Selection for weaning weight in Merino sheep. 3. Maintenance requirements and the efficiency of conversion of feed to wool in mature ewes

1967 ◽  
Vol 7 (25) ◽  
pp. 117 ◽  
Author(s):  
WA Pattie ◽  
AJ Williams
Keyword(s):  
Body Weight ◽  
Feed Intake ◽  
Weaning Weight ◽  
Gross Efficiency ◽  
Wool Growth ◽  
Body Weights ◽  
Unit Body Weight ◽  
Selection For ◽  
Feed Costs ◽  
Maintenance Requirements

Net and gross efficiencies of wool growth have been estimated for ewes from three Trangie selection flocks, one selected for high weaning weight (Weight Plus), one for low weaning weight (Weight Minus), and a random control flock. Weight Plus ewes had 15 and 11 per cent heavier body weights than Weight Minus ewes at maintenance and unlimited levels of feeding respectively. At each level, feed intake was proportional to body weight both between and within flocks. In addition, the feed costs of a unit gain and loss of body weight were the same for each flock at each level of feeding. The Weight Plus ewes grew 7 and 10 per cent more wool than Weight Minus ewes at maintenance and unlimited levels of feeding. Consequently, there was only a small difference between the flocks in efficiency of conversion of feed to wool at maintenance, and there was no difference on unlimited intake. These results indicate that there is no genetic correlation between weaning weight and efficiency of conversion of feed to wool. At the three levels of controlled feeding (543, 725, 902 grams of dry matter a day) there were no differences in gross efficiency of wool growth, either between flocks or between levels within flocks, despite differing changes in body weight. During unlimited feeding, gross efficiency of wool growth was lower than that during controlled feeding. This was due to a reduced response in wool growth, as feed costs per unit body weight change were constant. As both production and feed intake changed in proportion to body weight, it is concluded that attention to weaning weight has little place in a Merino breeding program aimed at increasing wool production. However, selection for high weaning weight may be a useful tool in selecting ewes for crossbreeding because of the associated increases in milk production and lamb growth rate.

Effect of divergent selection for weaning weight on liveweight and wool growth responses to feed intake in Merino ewes

1993 ◽  
Vol 33 (6) ◽  
pp. 699 ◽  
Author(s):  
RM Herd ◽  
VH Oddy ◽  
GJ Lee
Keyword(s):  
Organic Matter ◽  
Feed Intake ◽  
Divergent Selection ◽  
Growth Responses ◽  
Weaning Weight ◽  
Wool Growth ◽  
Digestible Organic Matter ◽  
Selection For ◽  
Response To Change

During a 6-week experiment, the feed requirements for maintenance of liveweight (LW) by adult Merino ewes were measured in 2 flocks selected over 32 years for divergent weaning weight. Also examined were the net efficiency of LW gain and wool growth in response to change in feed intake, and the ability to digest dietary organic matter. Ewes selected for high weaning weight (W+) were 31% heavier than those selected for low weaning weight (W-) at the start of the experiment. To maintain LW, W+ ewes ate 24% more digestible organic matter (DOM) per day than W- ewes. There were no differences (P>0.2) in the net efficiency of feed use for LW gain. The W+ ewes digested more (P<0.01) dietary organic matter, by 1.8 percentage units, than W- ewes and, consequently, required only 22% more dry feed to maintain their heavier LW. Ewes from the 2 flocks did not differ (P>0.4) in the amount of wool grown, and as W+ ewes were larger, they produced less (P<0.01) wool per kg LW for the same DOM intake.

Efficiency of conversion of food to wool in selected and unselected Merino types

1972 ◽  
Vol 23 (1) ◽  
pp. 117 ◽  
Author(s):  
DG Saville ◽  
GE Robards
Keyword(s):  
Body Weight ◽  
Food Intake ◽  
Surface Area ◽  
Fibre Diameter ◽  
Response To Selection ◽  
Gross Efficiency ◽  
Wool Growth ◽  
Selection For ◽  
Fleece Weight ◽  
Growth Differences

Comparisons were made between Collinsville, Bungaree, and Peppin Merino ewes in efficiency of conversion of food to wool. The effect of selection for some characters on efficiency of conversion within the Peppin Merino was also investigated. The Collinsville ewes grew 14% more wool and had an 8% lower food intake at maintenance than did the Peppins. Differences in wool growth between the Peppin and Collinsville types fed ad lib. were mainly due to efficiency and body weight differences. Efficiency, intake, and body weight each had a similar influence on wool growth differences between Peppins and Bungarees. Peppin ewes selected for wool production, either alone or together with crimp frequency, had a higher gross efficiency than unselected sheep fed below maintenance (13 and 8%) or ad lib. (14 and 13%). The efficiency difference between selected and unselected sheep increased, then decreased, with increasing intake. The decrease in efficiency differences at higher intakes did not appear to influence the ranking of selected or unselected sheep. The response to selection for clean fleece weight was shown to develop a plateau after about one generation of selection. Selection had resulted in the elimination of a relationship between efficiency and wool growth. The present results indicate that further progress in fleece weight is unlikely to be made either by selecting for fleece weight with some control on fibre diameter or by selecting for increased surface area.

