Variation in feed intake as a cause of variation in wool production of grazing sheep

1960 ◽  
Vol 11 (4) ◽  
pp. 585 ◽  
Author(s):  
PG Schinckel
Keyword(s):  
Body Weight ◽  
Feed Intake ◽  
High Group ◽  
Wool Production ◽  
Unit Body Weight ◽  
Ad Libitum ◽  
Low Levels ◽  
Grazing Sheep ◽  
Ad Libitum Feeding

Observations were made to determine whether differences between sheep in wool production under field grazing conditions reflected differences between individuals in feed intake. Sheep were selected for high, intermediate, and low levels of clean wool weight per unit body weight under field grazing conditions, and the feed intakes and wool production of these sheep were subsequently measured under pen conditions. On controlled feed intakes differences between sheep and between groups were less than those under field grazing conditions or under ad libitum pen feeding conditions. It was concluded that a, significant portion of the differences in wool production at grazing was referable to differences in feed intake. The group of sheep having high levels of wool production per unit body weight were found to have higher efficiency of conversion of feed to wool and also to have higher levels of feed intake under ad libitum feeding conditions. The rate of wool production of the high group was 22 per cent. greater than that of the low group under conditions of equal feed intake and 37 per cent. greater under conditions of ad libitum feed intake.

scholarly journals Group-Adapted ad Libitum Feeding vs. Conventional Restrictive Feeding: Impact on Health, Behavior, and Reproductive Performance of Group-Housed Pregnant Sows

2020 ◽  
Author(s):  
Eva Angermann ◽  
Monika Wensch-Dorendorf ◽  
Stephanie Frenking ◽  
Nicole Kemper ◽  
Eberhard von Borell
Keyword(s):  
Body Weight ◽  
Group Size ◽  
Feed Intake ◽  
Management Practices ◽  
High Energy ◽  
Feeding System ◽  
Liquid Feeding ◽  
Whole Plant ◽  
Ad Libitum ◽  
Ad Libitum Feeding

Abstract BackgroundCommon feeding systems for pregnant group-housed sows meet the nutritional demand but do not sufficiently consider their natural feeding behavior. A new group-adapted ad libitum feeding system called “SWOF” (Hölscher + Leuschner GmbH & Co. KG®, Emsbüren, Germany) was developed to ensure that both optimal nutritional and behavioral needs are met. This feeding system comprises an activity and lying area and two areas with ad libitum liquid feeding on the basis of whole plant wheat silage. Passing through a sorting gate, sows could be given either a low- or high-energy diet according to their weight and parity. The study’s aim was to investigate the effects of this new system on sows’ body weight, health status (lameness), aggression parameters (integument injuries, vulva injuries, displacements at the trough), feed intake rhythm, and litter performance, and to compare these with restrictively fed group-housed sows, which is the common standard in Germany. ResultsIn the group-adapted ad libitum feeding system, significantly less risk for displacements at the trough and vulva injuries were observed, and sows followed their natural biphasic feed intake rhythm. This system also resulted in lower body weight and more integument injuries than the restrictively fed group-housed sows. However, these might be due to different management practices and group size between the two systems. No influence of the feeding system was observed, neither on lameness nor litter performance. ConclusionThe data reported here show the promising effects of the group-adapted ad libitum “SWOF” feeding system with regard to animal welfare, as sows can freely choose when and how much feed they want to consume without taking the risk of over conditioning. The “SWOF” feeding system remains to be further validated, also considering the group size and management practices.

Measurements of wool production and its physiological components in a group of South Australian Merino sheep.

