A note on crossbreeding for fat-lamb production in the hot tropics

1982 ◽  
Vol 35 (3) ◽  
pp. 435-438 ◽  
Author(s):  
J. P. Sehgal ◽  
S. A. Karim ◽  
Manohar Singh ◽  
R. M. Acharya

ABSTRACTTo compare the genetic group differences in live-weight gains, efficiency of food conversion (in terms of dry matter, total digestible nutrients, digestible crude protein, digestible energy and metabolizable energy) and physiological responses related to heat balance, a total of 24 male lambs (91 to 180 days old), four each of Malpura, Sonadi, and their crosses with Dorset and Suffolk breeds, were given a ration having a roughage to concentrate ratio of 250:750g/kg and metabolizable energy content of 100MJ/kg dry matter. Live-weight gain per day was higher and the food conversion ratio (the intakes of total digestible nutrients, digestible energy and metabolizable energy per kg gain) was lower in the crossbreds than in the native sheep. The crossbreds had higher respiratory rates (153 per min) than the natives (140 per min) but there was no significant difference in rectal temperature between purebreds and crossbreds. The crossbred lambs in the present experiment grew faster, consumed more food and utilized the food more efficiently than did the native lambs, despite the fact that they dissipated more energy as body heat. It was, therefore, concluded that the crossbreds performed better than the native breeds between 3 and 6 months of age, even though they were not permanently acclimatized to hot environmental conditions.

1982 ◽  
Vol 98 (2) ◽  
pp. 395-404 ◽  
Author(s):  
G. D. Tudor ◽  
D. J. Minson

SUMMARYThe net energy values for growth and fattening of two artificially dried tropical grasses-, pangola (Digitaria decumbens) and setaria (S. sphacelata var. sericea cv. Nandi), of similar estimated metabolizable energy content (8·07 and 7·96 MJ/kg D.M.) were determined with cattle using a slaughter technique. Growing cattle with a mean initial weight of 175 kg were given equal quantities of dry matter of the two grasses at each of three planes of nutrition above maintenance for a period of 152 days.The initial energy, fat and protein content of the total body of the 24 test animals was estimated from regressions relating fasted live weight to theśe components, derived from 12 similar cattle slaughtered at the beginning of the feeding period. The final energy, fat and protein content of the test animals was determined directly by chemical analysis. The metabolizable energy (ME) content of the grasses was estimated from the level of digestible energy (DE) determined with eight cattle, assuming that ME = 0·815 DE.The cattle fed pangola gained more live weight, empty-body weight, fat, protein and energy than animals fed similar quantities of setaria. The net energy value for growth and fattening (NEf) was determined using regressions relating energy retention to the quantity of dry matter eaten. NEf in MJ/kg dry matter was 2·27 for pangola and 1·31 for setaria.Efficiency of utilization of ME for growth and fattening (kf) was.27·7% for pangola and 16·9% for setaria. These values for tropical grasses are lower than any values reported for temperate pasture species. Thus the lower efficiency of utilization of ME may cause the lower production of cattle which graze tropical grasses.It was concluded that as the kf values of different tropical grasses are not constant, kf values should be measured on a wider range of tropical grasses so that this factor can be taken into account when evaluating grasses in animal production systems.


1980 ◽  
Vol 94 (3) ◽  
pp. 715-726 ◽  
Author(s):  
J. F. D. Greenhalgh ◽  
G. W. Reid

