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 หัวเรื่อง:ผลของอายุเมื่อเริ่มจำกัดแสงต่อลักษณะการเจริญเติบโตและการให้ไข่ของไก่พื้นเมือง ผู้เขียน: Ratana Chotesangasa,  ดร.นิรัตน์ กองรัตนานันท์, รองศาสตราจารย์ สื่อสิ่งพิมพ์:pdf AbstractAn experiment was conducted to study the effect of ages at the onset of light restriction during growing period on growth and laying performance in the native chicken. Four groups of the native chickens were subjected to normal day length (NDL) and to restricted 8 hours/days lighting: started from the age of 10 weeks (LR10), or 12 weeks (LR12), and or 14 weeks (LR14), respectively; before being exposed to the same photoperiod of 15 hours/day from the age of 20 weeks. The results showed no significant difference (P>0.05) in the growth characteristics studied. The NDL, LR10, LR12 and LR14 groups had average body weights at 20 weeks of age of 1.38, 1.37, 1.34 and 1.36 kg; cumulative feed conversion ratios of 6.4, 6.6, 6.4, and 7.0; prelaying mortality rates of 2.5, 1.7, 1.1, and 1.0%, respectively. Age at the onset of light restriction affected sexual maturity of the native chicken. Ages at the onset of lay of the LR14 and LR12 pullets were 159.3 and 161.5 days, respectively, which were earlier than (P<0.05) 164.0 days of the LR10 pullet and 167.3 days of the NDL pullet. Body weights and egg weights at the onset of lay of the four groups were, however, not significantly different (P>0.05). In term of laying performance, the LR12 and LR14 groups showed a trend of having higher hen-day egg production and lower feed conversion ratios (for eggs) than the LR10 and NDL groups. A significant difference (P<0.05) was, however, observed only at some stages of production. Cumulative egg production of the LR12 and LR14 hens were 73.9 and 71.4 eggs/hen/28 weeks, respectively, which were higher than (P<0.05) 65.4 eggs/hen/28 weeks of the LR10 hen, and 64.2 eggs/hen/28 weeks of the NDL hen. Cumulative feed conversion ratios of the LR12 and LR14 groups were 4.9 and 4.8, respectively, which were lower than (P<0.05) 5.4 of the LR10 group and 5.5 of the NDL group. Subsequent laying mortality rate as well as egg weight and egg component were unaffected by light restriction during the growth phase. |
หัวเรื่อง:พัฒนาการและความสามารถทางการสืบพันธุ์ของไก่พื้นเมืองเพศผู้ เลี้ยงภายใต้ชั่วโมงแสงธรรมชาติและชั่วโมงแสง 15 ชั่วโมงต่อวัน ผู้เขียน:Ratana Chotesangasa, Nirat Gongrattananun สื่อสิ่งพิมพ์:pdf AbstractTo study the effect of photoperiod on growth and development of male reproductive organs and change of plasma testosterone levels, two groups of a hundred each of 12-week-old male native chickens were used. During 12-20 weeks of age both groups were kept under the same photoperiod of natural day length (NDL) and from 20 weeks of age onwards one group was assigned to the photoperiod of 15 hours a day (15L : 9D) while the other was remained under the NDL. It was found that, at some age levels, the 15L : 9D group had greater values (P<0.05) of the following characteristics than the NDL group, they were testicular weight (at 22 w, 12.25g vs 8.56g) vas deferens weight (at 22 w, 0.71g vs 0.35g),and testosterone level (at 22 w, 7.58 nmol/l vs 1.73 nmol/ l; at 24 w, 8.46 nmol/l vs 4.21 nmol/l). Body weight, vas deferens length and comb weight of the two groups were not different (P>0.05). To study the effect of photoperiod on semen production and quality, ninety-six of 20-week-old cockerels were allocated into 2 photoperiods of NDL and 15L : 9D with 4 replications of 12 each. Although the 15L:9D and NDL groups had their onset of semen ejaculation occurred at the same age of 23 weeks and with similar (P>0.05) body weights (2.37 kg vs 2.34 kg), their first semen volumes (0.18 ml/bird vs 0.10 ml/bird), number of birds with synchronous entry into the onset of semen ejaculation (10.42% vs 2.08%) and ages at 100% ejaculation of flock (34 w vs 36 w) were different (P<0.05). In term of semen quality, the two photoperiods yielded similar results. Semen volume, spermatocrit value, and semen concentration of the male native chickens were within the range of 0.34-0.41 ml/bird/ejaculation, 13.10-14.92%, and 6.60-7.62 million/mm3, respectively. The semen concentration in this experiment was determined via the spermatocrit value of semen which was measured and then substituted for the x value in regression equation of y = -0.7318846+0.56000099x. The regression equation was acquired earlier by the means of regression analysis of semen concentration (dependent variable, y) on spermatocrit value (independent variable, x). The method was proved highly reliable with correlation coefficient, r = 0.988 (P<0.001). In addition, sperm fertilizing ability of the two groups was not diferent. Fertility rates of the 15-month-old Isa Brown hens artificially inseminated with semen obtained from cockerels of different photoperiods were comparable and ranged from 60 to 79 per cent. |