1961 ◽  
Vol 12 (4) ◽  
pp. 696 ◽  
Author(s):  
KJ Hutchinson
Keyword(s):  
Body Weight ◽  
Conversion Efficiency ◽  
Feed Intake ◽  
Dry Matter ◽  
Individual Values ◽  
Wool Production ◽  
Voluntary Feed Intake ◽  
Unit Body Weight ◽  
Prime Determinant ◽  
Fleece Weight

Data for wool production, feed intake, and body weight were recorded for a group of 31 rams selected from the South Australian strong-woolled Merino flock at Roseworthy. Measurements were made during (a) grazing, and (b) ad libitum pen feeding. A locally developed faecal nitrogen method was used to estimate intakes at pasture. For the pen diet, which contained 15% crude protein, two measurements of apparent dry matter and nitrogen digestibility were made for each sheep. The repeatability of gross conversion efficiency of feed into wool under grazing versus pen feeding was highly significant, viz. r = +0.79. While the repeatability of wool production was also highly significant, viz. r = +0 77, the repeatability of feed intake was not significant in these data, viz. r = +0 12 In pens, voluntary feed intake was found to vary with body weight to the power of + 1 09, the 99% fiducial limits extending from +0.81 to + 1 37 and thus excluding fractional powers conventionally assigned to basal metabolic nee&, e.g. +0.7. The physiological components of wool production were studied with the use of' the pen data. An identity was used which involved three terms, viz. gross conversion efficiency of feed into wool, gross feed intake per unit body weight, and body weight. Of these, gross conversion efficiency was the prime determinant of wool production. Gross feed intake per unit body weight was significantly associated with wool production (P<0.05), while the relationship between wool production and body weight was not significant in these data. In the pen experiment 'the regression relationship between voluntary feed intake and body weight accounted for approximately one-half of the variation in voluntary feed intake. A negative association between body weight and efficiency was also revealed. However, the general significance of this latter finding is doubtful, particularly in view of the variable relationships recorded between body weight and clean fleece weight for rams in 5 years' data from the general Roseworthy flock. For the experimental group of 31 rams, substantial differences were recorded in individual apparent digestive efficiencies for both dry matter and nitrogen. The ranges of individual values, expressed as four standard deviations, were 9.2 and 12.2% respectively. However, these differences did not contribute to differences in gross conversion efficiency of feed into wool, which suggests that the latter resides in either general or special aspects of metabolism.

Growth of sheep to the age of three years after a severe nutritional check in early post-natal life

1997 ◽  
Vol 128 (4) ◽  
pp. 479-494 ◽  
Author(s):  
D. I. KRAUSGRILL ◽  
N. M. TULLOH ◽  
D. L. HOPKINS
Keyword(s):  
Body Weight ◽  
The Other ◽  
Semitendinosus Muscle ◽  
Protein Ratio ◽  
X Ray ◽  
Wool Production ◽  
Significant Difference ◽  
Ad Libitum ◽  
Grazing Sheep ◽  
Free Body

