Growth Performance Characteristics Research Articles

Growth performance of broiler chicks fed graded levels of processed taro cocoyam (Colocasia esculenta) meal based diet

An eight-week feeding trial was conducted to evaluate the growth performance characteristics of (120) broiler starter fed varying levels of parboiled sundried taro cocoyam (Colocasia esculenta) meal (PSCM). Four treatments were formulated with diet one containing 100% maize as control, while in diet two, three and four parboiled sundried cocoyam meal (PSCM) replaced the percentage proportion of maize in diet one at 50, 75 and 100% inclusion level respectively. Thirty (30) birds were randomly assigned to the four treatment diets in a completely randomize designed (CRD) each treatment group comprising of three replicates with ten (10) birds each. Growth performance revealed a significant variation (P<0.05) in the values of final live weight, daily feed intake and weight gain with highest value (1.62kg, 480.00g and 62.00g/bird) among those fed 50% PSCM. Feed conversion ratio (13.02) was least and best among those on 50% PSCM and protein efficiency ratio was higher (0.06) among those fed the control. It is concluded therefore from this study that parboiled sundried taro cocoyam meal is a valuable replacement for maize up to 50% in broiler diets without adverse effects on the growth performance of starting broiler chickens.

English

Among the currently available poultry feed additives, natural herbs and plants have been widely advocated due to their reported widespread beneficial effects. Vernonia amygdalina is one of such potential feed supplements which have recently been reported as having a wide range of beneficial effects on production performance. This study was designed to evaluate the effect of varying levels of V. amygdalina leaf meal on growth performance, hematological parameters and as anticoccidial agent for broiler chicken. A total of one hundred and fifty day old marshal broiler chicks were randomly allotted to five dietary treatments with 30 birds per treatment, replicated thrice, in a completely randomized design. The treatments were: Treatment 1 (T1) served as control (positive control) with inclusion of coccidiostat but no inclusion of V. amygdalina, T2 served as negative control with no inclusion of either coccidiostat or V. amygdalina, T3 (200 g of V. amygdalina/ 150 kg of feed), T4 (400 g of V.amygdalina/ 150 kg of feed), and T5 (600 g of V. amygdalina/150 kg of feed). Significant differences (p < 0.05) were observed in the growth performance characteristics.  The result of hematological indices shows that there were no significant differences (p > 0.05) across the treatment except for hemoglobin in T2 that has the lowest (8.04 g/dl) and T4 that has the highest (12.03 g/dl). Eosinophil’s in T4 has the highest value (4.00%) and lowest in T5 (2.00%) and T2 (2.00%). However, all other parameters were within the normal range. It can be concluded that V. amygdalina can be used as anticoccidial in broiler chickens due to high fed conversion ratio and Eosinophil’s observed in T3 (200 g) and T4 (400 g), respectively.  Key words: Natural herbs, vernonia amygdalina, performance, haematological, coccidiostat. &nbsp

The Performance Characteristics and Economic Evaluation of Weaner Rabbits Fed Varying Levels of Sundried False Yam (Icacina Tricantha) Meal

A seven week feeding trial was conducted to evaluate the growth performance characteristics and economics of production of 15 unsexed weaner rabbits fed varying levels of Sundried false yam (Icacina tricantha) meal. Five treatments diets were formulated with diet 1 containing 100% maize as control, while in diet 2, 3, 4 and 5 Sundried false yam meal replaced the percentage proportion of maize in diet 1 at 25, 50, 75 and 100% inclusion level respectively. Rabbits were randomly assigned to the five treatment diets in a complete randomized designed (CRD) with three replicates of one rabbits each. Performance characteristics revealed that final live weight and weekly feed intake were significantly (P<0.05) influenced with highest value (2.12kg/rabbit and 407.33g/rabbit) recorded from rabbits fed 0% SDFYM comparable to (1.98kg/rabbit and 323.33g/rabbits) recorded in those fed 50% SDFYM. Avearage weekly weight gain was also significantly (P<0.05) influenced with highest value (197.00g/rabbit) from those fed 50% SDFYM. Feed conversion was lowest and best (1.28) from rabbits fed 25% SDFYM. Mortality rate was lowest (3.43%) in rabbits fed 50% SDFYM. Cost and return analysis revealed that total cost of feed consumed was least (378.24 N /rabbits) from those fed 50% SDFYM and highest in control, cost of feed per kg weight gain and total cost of production were lowest (30.50 and 2178.24 N /rabbits) from the rabbits that ate 75% SDFYM and highest in control. Income and net profit were highest (5000 and 1763.36 N /rabbits). It is concluded from this study that Sundried false yam meal is a valuable substitution for maize up to 50% in rabbit diets without any adverse effects on the performance characteristics and economic returns of rabbits.

