Subclinical selenium insufficiency. 2. The response in reproductive performance of grazing ewes supplemented with selenium

1991 ◽  
Vol 31 (1) ◽  
pp. 33 ◽  
Author(s):  
JP Langlands ◽  
GE Donald ◽  
JE Bowles ◽  
AJ Smith
Keyword(s):  
Muscular Dystrophy ◽  
Litter Size ◽  
Reproductive Performance ◽  
Stocking Rate ◽  
Se Status

Merino and Border Leicester x Merino ewes grazed improved pastures at 6.3 or 12.5 ewes/ha for 4 years and were supplemented or not supplemented with intra-ruminal selenium (Se) pellets. The Merino and crossbred ewes were mated to Merino and Dorset Horn rams, respectively, and various measures of reproductive performance were recorded. Two cases of muscular dystrophy were observed in 2-3-day-old lambs, but the incidence of oestrus and fertility was not affected by differences in stocking rate, genotype or Se supplementation. Fecundity was higher in crossbreds than Merinos (1.64 v. 1.25, P<0.001) but was not affected by stocking rate or Se status. Survival of lambs was increased (P<0.05) by Se supplementation -- at the high stocking rate (0.74 v. 0.86) but not at the low (0.84 v. 0.83), and a significant (P<0.01) genotype x litter size x Se interaction reflected greater sensitivity to Se supplementation by Merino singletons (from 0.75 to 0.95) than twins (from 0.75 to 0.69) and by crossbred twins (from 0.76 to 0.87) than singletons (from 0.89 to 0.87). Number of lambs weaned per ewe mated increased following Se supplementation from 0.81 to 1.04 at the high stocking rate, and decreased from 1.08 to 1.00 at the low; the interaction approached significance (P<0.09). It is suggested that the response to Se supplementation is sensitive to factors in addition to Se status, and such factors may explain some of the variability in responsiveness reported in the literature.

Subclinical selenium insufficiency. 1. Selenium status and the response in liveweight and wool production of grazing ewes supplemented with selenium

1991 ◽  
Vol 31 (1) ◽  
pp. 25 ◽  
Author(s):  
JP Langlands ◽  
GE Donald ◽  
JE Bowles ◽  
AJ Smith
Keyword(s):  
Reproductive Performance ◽  
Whole Blood ◽  
Fibre Diameter ◽  
Selenium Status ◽  
Stocking Rate ◽  
Seasonal Trends ◽  
Wool Production ◽  
Se Status

Fine wool Merino and Border Leicester x Merino ewes grazed improved pastures low in selenium (Se) for 4 years at 6.3 and 12.5 sheep/ha; half of the ewes were supplemented with Se given as an intra-ruminal pellet. Selenium status of the ewes was monitored from Se concentrations in whole blood and plasma, and wool production, fibre diameter and liveweight were recorded. The unsupplemented ewes showed no overt signs of Se insufficiency; Se status was consistently low; and Se supplementation increased wool production and fibre diameter. Selenium status was lower in unsupplemented ewes grazed at the higher stocking rate and in ewes supporting a lamb; it showed seasonal trends and was negatively correlated with rainfall. Selenium concentrations in whole blood but not in plasma were lower in Merino than in Border Leicester x Merino ewes. Data relating to reproductive performance and the productivity of the lambs are presented in accompanying reports.

THE ACCUMULATIVE EFFECT OF FINNSHEEP BREEDING IN CROSSBREEDING SCHEMES: REPRODUCTIVE PERFORMANCE

1988 ◽  
Vol 68 (1) ◽  
pp. 69-81 ◽  
Author(s):  
MOHAMED H. FAHMY ◽  
JACQUES J. DUFOUR
Keyword(s):  
Body Weight ◽  
Mortality Rate ◽  
Key Words ◽  
Litter Size ◽  
Reproductive Performance ◽  
Conception Rate ◽  
Ovulation Rate ◽  
Genetic Groups ◽  
Linear Regressions ◽  
Size At Birth

Reproductive performance and body weight were studied on 361 ewes, representing Finnsheep (F), DLS (a population of 1/2 Dorset, 1/4 Leicester, 1/4 Suffolk) and seven combinations ranging from 1/8 to 7/8 Finnsheep breeding. Conception rate in yearlings was 61.5% for DLS compared to 89.0% for F with the crosses being intermediate. Conception rate in older ewes was similar in the different genetic groups (avg. 94%). Ovulation rate and litter size at birth of DLS ewes were 1.72 and 1.44 lambs, which was less than half those of F ewes (3.51 and 2.86 lambs, respectively). Both traits increased progressively with an increase in F breeding in crosses and with advances in age. DLS ewes weaned 1.22 lambs compared to 2.03 lambs for F ewes and 1.84 lambs for 4/8 F ewes. The heaviest litters at weaning (31.7 kg) were raised by 4/8 F ewes, followed by 7/8 F (30.8 kg) while those raised by DLS ewes weighed 23.0 kg and F ewes 29.1 kg. Percentage of ova lost per ewe mated averaged 24% and ranged between 18% (DLS and 1/8 F) and 29% (6/8 F). About 3.6% of lambs were born dead and a further 13.8% died before weaning. Preweaning mortality rate was highest in F (22.9%) and lowest in 3/8 F (9.4%). Average kilograms of lambs weaned per ewe exposed was highest in 4/8 F (27.6 kg) followed by F (26.0 kg), whereas that of DLS was the lowest at 18.1 kg. The 4/8 F cross showed 25% heterosis in kg of lambs weaned per ewe exposed and 52.5% increase over DLS. Significant positive linear regressions were calculated for ovulation rate, litter size and preweaning mortality rate on proportion of Finnsheep breeding in crosses. The relation was quadratic for percent ova lost and lamb mortality at weaning. Yearling DLS females weighted 36 kg compared to 44 kg for F yearlings. However, at 5 yr of age DLS ewes weighed 62 kg, 5 kg heavier than F ewes. The heaviest ewes at all ages were the 4/8 F (45 kg at 1 yr, 65 kg at 5 yr). Key words: Reproduction, DLS sheep, Finnsheep, crossbreeding, heterosis, repeatabilities

