Stocking rate, joining time, fodder conservation and productivity of Merino ewes. 2. Birth weight, survival and growth of lambs

1977 ◽  
Vol 17 (89) ◽  
pp. 909
Author(s):  
JK Egan ◽  
RL Thompson ◽  
JS McIntyre

In an experiment at Hamilton in western Victoria, groups of 30 Merino ewes were stocked at 11.7, 15.4 or 19.2 ewes ha-1 and joined to Merino rams each year on April 5 or May 8 for five weeks. Hay was conserved on half the number of plots and fed back to the ewes before and during joining. Observations on birth weight, survival, and growth of lambs born between 1970-73 are presented. Both the highest stocking rate and the earlier lambing were associated with a depression of about 7 per cent in the birth weight of twin lambs, but single lambs had similar birth weights on all treatments. Lamb survival was highly variable and there were few significant treatment effects. However, mortalities within 48 hours of birth were lower amongst flocks joined to lamb in October than those lambing in September (single lambs 9.2 per cent vs. 14.7 per cent-twin lambs 19.9 per cent vs. 40.2 per cent). Most of the improvement was attributed to drier conditions and lower windspeeds in October. Lamb growth rates fell with increasing stocking rate but the variation in weaning weight was less than 2 kg. Lambs born in September were about 10 per cent heavier at weaning than those born in October. Compensatory growth after weaning resulted in negligible differences in weight at 12 months between lambs from the different stocking rate treatments, but lambs born in September were still significantly heavier than those born in October.

1974 ◽  
Vol 14 (69) ◽  
pp. 434 ◽  
Author(s):  
PA Kenney ◽  
IF Davis

A study of the survival and growth of lambs was made over a three year period (1968 to 1970) on a flock of 540 ewes grazing annual pasture at Werribee, Victoria. Ewes were stocked at three rates (5, 7 1/2 and 10 ha-1) and lambed between July 6 and August 20 or between September 10 and October 29 each year. Observations were made on the same ewes each year. Rate of stocking had no effect on the birth weight of lambs but single-birth lambs born in September were lighter than those born in July. More twins were born in September than in July and a smaller proportion of lambs born survived from the September than from the July lambing. Of the lambs born to ewes stocked at 10 ha-1 in 1968 and 1969 a smaller proportion survived than of the lambs born to ewes stocked at 5 ha-1. The growth rate of lambs born in July was constant between birth and weaning at 12 weeks of age but declined as rates of stocking increased. When the lambs born in September were about eight weeks old the pastures matured and growth rates of lambs declined and at weaning liveweights of lambs from plots stocked at different rates were similar. Lambs born in July on plots stocked at 5 and 79 ewes ha-1 were as much as eight kilograms heavier at weaning than the lambs born in September at equivalent rates of stocking. Neither rate nor time of onset of milk production was significantly affected by stocking rate.


1995 ◽  
Vol 35 (8) ◽  
pp. 1069 ◽  
Author(s):  
DG Hall ◽  
NM Fogarty ◽  
AR Gilmour

Merino rams of the Trangie Fertility and Booroola strains were joined to Poll Dorset ewes in single sire mating groups over 3 years. Forty sires produced a total of 1250 lambs in 885 litters from 451 ewes. Lamb birth weight averaged 4.1 kg, 80.8% of lambs survived to 3 days of age and growth rates to weaning (mean 93 days) averaged 289 g/day. Lambs with Trangie Fertility sires grew 15 g/day faster and were 1.3 kg heavier at weaning than those lambs with Booroola sires (P<0.001). There were no effects of sire strain on birth weight or lamb survival. Birth weight increased with dam liveweight in mid-pregnancy (P<0.001), and weaning weight and growth rate increased with dam liveweight at joining (P<0.001). Survival of lambs was predominantly a function of birth weight. Lambs weighing 4 kg at birth from primiparous dams had survival rates of 76% compared with 88% for lambs from multiparous dams (P<0.01). No lamb under 2.0 or over 6.3 kg survived, and 48% of deaths occurred within 1 day of birth. Dystocia, particularly of heavy, single-born lambs, caused 53% of observed lamb deaths. For the traits birth weight, lamb survival, weaning weight and growth rate, the direct heritabilities were 0.24 � 0.10, 0.05 � 0.05, 0.19 � 0.10 and 0.12 � 0.08 respectively; the corresponding maternal heritabilities were 0.08 � 0.05, 0.05 � 0.04, 0.05 � 0.05 and 0.07 � 0.05 respectively; and the common environmental effects among litter mates (c2) were 0.57 � 0.08, 0.47 � 0.08, 0.15 � 0.08 and 0.13 � 0.08 respectively.


2020 ◽  
Vol 42 (5) ◽  
pp. 347 ◽  
Author(s):  
Warwick B. Badgery ◽  
David Kemp ◽  
Zhang Yingjun ◽  
Wang Zhongwu ◽  
Han Guodong ◽  
...  