SummaryTwo experiments were made, each with 35 autumn-calving cows fed on complete diets containing 40–70% hay and 60–30% concentrates. In both experiments, cows fed to appetite on a diet containing 11 MJ metabolizable energy/kg D.M. for weeks 7–24 of lactation ate about 20% more than cows rationed according to yield, but produced only about 3% more milk. The cows fed to appetite gained more in live weight, but lost their weight advantage during the subsequent grazing season.In Expt 1, a further group of cows were fed to appetite on diets progressively reduced in metabolizable energy content from 11·0 to 9·2 MJ/kg. Dry-matter intake decreased by about 1·2 kg/day per 1 MJ reduction in energy content. The lower dry-matter and energy intakes of cows on this treatment did not significantly reduce their milk yield, but their response when turned out to grass suggested under-nutrition in late winter. In Expt 2, increasing the energy content of the diet in early lactation (weeks 7–12) and reducing it thereafter had no significant effect on milk yield.Within each treatment group there were reasonably close relationships between energy intake and energy requirement. Nevertheless, it seems likely that the efficiency of feed utilization of cows fed on complete diets will be low unless intake is controlled by energy dilution.


1972 ◽  
Vol 79 (1) ◽  
pp. 155-160 ◽  
Author(s):  
T. L. J. Lawrence

SUMMARYIn a randomized block 3x2 factorial experiment 72 Large White type and Large White x Landrace pigs were restrictedly fed to 160 lb (72–5 kg) live weight on diets (as wet mashes) containing high levels of maize, wheat or barley in either ground meal or ground flaked forms. A further five groups of six litter-mate Large White type hog pigs per group were used in digestibility and nitrogen balance studies. The diets of meal were formulated to be iso-nitrogenous and to contain similar levels of lysine and for each cereal similar levels of protein and vitamin/mineral supplements were included in the flaked diets. There were no significant cereal x processing interactions for any of the parameters studied. Overall, flaking improved digestibility and this was reflected in a higher (P >0-05) digestible energy content of the flaked diets (3402 kcal/kg air dry weight) compared with the meal diets (3334 kcal/kg air dry weight). The digestible energy contents of the maize, wheat and barley diets were significantly different (P < 0-001) at 3477, 3431 and 3195 kcal/kg air-dry diet respectively. Nitrogen retention, growth rate and efficiency of food conversion were all significantly poorer for the flaked, compared with the meal based diets. The nitrogen retained from the wheat-based diets was significantly lower than that retained from the maize- and barley-based diets. Growth rates of pigs given the wheat- and barley-based diets were similar but taken together were significantly (P < 0-05) better than those obtained from pigs given the maize-based diet. Efficiency of food conversion followed a similar pattern but the differences were not statistically significant.


1985 ◽  
Vol 104 (1) ◽  
pp. 47-59
Author(s):  
F. H. K. Asiedu ◽  
S. K. Karikari

SummaryPure and mixed swards of Centrosema pubescens (centro), Pueraria phaseoloides (puero) and Brachiaria mutica (para grass) established under a 12-year-old mango plantation were sampled at 6-week intervals for 2 years to determine crude-protein (CP) content, dry-matter (D.M.) and CP yields and apparent digestible energy and apparent digestible crude-protein (DCP) contents. Daily dry-matter intake (DMI) and apparent digestible energy and digestible crude-protein intakes (DEI and DCPI), as well as live-weight gain (LWG) by 11·5 kg penned West African cross-bred weaner lambs, were also determined.The pure legumes were better than the mixed swards in respect of CP (mean: 22·1, 18·8, 14·4 and 13·8% for centro, puero, centro-para grass and puero-para grass respectively) and DCP (mean: 16·2, 13·4, 10·4 and 10·0% respectively) contents, and daily DMI (mean: 50·8, 49·7, 41·8 and 41·3 g/kg W0·75 respectively), DEI (mean: 562, 531, 418 and 410 kj/kg W075 respectively) and DCPI (mean: 8·09, 6·55, 4·04 and 3·94 g/kg W0·75 respectively). On the other hand the legume-grass mixed swards, especially puero-para grass, were superior to the corresponding pure-legume swards with regard to D.M. yield (mean: 11·90, 7·69, 7·13 and 4·54 t/hafor puero-para grass, centro-para grass, puero and centro respectively) and CP yield(mean: 1·62,1·09, 1·32 and 0·99 t/ha respectively). The pure-legume stands gave the highest LWG per lamb (mean: 45·7, 3·89, 2·63 and 25·3 g/day for centro, puero, centro–para grass and puero-para grass respectively) but it was estimated that the legume-grass mixed swards would give higher returns in terms of lamb LWG on forages harvested per unit sward area than the corresponding pure-legume cover.It was concluded that legume-grass covers would be preferred to all-legume covers if livestock were to be integrated into tree crop farming systems. However, the choice of companion grass would have to be given proper consideration as shade-intolerant grass species, such as para grass, would detract from profit maximization.


