Effect of growth rate and mating age of dairy heifers on subsequent production over four years

1985 ◽  
Vol 25 (2) ◽  
pp. 263 ◽  
Author(s):  
RA Bettenay
Keyword(s):  
Growth Rate ◽  
Mediterranean Environment ◽  
Target Weight ◽  
Dairy Heifers ◽  
Mature Weight ◽  
Stocking Rates

An experiment was conducted using Friesian heifers in a Mediterranean environment to examine the effect of growth rate to mating and mating age on subsequent production. Heifers were mated at 12, 15, 18 or 24 months of age and at target mating weights of either 250 or 300 kg liveweight. Differential feeding ceased at the end of mating but, after calving, cows were grazed at one of two stocking rates. There were 64 cows in the milking phase of the experiment. Liveweight and production were measured over four lactations. There were no differences in production associated with target weight. Productions over four lactations for heifers first mated at 12, 15, 18 or 24 months were 15 500, 17 683, 16 779 and 18 855 kg fat-corrected milk, respectively. It was concluded that when differential feeding was discontinued at first mating, and feed was then not restricted up to calving, lifetime production was comparable whether heifers were mated at 48 or 58% of mature weight. Calving at less than 24 months of age could not be recommended.

The performance and intake of weaned lambs grazing S24 perennial ryegrass, with and without supplementation

1974 ◽  
Vol 18 (2) ◽  
pp. 191-199 ◽  
Author(s):  
J. E. Newton ◽  
N. E. Young
Keyword(s):  
Growth Rate ◽  
Perennial Ryegrass ◽  
Stocking Rate ◽  
Target Level ◽  
Target Weight ◽  
Herbage Intake ◽  
Level Increase ◽  
Stocking Rates ◽  
Lamb Growth ◽  
Better Than

SUMMARYTwo forms of supplement, barley or dried grass pellets (G) were given to weaned lambs, set-stocked at pasture, at three stocking rates (43·5, 60 and 87 per hectare). The supplements were given either from weaning or from the time growth rate fell below a target value. The supplements significantly increased the proportion of lambs reaching the target weight (35 kg) and G was significantly better than barley, but slightly more G was given. The substitution value of supplement for herbage was 0·48 ± 0·12 and there was no difference in this value between barley and G. The proportion of lambs reaching the target slaughter weight was not influenced by whether the supplement was offered at weaning or delayed until lamb growth declined below a target level. Increase in stocking rate depressed the herbage intake and growth rate of the unsupplemented control lambs.

scholarly journals Effect of Phosphorus Supplementation on Growth Rate, Blood Minerals, and Conception Rate of Dairy Heifers

1977 ◽  
Vol 60 (12) ◽  
pp. 1932-1940 ◽  
Author(s):  
C.H. Noller ◽  
A.G. Castro ◽  
W.E. Wheeler ◽  
D.L. Hill ◽  
N.J. Moeller
Keyword(s):  
Growth Rate ◽  
Conception Rate ◽  
Dairy Heifers

First calving performance of beef cattle. 1. Effects of moderate and slow growth between weaning and joining at 15 months of age

1985 ◽  
Vol 25 (2) ◽  
pp. 270
Author(s):  
DJ Barker ◽  
PJ May ◽  
CA Morris ◽  
PER Ridley
Keyword(s):  
Slow Growth ◽  
High Fertility ◽  
Mediterranean Environment ◽  
Weaning Weight ◽  
Calf Growth ◽  
Target Weight ◽  
The Mean ◽  
Calving Rate ◽  
Improved Pasture ◽  
Calving Performance

In each of 4 years, Shorthorn and Dairy x Shorthorn heifers were fed for moderate (55 to 101 kg) or slow (1 7 to 50 kg) growth from weaning at 7 months until joining at 15 months of age. Thereafter they grazed together on improved pasture in a 430 mm rainfall Mediterranean environment. Their performance was compared until their second calving and their calves' performance until weaning. The heifers that had grown moderately prior to their first joining had 25 to 73 kg higher average liveweight and 3 to 7 mm higher ultrasonic backfat reading during first joining, a 9% higher calving rate, 14 kg higher average liveweight but a 10% lower dystokia rate at calving, and 12 kg higher average liveweight and 1 mm higher ultrasonic backfat reading at their second joining, than those that had grown slowly. Survival of dams and calves, date of first calving, calf birth weight, second calving rate, intercalving interval and date of second calving were not significantly affected by the rate of growth prior to first joining. The effect upon dams' weight at weaning (moderate 11 kg higher than slow) was significant only at P< 0.1. Most aspects of performance differed widely amongst years, but significant year x growth interactions were only found for liveweight and condition of heifers at first joining, and for weaning weight of calf. The calves of moderately-grown heifers were of significantly lower mean weaning weight than those of the slowly-grown heifers, but only in those years when the mean mid-joining weight of the moderately grown heifers exceeded 315 kg. It is suggested that high fertility and satisfactory first calf growth are not incompatible provided that growth between the heifers' weaning and first joining is limited to that which results in a mean mid-joining liveweight not more than 20 kg higher than the target weight for 90% calving.