Growth Performance Characteristics of Broiler Chickens Fed Graded Levels of Sundried Cassava (Manihot esculenta) Peel Meal Based Diet

Growth Performance Characteristics of Broiler Chickens Fed Graded Levels of Sundried Cassava (Manihot esculenta) Peel Meal Based Diet

Pre-Weaning Growth Performance of Piglets at Smallholder Farms in Gauteng Province

The objective of the study was to determine pre-weaning performance of piglets born following artificial insemination (AI) at smallholder farms of Gauteng province. Data from 496 piglets originating from 73 multiparous crossbred sows were used in the study. Litter size, number of piglets born alive, number of piglets weaned, birth and weaning weights were recorded. Data was analysed using the Proc Univariate procedure of SAS. The average litter size was 11.8. The average birth weight and weaning weights were 1.9 and 6.2 kg, respectively. No significant differences were found between male and female piglets for all the growth performance characteristics. Piglets born during winter had a significantly higher (P < 0.05) birth and weaning weight as compared to autumn and summer months. Season had a significant effect on birth and weaning weight (P < 0.01). However, sex of piglets had no significant effect on all the characteristics recorded (P > 0.05). The interaction between sex and season was only confirmed on the total number of weaned piglets (P < 0.01). A highly significant positive correlation was found between litter size and number of piglets born alive (r = 0.86) and total number of piglets weaned (r = 0.50). A highly significant correlation was found between total number of piglets born alive and total number of piglets weaned (r = 0.55). In conclusion, season of birth had the greatest impact on birth and weaning weight, with the highest birth and weaning weights recorded during winter season. However, sex did not affect the pre-weaning performance of piglets.

The Effect of Growth Rate on Some Beef Performance Characteristics of Czech Fleckvieh Heifers

The objective of this study was to determine the effect of growth rate on some beef performance characteristics in Czech Fleckvieh heifers. Growth performance characteristics included age at slaughter (months) and daily weight gain (g). The observed beef performance characteristics were carcass weight, conformation class (SEUROP) and external fat deposition. The experimental group consisted of 480 heifers. The animals were assigned into three groups (A, B, C) based on age at slaughter. Group A consisted of 68 animals with the age at slaughter 15–21 months, group B 296 animals, age 22–28 months and group C 116 animals, age 29–35 months. A greater age at slaughter was significantly associated with a greater carcass weight which grew from 250.78 kg in group A to 317.69 kg in group C. The net weight gain decreased with age from 424.06 g in group A to 346.41 g in group C, the conformation improved from 4.46 in group A to 4.17 in group C and the external fat deposition increased from 2.5 in group A to 2.78 in group C. The dataset was again split into three groups differing in the daily weight gain (I, II, III). Group I consisted of 120 heifers with the daily gain up to 599 g, group II 303 animals with the daily gain of 600–799 g and group III only 57 animals with the gain of 800 g and more. A growing weight gain was significantly associated with a greater carcass weight (from 260.40 kg in group I to 338.66 in group III), a greater net weight gain (from 306.29 g in group I to 491.45 g in group III), improved conformation (from 4.75 in group I to 3.70 in group III) and the fat deposition was greater, too (from 2.35 in group I to 2.89 in group III).

