Body Weight Gain Of Lambs Research Articles

Moringa leaf meal exerts growth benefits in small ruminants through modulating the gastrointestinal microbiome

This study investigated the impact of feeding 17% moringa leaf meal (MLM) on the ruminal and fecal microbial composition and body weight gain (BWG) performance of lambs (Ovis aries) and kids (Capra hircus). A total of n = 28 lambs (n = 14, no-moringa, n = 14, 17% moringa) and 24 kids (n = 12, no-moringa, n = 12, 17% moringa) were involved in the experiment and body weight was recorded fortnightly. Metagenomic shotgun sequencing was performed on 28, 22, and 26 ruminal solid, liquid fraction, and fecal samples from lambs, and 23, 22, and 23 samples from kids. Moringa supplementation significantly increased BWG in lambs (21.09 ± 0.78 to 26.12 ± 0.81 kg) and kids (14.60 ± 1.29 to 18.28 ± 1.09 kg) (p-value ≤ 0.01). Microbiome analysis revealed an elevated Firmicutes:Bacteroidetes ratio in the moringa diet group. Moringa-fed animals exhibited increased microbial genera associated with volatile fatty acids (VFAs) production (Prevotella, Anaerovibrio, Lachnospiraceae, Butyrivibrio, Christensenella) and starch and fiber digesters (Proteobacteria, Ruminococcus). The increase in the bacterial genus Sharpea suggested possible methane reduction and decreased proportion of pathogens, Aliarcobacter_ID28198, Campylobacter_ID194 and Campylobacter_ID1660076 suggest health benefits. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis demonstrated significant alterations in microbial gene pool and metabolic pathways related to carbohydrate, protein, lipid and energy metabolism, indicating potential improvements in animal health. Overall, moringa feeding showed higher energy recovery, improved growth, and potential benefits in methane reduction and reduced pathogenic bacteria.

EFFECT OF BODY CONDITION SCORE AND WEANING AGE IN SOME PRODUCTIVE TRAITS OF AWASSI SHEEP

To study the impact of the body condition score (BCS) of ewes on body weight (BW) and body weight gain (BWG) of ewes and lambs and the effect of weaning age on BW and BWG of lambs, thirty Awassi ewes (2–3 years old) with their borne male lambs were used in the study. Ewes condition-scored and assigned to three groups, 1st, 2nd and 3rd groups were with BCS 2.5, 3 and 3.5 respectively. Lambs weaned neither 60 or 90 days (5 lambs for each), the study lasted 90 days. The analyzed data showed significant (P≤0.05) differences in high BCS ewes; also, lambs BW increased significantly by 3 and 3.5 compared with 2.5 BCS at the 4th, 6th, and 8th weeks of the study. Total BWG was higher significantly for BCS- 3 and 3.5 ewe’s lambs. While body weight increased significantly for BCS- 3 and 3.5 ewe lambs at the 10th and 12th weeks of study. Ewes were significantly heavier whose weaned her lambs at 60 days, while lambs weaned at 90 days had higher BW at the 10th and 12th weeks of the study. BWG was better significantly (P≤0.05) for BCS- 2.5 and 3 in lambs at 12th week. In conclusion, this means that BCS-3 lambs had a higher BW, while 2.5 and 3 BCS lambs had a better BWG at the end of the study.

Estimation of Repeatability and Most Probable Producing Ability (MPPA) of Sapudi Sheep Based on Daily Body Weight Gain of Lambs from Birth to Pre-weaning and Weaning

This research aimed to estimate the repeatability and MPPA values of Sapudi ewes based on the lamb’s daily gain from birth to pre-weaning and weaning. Using recorded data in a pedigree of lamb, 53 data with half-sib relationship came from 14 ewes which included the record of body weight gain of Sapudi lambs from birth to pre-weaning and weaning. The data were analyzed by descriptive method with a quantitative approach. The study showed that the average daily gain of pre-weaning and weaning was 007 kg/day. The repeatability value of pre-weaning and weaning daily gain was 0.636 in the high category and 0.377 in the medium category. The MPPA daily gain values for pre-weaning and weaning ranged from -0.032 to 0.018 and -0.016 to 0.009. The research concluded that the Sapudi sheep ewes based on the MPPA daily gain pre-weaning were six heads with four rankings, while the daily weight gain weaning was ten heads with ranking of five. The highest rank of Sapudi ewes in pre-weaning and weaning daily gain was ear tag 094 with MPPA values of 0.018 and 0.009. It is recommended that further research can be conducted to estimate the repeatability value of quantitative periodically as the basis for the selection and culling of livestock.

