Calving success of female caribou in relation to body weight

1993 ◽  
Vol 71 (3) ◽  
pp. 480-486 ◽  
Author(s):  
Raymond D. Cameron ◽  
Walter T. Smith ◽  
Steven G. Fancy ◽  
Karen L. Gerhart ◽  
Robert G. White

In late September and October 1987–1990 and early July 1988–1991, 66 radio-collared female caribou (Rangifer tarandus granti) of the Central Arctic Herd were captured and weighed 117 times. Caribou were relocated repeatedly during early June 1988–1991; parturition status, calving date, and perinatal calf survival were determined. Mean autumn body weights of subsequently parturient (90.0 kg) and nonparturient (82.5 kg) females differed significantly (P < 0.01). Mean summer weights 4 – 5 weeks after parturition were significantly higher for females that had calved on or before 7 June (82.2 kg) than for those that had calved after 7 June (72.1 kg; P < 0.01), and for females whose calves survived at least 2 days post partum (80.2 kg) than for those whose calves died within 2 days (70.3 kg; P < 0.01). Significant logistic models were generated for relationships between parturition rate and autumn weight (P < 0.01), between the occurrence of early calving and summer weight (P < 0.05), and between calf survival rate and summer weight (P < 0.02). Body weight appears to be a reasonable index of body condition, which in turn is related to reproductive performance. The probability of a successful pregnancy is largely predetermined at breeding, based on autumn condition, whereas calving date and early calf survival appear to be influenced primarily by maternal condition during late pregnancy.

1973 ◽  
Vol 16 (2) ◽  
pp. 165-171 ◽  
Author(s):  
T. H. McClelland ◽  
T. J. Forbes

SUMMARYSixty Scottish Blackface ewes were used in a 2 × 2 factorial experiment in which two levels of metabolizable energy (ME) were given during the final 6 weeks of pregnancy. In two treatments 1600 and 2000 kcal M E were given daily over the total period while in the remaining treatments daily ME intakes were 1200 and 1600 kcal ME during the first 3 weeks of the feeding period and 2000 and 2400 kcal ME during the last 3 weeks. Digestible crude protein (DCP) intakes were constant at approximately 30 g per head daily in the constant energy treatments and 15 and 45 g per head daily in the first and second periods respectively for the low-high energy treatments.Energy intake had no statistically significant effect on lamb birth weight nor on ewe net body-weight change (change from the start of the experimental feeding period to immediately post partum). Ewes on low-high energy intakes had a significantly lower net body-weight loss than did ewes on constant energy intakes. Pattern of feeding had no significant effect on lamb birth weights. Negative nitrogen balances were found during the first feeding period where the daily DCP intake was approximately 15 g per head.


Reproduction ◽  
2002 ◽  
pp. 419-427 ◽  
Author(s):  
JG Gong ◽  
WJ Lee ◽  
PC Garnsworthy ◽  
R Webb

Although it has become increasingly clear that fertility in modern dairy cattle is declining in association with increased milk yields, the underlying mechanism is poorly understood. The first ovulation post partum is delayed in dairy cows undergoing selection for genetic merit for milk yield in association with lower circulating insulin concentrations. The aim of this study was to investigate whether feeding a diet to increase circulating insulin concentrations can overcome this delay in the first ovulation post partum. The experiment was a 2 x 2 factorial design (n = 10 per group) involving diet and genetic merit for milk yield. The dietary treatment started on the day of calving and lasted for 50 days. Plasma samples were collected each day and ovarian ultra-sonography was performed three times a week during the experimental feeding period. Milk yield was recorded each day, and body weight and body condition score were determined each week. Milk samples were collected three times a week from day 50 to day 105 post partum, and reproductive performance data were recorded for all the cows as part of the routine farm practice. The dietary treatment induced significant differences in plasma insulin concentrations in both high and low genetic merit cows. Although high genetic merit cows produced more milk, lost more body weight and had lower body condition scores during the experiment, no significant effect of diet was observed on these measurements. The high insulin inducing diet increased the proportion of cows ovulating within 50 days of calving and reduced the intervals from calving to first ovulation, and tended to reduce the intervals from calving to first service and to conception. These fertility parameters were also more favourable in low than in high genetic merit cows, but no interaction between diet and genetic merit was observed for any of these parameters. Genetic merit, but not diet, also affected the number of services required per conception and the conception rate. In conclusion, these results have confirmed that genetic selection for high milk yield is associated with a decrease in reproductive performance in dairy cows. More importantly, this study has demonstrated that it is possible to alleviate this problem by nutritional manipulation.