The Feeding Value of Rice Husk with or Without Probiotics and Enzyme Supplementation in Replacing Groundnut Cake in the Diets of Juvenile Snails (Archanchatina Marginata)

A total of three hundred and sixty (360) juvenile snails (archanchatina marginata) of similar body weight and age were used to determine the effects of replacing rice husk for groundnut cake (GNC) with or without probiotics and enzyme supplementation. The experiment which lasted for ten weeks (10) was a 3x4 factorial experiment with three replacement levels of rice husk (0, 30 and 60%) for groundnut cake by four supplemental levels (No supplement, Probiotics A, Probiotics B and Enzyme). The results showed that increase in the inclusion level of rice husk had significant effects (P0.05) on the feed intake and rate of gain of shell thickness. There were significant effects (P0.05) of the supplementation was observed on the rate of gain of shell thickness. Juvenile snails fed probiotics B significantly (P0.05) than snails fed probiotics A. The interactions between the varying levels of rice husk and supplements had significant effects (P0.05) on the rate of weight gain, daily feed intake, rate of gain of shell length and rate of gain of shell thickness. This study showed that snails fed 30% inclusion level of rice husk supplemented with probiotics A is the best replacement for groundnut cake as it gave the best growth performance characteristics, snail shell parameters and financial returns.

Effect of different stocking densities on growth performance and profitability of Oreochromis niloticus fry reared in hapa-in-pond system

A one month trial of sex reversal treatment of O. niloticus fry of varying stocking densities was performed in hapas-in-pond to determine the growth performance characteristics and profitability. Larvae were selected, collected, weighed and stocked inside a 10.0 m2 hapas in a 0.2 ha pond with stocking densities of 10000 (A), 15000 (B) and 20000 (C). Each stocking were made in triplicate. Fry were fed with a 36% crude protein plus hormone incorporated feed five times a day. Weekly samplings of fry were done including water quality parameters. Final average body weights of treated fry were 0.226 ± 0.02, 0.125 ± 0.02 and 0.080 ± 0.01 g for treatments ‘A’, ‘B’, and ‘C’ stocks respectively. The fry growth in treatment ‘A’ was significant (at p < 0.05) among all other stocks. It also exhibited high specific growth rate and a lower feed conversion rate than others; however, high survival was achieved with fry in treatment ‘B’. High value of fry crop was achieved in treatment ‘C’ with a value of GH¢ 638.96. Although profit index did not vary significantly from each other, the treatment ‘B’ reached the highest value of 23.13 ± 9.01. The increasing fry stocking density of fry significantly affected the growth and feeding conversion rate, however, it did not affect the survival data. Due to the high profit index, relatively high growth rate and high survival, treatment ‘B’ is recommended for fry rearing in a 10.0 m2 hapa-in-pond system. Key words: Nile tilapia, hormonal feed, specific growth rate, profit index, feed conversion rate.

Meat quality of rabbits reared with two different feeding strategies: with or without fresh alfalfa ad libitum

The aim of this study was to evaluate production performance, carcass characteristics and nutritive value of meat of rabbits reared under the 2 prevailing feeding strategies in Uruguay. One week after weaning, 96 purebred V line rabbits were randomly distributed between 2 treatments: (T1) commercial pelleted food ad libitum and (T2) commercial pelleted food ad libitum plus fresh alfalfa ad libitum. Each treatment included 12 cages containing 4 individuals each (2 males and 2 females). Growth performance characteristics (live weight evolution, commercial food consumption and food/gain ratio) were evaluated. The consumption of alfalfa was not measured. Rabbits were slaughtered at a live weight of 2500 g and carcass characteristics were evaluated. Samples of meat and dissectible fat were analysed to determine intramuscular fat content at muscle L. dorsi, dissectible fat and intramuscular fat composition, minerals (Zn, Fe, Mg and Na), vitamin E and purines. Sensory evaluations were conducted to assess the effect of treatments on the consumer’s perception of differences and the existence of attributes determining preferences. Differences between treatments were significant for total commercial food intake (23 356 vs. 20 930 g/cage; P<0.001) and feed conversion ratio (3.82 vs. 3.41; P<0.01) for T1 and T2 respectively. No significant differences were found in average daily gain, age at slaughter and carcass characteristics. There were no significant differences in the intramuscular fat content. The fatty acid composition of dissectible and intramuscular fat was affected the inclusion of alfalfa in the diet increasing the linolenic acid content (1.82 vs. 3.28% and 2.29 vs. 5.15% for T1 and T2 at intramuscular and dissectible fat, respectively; P<0.001), and improving the n-6/n-3 relationship (8.60 vs. 5.82 and 11.58 vs. 5.64 for T1 and T2 at intramuscular and dissectible fat, respectively; P<0.001). There were no significant differences in vitamin E, Fe or Zn content between treatments, but in Mg (22.5 vs. 24.4 mg/100 g for T1 and T2; P<0.05) and Na (44.1 vs. 48.2 mg/100 g; P<0.05). In the sensory evaluation, panellists significantly perceived differences between treatments with 95% confidence.

