Effects of shearing and prebreeding ram exposure on days to first mark and pregnancy rate of ewe lambs

1991 ◽  
Vol 71 (3) ◽  
pp. 905-907
Author(s):  
R. A. Kemp ◽  
S. F. Lane ◽  
Y. M. Berger

Crossbred ewe lambs were used to examine effects of shearing and prebreeding ram exposure on age at puberty and pregnancy rate. Shearing did not significantly affect age at puberty or growth rate of ewe lambs. Prebreeding ram exposure and/or shearing did not influence pregnancy rate. Key words: Shearing, ram exposure, pregnancy rate, growth

1991 ◽  
Vol 53 (3) ◽  
pp. 407-409 ◽  
Author(s):  
F. Forcada ◽  
J. A. Abecia ◽  
L. Zarazaga

The attainment of puberty in September-born early-maturing ewe lambs was studied at Zaragoza (latitude 41° 40' N). Thirty twin Salz females were allocated to two groups receiving two nutrition levels after 3 months of age: high (500 g/day lucerne hay and 500 g/day concentrate) (H) and low (500 g/ day lucerne hay) (L). Oestrus was detected daily by aproned rams. Corpora lutea were counted after oestrus and plasma progesterone levels monitored each week.In the first breeding season (January to February) the percentage of females showing sexual activity (silent emulation or oestrus and ovulation) was higher in the H compared with the L group (67 and 20%; P < 0/05). Nonpubertal oestrus before the main breeding season was detected in 67% of animals. In the main breeding season and for H and L groups respectively, percentage of females showing silent ovulation before puberty was 67 and 33% and mean age at puberty extended to 319 (s.e. 4-8) and 314 (s.e. 3·7) days. Ovulation rate at puberty was 1·73 (s.e. 0·13) and 1·33 (s.e. 0·15) respectively (P < 0·05).


1970 ◽  
Vol 12 ◽  
pp. 11-20
Author(s):  
M. Z. Rozainah ◽  
U. R. Sinniah

A study of an acaulescent palm, Johannesteijsmannia  lanceolata J. Dransfield was carried out in Angsi Forest Reserve Negeri Sembilan Malaysia for a period of 19 months A total of 32 adults, 24 juveniles and 32 seedlings from 3 different plots were censused every two weeks. The results showed that the average numbers of new leaves entering the crown with in the study period (19months) were: 3.3, 2.6 and 1.3 for 2.1, 1.6 and 0.8 leaves per year for adult juvenile and seedling, respectively. From the calculation it was discovered that the time spent by each leaf in the crown before it died was 8.8 years for adult and 8.4 years for juvenile. Key words: Johannesteijsmannia; Growth rate; Vegetative phenology; Arecaceae doi: 10.3126/eco.v12i0.3190 Ecoprint: An International Journal of Ecology 12: 11-20, 2005


2009 ◽  
Vol 49 (6) ◽  
pp. 399 ◽  
Author(s):  
D. J. Johnston ◽  
S. A. Barwick ◽  
N. J. Corbet ◽  
G. Fordyce ◽  
R. G. Holroyd ◽  
...  

A total of 2115 heifers from two tropical genotypes (1007 Brahman and 1108 Tropical Composite) raised in four locations in northern Australia were ovarian-scanned every 4–6 weeks to determine the age at the first-observed corpus luteum (CL) and this was used to define the age at puberty for each heifer. Other traits recorded at each time of ovarian scanning were liveweight, fat depths and body condition score. Reproductive tract size was measured close to the start of the first joining period. Results showed significant effects of location and birth month on the age at first CL and associated puberty traits. Genotypes did not differ significantly for the age or weight at first CL; however, Brahman were fatter at first CL and had a small reproductive tract size compared with that of Tropical Composite. Genetic analyses estimated the age at first CL to be moderately to highly heritable for Brahman (0.57) and Tropical Composite (0.52). The associated traits were also moderately heritable, except for reproductive tract size in Brahmans (0.03) and for Tropical Composite, the presence of an observed CL on the scanning day closest to the start of joining (0.07). Genetic correlations among puberty traits were mostly moderate to high and generally larger in magnitude for Brahman than for Tropical Composite. Genetic correlations between the age at CL and heifer- and steer-production traits showed important genotype differences. For Tropical Composite, the age at CL was negatively correlated with the heifer growth rate in their first postweaning wet season (–0.40) and carcass marbling score (–0.49), but was positively correlated with carcass P8 fat depth (0.43). For Brahman, the age at CL was moderately negatively genetically correlated with heifer measures of bodyweight, fatness, body condition score and IGF-I, in both their first postweaning wet and second dry seasons, but was positively correlated with the dry-season growth rate. For Brahman, genetic correlations between the age at CL and steer traits showed possible antagonisms with feedlot residual feed intake (–0.60) and meat colour (0.73). Selection can be used to change the heifer age at puberty in both genotypes, with few major antagonisms with steer- and heifer-production traits.


