Journal of Agricultural Sciences and Natural Resources
Year:2006 | Volume:13 | Issue:Supplement (Special Issue Animal Science)|Papers Count:17

Effects of various concentrations of egg-yolk of 1.5, 2.5, 4 and 6% in tris diluent on the motility percentage of South Khorasan Cashmere goat's spermatozoa, after removing seminal plasma, in liquid storage at 4°C were studied in sheep breeding center of Abbas-abbad, Khorasan. Semen samples from five cashmere bucks were collected by an electro-ejaculator and centrifuged for seminal plasma removal. Washed semen samples were then extended in four diluents of tris buffers containing 1.5, 2.5, 4 and 6% egg-yolk, at a ratio of one part semen to two parts diluent. This experiment was carried out in a completely randomized design with 5 replications. The motility percentage of spermatozoa was 89.07, 84.99, 75.06 and, 66.01 in tris buffers containing 1.5, 2.5, 4 and, 6% egg-yolk, respectively. The motility percentage was highest in 1.5% and lowest in 6% egg-yolk concentration. The results show a significant decrease in sperm motility by increasing the egg-yolk in tris buffer (P<0.001). There fore, using egg-yolk concentration of 1.5% in tris diluents after the removal of seminal plasma is recommended for liquid storage of Cashmere goat semen.

An experiment was conducted in order to investigate the protein quality of canola meal compared to the protein quality of cottonseed meal and some nutritional characteristics of canola in two stages.In first stage, the amount of glucosinolate was measured in canola meal and CNCPS parameters evaluations were undertaken for canola and cottonseed meals. In second stage, a completely randomized with 4 treatments and 5 replications (Atabay lambs with average body weight 31+0.5kg) in each treatment was used to investigate the effect of different levels of canola meal on T3 and T4 levels of lambs blood. The results indicated that the canola meal used in the experiment contained about 14.75 micromole per gram DM aliphatic glucosinolates. Moreover, evaluation of CNCPS showed that there are some differences between these meals especially in B2 fraction of crude protein.The results of the next stage, indicated that the effect of different levels of canola meal on T3 and T4 levels was not statistically significant (p>0.05). Therefore, canola meal can be substituted in replace of cottonseed meal without any problem.

In order to determine in vivo and in vitro corn silage and alfalfa digestibility, an experiment was conducted with 16 Ghezele wethers. The chemical analysis of alfalfa and corn silage was determined. In this experiment, the digestibility was determined through regression equations. In vivo method, four treatments containing 0, 25, 50 and 75 percent of corn silage were considered with alfalfa-based diet. In this method, digestibility of all nutrients except crude protein were increased significantly with increased corn silage levels but a significant difference was not observed between digestibility of nutrients in rations containing 50 and 75% of corn silage. Relationship between corn silage levels and all of digestible nutrients was non- linear (second order equation) and its r2 was 96%. In the method of in vitro, digestibility of dry matter, organic matter and organic matter per dry matter of ration were increased with increasing of corn silage ratio from zero to 100%. The correlation coefficients between results of in vivo and in vitro methods on dry matter, organic matter and D-value for alfalfa were 99, 99 and 97 and corn silage was 96, 98 and 98 respectively. Among treatments, feed containing 75% alfalfa and 25% corn silage had the highest voluntary intake, but metabolically energy from intake containing 50% alfalfa and 50% corn silage was the highest. It is worth mentioning that concentration of metabolically energy increased with increasing of corn silage ratio.

The goal of this experiment was to determine the effect of restricted energy intake on plasma leptin concentration and ovulation rate in fat-tailed Chal ewes. Twenty-eight ewes with synchronized estrous cycles were selected and randomly assigned to control (n=14) or dietary energy-restricted (treated; n=14) groups. The ewes were fed at 60% (treatment) or 100% (control) of maintenance energy requirements level for 12 weeks (or six estrous cycles). Blood samples from four ewes in each group were collected twice weekly to measure plasma leptin concentration. In each oestrous cycle, ovulation number (by laparoscopy), body weight (BW), and body condition score (BCS) were determined.Differences in ovulation rate were compared by a Chi-squared test. RIA kits determined plasma leptin concentrations. BW, BCS and plasma concentrations were analysed by a repeated measures analysis of variance in the GLM procedure. In energy-restricted group, mean BW (P<0.01) and BCS (P<0.01), from 2nd to 6th oestrous cycle; mean plasma leptin concentration (P<0.01), from early 3rd oestrous cycle to the end of experiment; and ovulation rate, from 4th oestrous cycle to the end of experiment, were significantly decreased (P<0.05). A positive correlation between BW and BCS (P<0.01, r=+0.79), between BW and plasma leptin concentration (P<0.05, r=+0.50), and between BCS and plasma leptin concentration (P<0.01, r=+0.70) were obtained. The results indicated that there may be a remarkable relationship between plasma leptin concentration and energy intake level, BW, BCS and ovulation rate in fat-tailed ewes.