1986 ◽  
Vol 42 (3) ◽  
pp. 397-410 ◽  
Author(s):  
F. D. Brien ◽  
W. G. Hill

ABSTRACTFemale reproductive performance over four parities was studied for lines of mice selected for one three criteria: appetite (A), total lean mass (P), or proportion of fat (F). Female mice were first bred 8 weeks of age, and thereafter at intervals of about 7 weeks until fourth parity when they were dissected in late pregnancy to measure components of litter size.The high A lines had higher litter sizes at the first three parities and higher ovulation rates, numbers of implantation sites and live foetuses at the fourth parity than the low A lines. The high P lines were also higher than the low P lines for each of these traits. In contrast, litter sizes and ovulation rates differed little between the high and low F lines. Fitting body weight as a covariate removed the high-low differences in ovulation rate and litter size between the P lines, but not all the differences between the A lines.Pre-implantation survival at the fourth parity was slightly lower in the high than in low A and in high than in low P lines. Differences in post-implantation survival were very small. No component of prenatal survival differed substantially at fourth parity between the high and low F lines.Differences in fertility at each parity and the percentages of females surviving to the end of the study were small. At each litter, dams of the high A lines produced heavier total weights of litters at 12 and 21 days than dams of the low A lines and the corresponding high-low differences in the P lines were larger. There were only small differences in these traits between the F lines. When litter size, fertility and survival were summed over parities, the average total number of young produced per female was substantially higher in the high than in the low A lines (5·0 young born alive or dead) and the P lines (7·2), but the high-low difference was small in the F lines (2-0). For all lines, litter size at first parity gave a reliable indication of reproductive rate during a major portion of the reproductive lifespan.


2018 ◽  
Vol 74 (8) ◽  
pp. 540-543
Author(s):  
WIKTOR BOJAR ◽  
ANDRZEJ JUNKUSZEW ◽  
MONIKA OLECH

The aim of the study was to determine the influence of the occurrence of SRLV infections on lamb growth and reproductive performance of sheep. The study was carried out on 98 sheep flocks from mid-Eastern Poland, covering the area of Lubelskie, Świętokrzyskie and Podkarpackie provinces. The study included 6,470 mother ewes. Flocks with at least one detected case of SRLV-positive serological test were considered infected. All flocks included in the experiment were subjected to the analysis of lamb growth on the basis of their body weight achieved on the 56th day of life. Moreover, traits related to reproductive performance, such as fertility, lamb/ewe rate and lamb weaning rate, as well as the reproductive performance itself were evaluated. The observations showed that both ewes (18.98 kg) and rams (19.70 kg) achieved higher body weights in the flocks where SRLV had not been detected. In the flocks in which the presence of SRLV was detected the achieved body weight was lower by 0.93 kg and 1.26 kg, respectively. The sheep in the SRLV-infected flocks were characterized by a significantly lower fertility and higher lamb/ewe rate in comparison to other flocks. The analysis conducted for the purpose of the study showed that the presence of SRLV in a flock resulted in a worse lamb weaning rate by about 6.69 percentage points. To sum up, the flocks with detected presence of SRLV were characterized by a significantly lower fertility and greater lamb mortality rate. The presence of SLRV also had a detrimental effect on the body weight obtained on the 56th day of life, both in rams and ewes. The results of the study clearly indicate the negative influence of SRLV on the reproductive performance of sheep..


2020 ◽  
Vol 49 (1) ◽  
pp. 13-21
Author(s):  
M Solaiman ◽  
AS Apu ◽  
MY Ali ◽  
M Fakruzzaman ◽  
MO Faruque

The present study was undertaken to evaluate the availability of breeding bucks as well as growth and reproductive performances of Black Bengal goat under community based breeding program. A total of 30 goat rearers in three areas of Sakhipur upazilla were selected based on the survey result. Selected goat rearers were trained on scientific rearing, management and community-based breeding of Black Bengal goat and also build up community link with them. Three Black Bengal breeding bucks have been distributed among three potential farmers in three villages under Sakhipur upazilla. The management and performance of Black Bengal goats were monitored closely and analyze the impact of community based breeding program. The analysis of the growth performance showed that male kids attained significantly (p<0.05) higher birth weight (1.28±0.04 kg) than that of female kids (1.06±0.02 kg). The body weights of male at 3, 6, 9 and 12-month were 5.41±0.28, 9.18±0.32, 12.87±0.35 and 16.91±0.46 kg whereas female reached significantly (p<0.05) lower body weight as 4.97±0.16, 8.02±0.21, 10.91±0.23 and 14.21±0.34 kg at the same ages, respectively. Average daily body weight gain up to 12 months of age was also significantly (p<0.05) higher in males (43.42±1.17 g/day) than females (36.53±2.49 g/day). On the other hand, season had a significant effect (p<0.05) on the body weights of Black Bengal goat at 0 (birth), 3, 6, 9, 12-month of age. In case of reproductive performances, it was revealed that age at sexual maturity was 199.32±2.41 days; age at first kidding 393.23±1.38 days; service per conception 1.17±0.04, and litter size was 1.76±0.08 in community based breeding program. Beside these, post-partum heat period of Black Bengal goat was found 47.50±0.87 days. Comparing with the findings of previous research works, these results suggested that community based breeding program has not only reduced the scarcity of good quality breeding bucks but also improved the growth and reproductive performances of Black Bengal goats. Bang. J. Anim. Sci. 2020. 49 (1): 13-21