At Mount Derrimut Field Station from 1982 to 1985, growth and body composition was studied in three groups of wethers from the same flock. A control group (C) and a restricted group (R) were housed from the age of 1 day until slaughtered. The first slaughter was at the age of c. 1 year (reported elsewhere) and the second at the age of c. 3 years. Apart from the first 36 days, when group R was fed a severely restricted ration, both groups were fed a high quality diet ad libitum throughout the experiment. At the end of the second year, a group of 2-year-old wethers (G) was introduced, to compare the growth of these sheep with those in groups C and R. Group G sheep were reared on their dams, kept as grazing animals and killed at the second slaughter.At the age of c. 3 years there was no significant difference between groups C and R for mean fleece-free body weights, but the sheep in group G were significantly lighter (P<0·01) in spite of reaching mature size for grazing sheep in the general flock.After the age of 7 months there was no significant difference between groups C and R in rate of wool production. Rate of wool production in group G sheep was not significantly different from that of sheep in the other groups except during the last 6 months, when they produced significantly less wool (P<0·05).Regression analyses for surface and X-ray measurements against fleece-free body weight (independent variable) showed no differences between groups C and R, except for width of metacarpal (X-ray measurement). In this case, the regression coefficients were different (P<0·01) but, at slaughter, actual bone measurements were the same. Both X-ray measurements and those at dissection showed that the metacarpals of group G were significantly (P<0·05) longer and narrower, and had a narrower cortex, than those in the other two groups (P<0·05).There were no significant differences between groups C and R in mean weight and chemical composition of the parts and tissues examined; however, the carcass fat content of sheep in group G was significantly less (P<0·01) than in the other two groups. The sheep in group G had higher weights (P<0·01) for the brain, the digestive tract (DT), kidneys and liver than those in groups C and R.Cell size in the semitendinosus muscle, as indicated by the protein[ratio ]DNA ratio, increased (P<0·01) between the first and second slaughters. There were no differences between groups in protein[ratio ]DNA ratios, but the DNA and protein contents were significantly higher (P<0·05) in the kidneys and liver in group G than in the other groups. Although the weights of the semitendinosus muscle were heavier (P<0·01) in groups C and R than in group G, on a fat-free basis, there were no significant differences between treatments in muscle weight or in DNA and protein contents.It is concluded that sheep will make a complete recovery after a severe nutritional check in early post-natal life if given the opportunity to do so. Even though large differences in body weight may develop between sheep, this appears to have little effect on mature skeletal dimensions. However, at maturity, with grazing sheep that grow relatively slowly, the metacarpals are likely to be narrower and longer than those of the same genotype fed to grow faster. Even with sheep fed ad libitum throughout life, the use of X-ray and surface measurements in young sheep at a particular body weight are unlikely to be useful for the accurate prediction of mature body weight.

scholarly journals Short-term consequences of a sudden increase in feed allowance in broiler breeder hens

1993 ◽  
Vol 73 (1) ◽  
pp. 159-167 ◽  
Author(s):  
F. E. Robinson ◽  
M. W. Yu ◽  
M. E. Lupicki ◽  
R. T. Hardin
Keyword(s):  
Feed Intake ◽  
Egg Production ◽  
Liver Fat ◽  
Sudden Increase ◽  
Broiler Breeder ◽  
Breeder Hens ◽  
Preovulatory Follicles ◽  
Broiler Breeder Hens ◽  
Ad Libitum ◽  
Ad Libitum Feeding

The immediate effects of a sudden increase in feed allowance on selected morphological and reproductive traits were investigated in broiler breeder hens at 44 wk of age. Fifty Indian River hens were individually caged at 40 wk of age. Prior to 40 wk of age the birds had been feed restricted in accordance with the breeder's recommended feeding program. Five treatment groups (T1, T2, T3, T4 and T5) of 10 birds each were formed based on level of feeding and duration of exposure to such feeding. T1, T2 and T3 birds were feed restricted (128 g of daily feed bird−1) from 40 to 44, 40 to 45 and 40 to 46 wk of age, respectively. T4 and T5 birds were also feed restricted at the same level as the other groups to 44 wk of age and then were full fed from 44 to 45 and 44 to 46 wk of age, respectively. To facilitate study of follicular recruitment and yolk deposition, hens were fed 10 g of oil-soluble red and black dyes, daily, on alternate days, beginning at 42 wk of age. Birds were killed on day 0 (44 wk; T1), day 7 (45 wk; T2, T4), or day 14 (46 wk; T3, T5). Full-fed hens consumed approximately 100 g more feed per day than did feed-restricted hens, with marked increases in feed intake on the first day of full feeding. After 7 d of ad libitum feeding, significant increases were seen in body weight, liver weight, percent liver fat, plasma lipid concentration, ovary weight, and the incidence of a double hierarchy (simultaneous development) of large follicles. After 14 d of ad libitum feeding, significant increases were also observed in absolute fat-pad weight, individual weights of the four largest preovulatory follicles and number of large preovulatory follicles. The increased number of large follicles in the ovary was not associated with any change in egg production. It is apparent that the morphological disruptions associated with overfeeding broiler breeder hens can be identified within 7 d of full feeding, while any effects on egg production are not seen within the first 14 d of ad libitum feeding. Key words: Broiler breeder, feed intake, yolk deposition, ovarian morphology, egg production