Rearing Dairy Heifers on Pastures Fertilized at Moderate Levels With or Without Supplemental Concentrates at Different Stages.

1969 ◽  
pp. 143-154
Author(s):  
Paul F. Randel ◽  
Jaime Vélez-Santiago
Keyword(s):  
Crude Protein ◽  
Phase 1 ◽  
Protein Concentrate ◽  
Phase 2 ◽  
Phase 3 ◽  
Concentrate Supplementation ◽  
Dairy Heifers ◽  
To Receive ◽  
Stocking Rates ◽  
Total Gain

The experiment involved 3 successive phases in rearing Holstein heifers at Corozal on pastures of mixed grasses, fertilized annually with 168, 56 and 112 kg/ha of N, P2O5 and K20, respectively, in 3 applications. Mean initial age was 9 months and liveweight (LW) 167 kg. In phase 1 (91 days), 39 control animals stocked at 5/ha and not supplemented gained 0.41 kg daily, inferior (P < 0.01) to the gain of a like number supplemented with 2 kg daily of 14% crude protein concentrate (0.64 kg), 8.6 kg of concentrate per kg of extra gain over the control. In phase 2 (182 days), 32 animals stocked at 4/ha gained less (P = 0.01) per head than 24 stocked at 3/ha (0.53 vs. 0.59 kg daily), but total gain per ha was 16.4% greater for the former. During 259 days of phase 3, while 3 groups of 19 each remained intact, grazing at 3.75 animals/ha without supplementation (treatment 1) resulted in lower (P = 0.01) gain than treatments 2 and 3, involving concentrate supplementation at 2.5 or 4 kg daily beginning 200 or 125 days before expected parturition (0.57 vs. 0.64 and 0.62 kg, respectively), but supplementation increased gains over the control very inefficiently. Mean LW increased from 318 kg in all 3 groups to 485, 513 and 497 kg in treatments 1, 2 and 3, respectively. Only heifers of the latter 2 groups continued to receive concentrates after returning to their home farms in Cayey and Manatí until first calving. All animals received usual herd management postpartum. Mean 305-day first lactation milk production was 4292 kg in 18 control animals of phase 3, surpassing (not significantly, P = 0.05) productions of 3,771 and 3,869 kg by 16 and 17 former treatment 2 and treatment 3 animals, respectively. Stocking rates employed at each stage seemed suited to available pastures, and concentrate supplementation was unnecessary for rearing dairy heifers under these conditions.

Fertilization and Predator Control to Improve Trout Angling in Natural Lakes

1955 ◽  
Vol 12 (2) ◽  
pp. 210-237 ◽  
Author(s):  
M. W. Smith
Keyword(s):  
Growth Rate ◽  
New Brunswick ◽  
Brook Trout ◽  
Predator Control ◽  
Stocking Rate ◽  
Natural Lakes ◽  
Natural Reproduction ◽  
Stocking Rates

A significantly faster growth rate by native and planted eastern brook trout followed the addition of commercial fertilizers in sufficient quantities to provide potential additional concentrations of 0.39 mg. P, 0.21 mg. N and 0.27 mg. K per litre in Crecy Lake (20.4 ha.; mean depth, 2.4), New Brunswick. Largely because trout planted as fingerlings attained suitable angling size when yearlings, the rate of capture and the yield by weight to anglers approximately doubled. The improved growth rate, but not yields, persisted into the second and third years after fertilization. Coincident was an increase in predation by fish-eating birds and mammals. With predator control and the same stocking rates, the yield of trout flesh produced in the lake increased from 0.9 to 5.9 kgm. per hectare over the next two-year period. With predator control extended to trapping eels in the lake, a second comparable fertilization with respect to concentrations of P, N and K, and a doubling of the stocking rate, a yield of 9.7 kgm. per hectare was realized. The growth rate was somewhat depressed with the heavier stocking, notwithstanding a second fertilization. Facilities for natural reproduction were poor and planted trout (fingerlings and yearlings) sustained the fishery. Maximum survivals of planted trout (all marked) to anglers' catches were 20 per cent for fingerlings and 88 per cent for yearlings. Cropping of trout of age II was thorough. For the most part, movements of planted trout (trapped in outlet) from the lake would have occasioned minor losses.Neighbouring Gibson Lake (24.0 ha.; mean depth, 4.0 m.) was fertilized with one-half of the concentrations of P, N and K applied to Crecy. Stocking with trout was at comparable rates but no predator control was exercised. Little improvement was noted in the growth of the trout. Only when yearlings were planted late in the fall and angled early in the spring was there any improvement in the anglers' catches.