63 Effect of Chicory Silage and Se-yeast on Peripartum Ewes: Performance Data

Abstract The objective of this study was to test the possibility of improving the performance of peripartum ewes by feeding a combination of chicory silage and Se-yeast. Approximately four weeks prior to lambing, 36 pregnant Polypay ewes were moved into single pens and randomly assigned to one of four groups to be fed either grass or chicory silage and supplemented or not with 3.6 mg Se/day (DiaMune, Diamond V). Daily dry matter intake (DMI), water intake, body weight gain of lambs and body weight changes of the ewes, milk yield using a weigh-suckle-weigh system, and milk components were recorded. Data were analyzed using GLIMMIX (SAS v9) with time, silage, and Se interaction as fixed effects and ewe as random effect. Significance was declared with P ≤ 0.05. The DMI was lower in ewes fed chicory compared to grass silage with no effect of Se. Water intake was greater in ewes that were fed chicory silage than grass silage but lower in those supplemented with Se. Milk production of ewes and BW gain of the lambs were not affected by the treatments, but the gain efficiency (G:F) of lambs was larger in animal fed chicory vs. grass silage. Few differences were observed in milk components between the treatments. Protein content and SNF tended to be reduced by feeding Se (P = 0.08) while feeding Se increased C18:0 and preformed fatty acids in milk. Feeding chicory+Se tended to increase percentage of de novo-derived fatty acids in milk compared to feeding grass+Se. Somatic cell count (SCC) was not affected by the treatments. Overall, our data indicated that performance of the animals as well as milk components were not affected by feeding chicory and/or Se despite a lower feed intake when chicory was fed. Higher feed efficiency by using chicory is suggested by the DMI/gain of lambs.

Effect of different milking methods on milk yield and growth of lambs

Indian sheep are unexploited for their milk production potential. Among 43 sheep breeds, Patanwadi is considered to have higher milk yield. With the aim to compare different milking methods to get more yield and better lamb growth, 18 Patanwadi ewes having single born lambs were selected along with their lambs and randomly divided into three groups. Milk yield potential of ewes in Gr A was measured by hand milking method, whereas of Gr B by weigh-suckle-weigh method and of Gr C by hand milking followed by weigh-suckle-weigh method. Average daily milk yield was significantly (P<0.05) higher (658.00±24.60 ml) in Gr C compared to the ewes in Gr A (541.89±20.00 ml). Gr A lambs were fed by bottle feeding method while, Gr B and C lambs by suckling their dams. The lambs in suckling groups (Gr B and C) had significantly (P<0.05) higher growth compared to group A. The pre-weaning average daily gain (ADG) for Gr A lambs was 119 g as compared to Gr B and C (156 g). It was inferred that post-milking suckling method is the better method in Patanwadi ewes with respect to milk yield as well as for higher body weight gain in lambs.

Effects of dietary sepiolite usage on performance, carcass characteristics, blood parameters and rumen fluid metabolites in Merino cross breed lambs