Methods of feeding growing pigs to maximise feed intake

1986 ◽  
Vol 1986 ◽  
pp. 128-128 ◽  
Author(s):  
A.L. Lightfoot ◽  
A.W. Armsby ◽  
C.F. Widdows
Keyword(s):  
Conversion Efficiency ◽  
Feed Intake ◽  
Growth Rates ◽  
Growing Pigs ◽  
Limited Information ◽  
Feed Conversion ◽  
Feeding Method ◽  
Genetically Improved ◽  
Ad Libitum ◽  
Ad Libitum Feeding

An experiment was carried out to determine which feeding method maximised feed intake of growing pigs and to record growth rates, feed conversion efficiency and backfat measurements. There is an increasing tendency for dry fed pigs to be fed ad libitum or to appetite in order to increase growth rates and throughput of building.Limited information is available on how the modern genetically improved pig will respond to high levels of feeding and whether ad libitum feeding will encourage higher feed intake than feeding to appetite either wet or dry.

scholarly journals Effects of Replacing Groundnut Cake with Blood Vegetable Waste Meal in the Diets of Weaner Rabbits

2012 ◽  
Vol 2012 ◽  
pp. 1-4
Author(s):  
Adedayo Abiodun Adeniji
Keyword(s):  
Body Weight ◽  
Weight Gain ◽  
Feed Intake ◽  
Crude Protein ◽  
Body Weight Gain ◽  
Control Diet ◽  
Vegetable Waste ◽  
Gain Ratio ◽  
Groundnut Cake ◽  
Ad Libitum

A total of seventy-two weaner rabbits of eight weeks of age were used to assess the effects of replacing groundnut cake (GNC) with blood vegetable waste meal (BVWM) in the diets of rabbits. The BVWM was fed to replace dietary GNC at 0, 15, 30, and 45%, with GNC being 15% in the control diet. The four experimental diets were fed ad libitum for a period of eight weeks. BVWM was analyzed to contain a crude protein value of 62.35%. There were comparable feed intake values by rabbits on all the diets although the rabbits in the higher replacement levels of BVWM tended to have consumed more of the feed. There were significant increases (P<0.05) in body weight gain by rabbits as the BVWM level increased in the diet. Similarly, the feed to gain ratio improved and nitrogen digestibility increased (P<0.05) with higher levels of BVWM in the diet. This study shows that rabbits can tolerate the 45% BVWM replacement of groundnut cake effectively.

The effects on feed intake in weaned calves of low-glucosinolate rapeseed meal as the sole protein supplement

1990 ◽  
Vol 1990 ◽  
pp. 141-141 ◽  
Author(s):  
Isobel C Vincent ◽  
J Thompson ◽  
R Hill
Keyword(s):  
Feed Intake ◽  
Rapeseed Meal ◽  
Protein Supplement ◽  
Daily Feeding ◽  
Soyabean Meal ◽  
Ad Libitum ◽  
Ad Libitum Feeding

Concentrate feed with high-glucosinolate rapeseed meal (BRSM) as the sole protein supplement was eaten less readily by weaned calves than a similar feed based on soyabean meal (Stedman et al, 1983), and this was so whether intake was measured during continuous ad libitum feeding, or for short periods, 0.5 h, after twice-daily feeding with changes of feed each day. In these and other experiments with calves (Stedman and Hill, 1987), concentrate feeds based on low-glucosinolate rapeseed meal were eaten more readily than those based on high-glucosinolate meal, but intake of the low-glucosinolate feeds rarely matched that of the corresponding feed containing soyabean meal.