Overgrazing has extensively degraded Chinese grasslands. A reduction in stocking rate of 30–50% below the district averages is required to increase the profitability of livestock production and protect vital ecosystem services such as mitigation of greenhouse gases (GHG). Grazing experiments located in the desert steppe, typical steppe and alpine meadow verified the influence of stocking rate and grazing management on livestock production, grassland composition and associated ecosystem services. The desert steppe experiment found lower stocking rates of ~150 SE (where SE is sheep equivalent, which is a 50kg animal) grazing days ha–1 (1 SE ha–1 over 150 days) enhanced botanical composition, maintained profitable lamb growth rates and reduced GHG emissions intensity. The typical steppe experiment found moderate grazing pressure of ~400 SE grazing days ha–1 (4 SE ha–1 over 100 days) maintained higher lamb growth rates, an average herbage mass &gt;0.5t DM ha–1 that maintained the content of Leymus chinensis above 70% and Artemisia frigida below 10% of the grassland and had the highest level of net carbon sequestration. In the alpine meadow experiment the district average stocking rate of ~16 SE ha–1 (1440 SE grazing days ha–1 over 90 days) was not too high, but extending grazing into the non-growing season had no benefit. The findings of these experiments highlight that many of the benefits to ecosystem services can be achieved with reduced stocking rates which also generate profitable levels of livestock production. In both the desert and typical steppe experiments, the results were optimal when the stocking rates were adjusted to maintain average herbage mass over summer above ~0.5t DM ha–1, whereas herbage mass was higher with the local, conservative stocking rates in the alpine meadow.


2008 ◽  
Vol 48 (7) ◽  
pp. 966 ◽  
Author(s):  
S. Hatcher ◽  
J. Eppleston ◽  
R. P. Graham ◽  
J. McDonald ◽  
S. Schlunke ◽  
...  

Two monitoring projects were conducted to investigate weaner mortality in commercial Merino flocks in the Yass and the Central Tablelands Rural Lands Protection Boards located in the Southern Tablelands agricultural region of New South Wales. The projects were conducted in Yass in 2005 and in the Central Tablelands in 2006. A random sample of weaners from four flocks in the Yass board and 11 flocks in the Central Tablelands board were regularly weighed, growth rates were calculated after weaning and survival was determined by the continuing presence of an individual weaner at subsequent weighing activities. Weaning weight was the most important factor in determining postweaning liveweight, growth rates and survival with the significant impact of weaning weight on liveweight persisting for up to 6 months after weaning. Despite the lightest weaners being capable of considerable compensatory growth given sufficient postweaning nutrition, the lightest 25% of weaners were more than twice as likely to die as heavier weaners. A focus on ewe nutrition and parasite control during late pregnancy and lactation will allow Merino producers to achieve higher weaning weights that will set their weaners up for strong postweaning growth with a decreased likelihood of mortality.


1992 ◽  
Vol 70 (8) ◽  
pp. 2296-2303 ◽  
Author(s):  
S. J. Gaertner ◽  
F. M. Rouquette ◽  
C. R. Long ◽  
J. W. Turner

Author(s):  
J A Milne ◽  
Angela M Sibbald

A desirable liveweight for red deer at 15 months of age is approximately 80 kg. This will provide a saleable carcase and a liveweight at which yearling hinds will successfully breed. Live-weight at 15 months will be influenced by a large number of factors including date of birth, birth-weight, liveweight gain to weaning, date of weaning, liveweight gain during the first winter and subsequent summer, and the interactions between weaning weight and subsequent levels of nutrition and between winter levels of nutrition and liveweight gain at pasture in the following summer. These latter two aspects were examined in two experiments and the effect of date of weaning on contemporary calf growth rates and on hind calving date in the following year were studied in a third experiment. The objective was to provide information which would allow the development of effective systems of deer meat production based on slaughter at 15 months of age.


1977 ◽  
Vol 57 (4) ◽  
pp. 697-703 ◽  
Author(s):  
E. E. SWIERSTRA ◽  
G. W. RAHNEFELD ◽  
R. L. CLIPLEF ◽  
J. H. STRAIN

Age and weight at first observed estrus (puberty) were studied in 471 crossbred heifers produced by inseminating Angus, Hereford, and Shorthorn cows with semen from Charolais, Limousin, and Simmental bulls. Heifers were kept in drylots after weaning and gained an average of 0.68 kg/day. Visual observations and vasectomized bulls fitted with marking harnesses were used for estrous detection. At puberty, the median and mean ages were 336 and 342 days, and the median and mean weights 296 and 305 kg. At puberty, Charolais- and Simmental-sired heifers were about 22 days younger (median age; P < 0.01) than Limousin-sired heifers (324 and 326 vs. 347 days, respectively). Charolais-sired heifers were significantly heavier (median weight) than Limousin- and Simmental-sired heifers (306 vs. 294 and 292 kg, respectively). Heifers from Angus and Hereford dams were about 22 days older (P < 0.01) at puberty than heifers from Shorthorn dams (median 347 and 346 vs. 324 days). Heifers with high preweaning growth rates attained puberty at an earlier age (r = −0.24; P < 0.01). Day of birth within the year had a significant effect on age and weight at puberty; i.e., heifers born early in the calving season were older and heavier at puberty. Weight at puberty was associated with weaning weight (r = 0.61; P < 0.01), birth weight (r = 0.41; P < 0.01), and preweaning average daily gain (r = 0.54; P < 0.01). Calves that were heavy at birth tended to be heavy at weaning, and heavy weaning weights, in turn, were associated with heavy weights at puberty. By 15 mo of age, 99% of all heifers were cycling.