1991 ◽  
Vol 71 (1) ◽  
pp. 237-239 ◽  
Author(s):  
P. A. Thacker ◽  
A. D. Gooneratne ◽  
R. N. Kirkwood

Pregnancy rates and litter sizes following insemination of sows with fresh-extended and frozen-thawed semen averaged 71 vs. 53% and 10.6 vs. 4.4, respectively, and was not affected by the addition of 12.5 μg relaxin to semen. These results indicate no relaxin mediated effect on either pregnancy rate or litter size when sows are artificially inseminated with relaxin-supplemented semen. Key words: Artificial insemination, relaxin, sows


1993 ◽  
Vol 73 (2) ◽  
pp. 287-293
Author(s):  
S. L. Boyles ◽  
L. J. Johnson ◽  
W. D. Slanger ◽  
B. J. Kreft ◽  
J. D. Kirsch

Twenty-six of 52 heifers with an average liveweight of 318 kg were dewormed by intraruminal injection of oxfendazole and placed in drylot on 31 January. The other 26 animals served as controls. All heifers were pastured starting on 14 June and the treatment heifers were dewormed in the same manner as at the start of the experiment (31 January) on 1 July and 31 July. The groups started out with similar total worm eggs per gram of fecal sample, but the dewormed heifers had fewer counts each month thereafter. The drylot average daily gain of the treated heifers was higher (P = 0.01) and less variable (P = 0.12) and by 29 May these animals were heavier by 11.7 kg (P = 0.10). The treated animals did not gain as fast on pasture (P = 0.20), but the gain continued to be less variable (P = 0.09). Age at puberty was not different. Number of open heifers in the treated group was 4 vs. 15% for the control group (P = 0.18). Deworming by intraruminal injection resulted in faster feedlot gains, more uniform gains during both drylot and pasture, reduced parasites and no abscess at injection sites. Key words: Anthelmintics, oxfendazole, cattle, heifers


1986 ◽  
Vol 66 (3) ◽  
pp. 817-820
Author(s):  
J. S. WALTON ◽  
B. W. McBRIDE ◽  
N. A. MARTINEAU ◽  
T. D. BURGESS

Completely pelleted diets were fed to rams under a facsimile of Ontario Ram Performance Test procedures. Twenty rams were fed for 50 d on completely pelleted rations without impairment of growth rate and without any effects on rumen health or ingestive behavior. Key words: R.O.P. testing, rams, pelleted feeds, growth rate, rumen lining


1996 ◽  
Vol 76 (2) ◽  
pp. 271-273 ◽  
Author(s):  
T. A. Van Lunen ◽  
H. Schulze

A trial was conducted to evaluate the effects of supplementing wheat- and corn-based diets with xylanase on growth performance and FCR of pigs from 10 to 18 wk of age. Seventy-tow castrated male pigs were assigned to pens of two and in a randomized block design to six dietary treatments consisting of diets containing 60% wheat, 40% wheat and 20% corn, and 20% wheat and 40% corn with and without supplementation with xylanase. Feed and water were available ad libitum. Xylanase supplementation improved growth rate and FCR by 9.2 and 5.3%, respectively, regardless of level of wheat and corn inclusion. Key words: Pig, growth, feed enzyme, Trichoderma longibrachiatum xylanase, wheat, corn


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