Genetic variation in feed consumption, growth, nutrient utilization efficiency and mitochondrial function within a farmed population of channel catfish (Ictalurus punctatus)

We evaluated the effects of diets (32/4 or 36/6 percent protein/fat) and six channel catfish families for growth performance characteristics. Two families with fast- (C) and slow- (D) growth rate and with low and high feed efficiency (FE) were selected for analyses of mitochondrial complex enzymatic activities (I, II, III, and IV) and gene expression (ND1, CYTB, COX1, COX2, ATP6) levels in liver, muscle, and intestine. There were significant differences in growth rate and nutrient retention among the families. Mitochondrial enzymatic complex activities (I-V) in the tissues were all lower in family C. Four of the five genes were down-regulated in the liver and up-regulated in the muscle for the fast growing family C. There were significant differences between diets for some mitochondrial respiratory chain enzyme activities and gene expression levels. Significant diet×family interactions were observed for some enzyme activities and gene expression levels. Changes in mitochondrial respiratory chain enzyme activities and gene expression levels provide insight into the cellular mechanisms of fish with differences in growth rate and feed efficiency. Results also suggest that genotype×diet interactions should be accounted for when considering strategies for using mitochondrial function as a criteria in channel catfish selection programs for improved growth performance characteristics.

Comparative effects of virginiamycin supplementation on characteristics of growth-performance, dietary energetics, and digestion of calf-fed Holstein steers

Two trials were conducted to evaluate the influence of virginiamycin supplementation on growth performance and digestive function. In trial 1, 144 Holstein steer calves (119 kg of initial BW) were used in a 340-d trial. Treatments were (DM basis) 1) control (no antibiotic); 2) 16 mg/kg of virginiamycin; 3) 22.5 mg/kg of virginiamycin; and 4) 28 mg/kg of monensin. Calves received a steam-flaked corn-based growing diet for the first 112 d and thereafter were fed a finishing diet from d 112 until slaughter. Steers were divided into 2 BW groups (lighter-half and heavier-half), and assigned within groups to 24 pens (6 steers/pen). Virginiamycin did not affect (P > 0.20) ADG, but increased 340-d G:F (linear; P = 0.02) and dietary NE (linear; P = 0.04). Improvements in dietary NE were most pronounced during the final 116 d of the feeding period (linear; P = 0.04) that comprised the hot summer months (June through September). Monensin did not affect (P > 0.20) growth performance or dietary NE. Although average initial BW of the lighter-half and heavier-half BW groups differed by only 4 kg, the heavier BW group had greater HCW (13 kg, P = 0.02), LM area (5.4%, P = 0.01), ADG (4.3%, P = 0.02), G:F (2.3%, P = 0.08), and dietary NE (3.2%. P = 0.01) than the lighter BW group. In trial 2, 4 Holstein steers (269 +/- 3.5 kg) with cannulas in the rumen and proximal duodenum were used in a 4 x 4 Latin square design to evaluate treatment effects on digestion. Virginiamycin did not affect (P > 0.20) ruminal digestion of OM, NDF, starch, and N, and microbial efficiency, but tended to linearly increase (P = 0.09) ruminal N efficiency (nonammonia N flow to the small intestine/N intake). Likewise, virginiamycin did not affect (P > 0.20) postruminal or total tract digestion of OM, starch, NDF, and N. Compared with the control diet, monensin depressed total tract digestion of OM (4.2%, P = 0.03) and NDF (29.5%, P = 0.02). There were no treatment effects (P > 0.20) on ruminal pH, or ruminal lactate and total VFA molar concentration. Virginiamycin increased ruminal molar proportion of acetate (quadratic; P = 0.04) and estimated methane production (quadratic; P = 0.07), and decreased propionate molar proportion (quadratic; P = 0.09). Monensin did not affect (P > 0.20) ruminal VFA molar proportions or estimated methane production. We concluded that virginiamycin supplementation can enhance feedlot growth-performance and dietary energetic efficiency of calf-fed Holstein steers.

