the objective of the present study was to investigate the effects of a sustained-release multi-trace element ruminal bolus on sex ratio, the reproductive performance and lambs growth of afshari ewes. eighty afshari cycling ewes during breeding season were used in the trial. the animals were synchronized using cidr for 14 days and assigned into 4 groups including: group 1 (n=20) received a singl...

The objective of this study was to test the hypothesis that a combination of induced estrus (IE) and melatonin (MEL) would increase reproductive performance in breeds characterized by late maturity more than either IE or MEL alone. Spring-born Columbia (C; n = 161; 188 to 222 d range of age at breeding; 49 to 80 kg range of BW at breeding) and Targhee (T; n = 166; 183 to 210 d range of age at b...

THE OBJECTIVE OF THIS STUDY WAS TO COMPARE THE GOODNESS OF FIT OF FOUR LACTATION CURVE MODELS: Wood's Gamma model (WD), Wilmink (WL), and Pollott's multiplicative two (POL2) and three parameters (POL3) and to determine the environmental factors affecting the complete lactation curve of F1 dairy sheep under organic management. A total of 5,382 weekly milk yields records from 150 ewes, under orga...

In this study, we aimed to investigate reproductive performance in estrus-induced Zandi ewes treated with equine chorionic gonadotrophin (eCG) injection in combination with prostaglandin F2α (PGF2α)and gonadotrophin releasing hormone (GnRH) during non-breeding season. The estrous cycle was synchronized using controlled internal drug release (CIDR) for 12 days. The ewes were randomly assigned to...

Selection for fertility in a fall lambing system was applied for 5 yr (1.45 generations) in a crossbred sheep population. Three flocks were involved: a fall-lambing selected (S) flock of 125 ewes and 10 rams, a fall-lambing environmental control (EC) flock of 55 ewes and five rams, and a spring-lambing genetic control flock of 45 ewes and five rams used to produce replacements for EC. Estimated...

Reproductive performance was evaluated in non-lactating crossbred ewes to which were administered the exogenous GnRH and PMSG. The ewes were randomly allocated in three treatment groups (n=40).After accurate detection of estrus and 2 hours prior to mating, 2.5 mL of distilled water and 2.5 mL of GnRH were injected intramuscular to each ewe of the first (control) and second group, respectively. ...

The number of lambs sold per ewe mated in the breeding flock has a considerable impact on sheep operation profitability. This depends primarily on fertility, prolificacy (# of lambs), and lamb survival, mothering ability, milk production of the ewe and lamb growth rate. Optimal reproduction does vary by environment and management system – some sheep operations don’t want a lambing rate over 200...

The number of lambs sold per ewe mated in the breeding flock has a considerable impact on sheep operation profitability. This depends primarily on fertility, prolificacy (# of lambs), and lamb survival, mothering ability, milk production of the ewe and lamb growth rate. Optimal reproduction does vary by environment and management system – some sheep operations don’t want a lambing rate over 200...