scholarly journals The birth weight of rabbits born after heterospermic insemination

1960 ◽  
Vol 1 (1) ◽  
pp. 39-49 ◽  
Author(s):  
R. A. Beatty
Keyword(s):  
Growth Rate ◽  
Birth Weight ◽  
Previous Experiment ◽  
Gestation Period ◽  
Enhancement Effect ◽  
Average Birth Weight ◽  
Prenatal Growth ◽  
Mature Weight ◽  
The Difference ◽  
Object Of Study

1. Two rabbit sires were used for insemination of sixty-eight females. Insemination was either homospermic (one sire at a time) or heterospermic (mixed semen from the two sires). Each offspring could be traced to its sire by genetic marks. The sires differed in weight and were known to give offspring differing in mature weight and named Large and Small offspring. The object of study was the birth weight of these offspring in logarithmic transformation.2. After heterospermic insemination, there was no evidence of any real ‘heterospermic vigour’ in the average birth weight of the litter as a whole.3. After heterospermic insemination, the difference in birth weight between the two kinds of offspring was accentuated (enhancement effect). This confirms a previous experiment.4. The enhancement effect is ascribed to competition among embryos. It is not attributable to postulated changes in the gestation period. It appears to arise from an increase in the birth weight of Large offspring, together with a possible decrease in the birth weight of Small offspring. These changes in birth weight are attributable to changes in prenatal growth rate.5. The bearing of this work on Russian experiments with heterospermie insemination is discussed.

Relationships between pre-weaning growth, post-weaning growth and mature body size in Chios sheep

1990 ◽  
Vol 50 (2) ◽  
pp. 271-275 ◽  
Author(s):  
A. P. Mavrogenis ◽  
A. Constantinou
Keyword(s):  
Growth Rate ◽  
Body Size ◽  
Birth Weight ◽  
Growth Traits ◽  
Genetic Correlations ◽  
Live Weight ◽  
Pedigree Information ◽  
Mature Weight ◽  
Chios Sheep ◽  
Birth Type

ABSTRACTThe study examined early measures of growth and their relationships with mature body size. Data on 792 purebred females of the Chios breed, born and reared on two experimental farms between 1978 and 1986, were analysed. Pedigree information and records on live weight at birth, at weaning, 105 days of age and at first and subsequent matings was recorded. There were flock-year differences for all traits studied (P < 0·01) and birth type was important for all traits except post-weaning growth rate. Dam lactation number had no significant effect on birth weight and pre-weaning growth rate, but it significantly affected all subsequent weights and post-weaning growth rate. Estimated heritabilities increased with age and ranged from 0·13 (s.e. 0·14) (birth weight) to 0·30 (s.e. 0·15) (mature weight). Genetic correlations were generally positive between weights and growth traits. Phenotypic correlations were positive and followed the pattern of the genetic correlations. The results suggest that selection for 105-day weight will result in increased mature weight.

A comparison of the sown swards of perennial ryegrass S. 24 and Italian ryegrass RvP in a two-year lamb production system, with different breeds of sheep

1976 ◽  
Vol 87 (3) ◽  
pp. 605-616 ◽  
Author(s):  
J. E. Newton ◽  
N. E. Young ◽  
R. J. Orr
Keyword(s):  
Growth Rate ◽  
Body Weight ◽  
Perennial Ryegrass ◽  
Italian Ryegrass ◽  
First Year ◽  
Stocking Rate ◽  
Second Year ◽  
Stocking Rates ◽  
Lamb Growth ◽  
Intensive System

SummaryA comparison was made between an intensive system of lamb production based on Italian ryegrass RvP and one based on perennial ryegrass S. 24, over 2 years, each at three stocking rates (14, 17, 20 ewes/ha). More grass was grown in the first year than in the second when the yield of RvP was particularly reduced. The ewes and lambs ate more RvP than S. 24 but there was no difference in lamb growth rate. The lambs grew faster at the low stocking rate from 0 to 18 weeks and from 0 to slaughter than at the medium and high stocking rates, in both years. Ewe intake and lamb growth rate were higher in the second year than the first. The Masham ewes with two lambs ate significantly more grass per unit of body weight than the Finnish Landrace × Scottish Halfbred and Finnish Landrace × Scottish Blackface ewes, and their lambs grew significantly faster. It was concluded that for an intensive system of lamb production from grass, S. 24 was more suitable than RvP.

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