1982 ◽  
Vol 34 (1) ◽  
pp. 17-29 ◽  
Author(s):  
J. I. Elliot ◽  
G. A. Lodge ◽  
A. Fortin ◽  
Elizabeth Larmond

ABSTRACTSeventy-four Yorkshire gilts, mated at puberty, were used in three experiments to study the effect of severe food restriction, 0·45 kg/day for either the last 15 or 30 days of gestation, on reproductive performance, body-weight change, and carcass quality and meat acceptability. The objective of the experiments was to assess the feasibility of limiting weight gain during gestation to produce an acceptable carcass post-partum, within the market weight range of 55 to 90 kg. Age and weight at puberty averaged 170·3 days and 99·1 kg respectively. Litter size averaged 9·3 liveborn piglets at an average weight of 1·13 kg. The necessary reduction in weight gain during gestation to bring final carcass weight within the acceptable range was associated with a significant reduction in mean individual birth weight to below 1·0 kg. Sensory evaluation of loin and ham joints from mated and unmated gilts of market weight revealed no differences in juiciness or flavour but both loin and ham joints from maiden gilts were significantly more tender than those from gilts that had farrowed and from unmated controls of the same age as those that had farrowed


1985 ◽  
Vol 41 (1) ◽  
pp. 13-22 ◽  
Author(s):  
M. J. Ducker ◽  
S. V. Morant ◽  
W. J. Fisher ◽  
Rosemary A. Haggett

ABSTRACTOne hundred first lactation Friesian dairy heifers were used to investigate the effect of level of feeding n i late pregnancy (83·6 or 64·6 MJ metabolizable energy (ME) per head daily and around the time of first artificial insemination (AI) (weeks 6 to 18 of lactation: 146·8 or 119·8 MJ ME per head daily) on reproductive performance.Heifers receiving the high level of feeding in lactation had a successful pregnancy rate to first AI of 0·42 compared with 0·63 for heifers receiving the lower level of feeding. Heifers receiving the higher level of feeding in late pregnancy followed by the lower level in lactation had a pregnancy rate of 0·72 o t first AI resulting in a median interval from calving to pregnancy of 75 days compared with figures of 0·35 and 95 days respectively, for heifers receiving the higher levels of feeding throughout the experiment (P < 0·001).Blood samples were taken from all heifers 2 weeks before and on weeks 1, 5, 9, 13 and 18 after calving, and were analysed for 13 components. Of the blood components measured, only p"-hydroxy-butyrate concentrations, particularly at week 9, were affected by the nutritional treatments imposed and consistently related to fertility (P < 0·01 to P < 0·001).Milk yield and live-weight change, individually and as the components of net energy output, showed the strongest relationships with reproductive performance (P < 0·01 to P < 0·001). The three variables which together accounted for the highest proportion (0·30) of the variation in days to successful pregnancy were net energy output at AI, (3-hydroxy-butyrate at week 9, and mean tail score in weeks 10 o t 13. These enabled the calving to successful pregnancy interval for an individual or 100 first lactation heifers to be predicted with a 95% confidence interval of ±58 days or ±8·6 days, respectively.


1996 ◽  
Vol 8 (3) ◽  
pp. 311 ◽  
Author(s):  
SJ Potocnik ◽  
EM Wintour

In adult sheep and other animals the spleen is a reservoir of red blood cells (RBCs), which can be mobilized by adrenaline-induced splenic contraction. Adrenaline does not increase the haematocrit in the ovine fetus. This study examined the development of a releasable store of RBCs in the spleen of lambs during the neonatal period. Spleen and body weights were measured in 126 fetuses and lambs, ranging in age from 60 days' gestation to 94 days post partum. Spleen weight, as a percentage of body weight, stabilized at 0.56 +/- 0.02%, 20 days post partum. Adrenaline infusion (5 mg kg-1 min-1) was associated with a mean increase in arterial haematocrit (Hct) of 7.6 and 5.8 Hct % in lambs at 20-24 and 50-52 days of age respectively (n = 4 at each age). The spleen in lambs has become a significant reservoir of RBCs by 20-24 days of age and may contain reserves equivalent to those in adult sheep. This splenic reserve is developed before the post-natal drop in haematocrit occurs.


2008 ◽  
Vol 51 (4) ◽  
pp. 318-328 ◽  
Author(s):  
R. Pilarczyk ◽  
J. Wójcik

Abstract. The aim of the study was to compare the body weight and the parameters of reproductive performance in beef cows of various breeds following their import to Poland from 1995–1997. The analyses included cows of five beef breeds: Red Angus, Salers, Hereford, Limousin and Simmental. We have compared the body weights and calving intervals during the period from their arrival to Poland in 1995 until 2002, with subsequent calvings included in the analyses. Other aspects included calving difficulty, abortions, stillbirths and twin births. The analysis of the cows’ reproductive performance has revealed that the studied breeds differ in the calving interval. Best results were achieved by Simmental and Limousine cows, while Red Angus cows exhibited the poorest performance. The effect of subsequent calving on the calving interval was also confirmed. We have observed no differences among the mature cows with respect to the body weight and calving ease.


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