This paper examines the environmental and management factors affecting lamb survival on high-performing sheep farms in New Zealand. Improved lambing percentage is the biggest contributor to higher profits on New Zealand sheep farms. Many sheep breeders have selected and bred ewes for increased fecundity over the last 4 decades. The increased proportion of ewes having triplets is of concern to f...

A 3-yr study was conducted to comprehensively evaluate Columbia, Suffolk, USMARCComposite (Composite), and Texel breeds as terminal sires in an extensive rangeland production system. The objective was to estimate breed-of-ram effects on ewe fertility, prolifi cacy, and dystocia, and sire breed effects on lamb survival and growth until weaning at approximately 132 d of age. Data were from 22 Col...

A 3-yr study was conducted to comprehensively evaluate Columbia, Suffolk, USMARC-Composite (Composite), and Texel breeds as terminal sires in an extensive rangeland production system. The objective was to estimate breed-of-ram effects on ewe fertility, prolificacy, and dystocia, and sire breed effects on lamb survival and growth until weaning at approximately 132 d of age. Data were from 22 Col...

The GH gene and BMP15 gene have been used as candidate genes for ­marker-assisted selection in different livestock species. Random blood samples were obtained from 180 Zel sheep breed to study genetic polymorphism of these genes. DNA was extracted from blood samples and a 365 bp fragment from the exon V of the ovine growth hormone gene and a 312 bp region from exon II of BMP15 gene were amplifi...

BACKGROUND:Abortion is one of the most important factorsreducing lambing rate and consequently profitability of sheepfarms. In addition to financial losses, it is also important from azoonotic point of view. OBJECTIVES: The aim of this study wasto investigate bacterial abortifacient agents in an outbreak ofabortion occurring in Afshari sheep in the northwest of Zanjanprovince. METHODS:Vaginal s...

A total of fifty multiparous ewes were selected immediately after lambing to study the relationship between udder morphology traits and milk production Najdi Naeimi (n=25/ breed) under intensive Saudi Arabia condition. Immediately lambing, lambs allowed suckle freely for 8 weeks; there weaned. During suckling period, typology, depth suspensory ligament in wear visually evaluated 3 weeks lambing...

St. Croix White hair sheep ewes lambing in July (n = 20) or November (n = 26) were used to evaluate the effect of ram exposure on uterine involution and postpartum luteal function. Ewes were exposed to an epididymectomized ram (EXPOSED) beginning on d 7 after lambing (d 0) or kept isolated from rams (CONTROL) through d 63. The width of each uterine horn was measured using transrectal ultrasonog...

Economic weights have been estimated in two breeds (Latxa and Manchega) using economic and technical data collected in 41 Latxa and 12 Manchega dairy sheep flocks. The traits considered were fertility (lambing per year), prolificacy (number of lambs), milk yield (litres) and longevity (as productive life, in years). A linear function was used, relating these traits to the different costs in the...