1975 ◽  
Vol 20 (2) ◽  
pp. 199-205 ◽  
Author(s):  
D. Levy ◽  
Z. Holzer ◽  
Y. Folman

SummaryThe effects of roughage level (15 and 35% of the ration) and of slaughter weight (400,450 and 500 kg) were studied in an experiment of 2 x 3 factorial design. Daily live-weight gains and carcass gains were significantly higher on the lower roughage levels, but there was no difference in degree of fatness of the carcass. Dry-matter intake expressed as a percentage of body weight was 2·91 on 35% roughage compared with 2·53 and 15% roughage, i.e. 15% higher on the highroughage diet. This compensated the animals on the high-roughage diet for the lower energy content of their feed. Rate of gain increased with an increase in slaughter weight. The percentage of fat trim and of saleable meat increased, while that of bone decreased significantly with an increase in slaughter weight. The animals on the lowroughage diet were approximately 11% more efficient than the others in converting metabolizable energy into live weight.


1997 ◽  
Vol 65 (2) ◽  
pp. 143-149 ◽  
Author(s):  
J. E. Offer ◽  
D. N. Logue ◽  
D. J. Roberts

AbstractTwo groups of 16 cubicle-housed Holstein-Friesian cattle from weeks 3 to 27 of lactation were offered either a proprietary protein supplement of animal origin (P) or soya-bean meal (S) as the protein source in the concentrate in a continuous design experiment. Concentrates were offered mixed with grass silage as complete diets to give a forage: concentrate ratio of 41: 59 and a crude protein content of 213 and 210 g/kg dry matter (DM) and a metabolizable energy content (MJ/kg DM) of 11·9 and 12·0 for P and S respectively. There was no significant difference due to diet for mean locomotion score (1·75 v. 1·66 (s.e. 0·15)), prevalence (0·1 v. 0·09 per cow per week) or incidence of lameness (0·04 v. 0·04) for P and S respectively. Similarly there was no effect on hoof growth, wear, hardness or conformation. Sole haemorrhages, indicative of subclinical laminitis, were observed throughout the experiment but were most severe at approximately 16 weeks after calving. Levels of heel erosion remained constant throughout. There was no significant effect of treatment on either heel or sole lesion formation. No significant differences were observed between treatments for milk yield, live weight, condition score or blood metabolites. The conclusions from this study were that source of dietary protein has no effect on dairy cow lameness or the development of sole lesions indicative of subclinical laminitis.


1967 ◽  
Vol 9 (2) ◽  
pp. 141-148 ◽  
Author(s):  
D. J. A. Cole ◽  
J. E. Duckworth ◽  
W. Holmes

1. The voluntary feed intakes of pigs fed on diets having calculated digestible energy contents of 2,970, 3,356, 3,630 and 3,910 kcal/kg. dry matter were measured over four periods from 38 to 105 kg. live-weight.2. The pigs achieved similar daily digestible energy intakes regardless of the digestible energy content of the diet.3. When housed in metabolism crates pigs ate less than when housed in holding pens and the difference was greater than would be expected solely from the reduced exercise of the pigs in crates.4. Daily digestible energy intake was 575 kcal/kg. live-weight 0.675 when the pigs were in holding pens. The daily digestible energy intake of pigs in metabolism crates increased less with live-weight.5. The use of metabolism crates to obtain digestibility coefficients and values for nitrogen retention to be applied to animals housed under other conditions is discussed in relation to the differences found in apparent digestibility coefficients, feed intake and growth rates between pigs in crates and in holding pens.


