the reproductive life of the rabbit female and their correlations when a semi-intensive reproductive rhythm is applied. A total of 46 lactating females were used. Body weight, PFT, and NEFA and leptin concentration were recorded at 12 weeks of age, at first mating and delivery, and at second, third, and fourth mating, 12th d of gestation, and delivery. The highest body weight was detected on the 12th d of any gestation, around 4280 g, and the lowest weight was at delivery, around 4030 g. PFT increased until third mating. NEFA and leptin concentration showed a cyclical pattern throughout the reproductive lifespan of the females. NEFAs presented the highest concentration at delivery within each reproductive cycle and levels decreased over the course of the deliveries (0.423 mmol/L at first delivery, 0.406 mmol/L at second delivery, 0.371 mmol/L at third delivery, and 0.309 mmol/L at fourth delivery). Similar NEFA concentrations at mating and on the 12th d of gestation were obtained. Leptin showed the highest concentrations at mating within each reproductive cycle. Leptin decreased between mating and delivery in all reproductive cycles and it was close to 1 ng/mL HE. Low or null correlations were shown between body weight, PFT, and NEFA and leptin concentration at mating, 12th d of gestation, and delivery. In conclusion, females are able to maintain a semi-intensive reproductive rhythm across four parities weighing around 4 kg from first mating. Females had an increased perirenal fat thickness until third delivery, and their NEFA concentration was maximum at delivery and leptin concentration was maximum at mating. Body weight, PFT, and NEFA and leptin concentration should be measured during critical moments of reproductive life in order to determine body condition and energy mobilization, due to their low or null correlations.
本研究旨在探讨在半集约化繁殖节律下，母兔整个繁殖期内体重、肾周脂肪厚度（PFT）、非酯化脂肪酸（NEFA）和瘦素浓度的变化及其相关性。共使用了46只泌乳母兔。在12周龄、首次配种和分娩时，以及第二次、第三次和第四次配种、妊娠第12天和分娩时记录体重、PFT、NEFA和瘦素浓度。在任何一次妊娠的第12天检测到最高体重，约为4280 g，最低体重在分娩时，约为4030 g。PFT在第三次配种前增加。NEFA和瘦素浓度在母兔的整个繁殖寿命中呈周期性模式。在每个繁殖周期内，NEFA在分娩时浓度最高，且随着分娩次数的增加而降低（第一次分娩时为0.423 mmol/L，第二次分娩时为0.406 mmol/L，第三次分娩时为0.371 mmol/L，第四次分娩时为0.309 mmol/L）。在配种时和妊娠第12天获得了相似的NEFA浓度。瘦素在每个繁殖周期的配种时浓度最高。在所有繁殖周期中，瘦素在配种和分娩之间降低，且接近1 ng/mL HE。在配种、妊娠第12天和分娩时，体重、PFT、NEFA和瘦素浓度之间显示出低相关性或无相关性。总之，母兔从首次配种开始能够维持半集约化繁殖节律，历经四胎，体重约4 kg。母兔在第三次分娩前肾周脂肪厚度增加，其NEFA浓度在分娩时最高，瘦素浓度在配种时最高。由于体重、PFT、NEFA和瘦素浓度之间的相关性较低或无相关性，因此在繁殖生命的关键时期应测量这些指标，以确定身体状况和能量动员情况。