The aim of this experiment was to determine the effects of dietary sepiolite supplementation on performance, carcass characteristics, blood parameters and rumen fluid metabolites in Merino cross breed lambs. For this purpose, a total of 21 weaned lambs, which were 3–3.5 months of age were allocated to one control group and two treatment groups each containing 7 lambs. The experiment lasted for a total of 90 days, of which the adaptation and experimental periods were 22 and 68 days, respectively. Pelleted alfalfa and concentrates were given to lambs individually. Concentrate diets of first and the second treatment groups were supplemented with 1 and 2% sepiolite as top dressed, respectively. There were no significant differences observed in body weights, body weight gains, hot and cold carcass yields, meat pH and meat composition among the groups. Relative weights of internal organs and carcass parts were also not affected by sepiolite supplementation. The addition of 1 and 2% sepiolite to the diets of animals increased the consumption of concentrates and total dry matter intake (P < .05). There were no differences among the groups in terms of consumption of dry matter of alfalfa, concentrates and total feed required for one kg body weight gain in lambs. However, body weight gain was increased by 4.22% and total feed conversion ratio was improved by 4.56% with 2% dietary sepiolite supplementation. Haematological and biochemical blood parameters and fecal dry matter were also not affected by the usage of sepiolite. Blood serum IgG levels were increased with sepiolite supplementation (P < .05). While the percentage of acetic acid in the total volatile fatty acids (VFA) in rumen fluid was decreased, neither the proportion of other volatile fatty acids nor the quantity of total volatile fatty acids were affected by dietary addition of sepiolite. It was concluded that 2% sepiolite supplementation in diets of Merinos cross bred lambs as top dressed may have economic benefits based on animal's immunity enhancement and some improvement in body weight gain and total feed conversion ratio without any negative effects on performance, carcass characteristics, rumen metabolites and blood parameters.

Effects of physical form of diet on nutrient digestibility, rumen fermentation, rumination, growth performance and protozoa population of finishing lambs.

This study was conducted to compare effects of 3 physical forms of feed including mash (diet 1), pellet (diet 2) and complete feed block (CFB; diet 3) on digestion, fermentation and performance of lambs. Twenty-one lambs with an initial average body weight of 26 ± 2.5 kg and 6 ± 1.5 months of age were assigned through a completely randomized design to 3 treatments and 7 replicates. The experimental treatments had the same formulation. The results of present experiment showed that CFB significantly increased feed intake and nutrient digestibility (P < 0.05). There was no significant difference among the diets for rumen fluid pH, blood glucose, concentration of volatile fatty acids (P > 0.05), except acetic acid (P < 0.05). The rumen ammonia nitrogen (NH3—N), mixed rumen protozoa population (RPP), Entodiniums spp., Epidiniums spp., blood urea nitrogen (BUN) concentration, rumination time adjusted for dry matter (DM), neutral detergent fiber (NDF), acid detergent fiber (ADF) intake, and total body weight gain of lambs in CFB diet were the highest among all diets (P < 0.05). Feed conversion ratio at days 31 to 45 and whole experimental period were better in CFB than in other diets (P < 0.05). Overall, according to the findings of the present study, among 3 physical forms of the diets, CFB had the best efficiency due to improvement of nutrient digestibility, rumen fermentation and performance of lambs. Therefore, the CFB diet offers the best result in lambs compared with mash and pellet diets.

Effects of anthelmintic treatment on ewe feed intake, digestion, milk production and lamb growth

SUMMARYTwenty Small Tailed Han (STH) and 20 Ujumqin (UJU) ewes naturally infected with gastrointestinal nematodes were randomly assigned to one of four treatments arranged in a 2 × 2 factorial design, receiving anthelmintic treatment (AT) or non-anthelmintic treatment (NonAT) prior to lambing. After lambing, the effects of AT on feed intake, digestion and milk yield in ewes, and the growth rates of lambs fed their mother's milk were assessed for 28 days. Faecal samples were collected to determine faecal egg counts (FECs), milk was collected to measure milk yield and ewes and lambs were weighed to quantify daily body weight change. The results showed that AT significantly increased ewe dry matter intake (2411 g/d for AT and 2209 g/d for NonAT) and decreased FECs (50 eggs/g for AT and 2655 eggs/g for NonAT). All ewes lost weight after lambing, but body weight loss in the AT (43 g/d) was significantly less than in NonAT (84 g/d), and STH ewes (70 g/d) lost more weight than UJU ewes (58 g/d). Anthelmintic-treated ewes produced more milk for their lambs to consume. However, the extent of these positive effects of AT differed between STH and UJU ewes. The average daily body weight gain of lambs in AT was higher than those in NonAT. In conclusion, effective AT in ewes before lambing benefits subsequent lactation in ewes and growth rate in lambs.