2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 251-252
Author(s):  
Allison Mosichuk ◽  
Katherine Petersson ◽  
Maria L Hoffman

Abstract Research evaluating the effects of ewe gastrointestinal nematode infection (GNI) during the periparturient period (PPR) on offspring growth is limited. We hypothesized ewes with a greater parasite burden during the PPR will negatively impact birth and weaning weight. Packed cell volume (PCV) was measured in ewes (2018, n = 11) at 3 weeks pre-partum (-3), birth, 3 (+3) and 6 (+6) wks postpartum. Lamb birth weight, weaning weight (WW), and ADG (birth - 8 weeks) were collected. Ewes in the upper 50% (n = 5–6) and lower 50% (n = 5–6) for PCV were classified as either HIGH and LOW at each time period. Data were analyzed in SAS using proc mixed (significance P ≤ 0.05). PCVs for LOW and HIGH ewes were (mean ± SEM) 27% ± 0.2% vs 30% ± 0.8% at -3, 28% ± 0.3% vs 32% ± 0.4% at birth, 24% ± 0.4% vs 29% ± 0.6% at +3, and 25% ± 0.2% vs 30% ± 1.0% at +6 respectively. Post-partum, lambs reared by LOW ewes exhibited reduced ADG (0.69 ± 0.03 kg/d vs 0.81 ± 0.03 kg/d; P = 0.02) and WW (29.34 kg ± 1.41 kg vs 33.64 kg ± 1.47 kg; P = 0.04) compared to lambs reared by HIGH ewes. Lambs reared by LOW ewes at +3 exhibited reduced ADG versus lambs reared by HIGH ewes (0.69 ± 0.034 kg/d vs. 0.81 ± 0.034 kg/d; P = 0.02). No effect of maternal PCV on birth weight or WW, at -3, birth, or +6 was observed on offspring birth weight, WW, or ADG (P ≥ 0.13). In conclusion, the effects of PPR GNI appear to be postnatal.


Author(s):  
T.J. Fraser ◽  
D.J. Saville

The effect of weaning weight on the subsequent growth rate of lambs was estimated from data collected at Winchmore Research Station. The lamb weight data were collected over a 3-year period involving dryland and irrigated farmlets with two contrasting forage systems. Lambs were weighed at 2-weekly intervals with the weights for the periods immediately pre- and post-weaning being used for the comparisons in this study. Results overall indicated that, following adjustments for pasture type, gender, birth and rearing rank, heavier lambs at weaning had faster growth rates post-weaning than lighter lambs. However, lighter lambs suffered a lower drop in growth rate (defined as growth rate before weaning minus growth rate post-weaning) than heavier lambs. This was universal across both pasture types, both genders and all combinations of birth and rearing ranks. Possible explanations are that the lighter lambs at weaning were receiving less milk from their mothers or that they were under some mob pressure and had limited access to quality pastures. In some cases, the lighter lambs even increased their growth rates post-weaning when compared to pre-weaning. It is suggested that weaning light lambs is an option for farmers, particularly when feed supply is limiting or when dry stock are required to clean up poor quality pastures and set up high quality feed for young stock. Keywords: dryland, irrigated, lamb growth, lamb weaning, pasture quality, weaning weights


1958 ◽  
Vol 38 (1) ◽  
pp. 91-96
Author(s):  
S. Smoliak ◽  
S. B. Slen

A 3-year study compared the effects on lamb and wool production of methods of feeding different supplements to ewes during the last 6 to 9 weeks of pregnancy. The four treatments were: 0.56 lb. barley and 3.5 lb. hay per head daily; 0.5 lb. linseed oilcake and 3.5 lb. hay per head daily; 3.5 lb. linseed oilcake and 24.5 lb. hay per head once weekly; 3.5 lb. hay per head daily.No significant treatment differences in birth weight of single lambs were found. However, the ewes fed linseed oilcake gave birth to heavier twin lambs than the ewes receiving no supplement (P < 0.01). There were no significant treatment differences in weaning weight of single or twin lambs, although the average weaning weights of the lambs in the supplemented groups were slightly higher than those in the control group. Of the ewes giving birth to twin lambs, those receiving linseed oilcake daily weaned more pounds of lamb than the control ewes (P < 0.05).The ewes supplemented with linseed oilcake produced more grease wool and lost less body weight than the control group (P < 0.01). There were no significant treatment differences in clean fleece weight.Weekly feeding offers some possibilities, either as a method of saving labour or as a means of supplying supplement to ewes when deep snow or cold weather prevents grazing.


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