หัวเรื่อง:การเจริญเติบโตและคุณภาพซากของไก่พื้นเมือง เลี้ยงภายใต้ชั่วโมงแสงธรรมชาติ และชั่วโมงแสงยาว 23 ชั่วโมงต่อวัน ผู้เขียน:Ratana Chotesangasa, Nirat Gongrattananun สื่อสิ่งพิมพ์:pdf AbstractThe effect of long photoperiod on growth, carcass yield, and carcass composition in native chickens were examined. Two lighting programmes of natural day length (NDL) and photoperiod of 23 hours/day (23L:1D) were set. It was found that the 23L:1D group tended to have better growth than the NDL group. Average body weights of the 23L:1D and NDL groups at 16 weeks of age were 1,508 g and 1,451 g and at 20 weeks of age were 1,803 g and 1,746 g, respectively, while feed conversion ratios of the two groups were not different (P>0.05). Both groups had low mortality rate of only 2-3% with no sign of leg disorder, ascites, and breast blister. In term of carcass yield, males responded to the long photoperiod more than females. As carcass weights of the females of both groups were not different (P>0.05), carcass weights of the male of 23L:1D group were higher than (P<0.05) those of the NDL group. Higher yields were found of those killed at 16 weeks of age in chilled carcass weight (1,606 g, 1,479 g, P<0.05), breast weight (317.9 g, 269.3 g, P<0.05), and drumstick weight (232.5 g, 208.0 g, P<0.05), and of those killed at 20 weeks of age in breast weight (378.4 g, 344.9 g, P<0.05). When compared between age, killing at the older age yielded more meat in term of actual carcass weight (P<0.05) but not in term of percentage of chilled carcass weight (P>0.05) except for the drumstick weight in the male (P<0.05). Chemical compositions of the carcass did not change due to photoperiods (P>0.05) but changed considerably due to ages at killing. In general, meat protein was increased from about 61.0% to 65.2% (P<0.05), meat ash was decreased from about 3.9% to 3.4% (P<0.05), and meat fat showed no noticable change (P>0.05) when compared between killing at 16 and 20 weeks of age. |
หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Effects of Mating Ratio, Cock Number in the Flock and Breeder Age on Fertility in Thai Native Chicken Flock) ผู้เขียน:Ratana Chotesangasa สื่อสิ่งพิมพ์:pdf AbstractTrials were conducted to determine general semen characteristics of the male native chicken and effects of mating ratio, cock number in the flock, and breeder age on fertility in the native chicken flock. The results revealed that the mature native male had the semen volume of about 0.4 ml/bird/ejaculation, spermatocrit value of about 13.86-15.60%, semen concentration of about 7031-8001 million cells/ml, and total sperm of about 2870-3200 million cells/ejaculation. The motility score and pH value were around 4- 5 and 7.7-8.4, respectively. The effect of mating ratios on fertility of the flock was not significantly different (P>0.05). The mean fertility rates measured during 35-44 weeks of (hen) age of the mating ratios of 1:7, 1:10, 1:13, and 1:16 were 88.21, 91.20, 88.20 and 79.82% ; and during 34-44 weeks of age of the mating ratios of 1:8, 1:12, and 1:16 were 84.31, 90.84, and 81.76% , respectively. The evidence which the lower trend of fertility rate occurring in the 1:16 flock disappeared after the exchange of cocks between the flocks indicated that sexual competency of the male played a major role in fertility of the breeding flock. Continuous surveillance on egg incubation results and immediate replacement of the ill with the healthy cocks wherever needed were suggested. Housing two cocks within a flock showed ambiguous influence. While it caused a decrease in fertility percentage on the 1:8 flock, it showed no ill effect at all on the 1:16 flock. Furthermore, the incidence of low fertility observed in the 1:12 flock when its sole male was ill confirmed that the high fertility of the flock depended heavily on sexual competency of the male and it could possibly have been secured if there were two cocks in the flock. The results revealed more of the benefit of housing two cocks within the same flock. The declining fertility rate of the old hens in their third year of age was greatly improved from the mean value of 58.32% for the flock with one cock to 81.20% for the flock with two cocks. For the effect of breeder age on fertility, the overall results of these experiments indicated that the native cocks aged from nine months to two years had similar fertilizing ability of about 80-90% whereas the native hens had their fertilizing ability decreased annually from about 80-90% in the first year, to about 70-80% in the second year, and 60-70% in the third year. |