Avaliação do ganho em peso de cordeiros da raça Santa Inês no periparto criados na região do Planalto Central brasileiro

The beef goat activity has been developed and expanded in the last years, attracting lots of business men to invest in the activity potentials. The aim of this study was to evaluate the body weight gain in lambs of Santa Inês breed,in the periparturition, proceeding from Brazilian Central tableland. The data used were provided from three different livestock (livestock 01; livestock 02 and livestock 03). In the livestock 01 was to evaluated the weight and weight gains until the 60 days of age in pasture system compared topost-birthfeedlot system. In the livestock 02 was considered two year seasons (dry and water station) evaluating theirs effects upon the kind of birth (simple and twin) andweight gain. In the livestock 03 was evaluated the influence of two year season (dry and water station) upon the male and female of simple birth. The statistical analyses were carried out by the SAS statistical program and the means were compared by the t test (p

Effect of supplementary feeding of concentrate feed in Madras Red lambs under field conditions

A trial was conducted to study the effect of supplementary feeding of concentrate feed on growth in Madras Red lambs under field conditions during summer season. Body weight gain and average daily gain (ADG) were compared among control and treatment groups supplemented with either 125 or 200 g of concentrate feed daily. The mean body weight and ADG was higher in the group fed 200 g concentrate feed/day; however, repeated measures ANOVA for growth and univariate analysis for ADG, after adjustment for initial weight indicated absence of significant difference among the groups. The study suggests that supplementation of 200 g concentrate feed had no additional benefit in term of body weight gain in lambs.

A simulation model to predict body weight gain in lambs fed high-grain diets

A simulation model was developed to predict the average daily gain (ADG) in lambs fed high-grain diets. The model is deterministic and is based on the energy intake estimated from the digestibility of the ration as well as based on the California Net Energy System. The model was evaluated using data from eight experiments (28 treatments), with diets containing 50–72% grain. The ADG estimated with the model (244±44g/d) was similar to the observed ADG (249±44g/d; t test, P=0.70). The model was described by the following equation: Y=40.96+0.85X (r2=0.74; P<0.001), with an ADG residual value of −4.6±23g. A statistical evaluation indicated a mean bias value of 4.6, a root mean square error of prediction of 23, and a concordance correlation coefficient of 0.86. The results indicate that the gain can be predicted in finishing lambs with an acceptable accuracy and precision according to the developed model, with an underestimation of 1.85%.

Effect of balanced concentrate ration on the performance and hematobiochemical profile of lactating native ewes and lambs in coastal Odisha

Aim: The present study was conducted to evaluate the effect of supplementation of balanced concentrate ration during lactation on the growth performance, blood and metabolic profiles of native ewes and lambs in coastal Odisha. Materials and Methods: A total of 40 numbers of lactating ewes of the same parity comprised the experimental animals. The selected ewes were randomly assigned to two groups of twenty each, maintaining uniformity in body weight (13.36±0.33 kg for Group 1 and 13.48±0.37 kg for Group 2). Group 1 was maintained on grazing only while Group 2 was supplemented with a balanced concentrate mixture @ 200 g/head/day during the first 2 months of lactation. The concentrate was fed individually in separate containers in the morning hours before the animals were taken out for grazing. Results: The ewes in Group 2 registered higher body weights at every fortnight. The differences were found to be highly significant (p<0.01) from 2 nd to 5 th fortnight and significant (p<0.05) for the remaining fortnights. The ewes in Group 2 showed significantly (p<0.01) higher daily gains than those in Group 1 at every fortnight. The hemoglobin (Hb) concentration, mean cell hemoglobin (MCH) and total leukocyte count (TLC) values were significant (p<0.05) between groups at the end of 4 th fortnight after lambing and the mean cell hemoglobin concentration (MCHC) values is significantly (p<0.05) higher in Group 2 over Group 1. Conclusion: It was concluded that supplementation of a balanced concentrate mixture (crude protein 18.21%) @ 200 g/ewe/day along with grazing during the first 2 months of lactation resulted in higher ewe body weight gain. It improved their hematological and metabolic profiles and also resulted in higher body weight gain in lambs born to these supplemented ewes.

