Effect of anthelmintic dosing and stocking rate on the productivity of weaner sheep in a Mediterranean climate environment

1985 ◽  
Vol 36 (6) ◽  
pp. 845 ◽  
Author(s):  
TH Brown ◽  
GE Ford ◽  
DW Miller ◽  
I Beveridge

The effects of nematodiasis on productivity in weaner sheep was measured at Kybybolite Research Centre, South Australia, during 1976-81. Three levels of control were compared at two stocking rates (7.5 ha-1 and 16 ha-1). One group was not treated with anthelmintics, another group was treated every 3 weeks and the third group (Planned) was given five doses of anthelmintics each year: once in October, twice during the hot dry summer and twice during the winter months. The sheep were replaced by weaner sheep at shearing in October each year. The drenching regime of sheep on a particular paddock was the same for all five years. Nematodes, particularly Trichostrongylus spp., had a very large effect on the production of the sheep. The mean annual death rate of the untreated sheep was 22% and 56070, for the low and high stocking rates respectively. The regularly drenched sheep were 9-31% heavier and cut 11-46% more wool than the survivors of the untreated sheep at the low stocking rate. At the high stocking rate the regularly drenched sheep were 17-58% heavier and cut 14-56% more wool than the survivors of the undrenched sheep. The sheep given the Planned drenching program had similar final liveweights each year to the regularly drenched sheep, and in only two years out of five did the regularly drenched sheep produce significantly more wool than the sheep given the Planned program. The effect of drenching on the contamination of wool with faeces, and the resultant effect on the incidence of fly strike, is discussed. There was a significant variation between years in amount of available pasture, and there was generally slightly more pasture available on the Nil drench treatment paddocks.


1976 ◽  
Vol 16 (79) ◽  
pp. 181 ◽  
Author(s):  
TH Brown

The effect of deferred autumn grazing and stocking rate on an annual pasture was monitored for five years at Kybybolite Research Centre in the south-east of South Australia. Pasture availability, yearly production and botanical composition were measured under a series of eight stocking rates from 12.4 to 29.7 Merino wethers per hectare. Autumn deferment resulted in extra available pasture during the winter months of June, July and August. However, the continously grazed pastures reached the same level of availability as the deferred pastures in spring. By the third year of the experiment yearly pasture production irrespective of grazing management was greatly reduced at the higher stocking rates. This reduction was associated with an invasion of Poa annua and Juncus bufonius. Autumn deferment tended to favour the growth of Wimmera ryegrass at the lower stocking rates whereas continuous grazing tended to favour clover growth at these stocking rates.



1977 ◽  
Vol 28 (5) ◽  
pp. 947 ◽  
Author(s):  
TH Brown

The performance of Merino ewes and their lambs was measured when the sheep were either continuously grazed or autumn-deferred on annual pastures. The two management systems were compared at a series of 13 stocking rates from 4.9 to 19.8 ewes ha-1 for 5 years from 1970 to 1974 at the Kybybolite Research Centre, South Australia. The deferred sheep were fed in yards on a mixture of oat grain and hay at 6.8 kg per head per week during the 6-week deferment period. It was found that the continuously grazed ewes required very little hand-feeding up to a stocking rate of 17.3 ewes ha-1. Grazing management had little or no effect on wool production in ewes or lambs, on the number of lambs born and weaned, or on lamb growth rates. Although the incidence of pregnancy toxaemia was very low (1%) it was higher in the deferred treatments. Autumn deferment resulted in extra pasture during the winter months of June and July. However, the continuously grazed pastures reached the same level of availability as the deferred pastures in late winter and early spring. Total yearly pasture production tended to be greater on the continuously grazed pastures and increased as the stocking rate increased. It is concluded that there is little merit in adopting an autumn deferment system of grazing management for Merino ewes and lambs. A relationship between lamb growth rate and both available pasture and pasture height is presented. It would appear that pasture height measurements are no better predictors of Iamb growth rates than pasture yield measurements.