Enhancement of meat production by environmental manipulations in embryo and young broilers

Enhancing meat production by genetic selection for growth has already produced 5-week-old broilers weighing more than 2 kg. As growth performance characteristics continue to improve and the time it takes to achieve market size decreases, the period of embryonic development becomes a greater proportion of the bird's life. Therefore, in parallel to genetic selection, other approaches, such as environmental manipulations in the embryo or in the early days posthatch, are becoming more relevant for increasing muscle growth and meat production.Recently, we have shown that nutritional treatments, i.e., providing feed immediately posthatch, or environmental treatments, such as heat conditioning or monochromatic green-light illumination during the first days posthatch, increase muscle growth and breast muscle weight at marketing day. In all cases, the increase in muscle growth was due to changes at the cellular and molecular levels leading to increased satellite cell proliferation and differentiation.The significant effects on muscle growth resulting from the treatments in the first days posthatch raised the hypothesis that muscle growth could be affected during the embryonic development. In experiments in which eggs were illuminated under monochromatic green light from embryonic day 5 (E5), there was a positive effect on embryo development and posthatch muscle growth. Further studies revealed that this enhanced muscle weight was due to increased satellite cell number and fiber synchronization during early days posthatch. Thermal manipulation at 38.5°C from E16 to E18 for 3 h/day had a delayed effect on satellite-cell proliferation and differentiation, resulting in enhanced hypertrophy of myofibers at market age.

Effect of wheat enzyme preparation on the performance characteristics of Tom turkeys fed wheat-based rations

Wheat contains 5 to 8% nonstarch polysaccharides (NSP). The NSP complex forms a viscous mass when fully hydrated, which impedes the absorption of nutrients from chyme and causes reduced growth performance and osmotic diarrhea and associated wet litter. These adverse effects can be alleviated by appropriate enzyme supplementation. The objective of this experiment was to evaluate the efficacy of endoxylanase and beta-glucanase enzyme mixtures supplemented to wheat-based diets on growth performance characteristics of turkeys. Seven-day-old Large White male turkeys were randomly assigned to 40 litter floor pens of 12 poults each as a completely randomized block design arrangement of four experimental treatments and were raised to 140 d. The dietary treatment consisted of a control treatment (no supplemental enzyme) and three dietary enzyme treatments: 1) Lyxasan forte, 2) Natugrain Blend, and 3) Natugrain. Body weight, feed consumption, and mortality were recorded weekly. Feather condition was evaluated at 98 d of age. Natugrain Blend improved BW at 84 d (P < 0.075) and 112 d (P < 0.01) in comparison to the unsupplemented control diet. Lyxasan forte had the best feed/gain ratio throughout the experiment. Subjective feather condition score was significantly improved (P < 0.05) by all the three enzyme treatments and corresponded with reduced incidence of neck and back picking behavior. The enzyme treatment groups had lower mortality than the control group with the Natugrain blend treatment having the lowest mortality rate through the experiment. The results of this experiment demonstrate marginal improvement in growth performance of turkeys depending upon enzyme formulation.

Performance and hormone levels of immunocastrated, surgically castrated and intact male pigs fed ad libitum high- and low-energy diets