1982 ◽  
Vol 34 (3) ◽  
pp. 351-353
Author(s):  
Jean M. Bass ◽  
G. Fishwick ◽  
J. J. Parkins

ABSTRACTGroups of Hereford-cross steers weighing 283 kg were given 0·6 kg dry matter hay per head per day, and bruised barley supplemented with 40 g of a fully soluble liquid product per kg, containing urea, minerals and vitamins, ad libitum. Half the animals received 10 g limestone per kg diet as an additional supplement. Over a 105-day period the food intake of the limestone-supplemented animals was 0·20 higher than that of unsupplemented animals. The resultant daily live-weight gain was 1·22 kg compared with 0·92 kg for the animals receiving the diet containing no additional limestone. Food conversion ratios (kg/kg live-weight gain) were improved by limestone supplementation from 6·84 to 6·19. Limestone inclusion did not appear to influence the low concentrations of starch (ca. 15 g/kg) present in the faecal dry matter but there was a small significant difference in faecal pH.


2010 ◽  
Vol 39 (6) ◽  
pp. 1237-1245 ◽  
Author(s):  
Adimar Cardoso Júnior ◽  
Paulo Borges Rodrigues ◽  
Antônio Gilberto Bertechini ◽  
Rilke Tadeu Fonseca de Freitas ◽  
Renato Ribeiro de Lima ◽  
...  

Two experiments using Cobb broiler chicks from 8 to 35 days of age were carried out to evaluate the effect of reducing levels of calcium and available phosphorus in diets supplemented with 500 ftu phytase/kg on the performance of the birds, the content of ashes in the tibia, the metabolizable energy of the diet, and the metabolizability of the dry matter and crude protein. It was used 1,404 broiler chicks in the experiment 1 to evaluate feed intake, weight gain, food conversion and percentage of the ashes in the tibia. In the experiment 2, simultaneously carried out with experiment 1, a total of 390 birds were transferred to a metabolism room to determine the metabolizable energy and metabolizability of the dry matter and crude protein. It was used in the two experiments, a complete random design in a 3 × 4 + 1 factorial scheme with three levels of available phosphorus (0.375; 0.325; and 0.275%) and four levels of calcium (0.85; 0.75; 0.65 and 0.55%) in the diets, supplemented with phytase. It was also used a control diet without phytase, based on corn and soybean bran, formulated with 0.425% of available phosphorus and 0.85% of calcium. In the experiment 1, the reduction of levels of calcium and phosphorus did not cause a significant difference on the performance and percentage of bone ashes. The levels of calcium and available phosphorus used in the experiment 2 can be reduced down to 0.65 and 0.325%, respectively, because the effects are similar to those obtained with the currently suggested levels.


1990 ◽  
Vol 51 (2) ◽  
pp. 221-227 ◽  
Author(s):  
E. F. Kelly ◽  
J. D. Leaver

ABSTRACTA concentrate containing ground barley, soya-bean meal and fish meal was compared with one containing dried molassed sugar-beet pellets, dried distillers' grains and fish meal, in its influence on lameness in housed dairy cattle. Two groups of 24 cows were offered the diets in a 60:40 concentrate dry matter: grass silage dry matter ratio during weeks 3 to 26 of lactation. The same daily amounts of metabolizable energy and crude protein were offered to the two groups. The barley-based concentrate diet significantly increased locomotion score (indicating poorer locomotion), and the number and duration of clinical cases of lameness, compared with the sugar-beet concentrate diet. Hoof growth, wear, shape and hardness were not significantly affected by the diets. There were 16/24 cows with a locomotion score of 3 or over (1 to 5 scale) for an average of 7·3 weeks on the barley concentrate compared with 10/24 cows for 3·7 weeks on the sugar-beet concentrate. There was no significant difference between treatments in milk production or live-weight gain.


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