1976 ◽  
Vol 16 (79) ◽  
pp. 189 ◽  
Author(s):  
TH Brown

Liveweight, seasonal wool growth rates, annual wool production, wool quality and hand feeding requirements were recorded for Merino wethers when autumn deferred or continuously grazed. The two management systems were compared at a series of eight stocking rates from 12.4 to 29.7 sheep per hectare for five years from 1967 to 1971 at the Kybybolite Research Centre, South Australia. Autumn deferment resulted in increased liveweight and wool growth rate during the months of June to September. However, liveweights and wool production under either management were similar for the remainder of the year. Because deferred grazing did not increase liveweights during the critical autumn period, and since hand feeding requirements were similar under either management system at the higher stocking rates, it is suggested that yearly stocking rates can not be increased by autumn deferment. Apart from the drought year of 1967, the continuously grazed sheep required little or no hand feeding up to 22.2 wethers per hectare. It is unlikely that the cost of hand feeding deferred sheep up to this stocking rate would be covered by the small increase in wool production. However, this would depend on the cost of conserved fodder and price received for the wool.



1979 ◽  
Vol 19 (97) ◽  
pp. 140 ◽  
Author(s):  
EJ Bowen ◽  
KG Rickert

At Gayndah, south-eastern Queensland, a native Heteropogon contortus pasture, sown to fine-stem stylo (Stylosanthes guianensis var. intermedia), and invaded by red natal grass (Rhynchelytrum repens), was grazed by weaner steers from June 1 in three treatments : heavy and light put-and-take grazing for five years from 1971, and set-stocked at 1.37 animals ha-1 for two years from 1974. Weight gains in the put-and-take treatments were not significantly different. The mean annual liveweight gain was 167 kg animal-1 at a mean equivalent stocking rate of 1.47 animals ha-1. Over the same period unsown native pasture, cleared of timber, gave a gain of 62 kg animal-1 at 0.62 animals ha-1. In all seasons except summer, weight gains declined linearly with stocking rate and in 1972-73, with a mean equivalent stocking rate of 2.66 animals ha-1, the annual gain was almost halved. When equivalent stocking rates were 0.9, 0.9, 1.8 and 1.2 animals ha-1 in winter, spring, summer and autumn, the respective gains were 4, 73, 65 and 45 kg animal-1. The set-stocked treatment had a mean annual gain of 147 kg animal-1. At another site 116 km north-west of Gayndah, two paddocks of Heteropogon contortus and fine-stem stylo were set-stocked with weaners over four years. One paddock had four applications of superphosphate of 250 kg ha-1. The mean annual liveweight gains were significantly different, being 154 and 143 kg animal-1 in the fertilized and unfertilized paddocks at mean stocking rates of 0.83 and 0.74 animals ha-1, respectively. In a grazing protection experiment the density of fine-stem stylo declined exponentially with an accumulation of pasture dry matter in spring and summer. Heavy continuous grazing, an annual hay cut and an accidental fire all increased the density of fine-stem stylo. Management options to maintain the density of fine-stem stylo and the relative importance of the legume and grass to animal production are discussed.



1975 ◽  
Vol 15 (73) ◽  
pp. 159 ◽  
Author(s):  
PA Kenney ◽  
IF Davis

A study was made during a three year period (1 968-1 970) of wool production by a flock of 540 ewes grazing annual pasture at Werribee, Victoria. The ewes were stocked at three rates (5, 7 1/2 and 10 ewes ha-1) and lambed between July 6 and August 20 or between September 10 and October 29 each year. Fibre diameter and length of wool samples were measured in 1968, 1969 and 1970 ; in 1970 growth of greasy wool was calculated from staples of dye-banded wool. Wool growth was reduced in all ewes during late pregnancy and early lactation but was not affected during late lactation in ewes lambing in September. The proportion of tender fleeces from all ewes was greater in 1970 and the weight of fleeces from only those ewes bearing single lambs was less in all years for ewes lambing in July than for ewes lambing in September. More ewes were barren and fewer ewes had twins in July and consequently the mean fleece weights of all ewes from both groups were similar. Fleeces from ewes stocked at 10 ha-1 were lighter, shorter and finer than fleeces from ewes stocked at 5 and 7 1/2 ha-1, but the proportion of tender fleeces did not differ between the groups. Wool production of ewes stocked at 5 and 7 1/2 ha-1 increased from 1968 to 1970, whereas that of ewes at 10 ha-1 did not. This was associated with differences in pasture availability and composition. At 10 ewes ha-1 less pasture was present in winter and spring in 1970 than in 1968, whereas at the other stocking rates it was greater. In 1970 the density of weeds in autumn was greater and in spring more silver grass (Vulpia spp.) and less brome grass (Bromus spp.) was available at the high stocking rate.