scholarly journals Effects of cooling on the reproductive performance of gilts

2016 ◽  
Vol 20 (2) ◽  
pp. 357-361
Author(s):  
J.O. Oyedeji ◽  
G.O. Imagbenikaro
Keyword(s):  
Birth Weight ◽  
Litter Size ◽  
Reproductive Performance ◽  
Feed Intake ◽  
Cooling System ◽  
Large White ◽  
Feed Cost ◽  
Randomized Design ◽  
Significant Difference ◽  
Level Of Significance

The study examined the effect of cooling on the reproductive performance of gilts using 27 Large White Experimental Gilts on a Completely Randomized Design (CRD) with 3 systems of cooling, namely Wallow Cooling (WC), Sprinkler Cooling (SC) and Zero Cooling (ZC). Gilts were weighed at the commencement of the experiment and thereafter fed ad libitum from service to farrowing. Feed intake till farrow, feed cost, gilt weight at farrow, date of farrow, litter size and weight were recorded. The feed/piglet weight, feed intake/litter, feed cost/litter and birth weight/piglet were derived. The results showed that feed intake per litter and feed per piglet weight were highest for gilts placed on WC(P< 0.05), followed by SC and least for sow placed on ZC; gilt weight before farrow was highest for sow placed on SC (69.78±0.92), followed by ZC (69.33±0.94) and least for gilts placed on WC (67.33±0.87); litter sizes of gilts placed under the WC and SC systems were similar (5.6±0.41) while that under the ZC system was comparatively smaller (5.4±0.40);while the date of farrow was lowest in the ZC system (113.8±0.32) followed by SC (114.0±0.33) and highest under the WC (114.1±0.33). However, the feed intake per litter, feed per piglet weight, litter sizes of gilts, birth weight per piglet of gilts and the average date of farrow among gilts placed on WC, SC and ZC were not statistically different at 5% level of significance. Though, there is no significant difference in the performance among gilts placed on WC, SC and ZC, temperature regulation through provision of efficient cooling system in piggery would help to increase litter size, improve feed intake per litter and reduce the average cost of feeding gilt per day in maximizing reproductive performances in pigs.Keywords: Cooling, gilts, service, farrow, piggery, litter size, piglet and birth weight

scholarly journals The influence of adding estradiol to semen on reproductive performance of sows

1991 ◽  
Vol 71 (2) ◽  
pp. 589-591 ◽  
Author(s):  
R. N. Kirkwood ◽  
P. A. Thacker
Keyword(s):  
Key Words ◽  
Litter Size ◽  
Reproductive Performance ◽  
Artificial Insemination ◽  
Pregnancy Rates ◽  
And Control ◽  
Estradiol 17Β

One hundred gilts and one hundred mixed-parity sows of Yorkshire and Landrace breeding were inseminated with semen with or without an additional 10 μg estradiol-17β. Pregnancy rates of gilts receiving estradiol-supplemented and control semen were 90 and 79%, respectively (P < 0.09). The estradiol supplementation of semen did not improve the pregnancy rates or litter size in sows. Key words: Swine, artificial insemination, estradiol

scholarly journals Effect of parity on reproductive performance sows of different breeds

2020 ◽  
Vol 50 (3) ◽  
pp. 434-441
Author(s):  
R. Klimas ◽  
A. Klimienė ◽  
W. Sobotka ◽  
W. Kozera ◽  
P. Matusevičius
Keyword(s):  
Survival Rate ◽  
Litter Size ◽  
Reproductive Performance ◽  
Weaned Piglets ◽  
Large White ◽  
Litter Weight ◽  
Piglet Survival

