Effects of ewe live weight and age on reproductive performance, lamb growth, and survival in Central Anatolian Merino sheep

Abstract

Abstract. The aim of this study was to evaluate the effects of premating ewe weight and age on ewe reproductive performance, lamb growth and survival in Central Anatolian Merino (CAM) sheep.The trial included 4935 ewes and 5548 lambs from 23 breeder flocks in Eskişehir Province. The live weights (LWs) and ages of the ewes were recorded 1 week before the mating season. The number of lambs born, fertility rate, multiple birth rate (MBR), and lamb survival rate (SR) at days 75 and 120 were determined. The effects of the LW and age of the ewe were found to be important for the reproductive performance of ewes and for the lamb's growth rate (P < 0.05-0.001). Ewe MBRs and the birth weight (BW) and LW of the lambs at days 75 and 120 increased proportionally with the increase in LW in ewes prior to mating. The fertility rate and MBR were lower (P < 0.05-0.001) in 1.5-year-old ewes than in older ewes. However, lambs' SR at days 75 and 120 were not affected by the premating LW and age of the ewe. In summary, a better reproductive performance and lamb growth rate in CAM flocks may be achieved by the selection of breeding ewes from ewes weighing more than 60 kg.

Effects of protein supplements on fertility and assessment of the fertility genes (GDF9andBMP15) in indigenous sheep of Bangladesh

“…The nutrition and age had no effect on the litter size of ewes, which were similar to the outcomes of Banerjee (2008). However, the findings of the study disagreed with the results of Al-Haboby et al (1999), Sultana et al (2011) and Aktaş et al (2015), who showed that litter size was more in the protein supplement group than the control group (no supplements of protein).…”

“…However, among the age group of ewes no differences were found in treatments for the conception rate. Conception rate was found to be superior with the increases of protein supplements and age of the sheep, this finding was similar to the other researcher (Kabir et al 2004;Aktaş et al 2015) but differed with the findings of Fukui et al (2010), they stated that old aged ewes had a less conception rate than 1 to 2 years aged ewes.…”

“…However, the current findings of birth weight were not supported by the findings of Hassan and Talukder (2012), who observed, there was no relation of birth weight of lamb with feed treated groups. Aktaş et al (2015) showed that, age has a positive impact on birth weight. The amount and type of feed provided to pregnant ewe have influences on birth weight of lamb.…”

Indices of renewal of ewe sexual activity and its correlation with age, weight, traditional reproductive traits and climatic conditions

“…It is known that sexual activity and fertility of animals, which belong to the same breed and kept under identical conditions, are significantly affected by the age and the weight at time of insemination [1,16]. So, in the first stage how age, weight and its change correlate with each other were analysed.…”

Genetic analysis of longevity and lamb survival from birth to yearling in Moghani sheep

“…Survival of lambs is a compound character affected by many various effects connected to weather conditions, management, lamb and ewe behaviour, and other environmental factors (Smith 1977;Christley et al 2003;Everett-Hincks et al 2005;Tomaszyk et al 2014;Aktaş et al 2015;Moraes et al 2016). Increasing lamb numbers raised per ewe in a given year would result in improved productivity of ewes.…”