1978 ◽  
Vol 18 (91) ◽  
pp. 202 ◽  
Author(s):  
DJ Cannon ◽  
MJ Sharkey ◽  
PT Stewart

Oat yields and wool production of Merino wethers were measured at five stocking rates in five systems of land use in each of two years, 1971 and 1972, in north-east Victoria. Nominal stocking rates were 6.8, 8.6, 10.5, 12.4 and 14.2 sheep ha-1. The production at each stocking rate was compared in the following systems: 1, all pasture; 2, and 3. pasture grazed year long with oats grazed in winter and oat stubbles in summer on 15 per cent (system 2) or 30 per cent of the plot area (system 3) ; 4. and 5. pasture grazed throughout with oat stubbles grazed in summer but crops not grazed during the growing season and crops comprised either 15 per cent (system 4) or 30 per cent of the plot area (system 5). In 1971 the rainfall of 540 mm was sufficient to produce a harvestable oat crop and to maintain sheep on all plots without supplements. The mean oat yield of 2.04 � 0.01 t ha-1 for system 3 far exceeded that of the more heavily grazed crops in system 2 (1.44-0.05) or of ungrazed crops in systems 4 and 5 (1.44i-0.07). Clean wool production per head from each system was compared in terms of an 'average' stocking rate S which accounted for variation in grazing intensity throughout the year inherent in systems 2, 3, 4, 5. In 1971 clean wool production kg-1 declined with increase in average stocking rate in all systems but the mean of the four dual land use systems did not differ from the all pasture system (1). 1972 was a drought year with only 330 mm of rain, oat crops failed to produce grain and were grazed from October. The wool production of sheep on systems 2 to 5 was greater than that of sheep at equivalent average stocking rates on the all pasture system. Growing oats for grazing and grain in association with wool production would appear to be more profitable than wool production alone. Light grazing of oats in winter may increase oat yield but more information is needed in relation to seasonal variation and oat variety.



1984 ◽  
Vol 24 (124) ◽  
pp. 20 ◽  
Author(s):  
WJ Scattini

The effects of stocking rate and hay conservation on liveweight gains of weanling Hereford cattle grazing a green panic (Panicum maximum var. trichoglume cv. Petrie) pasture in winter and spring only were measured over seven years. A 2 x2 factorial experiment included stocking rates of 1 .5 and 2 . 5 animals/ha, with and without hay conservation. Protein supplementation using a mixture of cottonseed meal and urea was an additional treatment in two winters. Stocking rate had little effect on pasture yields at the start of grazing or on hay yields. The mean liveweight gains per animal at stocking rates of 1 . 5 and 2.5 animals/ha were 69 and 50 kg, respectively, on non-conserved pasture, and 86 and 54 kg on conserved pasture. Liveweight gain response to conservation was greater at the lighter stocking rate and appeared due to greater accessibility of higher quality pasture in situ rather than to feeding of hay per se. At the light stocking rate, little or no hay was required. Feeding protein produced 6 kg more liveweight gain per animal during the supplementation period in the two winters but this advantage disappeared by the end of grazing. Liveweight gain per hectare decreased with increased stocking rate in both hay and no-hay groups in the first and third year, decreased in the hay group only in the second year and increased in both groups in the last four years of the experiment. The benefit from making and feeding hay was small and the economics of the practice would depend on alternative uses for excess hay.



2017 ◽  
Vol 9 (1) ◽  
pp. 54-58 ◽  
Author(s):  
Chidozie Nwabuisi OKOYE ◽  
Clifford Nwabugwu ABIAEZUTE ◽  
Okezie Samuel EKERE

