Productive performance of lambs born in different seasons of the year

Abstract

Background: The seasonality in lamb supply challenges the development of sheep production. Increasing the duration of the breeding season, aimed at distributing births throughout the year, enables a constant supply of lambs. However, the birth season can influence their productive performance. Aim: The objective was to evaluate the effect of birth season on birth live weight (BW), daily live weight gain from birth to weaning (DWGBW), weaning live weight (WW), and daily live weight gain from weaning to 150 days (DWGW-150) slaughter age, as well as the influence of ewe age and body condition score (BCS), sex of the lamb, and type of pregnancy (single or twin) on these productive indices. Methods: The study analyzed production data comprising ten breeding seasons (from 2015 to 2019), 643 matings, and 531 lambs, using binary logistic regression, ANOVA, Tukey’s, and t tests. Results: Lambs born in summer exhibited lower productive performance, as evidenced by lower DWGBW (0.22 ± 0.08 kg), WW (18.88 ± 7.82 kg), and DWGW-150 (0.13 ± 0.07 kg). Ewes with prepartum BCS between 3 and 4 gave birth to heavier lambs. After birth, lambs from ewes with BCS between 3 and 4 had a higher DWGBW, while lambs from ewes with postpartum BCS of 1.5 and 2 had a lower WW. Ewes aged 2 to 8 years gave birth to heavier lambs, and ewes aged ≥8 years weaned lambs at a lower weight. After weaning, the weight gain was similar among all age groups. Male lambs had higher DWGBW and WW than female lambs. Lambs from twin pregnancies had lower BW (3.95 ± 1.27 kg), lower DWGBW (0.21 ± 0.08 kg), and lower WW (17.59 ± 8.18 kg). The average lamb mortality rate between lambing and weaning was 12.5%, ranging from 9.8% to 13.9%, with no significant variations between birth seasons. Lambs born in spring and summer needed more anthelmintic treatments than those born in autumn and winter. Conclusion: The production of lambs outside the traditional season is possible; however, the productive performance of lambs born in the summer is lower than that in the other seasons of the year.

Norduz Kuzularının Doğum Ağırlığı Üzerine Bazı Çevresel Faktörlerin Etkileri

“…Bu çalışmada, Norduz kuzularının ortalama doğum ağırlığı Manchega (Molina ve ark., 1993), Akkaraman ve Malya (Çolakoğlu & Özbeyaz, 1999), Karacabey Merinosu (Sezenler ve ark., 2008) Romanov melezi (Ürüşan & Emsen, 2010), Kıvırcık (Koyuncu ve ark., 2018), Norduz (Karakuş & Atmaca, 2016), Texel ve Ile de France (Heinzen, 2023) koyunlarından daha düşük olduğu, Akkaraman (Aktaş & Doğan, 2014), Tuj (Aksoy ve ark., 2001;Sarı ve ark., 2013) ve Kıvırcık (Nageye, 2020) koyunlarından daha yüksek olduğu ve Akkaraman (Türkmen & Çak, 2021), İvesi (Şahin, 2022; Şireli, 2019) ve Suffolk (Heinzen, 2023) koyunu ile benzer olduğu gözlenmiştir.…”

“…( 2013 2014), Karakuş ve Atmaca (2016), Koyuncu ve ark. (2018), Şireli (2019), Nageye (2020) Şahin (2022), Türkmen ve Çak (2021) ve Heinzen (2023) tarafından bildirilen sonuçlara benzerdir. Doğum tipi açısından değerlendirildiğinde çalışmada tartışılan literatürlerin tümü tek doğan kuzuların doğum ağırlığının diğerlerine (ikiz ve üçüz) göre daha yüksek doğum ağırlığına sahip olduğunu bildirmişlerdir.…”

“…),Karakuş ve Atmaca (2016),Şireli (2019) veHeinzen (2023) tarafından erkek ve dişi kuzular arasındaki doğum ağırlığı farkının istatistiki olarak önemsiz olduğu bildirilmiştir. Ancak, Aksoy ve ark.…”