scholarly journals 269 Effects of high phytase supplementation in lactation diets on sow and litter performance

2020 ◽  
Vol 98 (Supplement_3) ◽  
pp. 101-102
Author(s):  
Kelsey L Batson ◽  
Hilda I Calderon Cartagena ◽  
Robert D Goodband ◽  
Jason C Woodworth ◽  
Mike D Tokach ◽  
...  
Keyword(s):  
Body Weight ◽  
Litter Size ◽  
Feed Intake ◽  
Control Diet ◽  
Small Scale ◽  
Body Weight Change ◽  
Weaning Weight ◽  
Commercial Trial ◽  
Quadratic Response ◽  
Dietary Treatments

Abstract A total of 109 sows (Line 241; DNA, Columbus, NE) were used in a study to evaluate the effect of increasing phytase concentration in lactation diets on sow and litter performance. On d 107 of gestation, sows were blocked by body weight and parity and allotted to 1 of 3 dietary treatments of increasing phytase concentration (0, 1,000, or 3,000 FYT/kg; Ronozyme HiPhos 2700; DSM Nutritional Products, Inc., Parsippany, NJ). The control diet contained no phytase and was formulated to contain 0.50% standardized total tract digestible phosphorus (STTD P; 0.45% available P) and 0.62% STTD calcium (0.90% total Ca). The same STTD P and Ca concentrations were formulated for the phytase diets considering a release of 0.132 STTD P and 0.094 STTD Ca in both diets. Diets were fed from d 107 of gestation until weaning (d 18 ± 2). Litters were cross-fostered within treatment until 48 h post-farrowing to equalize litter size. Linear and quadratic response to phytase concentration was evaluated using the lmer function in R. There was no evidence for difference in sow body weight change, farrowing performance, wean-to-estrus interval, or litter size among dietary treatments. Sow average daily feed intake from farrowing to weaning tended to increase (linear, P=0.093) as phytase increased. Although not significant (linear, P =0.226), farrowing duration decreased as phytase increased. Litter weaning weight increased (quadratic, P=0.039) and overall litter gain increased (quadratic, P=0.047) with 1,000 FYT of phytase. In summary, sow feed intake tended to increase linearly with increasing phytase; however, feeding 1,000 FYT/kg maximized overall litter gain and weaning weight. This small-scale study suggests sow and litter performance benefits due to high inclusions of dietary phytase; however, a commercial trial with more sows is warranted to confirm these results.

scholarly journals PSVIII-38 Late-Breaking Abstract: Estimating genetic parameters of feed efficiency traits in American mink

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 347-347
Author(s):  
Pourya Davoudi ◽  
Duy Ngoc Do ◽  
Guoyu Hu ◽  
Siavash Salek Ardestani ◽  
Younes Miar
Keyword(s):  
Body Weight ◽  
Genetic Correlation ◽  
Feed Intake ◽  
Feed Efficiency ◽  
Fixed Effects ◽  
Genetic Parameters ◽  
American Mink ◽  
Genetic Correlations ◽  
Final Body Weight ◽  
Selection For

Abstract Feed cost is the major input cost in the mink industry and thus improvement of feed efficiency through selection for high feed efficient mink is necessary for the mink farmers. The objective of this study was to estimate the heritability, phenotypic and genetic correlations for different feed efficiency measures, including final body weight (FBW), daily feed intake (DFI), average daily gain (ADG), feed conversion ratio (FCR) and residual feed intake (RFI). For this purpose, 1,088 American mink from the Canadian Center for Fur Animal Research at Dalhousie Faculty of Agriculture were recorded for daily feed intake and body weight from August 1 to November 14 in 2018 and 2019. The univariate models were used to test the significance of sex, birth year and color as fixed effects, and dam as a random effect. Genetic parameters were estimated via bivariate models using ASReml-R version 4. Estimates of heritabilities (±SE) were 0.41±0.10, 0.37±0.11, 0.33±0.14, 0.24±0.09 and 0.22±0.09 for FBW, DFI, ADG, FCR and RFI, respectively. The genetic correlation (±SE) was moderate to high between FCR and RFI (0.68±0.15) and between FCR and ADG (-0.86±0.06). In addition, RFI had low non-significant (P &gt; 0.05) genetic correlations with ADG (0.04 ± 0.26) and BW (0.16 ± 0.24) but significant (P &lt; 0.05) high genetic correlation with DFI (0.74 ± 0.11) indicating that selection for lower RFI will reduce feed intake without adverse effects on the animal size and growth rate. The results suggested that RFI can be implemented in genetic/genomic selection programs to reduce feed intake in the mink production system.