The objective of this study was to describe a mechanistic model, which stimulates preruminant calves growth based on three different indexes (Net energy, Apparently digestible protein and mean of them). Calves growth period was divided into: 1) Milk fed calves, 2) Milk+calf starter fed calves (Pre-weaning period) and 3) Post-weaning period. Model containts six pools: 1) Daily dry matter intake stimulation, 2) Feeds and their percent, Weather condition and calves birth weight, 3) Stimulation of feed's nutrients and their efficiency for growth or maintenance, 4) Simulation of protein requirement of calves, 5) Simulation of energy requirements of calves and 6) Simulation of weight gain, based on net energy and apparently digestible protein. The lowest estimation is based on net energy and highest one is based on apparently digestible protein in growth period, but simulation values basewomen energy, apparently digestible protein and mean of them are in the range of other studies. Model behavior about daily weight gain is similar to body weight at different days. Model made good dry matter intake stimulation in 90 days, although it was really hard to stimulate the dropping dry matter intake at weaning. Generally, it seems that based on recommended equations for calves growth up to 90 days of age, this mechanistic model could simulate calves growth completely sound.

The effect of alf alfa hay substitution with barley silage in diets containing whole cottonseed was studied using 8 precipitous Holstein cows. The animals were in early lactation period with live weight of 590±10 kg and 30±3.8 kg milk per day. In the control group, alfalfa hay was the only source of forage. In the other groups, alfalfa hay was replaced by barley silage at 33.3, 66.6 or 100 %. In all the rations, the forage: concentrate ratio was 36:64. Ten percent of whole cottonseed was added to all treatments. All diets were fed in form of TMR. The experimental cows were individually installed indoors and had free access to fresh water and salt blocks. Feed intake and milk yield were recorded daily. The dry matter digestibility (DMD), organic matter digestibility (OMD) and acid detergent fiber digestibility (ADFD) were measured using total faucal collection method. Data were statistically analyzed in a change over design with four treatments in four periods of 21 days. There were no significant differences between the average daily dry matter intake (19.5, 19.1, 19.3 and 20.1 kg/d for treatments 1, 2, 3 and 4, respectively). The ration had no effect on the DMD, OMD and ADFD. In addition, daily milk production, percentage and daily yields of fat, protein and lactose were not significantly affected by the different diets. Based on the cost of the rations, which were 29540, 28870, 28900and 29970 Reials respectively, the second ration is the most economical viable one.

A study was conducted to evaluate the efficacy of clinoptilolite to reduce the deleterious effects of aflatoxin in diets of broiler chicks. In this study 480 day-old Ross male chicks were used in six treatment (1: control, basal diet (without aflatoxin), 2:basal dite+500 ppb of total aflatoxins (AP), 3: basal diet+975 ppb of AF., 4: basal diet+clinoptilolite (20g/kg)., 5: basal dite+clinoptiolite (20g/kg)+aflatoxin (500ppb)., 6: basal dite+clinoptilolite (20g/kg)+aflatoxin (975 ppb)) with four replicates in completely randomized design from 1 day to 6 weeks of age. When compared to control, the AF treatment significantly decreased body weight gain, feed intake and increased feed conversion ratio (P<0.05). Changes in feed consumption, body weight gain and feed conversion ratio values were not significant by adding clinoptiolite to the AF-containing diet (5 and 6). Serum cholesterol, total protein, albumin, alkaline phosphatase and haematocrit values decreased significantly (P<0.05) in diets contaminated with aflatoxin (2 and 3). The aflatoxin treatment (2 and 3 groups) significantly increased values of white blood cell (WBC) primarily in heterophil counts (P<0.05). Supplementation of clinoptilolite to diets containing AF showed significant improvement in cholestrol, total protein, albumin, lactate dehydrogenase, aspartat amino transferees as well as values of haematocrit and WBC as compared to control group. The results showed that clinoptilolite supplementation could be used for detoxifying ration contaminated with aflatoxin.

