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Male Lambs (male + lamb)
Selected AbstractsNo Change Detected in Body Weight, Scrotal Circumference, Semen Characteristics and Sexual Behaviour during the Development of Prepubertal Milchschaf Lambs after Weekly Administration of eCGREPRODUCTION IN DOMESTIC ANIMALS, Issue 4 2008R Ungerfeld Contents To study the effects of equine chorionic gonadotropin (eCG) on pubertal development, 38 Milchschaf spring born male lambs fathered by the same ram and grazing over native pasture as a single mob during all the experiment were divided into three groups as follows: group 100 (100 IU of eCG weekly i.m., n = 11), group 400 (400 IU of eCG weekly i.m., n = 12) and group 0 (controls, n = 15). Lambs were weighed and scrotal circumference was registered every 2 weeks since birth until 170 days of age (end of experiment). On days 125 and 167 semen was collected using an electroejaculator. Semen volume and concentration, mass and individual sperm motility (scale 0 to 5) and total number of spermatozoa in the ejaculate were recorded. The sexual behaviour of the lambs was evaluated twice, on days 127 and 170 in a pen test with oestrous ewes. There were no significant effects of treatment on body weight or scrotal circumference, semen characteristics or sexual behaviour. At least in the administration regimens tested, eCG treatment has no effect on prepubertal reproductive development of male lambs. [source] Polymorphisms in the ovine myostatin gene (MSTN) and their association with growth and carcass traits in New Zealand Romney sheepANIMAL GENETICS, Issue 1 2010J. G. H. Hickford Summary Myostatin is a regulator of myogenesis and has been implicated in the regulation of adiposity and in controlling the structure and function of tendons. Polymerase Chain Reaction Single-Stranded Conformational Polymorphism (PCR-SSCP) analysis of intron-1 was used to identify five variants (designated A-E) of the myostatin gene (MSTN). The effect of this genetic variation on growth and carcass traits was investigated in 517 Romney male lambs from 17 sire-lines, born on a South Island New Zealand farm. General linear mixed effect models revealed that the presence of allele A in a lamb's genotype was associated with decreased leg, loin and total yield of lean meat, whereas the presence of allele B was associated with increased loin yield and proportion loin yield (loin yield divided by total yield expressed as percentage). The effect of the number of allele copies present was investigated, and it was found that the absence of A, or the presence of two copies of B, was associated with increased mean leg yield, loin yield and total yield. Two copies of B were also associated with a decrease in proportion of shoulder yield, whereas two copies of A were associated with a decrease in proportion of loin yield. Associations with allele C were not detected. No associations of MSTN variation with birth weight, weaning weight, pre-weaning growth rate, draft age and hot carcass weight (H-W) were detected. These results suggest that variation in ovine MSTN is associated with meat production, but not birth weight or growth rate in New Zealand Romney sheep. [source] The structure of vocalization of ewes and male lambs at pastureANIMAL SCIENCE JOURNAL, Issue 1 2009Hirofumi NAEKAWA ABSTRACT We performed an analysis of the vocalization of 161 ewes and 50 male lambs that were pastured day and night. The vocalization structures of the phonetic notations of the opened-mouth from closed mouth /,aee/ and /,naeee/ and closed-mouth /,,,,/ of ewes, and the opened-mouth from closed-mouth /,eee/ and /,neeee/ and closed-mouth /,,,,/ of male lambs were studied in terms of their audio characteristics. The items subject to analysis included duration of each vocalization, fundamental frequency, sound pressure and first formant (F1), second formant (F2), and third formant (F3). Among the male lambs, the duration of each call type showed significant differences depending on the behavior types or the target types, and the closed-mouth to open-mouth sounds, /,eee/ and /,neeee/ showed a tendency to be longer than the closed-mouth sound of /,,,,/. A significant correlation (r = 0.9, P < 0.05) was observed between the fundamental frequency and F1 with the /,eee/ type of call of the male lambs when the vocalization was targeted toward the stockperson. When the ewes' behavior pattern was grazing and moving and the calling target was an ewe, the sound pressure significantly differed between /,,,,/ and /,naeee/ (P < 0.05). From the analysis of the call durations, the fundamental frequencies, the sound pressures and formants, and the particular characteristics in sound structure were shown to vary according to the vocalization conditions and the situations, and where the animals were placed, even within the same call types. [source] | ||||||||||