This study aimed to determine the changes in the biometry of the ovaries, of the uteri and its contents in the Maradi doe-goat during the three terms of pregnancy. Pregnant uteri from 28 female goats and their corresponding ovaries were used to study the biometric changes in the ovaries, gravid uteri, amniotic and allantoic fluids volumes, fetuses and plancentomes during the three terms of pregnancy. The results revealed that there was no significant variation in the ovarian weight during the three terms of pregnancy. However, there were significant variations in the ovarian length (left ovary 2.15 ± 0.16 cm; right ovary 2.10 ± 0.10 cm) and width (left ovary 1.77 ± 0.19 cm; right ovary 1.60 ± 0.10 cm) in the third term of pregnancy compared to the ovarian length and width in the first term of pregnancy. The uterine weight showed significant variation in the first term, second term   and in the third term of pregnancy. The uterine length of both horns also showed significant variations in the first term (left side 31.40 ± 1.79 cm; right side 28.22 ± 0.98 cm), second term (left side 51.58 ± 4.14 cm; right side 50.51 ± 3.62 cm) and in the third term (left side 70.67 ± 1.76 cm; right side 80.38 ± 2.75 cm) of pregnancy but only in the third term of pregnancy was a significant difference in the lengths of the left side uterine horn (70.67 ± 1.76 cm) compared to the right side (80.38 ± 2.75 cm). The number of plancentomes was constant in both uterine horns throughout gestation; however the mean caruncular diameter increased progressively from the first term of gestation through the third term of pregnancy. The smallest and largest caruncles were observed on the ventral surfaces of the uterine horns, and the plancentomes were observed to be aligned in a linear manner along the longitudinal axis of the uterine horns. This study shows that there are differences in the biometrics of the ovary and uterus in Maradi goats compared to some other breed.



1975 ◽  
Vol 26 (1) ◽  
pp. 93
Author(s):  
GD Kohn

A grazing experiment was carried out at the Agricultural Research Institute, Wagga Wagga, over the period 1962-1966. The treatments involved three stocking rates (5, 10 and 15 sheep per ha) and four superphosphate topdressing rates (0, 125, 250 and 375 kg ha-1) with three replications. After the grazing phase three successive crops were grown. Superphosphate was applied with the crops at 0, 63, 125 and 250 kg ha-1. Current and residual effects of this superphosphate were measured. Nitrogen (as urea at 78 kg ha-l) was topdressed on half of each plot. The low stocking rate plots were further tested for response to sulphur. Superphosphate applied to one crop had no residual effect on subsequent crops, regardless of the previous pasture treatment. On the average the yield of the first crop sown without superphosphate increased about 1/3 kg ha-1 for each kilogram of superphosphate per hectare applied annually in the pasture phase, that of the second crop 1 kg and the third crop I-1/3 kg. First crops did not respond to superphosphate applied with the crop, but second crops on plots that were not topdressed in the pasture phase and all third crops did respond to current superphosphate. Yields of third crops receiving superphosphate at 250 kg ha-1 on land that was not topdressed in the pasture phase exceeded those of similar crops on land that had been topdressed in the pasture phase (five out of six comparisons were significant at P = 0.01). A similar effect was found in the second crop in one replicate. The effect of nitrogen varied with the climate. In the drought year of 1967 there was one negative response to nitrogen. In 1968 yields were high and nitrogen decreased yield by increasing lodging. In the following 3 years nitrogen increased yield and the increase was generally greater as the rate of pasture topdressing increased. The stocking rate of the pasture did not affect the yield of the following wheat crops. There was no response to sulphur by the crops. It is suggested that superphosphate can be more efficiently used by omitting pasture topdressing and applying 125 kg ha-I or more with crops. Farmers in the clover ley farming areas could considerably reduce their annual superphosphate requirements. *Part I, Aust. J. Agric. Res., 25: 525 (1974).



1975 ◽  
Vol 15 (73) ◽  
pp. 173 ◽  
Author(s):  
AH Bishop ◽  
HA Birrell

In a 4 x 4 x 3 factorial experiment lasting three years, the effects of stocking rate, fodder conservation and three grazing management systems (continuous, deferred and rotational) on the wool production of wethers grazing perennial pasture were assessed. The hay conserved on the plots was fed to the sheep in such a way that the quantities made and fed would balance over a period of years. At the highest rate of stocking some oats were fed in adverse seasons. Stocking rate had the major effect on wool production in all years. Improving wool production by fodder conservation was shown to depend on stocking rate, grazing management and the seasonal conditions. In some instances fodder conservation was shown to interact with stocking rate in a manner such that the maximum response tended to occur when smaller proportions of area were conserved as stocking rate increased. The implications of this interaction are discussed. Fodder conservation increased wool production in the continuous and rotationally grazed systems in all years, but did not in two of the three years with deferred grazing. The biggest increases in wool production due to fodder conservation occurred in the third year, the driest on record when a drought reserve was used. Wool production was also influenced by the grazing management. In alt-years there was a consistent interaction with stocking rate in which the highest wool production was produced in the rotational system at high stocking rates and in the deferred system at low stocking rates.



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