หัวเรื่อง:ระดับสเตอรอยด์ฮอร์โมนพื้นฐาน และการพัฒนาการของอวัยวะสืบพันธุ์ของไก่พื้นเมืองและไก่ไข่ลูกผสมทางการค้าในสภาวะการให้ผลผลิตไข่ที่แตกต่างกัน ผู้เขียน:Ratana Chotesangasa, Supaporn Isriyodom, ดร.นิรัตน์ กองรัตนานันท์, รองศาสตราจารย์ สื่อสิ่งพิมพ์:pdf AbstractBasal steroid hormone profiled in plasma of the chicken changed according to states of egg production and degrees of oviduct development. Whereas the levels of basal progesterone and estradiol showed a clear connection with the he-day egg production, the levels of testosterone and progesterone were more likely involved with the degree of oviduct development. The hen with its hen-day egg production record above 80% (Good layer) had higher (P<0.05) concentration of progesterone and estradiol than the hen with its egg production record below 25% (Layer) and the hen which laid no egg at all (Nonlayer). When a comparison was made between the 2 breeds within the same group of Good layer, it was found that the native Good layer had lower testosterone and progesterone concentrations as well as lower oviduct weight than the commercial Good layer (P<0.05). The coincidence indicated a probable involvement of the two hormones in growth and development of the oviduct. States of development of the ovary and oviduct were also related to states of egg production. It was clear that the Good layer always had heavier and longer oviduct than the Layer and the Nonlayer (P<0.05). Despite holding the same good egg production record, the native Good layer tended to have lower degree of the oviduct development than the commercial Good layer, but only the oviduct weight that the significant difference (P<0.05) was observed. The numbers of small-sized follicles (diameter < 2 mm.) of the hens in different states of egg production or of different breeds were comparable (P>0.05). The numbers of medium-size (diameter 2-8 mm.) and large-size (diameter > 8 mm.) follicles tended to increase with the hen-day egg production. The native hen also showed a trend of having fewer number of the medium-sized and large-sized follicles. The differences were, however, not significant (P>0.05). |
หัวเรื่อง:ผลของวิธีการให้แสงต่อการเจริญเติบโตและความสามารถทางการให้ไข่ของไก่พื้นเมือง ผู้เขียน:Ratana Chotesangasa, Pinate Santipong สื่อสิ่งพิมพ์:pdf AbstractAn experiment was conducted to determine the effect of three lighting programmes on growth, laying performance, mortality rate and egg component in the native chicken. The three lighting programmes were : (a) the natural photoperiod during both growing and laying periods (group 12L,12L) the natural photoperiod during growing period and the photoperiod of 15 hours/day during laying period (group 12L,15L), and (c) the photoperiod of 8 hours/day during growing period and 15 hours/day during laying period (group 8L,15L). Average body weight gains, feed conversion ratios and prelaying mortality rates during growing period of three groups were not different (P>0.05). Of the 8L,15L group, 12L,15L group and 12L,12L group, ages at the onset of lay were 165.8, 171.8, and 188.8 days (P<0.05); body weights at the onset of lay were 1.5, 1.6, and 1.8 kilograms (P<0.05); and their first egg weights were 31.4, 34.7, and 35.7 grams (P<0.05), respectively. Percentages of hen-day egg production measured at 2-week intervals of the 8L,15L hen were higher (P<0.05) or tended to be higher than those of the other 2 groups. In term of cumulative egg production, the 8L,15L hen peoduced 70.7 eggs/hen/28 weeks which was higher than (P<0.05) 50.6 and 45.0 eggs/hen/28 weeks of the 12L,15L and 12L,12L hens, respectively. In general, the three different lighting programmes had no ong-term effect on feed conversion ratio in the native hen though different values (P<0.05) were sometimes observed in the early laying period. Laying mortality rate of the 8L,15L group was 40.9% which was higher than (P<0.05) 26.2% and 23.9% of the 12L,15L and 12L,12L groups, respectively. Average egg weights presented at 2-week intervals of the 8L,15L hen were lower or tended to be lower than those of the 12L,15L and 12L,12L hens almost throughout the laying period. The higher yolk percentage and lower albumen + shell percentage of the 8L,15L native hen were suggested to be the consequence of its imbalanced-increased function of the albumen + shell secreting oviduct to the yolk-ovulation ovary. |