Body composition and nutritional requirements of protein and energy for body weight gain of lambs browsing in a tropical semiarid region

This study evaluated body fat, protein and energy contents and nutritional requirements for body weight (BW) gain of lambs in tropical semiarid conditions. Thirty-two castrated Santa Inês 3-to-4-month old lambs (initial BW: 15.8 kg ± 1.4 kg) were used. Eight lambs were initially slaughtered to serve as the reference for initial body weight composition. The remaining 24 animals were placed in a randomized block with three treatments and eight replications. Each one of the eight experimental blocks consisted initially of three 15 kg lambs to which treatments (daily supplement levels: 0.0, 1.0, and 1.5% of body weight of a corn, soybean and minerals concentrate mixture adjusted for a daily 200 g BW gain at 1.5% level) were randomly assigned. As one of the lambs reached 30 kg all three were slaughtered. Body composition (per kg of empty body weight - EBW), ranged from 171.59 to 145.84 g protein, from 0.53 to 319.00 g fat, and from 2,06 to 3,90 Mcal energy, for lambs from 15 to 30 kg EBW, respectively. Net requirements for 200 g BW gain/day ranged from 25.99 to 22.09 g protein and from 0.311 to 0.591 Mcal energy for lambs from 15 to 30 kg EBW, respectively. Santa Inês lambs browsing in tropical semiarid regions require more protein and less energy than lambs raised in temperate regions or kept in feedlots in tropical areas, as reported in the literature.

Effect of urea and oregano oil supplementation on growth performance and carcass characteristics of lamb fed diets containing different amounts of energy and protein

The experiment was carried out using a 4 × 4 factorial design. There were 16 experimental groups. Each group consisted of 3 lambs. The experiment lasted 56 days. During the experiment, the oregano oil (0 and 5 g/kg DM) and urea (0, 6, 12, and 18 g/head per day) were given to lambs consuming low energy/low protein diets (2350 Kcal/kg DM/ 10.80% CP/DM, respectively) and normal energy/normal protein (2600 Kcal/kg DM, 14.97% CP/DM, respectively) diets. Daily body weight gain of lambs consuming normal energy/normal protein diets and supplemented with 6, 12 and 18 g/head per day urea were significantly (P < 0.01) higher compared to those consumed low energy/low protein diets and supplemented with oregano oil. The voluntary feed intake of lambs consuming the normal energy/normal protein diets supplemented with urea (6, 12 and 18 g/head per day) was lower compared to lambs consuming low energy/low protein diets supplemented with oregano oil and urea. On the other hand, the feed efficiency of lambs consuming the normal energy/normal protein diets supplemented with urea (6, 12 and 18 g/head per day) was significantly (P < 0.01) higher compared to lambs consuming the low energy/low protein diets supplemented with oregano oil and urea. The supplementation of urea to lambs consuming the low energy/low protein diets and the normal energy/normal protein diets increased the weight of cold carcass. The supplementation of urea had no significant (P > 0.01) effect on the other carcass characteristics.

Effect of individual and mixed live yeast culture feeding on growth performance, nutrient utilization and microbial crude protein synthesis in lambs