Comparative performance of Omani goats and sheep

1996 ◽  
Vol 127 (1) ◽  
pp. 117-121 ◽  
Author(s):  
F. M. S. Al-Nakib ◽  
E. S. S. Al-Shukaily ◽  
S. S. S. Al-Hanai ◽  
S. A. M. Al-Nabhani
Keyword(s):  
Body Weight ◽  
Litter Size ◽  
Performance Test ◽  
Comparative Performance ◽  
Rhodes Grass ◽  
Sheep Industry ◽  
Body Weights ◽  
Selection For ◽  
Performance Trial

SUMMARYAs part of a long-term breeding programme aimed at improving the performance of Omani goats and sheep, a 3-year performance trial was carried out between 1991 and 1993 to evaluate the reproductive and productive performance of three breeds of goat: Batinah (BT), Dhofari (DH) and Jabal Akhdar (JA), and one breed of local Omani sheep. In each year, flushing started on 1 September, mating started on 1 October and terminated on 15 November, and the kidding/lambing season started on average on 1 March. Kids and lambs were weaned at c. 3 months of age, then put on a 3-month performance test, fed on concentrates ad libitum and Rhodes grass hay. Some 3706 dam and 3011 progeny performance records were available over a 3-year period from 1991 to 1993. Ewes were lighter in body weight and lower in litter size weaned but higher in fertility than the does. Although the lambs had lighter birth weights, they were heavier at weaning and at 6 months of age. Among the goats, the DH does had lighter body weight but higher litter size weaned than both the BT and the JA goats. DH kids were somewhat lighter at birth, weaning and 6-month body weights than the other two breeds but had higher survival.The sheep had higher output per ewe exposed (3·28 kg, 33%) and per ewe lambed (3·27 kg, 26%) and were 35% more efficient in production than the goats. Although the DH goats had a lower output per doe exposed than the BT and JA goats (0·9 kg, 9 % and 0·76 kg, 7% respectively) and per doe kidded (1·11 kg, 9% and 1·29 kg, 10%), they had higher efficiency of production than both BT (0·05 units, 6%) and JA (0·11 units, 14%).In view of these results, attention should be paid to the sheep industry through the introduction of promotion schemes. The DH goats would be even more useful if involved in a crossbreeding scheme and the JA goats would benefit from selection for maternal care.

Comparative Dimensions of Testes, Epididymides and Spermatozoa of Australian Dingoes (Canis-Familiaris-Dingo) and Domestic Dogs (Canis-Familiaris-Familiaris) - Some Effects of Domestication

1993 ◽  
Vol 41 (2) ◽  
pp. 133 ◽  
Author(s):  
PF Woodall ◽  
P Pavlov ◽  
LK Tolley
Keyword(s):  
Body Weight ◽  
Sperm Competition ◽  
Seminiferous Tubule ◽  
Canis Familiaris ◽  
Domestic Dogs ◽  
Testis Weight ◽  
Body Weights ◽  
Selection For ◽  
Cauda Epididymidis ◽  
Free Ranging

The dimensions of testes, epididymides and spermatozoa of Australian dingoes (Canis familiaris dingo) and a sample of domestic dogs (Canis familiaris familiaris), chosen to lie within the range of dingo body weights, were compared. There were no significant differences for body weight or testis weight but total epididymal weight, the caput + corpus weights and sperm numbers in the cauda epididymidis were significantly larger in dogs. Dimensions of the spermatozoa were similar for dogs and dingoes except for a small but significantly larger head length in dingoes. Seminiferous tubule diameters were significantly larger in dingoes and epididymal tubule diameters were similar in dogs and dingoes except for significantly wider tubules in the cauda of dogs. The estimated length of tubules in the total epididymis and in the cauda was significantly greater in dogs than in dingoes. Greater size of the epididymis and especially of the cauda epididymidis probably reflect selection for larger sperm stores in free-ranging domestic dogs where there is a greater chance of intermale sperm competition. Two possible hybrids (determined by skull morphometry) were intermediate between dogs and dingoes for some of these dimensions.