The aim of conducting this research was determining the digestibility of some feedstuffs (barley straw and wheat straw of Ilam province, barley straw, wheat straw and clover "1st cut" of Kermanshah province) using in vivo method. For determination of digestibility, 4 male castrated adult sheep on the average 3 years old and 62±3.1 kg weight were used. Feeding level was regulated for clover adlibitum and for straws in maintenance (40 g DM/kg w0.75 of 60:40 for straw and cottonseed meal, respectively). Apparent digestibility of DM, OM and GE for Ham barley straw was 50.77±1.88, 54.00±1.87 and 40.73±3.38 percent, for Kermanshah barley straw 44.4±1.03, 48.3±1.33 and 33.8±1.12 percent, Ham wheat straw 45.69±2.96, 49.30±2.93 and 36.10±3.3 percent, Kermanshash wheat straw 44.65±1.32, 50.10±1.07 and 34.03±1.24 percent and clover 67.59±1.60, 71.84±1.72 and 65.13±1.73 percent respectively and digestibility of CP for clover 79.94±2.06 was determined. DMD, OMD and digestibility of GE for barley straw between provinces were significant (P<0.05). Significant difference wasn't observed between provinces for DMD, OMD and digestibility of GE for wheat straw (P>0.05).

To investigate the effects of different levels of calcium salt of long- chain fatty acids (Ca-LCFA) and replacing Cottonseed meal with Canola meal in dairy cow ration, an experiment was conducted with change over design (with a 2*2 factorial arrangement) including 4 rations, 4 periods of 21 days, and 8 dairy cows after calving. Treatments were including cottonseed meal or canola meal (15% of dietary dry matter) and fat supplement (Ca- LCFA) at 3 or 6% of dietary dry matter. Results of the experiment showed that there is no interaction between fat supplement and canola or cottonseed meal. Average daily milk production, milk fat percentage, Solid-Not-Fat (SNF), Dry Matter Intake (DMI) and Body Weight (BW), were not altered by inclusion of 15% canola meal or cottonseed meal (p>0.05), but milk protein percentage increased when cows fed with canola meal (2.86 vs. 2.81) (P<0.05). Daily milk production, milk protein percentage, milk fat percentage, body weight and SNF were not affected by feeding ration with 6% Ca- LCFA (p>0.05). 6% Ca-LCFA significantly decreased dry matter intake (24.94 vs 25.25 kg/day) (p<0.05). As a result, ration with 3% Ca-LCFA and replacing cottonseed meal with canola meal are suggested, without negative effects on milk production and composition in dairy cow ration in early lactation.

This experiment was conducted in order to evaluate effects of dietary protein level and betaine supplementation on performance and some blood parameters in broiler chickens subjected to heat stress. For this purpose, two basal diets were formulated according to NRC (1994) recommendation (19.4 % CP) and 0.85% of NRC (16.63 % CP) for protein. Each of the two basal diets was also supplemented with beanie at 1.5 gr/kg of diet, resulting to 4 dietary treatments. The diets were fed ad- Libitum to six replicate groups of 18 mixed sex broiler chicks of Ross strain from 21 to 49 days of age. The birds were exposed daily to heat stress for 8 hours (10:00 to 16:00h). Six birds in each replicate (3 birds from each sex) were wing banded in order to measure body temperature and blood parameters before and after heat stress. The results of experiment indicated that broilers were fed NRC protein diet with supplementation of betain had significantly higher weight gain (P<0.05) than those were fed low protein diets. Reducing dietary protein level resulted to decrease feed intake (P<0.05).Supplementing of betaine and dietary protein level had no significant effect on feed conversion ratio (P<0.05). Broilers were fed NRC protein diet had higher tight weight and lower abdominal fat than those were fed 0.85% NRC protein diet. Dietary protein level had no significant effect on blood glucose and urea before and after heat stress challenge (P>0.05), but had significant effecting blood uric acid concentration before heating time (P<0.05). Supplementing betain have not any significant effect on blood glucose, urea and uric acid (P>0.05). Blood uric acid concentration was higher in female than male before heating time (P<0.05). Heat stress challenge resulted to significantly increase of blood glucose, urea and uric acid concentrations (P<0.05).