Immunocastration by immunisation against gonadotrophin-releasing hormone (GnRH), is a good alternative for surgical castration in male pigs, both to prevent boar taint and for animal welfare reasons. In this study we investigated the effect of immunocastration on growth performance of pigs from 25 to 110 kg fed two diets differing in NE f content. Sixty piglets were divided into 20 blocks. Each block consisted of three littermates: a boar, a surgical castrate and an immunocastrate. Two blocks were housed in each pen. The pigs were fed ad libitum and individual feed intake was recorded with an automatic feed registration device. A high-energy and a low-energy diet were fed (9.70 and 8.30 MJ NE f/kg, respectively, based on tabulated values). The immunocastrates were immunised at 10 and 17 weeks of age with 62.5 μg d-Lys6-GnRH tandem dimer peptide conjugated to ovalbumin in Specol adjuvant. Plasma testosterone levels in immunocastrates decreased after the first injection and reached non-detectable levels at 20 weeks of age and thereafter. Immunocastrates had non-detectable fat androstenone levels at slaughter. The results of the concomitant digestibility experiments showed that the estimated NE f contents of the diets were 9.64 and 9.04 MJ/kg, respectively. No differences were observed in digestibility of proximate nutrients among sexes, but digestibility of Ca and P was higher for boars and immunocastrates as compared to surgical castrates ( P<0.05). There was no interaction between type of diet and sex for growth performance characteristics except for energy conversion ratio, that approached significance ( P=0.095). Feed intake for immunocastrates and surgical castrates was similar, and was higher than for boars on both diets ( P<0.001). There was a tendency towards a better growth rate for immunocastrates compared to surgical castrates, irrespective of the energy level of the diet. When compared to boars, growth rate was higher in both immunocastrates and surgical castrates, which was significant only for the low-energy diet ( P<0.01). Energy conversion ratio (ECR; expressed as MJ NE f/kg gain) was better for boars than for surgical castrates ( P<0.05). For immunocastrates, ECR was in between that of boars and surgical castrates, and was better than for surgical castrates on the low-energy diet ( P<0.05). Meat percentage was higher for boars than for surgical castrates and immunocastrates ( P<0.05). On the high-energy diet, meat percentage was lower in immunocastrates than in surgical castrates ( P<0.05) but on the low-energy diet it was similar. The results of the present study demonstrate that there was a tendency towards a better growth performance for immunocastrates as compared to surgical castrates, especially on the low-energy diet.

The potential of transgenic animals for improved agricultural productivity

The techniques involved in the transfer of foreign DNA to domestic animals have advanced to the stage where transgenic animals that express foreign genes can be reliably produced, albeit still at low efficiency. This paper reviews the current status of some of the more important areas in agriculture where this technology is being applied. Numerous attempts have been made to modify the growth performance characteristics of domestic animals by the introduction of metallothionein/growth hormone fusion genes. A summary of our work with transgenic sheep is presented. The results demonstrate that the unregulated production of growth hormone in transgenic sheep reduces carcass fat, elevates metabolic rate and heat production, causes skeletal abnormalities and impairs survival. The introduction of new metabolic pathways to domestic animals offers an attractive approach to improved animal productivity. This paper summarises recent results of research directed towards the introduction of a cysteine biosynthetic pathway and the glyoxylate cycle to transgenic sheep. So far, the genes encoding the enzymes have been isolated and expressed both in cells in culture and in transgenic mice. The results of work currently in progress demonstrate that some modification of the fusion genes is required to enhance their expression in transgenic animals.

Biological characteristics for assessing low phosphorus intake in growing swine.

A total of 195 swine from 18 to 35 kg were used to evaluate various biological responses of growing swine fed low P diets at different Ca:P ratios. Three replicates of a randomized complete-block design in a 3 X 3 factorial arrangement of treatments were used. Total dietary P levels of .12, .31 and .50% were fed in 1:1, 1.5:1 or 3:1 Ca:P ratios. Diets were formulated using corn starch, dextrin and soy protein concentrate, with monosodium phosphate and limestone used to supply appropriate dietary treatment levels of Ca and P. Gain and feed performance were generally influenced by both Ca:P ratio and dietary P level. Serum inorganic P decreased linearly as Ca:P ratio widened and increased linearly as dietary P increased. Serum Ca concentrations responded inversely to serum inorganic P in response to both Ca:P ratio and dietary P level. Serum alkaline phosphatase was not affected by Ca:P ratio, but declined quadratically with increasing dietary P level. Bone bending moment was influenced by both dietary P level and Ca:P ratio. Bone component weights (ash, organic matrix), percentage bone ash and net accretion of bone ash and organic component weights were not influenced by Ca:P ratio but increased linearly as dietary P level increased. These results suggest that bone component weights, net ash accretion and percentage bone ash were more sensitive criteria than bone bending moment or serum alkaline phosphatase, which in turn were more sensitive than serum inorganic P, Ca, Mg and growth performance characteristics in response to dietary P level.