The aim of this study was to determine the effect of parity on reproductive performance by sows of different breeds. The sows were raised on three farms, and had seven or more litters of not fewer than seven piglets. A total of 1511 litters from various parities of Lithuanian White (N =721), Large White (N = 162) and Landrace (N = 628) sows were contained in the data that were used in this study. Multiparous sows had larger litters than primiparous sows. Piglet survival rate declined from parity 7. An increase in litter size was observed until parity 5 in Large White and until parity 6 in improved Lithuanian White (P <0.05). In comparison with parity 1, Landrace sows up to parity 5 showed not only increased prolificacy, but also increased number and litter weight of piglets at 21 days old, and the number and litter weight of weaned piglets (P <0.01). The current findings indicate that sows of these breeds can be used effectively in breeding herds until parity 5 and parity 6.Keywords: Landrace, Large White, Lithuanian White, litter size

Effects of nutrition and photoperiod on reproductive physiology of Microtus montanus

1965 ◽  
Vol 208 (4) ◽  
pp. 633-638 ◽  
Author(s):  
Aelita J. Pinter ◽  
Norman C. Negus
Keyword(s):  
Dietary Supplement ◽  
Litter Size ◽  
Reproductive Performance ◽  
Wheat Plant ◽  
Reproductive Physiology ◽  
The Other ◽  
Active Principle ◽  
Microtus Montanus ◽  
Artificial Illumination ◽  
Group D

A total of 140 pairs (one male, one female) of known-age virgin Microtus montanus was used in two experiments lasting 18 weeks each. Pairs were divided into two groups, one placed under 18 hr, the other under 6 hr of artificial illumination daily. Under each of the two photoperiods, half of the pairs received a dietary supplement of sprouted wheat every 3 days (G), the other half every 15 days (D). The G groups produced significantly more litters and offspring than did the D groups. Irrespective of diet, mean litter size was significantly larger under 18-hr than under 6-hr illumination. Any superiority in reproductive performance due to diet could be attributed solely to frequent (G) supplementation with sprouted wheat. "Plant estrogens" are tentatively postulated as the active principle. Diet and photoperiod interact in their influence on reproductive physiology (G-18 was the most productive group, D-6 the least productive).

The influence of purified porcine relaxin on the reproductive performance of sows following artificial insemination with fresh or frozen semen

1991 ◽  
Vol 71 (1) ◽  
pp. 237-239 ◽  
Author(s):  
P. A. Thacker ◽  
A. D. Gooneratne ◽  
R. N. Kirkwood
Keyword(s):  
Key Words ◽  
Pregnancy Rate ◽  
Litter Size ◽  
Reproductive Performance ◽  
Artificial Insemination ◽  
Pregnancy Rates ◽  
Frozen Semen

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

The effect of level of nutrition prior to mating on the reproductive performance of ewes of two welsh breeds in different levels of body condition

1991 ◽  
Vol 52 (1) ◽  
pp. 157-163 ◽  
Author(s):  
R. G. Gunn ◽  
T. J. Maxwell ◽  
D. A. Sim ◽  
J. R. Jones ◽  
M. E. James
Keyword(s):  
Body Condition ◽  
Reproductive Performance ◽  
Body Condition Score ◽  
High Surface ◽  
Live Weight ◽  
Corpora Lutea ◽  
Stocking Rate ◽  
Treatment Groups ◽  
Condition Score ◽  
Body Condition Scores

ABSTRACTThe effects of high-low (HL) and low-high (LH) patterns of nutrition during the 5 weeks prior to a synchronized mating were studied on the reproductive performance of 115 Welsh Mountain and 114 Brecknock Cheviot ewes in a range of body condition at the start of treatment. For 2 months prior to treatment imposition, ewes were grazed in a systematic way at different stocking rates on different sward heights to obtain a range of body condition scores. Target score groupings were 2·00 to 2·25, 2·50 to 2·75 and 3·00 to 3·25 and although scores of 1·50 to 3·25 were obtained, most lay in the 2·00 to 2·75 range. Two treatment groups, balanced for live weight and body condition score, received high and low levels of nutrition for 16 days from mid October, achieved, respectively, by a low stocking rate on a sward with a high surface height plus ad libitum concentrate and a high stocking rate on a sward with a low surface height plus 200 g hay per head per day. Treatments were then reversed for the 17 days prior to mating. Live-weight and body condition-score changes were recorded and reproductive performance at first mating was measured from counts of corpora lutea and viable embryos at slaughter either at return to service or at 4 weeks after first mating. There were no differences due to nutritional pattern in live weight or body condition score at mating. The LH treatment significantly increased the rates of ovulation, conception, multiple ova survival and potential lambing per ewe pregnant and per ewe mated in the Welsh Mountain breed but significantly increased only the rates of ovulation and potential lambing per ewe pregnant in the Brecknock Cheviot breed compared with the HL treatment. The relatively poorer response in the latter breed was partially due to a lower ovulation rate potential coupled with non-significantly lower rates of conception and survival of single-shed ova associated with the LH treatment. Much of this relatively poorer reproductive performance in the Brecknock Cheviot breed was in ewes with body condition scores 3= 2·75. Reproductive performance increased with increasing body condition at the start of treatment over the range of scores =≤ 2·25 to 2·50 in both breeds and, while continuing to improve in scores above 2·50 in the Welsh Mountain breed, in the Brecknock Cheviot breed it started to decline. Ewes with a body condition score of 2·50 in both breeds showed the greatest response in potential lambing rate to the LH treatment.

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