This study investigated effects of feeding three individual, and a mixed, yeast culture ( Kluyveromyces marximanus NRRL3234, Saccharomyces cerevisiae NCDC42, Saccharomyces uvarum ATCC9080 all in a 1:1:1, ratio) on growth performance, nutrient utilization and microbial crude protein (CP) synthesis in feedlot lambs during the post-weaning phase of growth. Sixty weaner lambs (90 ± 3.5 d old and 15.9 ± 0.50 kg BW) were fed for 91 d in five equal groups. The control group of lambs received sterilized culture medium while the treatment groups were fed a yeast culture in addition to a ad libitum total mixed ration (TMR). The yeast culture, dosed at 1 ml/kg body weight (BW) had 1.5–2.0 × 10 9 live cells/ml. Yeast culture supplementation did not influence intake and digestibility of organic matter (OM), CP, neutral detergent fiber (NDF), acid detergent fiber (ADF) and hemicellulose and the metabolizable energy (ME) level of the diets were similar between control and yeast supplemented lambs. Lambs in all groups were in positive N balance, but N intake and N voided in feces and urine, as well as N balance, did not change due to yeast culture supplementation. Urinary allantoin excretion was similar, but purine derivatives absorbed (mM/d) were higher ( P<0.05) in yeast culture supplemented lambs. Yeast culture supplementation improved ( P<0.05) microbial CP synthesis. Supplementation of SC and mixed yeast improved ( P=0.002) BW gain of lambs by 21% and 16% respectively. All yeast culture supplemented lambs had higher feed efficiency in comparison to control lambs. Among the three yeast cultures used, S. cerevisiae had the most potential as a growth promoting feed additive in feedlot lamb production, and it may serve as an alternate to antibiotics and ionophores as a growth promoter of weaner lambs.

Effects of bovine growth hormone in suckling lambs.

The objective of this study was to determine the effects of bovine growth hormone (bGH) on body growth of suckling lambs. Suckling Merino lambs (fed on milk replacer from 4th day of life) were daily injected from 10th to 38th day of life with 80 micrograms bGH/kg b.w. Only insignificant increase of body weight was observed after 4 weeks of GH treatment. After 31st day of life body weight gain in the experimental lambs was significantly higher. It can be concluded that bGH increases body weight gain of lambs in 2nd month of life. It is probable that growth rate of sucklings is limited only by biological and biochemical capabilities of the organism and it can be hardly influenced by exogenous hormonal manipulation.

Effects of different forms of Acacia saligna leaves inclusion on feed intake, digestibility and body weight gain in lambs fed grass hay basal diet

The study was undertaken to determine the effects of different forms of Acacia saligna leaves inclusion on feed intake, digestibility and body weight gain in lambs fed grass hay basal diet. Twenty local ‘Farta’ yearling male lambs weighing 17.4 ± 0.10 kg (mean ± SD) were randomly allocated to four dietary treatments consisting of daily feeding of lambs in T1 with 700 g grass hay (dry matter basis), and daily free choice feeding of lambs in T2, T3, and T4 with 700 g grass hay + 700 g fresh, wilted, and dried A. saligna leaves, respectively. Inclusion of different forms of A. saligna leaves improved ( P<0.01) the daily intake of total DM by 8–9% and that of OM and CP by 7 and 38%, respectively compared to the control. The daily intake of NDFom was lower ( P<0.01) by 1–2.3%, whereas that of the ADFom intake declined ( P<0.01) by 1.3–3.4% for lambs on wilted and dried forms of A. saligna leaves. Inclusion of A. saligna leaves replaced the intake of the grass hay by 26–27% of the total diet and reduced ( P<0.05) apparent digestibility coefficient of the total DM by 9, 7, and 4%, OM by 7, 6 and 4%, and CP by 12, 12, and 9%, but improved ( P<0.05) apparent digestibility coefficient of NDFom by 3–4% compared to the control diet. Dried A. saligna leaves improved ( P<0.05) apparent digestibility of DM, OM and CP compared to fresh A. saligna leaves. Lambs fed on hay alone lost ( P<0.05) body weight, while the lambs supplemented with A. saligna leaves gained ( P<0.05) weight. The results of this study revealed that A. saligna leaves could be best included in the grass hay based feeding in dried form at the rate of 265 g/kg DM for improved nutrient utilization and growth performance of yearling lambs.