หัวเรื่อง:ผลตอบสนองต่อการคั่นด้วยชั่วโมงแสงสั้นในช่วงกลางการไข่ของแม่ไก่พื้นเมือง ผู้เขียน:Ratana Chotesangasa, ดร.นิรัตน์ กองรัตนานันท์, รองศาสตราจารย์ สื่อสิ่งพิมพ์:pdf AbstractHen-day egg production, measured at 2-week intervals of the native hens interrupted with short photoperiod of 8 hours/day for 4 weeks before resuming long photoperiod of 15 hours/day (8L-15L group), tended to be higher than those of the native hens kept under continuous long photoperiod of 15 hours/day (Cont. 15L group). Significant differences (P<0.05) were, however, observed only at a few laying intervals. Though the hen-day egg production after resuming the long photoperiod of 15 hours/day of the 8L-15L group seemed to be improved, the cumulative egg production throughout the whole experimental period which included two rounds of exposure to the 4-week-short photoperiod and 12-week-long photoperiod cycle was not positively changed. It was only 56.0 eggs/hen/32 weeks compared with 57.4 eggs/hen/32 weeks (P>0.05) of the Cont. 15L group. Average feed conversion ratios of the 8L-15L group tended to be lower than those of the Cont. 15L group, with a significant difference (P<0.05) was observed only in round II of the experiment (7.2 vs 9.7) when the chicken grew older. Average egg weights were also improved (P<0.05) after a temporary interruption with the short photoperiod for 4 weeks. The 8L-15L hen had higher egg weights than the Cont. 15L hen (47.0 g vs 46.1 g in round I, and 47.8 g vs 46.9 g in round II). Increases in both albumen and shell actual weights were considered to be the cause of the greater egg weight. It was clear that the activity of the ovary and oviduct was changed according to the photoperiod the native hens received. Sizes and degree of development of both the ovary and oviduct of the 8L-15L group decreased tremendously when interrupted with the short photoperiod of 8 hours/day and then returned to even greater size with higher degree of development than of its counterpart, the Cont. 15L group, after resuming the photoperiod of 15 hours/day. Average fertility (percentage of live-fertilized eggs at 7 days of incubation) of the 8L-15L group was higher than (P<0.05) that of the Cont. 15L group (81.8% vs 75.3%). |
หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Short-Term Stressor Effects of Water Deprivation Prior to the Onset of Lay on Subsequent Reproductive Performance of ISA Brown Pullets ) ผู้เขียน:ดร.นิรัตน์ กองรัตนานันท์, รองศาสตราจารย์, Ratana Chotesangasa สื่อสิ่งพิมพ์:pdf AbstractThe influence of water deprivation prior to the onset of production on sexual maturity and subsequent reproductive performance was investigated in commercial pullets. Three hundred 16-weekold ISA Brown pullets were used in this study. The birds were housed in cages (100 cages of 3 birds/cage) situated in an open sided poultry shed and randomly divided into three treatment groups. The 3 groups were 1) control (received feed with water at all times) 2) dehydrated and 3) dehydrated+NH4Cl. Following an acclimatization period of 4 weeks, the birds in all groups were placed on a commercial layer ration and the treatments began. In the dehydrated and dehydrated+NH4Cl groups, the drinking water was removed completely from the pullets for 48 hours of dehydration but feed available at all times. The water was then returned to the birds following the water withdrawal period, and thereafter until the end of the trial. The pullets in the dehydrated+NH4Cl group were fed on the layer diet supplemented with 1%NH4Cl throughout the experimental period. It was found that feed intake dropped rapidly, by approximately 50%, when the birds were subjected to water deprivation. Neither age at first egg nor at 50-60 % of production was influenced by the interruption of drinking water supply. Little difference in egg weight at first egg was noted between the dehydrated birds and the normally hydrated hens. Pullets deprived of water were slower coming into egg production especially during the first 2 weeks of production period, however, thereafter egg production was similar among all treatment groups with numerical advantages for the normally hydrated hens. There were no carryover effects of water deprivation on subsequent egg weight, albumen weight, Haugh units, yolk weight or yolk color throughout the entire 12 weeks of the test. Body weights were not different either before the treatment or at the end of the study (P>0.05). The results might be interpreted as indicating that an interruption of drinking water supply for 2 days prior to the commencement of egg production induced transient effects of nutrient deficiency resulted in retardation of reproductive development. The acidified layer ration failed to show any positive effects on reproductive performance for the first 12 weeks of lay. The pullets, however, appeared to overcome the detrimental effects as they approached sexual maturity. |