Superovulatory response of Garganica and Maltese goats to FSH-P was studied during anestrus period. We chose 40 goats from two different breed and divided into 4 equal groups. Groups 1 and 2 consist of Garganica breed (n=20) and groups 3 and 4 consist of Maltese breed (n=20). Progestagen intravaginal sponge (FGA) was used for groups 1, 3 and 4 for 18 days. Group 2 received the same treatment but only for 11 days, plus prostaglandin analogue (ICI) was administered on the 10th day. The FSH-P was administered in steps, 7 injections (72 hours) for groups 1, 2, 3 and 4 injections (36 hours) for group 4. The first injection was given 48 hr (groups 1, 2, 3) and 24 hr (group 4) before the sponge removal animals were mated. Embryo recovery was done 7 days after the sponge removal. The results showed that the time of estrous was significantly more synchronized in groups 2 vs 1 and 4 vs 3. Significant differences were found in the ova recovery of group 3 vs groups 1 and 4 (81.1 vs 59.4, 46.9, p < 0.01); ova fertilized of 1 vs 3 (77.3 vs 61.1, P < 0.05); viable embryos of 1 vs 3 and 2 (84.3 vs 56.4, 67.2, P<0.05). The yield of viable embryos tended to be higher in Garganica goats with the treatment of FGA+ PG and with 7 injections of FSH-P.

The influence of three levels of digestible undegradable protein, 19.36 (1), 26.47 (2) and 33.08 (3) (g/Kg DM) on the performance and carcass characteristics of kermani male lamb breed was investigated. Thirty-six lambs aged 6-7 months with an initial live weight of 29.0±2.5 Kg were used.The animals which were twin-penned were fed a period of 95 days. The level of metabolisable energy, 10.5 MJ/Kg DM, was similar in all the rations. Dry matter intake (DMI) was measured daily and live weight gain (LWG) was determined fortnightly. At the end of the trial, 50 percent of the animals were slaughtered to characterize the carcass quality. The data were statistically analyzed using completely randomized design with 3 diets (n=12). Mean values for the performance of the lambs for 1, 2 and 3 rations were as follows: DMI 1480, 1510 and 1600 g/day (SE 0.019, P<0.05); LWG 173.2, 200.8 and 210.4 g/day (SE 5.8, P<0.05); feed conversion efficiency 8.54, 7.39 and 7.58 (SE 0.19, P<0.05). The dietary effect had no significant differences in the whole carcass weight, lean percent and fat percent. In conclusion, the optimum performance of Kermani breed was met with the ration contains 26.47 g digestible undegradable protein/Kg DM.

Feed efficiency is one of the most important traits in the meat producing animals including sheep.This trait can only be assessed through individual measurement of the feed consumption for each animal, which is very troblesome and costly. A measure which seems to be correlated with feed efficiency is Kleiber ratio, defind as the ratio of average daily gain over metabolic body weigh at the end of the underlying period. This study examined Kleiber ratio as an indirect selection criterion in order to improve the feed efficiency for the Kurdish sheep. A fattenning trial, for 15 weeks and in individual boxes, was conducted on 65 Kurdish lambs. During the experimental period Growth traits (including: birth weight, weaning weight, initial and final weights) and feed consumption were recorded. The correlation between the Kleiber ratio with average daily gain and feed efficiency were 0.88 and 0.85 respectively, which are high enough to support the idea of including the Kliber ratio in selection criteria. The phenotypic correlation between Kleiber ratio with birth weight, weaning weight and initial and final weights were -0.141, -0.143, -0.458 and 0.163, respectively, which are relatively low.

This experiment was conducted in order to study the effect of changing time of feeding from starter to grower diet and supplementing L-Iysine to starter and grower diets on broilers performance during 1 to 35 days of age. For this purpose, a completely randomized design with a 2*2 factorial arrangement was used to test the effects of 2 times of feeding starter (14 & 21 days) and 2 levels of supplemental Llysine (0 and 0.2%) to starter and grower diets. Eight replicates of 16 day-old Ross 308 male broilers were allocated to each of 4 experimental treatments. Reducing duration of feeding starter diet from 21 to 14 days resulted decrease in body weight gain at 21st day, but not at 28th and 35th days (P>0.05).Feed intake was reduced at days 21 and 28 (P<0.05), but feed conversion ratio was reduced only at 21st day (P=0.057). Broilers were fed starter diet for 14 days had lower protein intake during all three periods of experiment (P<0.05) and higher protein and energy efficiency ratio. Supplementing of 0.2% L-lysine to starter and grower diets containing the NRC lysine level significantly improved body weight gain (P<0.05), but had no significant effect on feed intake and protein intake (P>0.05). Protein and energy efficiency ratio was increased and production cost decrease by addition of 0.2% Lysine to starter and grower diets. Results of this experiment indicated that adding 0.2% L-lysine to starter and grower diets containing the NRC lysine level improved broilers performance and also changing time of feeding from starter to grower diet as early as 14 days of age improved efficiency of energy and protein utilization and reduced the cost of production.