Estimates of genetic parameters for pre-weaning and post-weaning growth traits of Chios lambs

1980 ◽  
Vol 30 (2) ◽  
pp. 271-276 ◽  
Author(s):  
A. P. Mavrogenis ◽  
A. Louca ◽  
O. W. Robison
Keyword(s):  
Body Weight ◽  
Birth Weight ◽  
Genetic Parameters ◽  
Growth Traits ◽  
Genetic Correlations ◽  
Heritability Estimate ◽  
Weaning Weight ◽  
Phenotypic Correlations ◽  
Selection For ◽  
Daily Gain

ABSTRACTData on 792 Chios lambs born during the 1972/73 and 1973/74 lambing seasons were used to estimate genetic and phenotypic parameters for birth weight, weaning weight, age at weaning, pre-weaning daily gain, body weight at 5, 10, 15 and 20 weeks of age, and postweaning daily gain. Body weight at 15 weeks of age had the highest heritability estimate (0·73 ± 0·17) and that of post-weaning daily gain was also high (0·56 ± 0·15). Selection for either weight at 15 weeks or post-weaning daily gain would be expected to yield a greater response than selection for pre-weaning daily gain or weaning weight. Genetic correlations among weights and/or gains were positive (approximately 0·20). Phenotypic correlations among weights and gains were generally higher than genetic correlations. However, the correlation between pre— and post-weaning daily gain was small (0·08). Likewise, post-weaning daily gain had low correlations with all weights before 10 weeks. Age at weaning had moderate negative associations with all weights but a very low positive correlation with post-weaning daily gain.

Stimulation of wool growth by thyroxine implantation. II. Feed intake of grazing Merino wethers treated repeatedly with thyroxine.

1964 ◽  
Vol 15 (4) ◽  
pp. 676 ◽  
Author(s):  
LJ Lambourne
Keyword(s):  
Organic Matter ◽  
Feed Intake ◽  
Sheep Grazing ◽  
Wool Production ◽  
Wool Growth ◽  
Digestible Organic Matter ◽  
The Difference ◽  
Maintenance Requirements ◽  
Substantial Rise ◽  
Stimulation Of

Estimates have been made of the feed intake of wethers that received implantations of 60 mg thyroxine every 3 months, and of untreated sheep, grazing together. The estimated intake of digestible organic matter (D.O.M.) by treated wethers was higher than that of controls in 24 out of 27 measurement periods. The difference in feed intake was least in the iirst month after implantation, when the treated sheep lost weight, and greatest in the second and third months when the treated sheep were regaining weight. The overall increase in intake resulting from thyroxine treatment (20–25%) was greater than the increase in wool production (7% greasy weight, 3-7 % clean weight), and the efficiency of wool production was therefore lower in thyroxinetreated wethers. From the relationships between feed intake and rate of weight change it was concluded that in the month after implantation, when pulse rates indicated a substantial rise in metabolic rate, the maintenance feed requirement was raised from about 560 g to about 780 g D.O.M. per day. Observations in two winters with recently shorn sheep gave estimates of maintenance requirements for untreated wethers ranging from 850 to 1300 g D.O.M. per day. During recovery from repeated thyroxine implantation the wethers gained in weight no more efficiently than the controls. The mechanism of action of exogenous thyroxine is discussed in the light of these and other data.

Whole wheat grain feeding of pregnant and lactating ewes and their lambs. 1. The influence of energy, sodium chloride and elemental sulphur on ewe productivity

1975 ◽  
Vol 15 (76) ◽  
pp. 601
Author(s):  
DG Saville ◽  
PJ Nicholls ◽  
WR McManus
Keyword(s):  
Birth Weight ◽  
Sodium Chloride ◽  
Elemental Sulphur ◽  
Low Energy ◽  
Wheat Grain ◽  
Whole Wheat ◽  
Wool Growth ◽  
Body Weights ◽  
Maintenance Requirements ◽  
Central Composite

This experiment was designed to explore the influence of energy, sodium chloride and elemental sulphur on the productivity of pregnant and lactating ewes fed whole wheat grain diets. A central composite design was used to study the response over five levels of each factor. During the last 42 days of pregnancy, the energy treatments resulted in either maintenance of maternal body weights at about 42 kg, or losses of up to 5.5 kg. Ewe maintenance requirements were about 0.14 MJ ME kg-1 day -1 and their foetal requirement was 1 .I 5 MJ ME kg-1 day-1. Sodium chloride and elemental sulphur supplements had no influence on ewe liveweight change up to lambing, but wool growth increased with sulphur supplements of up to about 0.25 to 0.30 per cent. Energy intake and sodium chloride supplementation increased lamb birth weight. After lambing, ewes that had been offered low energy diets increased their liveweight gain and wheat intake with sulphur supplements whereas these supplements reduced the liveweight gain and wheat intake of ewes offered higher energy. Milk production measured on day 14 of lactation averaged 11 53 g day -1 and was not significantly influenced by treatment. These results are discussed in relation to the metabolism of pregnant and lactating ewes, and in the context of the composite design used.

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