耕作放棄地を利用した放牧における野菜クズの補助給与が子羊の行動および増体に及ぼす影響

Effect of the supplementary feeding of vegetable rubbish on grazing behavior and body weight gain of lambs in a less favored area (natural grassland) were investigated. Six Suffolk lambs were divided into two groups ; treatment (T) and control (C) groups. Both groups of lambs were kept in one side of the divided grazing area (3.9 a each) enclosed with electric fences. The lambs of group T were fed vegetable rubbish every morning as additional feed. Both groups of lambs maintained their body weight over the grazing periods. In the middle and the latter grazing periods, the proportion of lying-ruminating was significantly high in group C than T (both P<0.05). Group T showed higher proportion of moving than group C. The lambs of group T began to eat the vegetable rubbish from the second grazing week. These results suggest that it was useful to feed sheep on vegetable rubbish in natural grassland. Feeding sheep on vegetable rubbish can prevent unwitting feeding to wild animals by vegetable dregs left in the fields.

Influence of feeding type on production results of fattening lambs

Investigations were carried out on five private farms in the region of Stara Planina Mount, Dimitrovgrad municipality. The influence of the feeding type on production results of fattening lambs was investigated during the trial. Lambs obtained by crossing between Pirot Pramenka and Wurttenberg were used for investigations. Two feeding systems were investigated: extensive and semi-intensive. On three private farms extensive system of feeding was applied. In the extensive system of feeding lambs sucked milk during first fifteen days. After this period lambs were fed hay and grain mixture (barley, oats and wheat) ad libitum. Fattening period lasted to the age of 90 days. On two private farms semi-intensive feeding system was applied. In the semi-intensive system of feeding lambs sucked milk during first fifteen days, and next fifteen days they were fed concentrate-complete starter mixture and hay ad libitum. After this period lambs were fed hay and grain mixture (barley, oats and wheat) ad libitum. Fattening period lasted to the age of 75 days. During trial we have monitored gain of body mass and feed consumption (hay and concentrate). The highest average body weight gain (299 g) during all period of fattening was registered in lambs in semi-intensive feeding system. Average daily body weight gain in lambs on extensive feeding system was 251 g in relation to semi-intensive feeding system where it was lower by 19, 12%. Lambs in semi-intensive feeding system achieved final body weight (25, 25 kg) for 75 days of fattening (1-75 days) while lambs in extensive feeding system had similar final body weight (25, 65 kg) in the age of 90 days, what means that they needed 15 days more to achieve similar final body weight. Lambs in semi-intensive feeding system consumed 15, 09% hay less and 10, 94% less concentrate for unit of gain in comparison with lambs in extensive feeding system.

Protein, acetate and propionate for roughage-fed lambs. 1. Body and blood composition

AbstractSixty castrated male lambs fca. 37 kg) were allocated to an initial slaughter group (no. = 12) or to one of six treatment groups (no. = 8). Chopped oaten hay (sprayed with 10 g urea per kg) was offered ad libitum with 57 gjday chopped lucerne hay. Additional supplements were 0 or 57 g/day formaldehyde-treated casein (protected casein) and volatile fatty acids (VFAs) at ca. 1·45 MJ gross energy per day. The VFAs given were acetate or propionate or a mixture of these (molar ratio 4: 1). Daily food intake and weekly live-weight (LW) gain were measured and rumen fluid and blood were collected. The lambs were shorn, slaughtered and body composition was determined.Food intake (g/kg LW) was not affected by treatments. Supplementation with protected casein increased LW gain and wool growth. Supplementation with propionate reduced LW gain, but not when given with protected casein. Plasma concentrations of urea-nitrogen and insulin were increased, and plasma somatotropin decreased in lambs given protected casein. Final body content of water, fat, protein and gross energy, adjusted to the mean fleece/digesta-free body weight of 36·5 kg, was not affected by the treatments. The partitioning of water, fat and energy between the carcass and the rest of the body was affected by the treatments. Excretion of VFAs in urine was measured in two sheep in experiment 2, and was negligible compared with the quantity of VFAs given. It is concluded that energy from salts of VFAs, in particular propionate, is used inefficiently for body-weight gain in lambs given low-protein roughage diets. The nutritional treatments had only marginal effects on the composition of body gain.