Body weight of rats following area postrema ablation: effect of early force-feeding

1989 ◽  
Vol 256 (4) ◽  
pp. R939-R945
Author(s):  
N. J. Kenney ◽  
J. N. Kott ◽  
N. Tomoyasu ◽  
A. J. Bhatia ◽  
A. S. Ruiz ◽  
...  
Keyword(s):  
Body Weight ◽  
Preliminary Analysis ◽  
Area Postrema ◽  
Solitary Tract ◽  
Milk Diet ◽  
Medial Nucleus ◽  
Body Weights ◽  
Force Feeding ◽  
Ad Libitum ◽  
Ad Libitum Feeding

This study examined the effect of intragastric force-feeding of a milk diet on body weights of rats with lesions of the area postrema/caudal medial nucleus of the solitary tract (AP/cmNTS). Force-feeding was conducted over the first 10 days after the ablation. Body weight was monitored both during and after force-feeding. Food intake was measured during all ad libitum feeding periods. During force-feeding, rats with AP/cmNTS lesions gained weight at the same rate as force-fed sham-lesioned rats or sham-lesioned rats that voluntarily ingested an equal amount of the milk. When returned to ad libitum feeding, lesioned rats that had been force-fed were not hypophagic and did not lose weight. Body weights of such rats remained above those of lesioned rats that were not force-fed and similar to those of nonlesioned rats throughout this study. Despite their normal weights, preliminary analysis indicated that body fat of the force-fed lesioned rats may have been reduced. These findings suggest that the effects of AP/cmNTS ablation are multiple and that reduction of body weight need not be the primary effect of such lesions.

Adipose tissue transcriptome changes during obesity development in female dogs

2011 ◽  
Vol 43 (6) ◽  
pp. 295-307 ◽  
Author(s):  
Ryan W. Grant ◽  
Brittany M. Vester Boler ◽  
Tonya K. Ridge ◽  
Thomas K. Graves ◽  
Kelly S. Swanson
Keyword(s):  
Body Weight ◽  
Adipose Tissue ◽  
Repeated Measures ◽  
Expression Profiles ◽  
Weight Maintenance ◽  
Gene Expression Profiles ◽  
Global Gene Expression ◽  
Adipocyte Size ◽  
Ad Libitum ◽  
Ad Libitum Feeding

During the development of obesity, adipose tissue undergoes major expansion and remodeling, but the biological processes involved in this transition are not well understood. The objective of this study was to analyze global gene expression profiles of adipose tissue in dogs, fed a high-fat diet, during the transition from a lean to obese phenotype. Nine female beagles (4.09 ± 0.64 yr; 8.48 ± 0.35 kg) were randomized to ad libitum feeding or body weight maintenance. Subcutaneous adipose tissue biopsy, blood, and dual x-ray absorptiometry measurements were collected at 0, 4, 8, 12, and 24 wk of feeding. Serum was analyzed for glucose, insulin, fructosamine, triglycerides, free fatty acids, adiponectin, and leptin. Formalin-fixed adipose tissue was used for determination of adipocyte size. Adipose RNA samples were hybridized to Affymetrix Canine 2.0 microarrays. Statistical analysis, using repeated-measures ANOVA, showed ad libitum feeding increased ( P < 0.05) body weight (0 wk, 8.36 ± 0.34 kg; 24 wk, 14.64 ± 0.34 kg), body fat mass (0 wk, 1.36 ± 0.24 kg; 24 wk, 6.52 ± 0.24 kg), adipocyte size (0 wk, 114.66 ± 17.38 μm2; 24 wk, 320.97 ± 0.18.17 μm2), and leptin (0 wk, 0.8 ± 1.0 ng/ml; 24 wk, 12.9 ± 1.0 ng/ml). Microarrays displayed 1,665 differentially expressed genes in adipose tissue as weight increased. Alterations were seen in adipose tissue homeostatic processes including metabolism, oxidative stress, mitochondrial homeostasis, and extracellular matrix. Adipose transcriptome changes highlight the dynamic and adaptive response to ad libitum feeding and obesity development.

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