หัวเรื่อง:การศึกษาการเจริญเติบโตและผลผลิตซากของไก่เบตง เปรียบเทียบกับไก่พื้นเมืองและไก่ลูกผสมเบตง x พื้นเมือง ผู้เขียน:Nirat Gongruttanannu, Ratana Chotesangasa สื่อสิ่งพิมพ์:pdf AbstractThis experiment was conducted to determine the growth rate and carcass yield of Betong (B) compared with those of crossbred Native (male) x Betong (female) (NB), crossbred Betong (male) x Native (female) (BN), and Native chickens (N). Day-old straight chickens were placed on battery cages and were slaughtered at 16 weeks of age. Body weight (BW) of B was consistently greater than (P<0.05) the other 3 breeds for the duration of the study, from hatching (32.80) to 16 weeks (2.486 kg) while the average cumulative feed conversion ratios for these periods were 1.80 and 3.79, respectively. BW of NB and BN were similar through the study even though at hatching BN had BW lower than NB (28.30 versus 32.40 g, respectively). Weights of B of whole carcass and carcass parts B were considerably greater than those of (P<0.05) the others, with this difference pronounced in both sexes. Yield (expressed on a percentage of chilled carcass weight basis) of pectoralis major of B in male (14.67%) was greater than (P<0.05) those of the other breed, and the same difference was shown in female (17.10%). However, there was no difference in yield of pectoralis minor among the 4 breeds of both sexes. Thigh yield of B, NB and BN in male were 18.15, 18.74 and 18.40% respectively, greater than (P<0.05) that of N (17.17%). Both yield of drumsticks and wings of B in male were fewer than the others whereas there was no difference in female. Yield of abdominal leaf fat was affected by sex, the greater yield was in female, whereas there was no difference among the 4 breeds of chickens. |
หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Effects of Dietary Sodium Bicarbonate Supplementation on Eggshell Quality and Hatchability in Thai Native Hens) ผู้เขียน:ดร.นิรัตน์ กองรัตนานันท์, รองศาสตราจารย์, Ratana Chotesangasa สื่อสิ่งพิมพ์:pdf AbstractAn investigation was conducted on Thai native hens to determine the effects of dietary sodium bicarbonate (NaHCO3) supplementation on egg production, egg and eggshell quality, fecal moisture content, plasma sodium, and hatchability performance. Two hundred and forty of 24 wk-old hens were used in this study. The birds were housed in individual cage and received 1 of 3 experimental diets. The 3 experimental diets were control layer diet, the control diet added with 1% NaHCO3, and the control diet added with 1.5% NaHCO3. The experiment was conducted for 24 weeks. There were no significant differences in feed consumption, egg weight, yolk weight, albumen weight, Haugh units or fecal moisture content among the three bird groups throughout the experimental period. However, the birds in the two groups having received the diet supplemented with NaHCO3 gave a significantly higher level of yolk color, shell weight, and shell thickness than the control hens transiently (P<0.05). Likewise, the hens received the diet added with NaHCO3 had a higher level of plasma sodium concentrations than the birds fed with control diet at 32 and 36 wk of age. A smaller, but still significant, increase in plasma pH was also observed in the fowls having consumed the diet supplemented with 1.5% NaHCO3 at 28 wk of age (P<0.05). Hatchability, viability (hatchability of fertile eggs), and body weight of the chick at hatching were not affected by the experimental diets (P>0.05). The results indicated that at moderate temperatures eggshell quality of Thai native hens could be improved by dietary supplementation with 1.5% NaHCO3. This suggested that the response was associated to bicarbonate intakes. However, the beneficial effect was transient that would be resulted from the hens having no access to feed during the dark period, irrespective of bicarbonate content, the time during which eggshell formation occured. Hatchability and viability of chicken embryos were not evident. |
หัวเรื่อง:การศึกษาเปรียบเทียบลักษณะการให้ไข่ และส่วนประกอบฟองไข่ของไก่พื้นเมืองและไก่ไข่ลูกผสมทางการค้า ผู้เขียน:Ratana Chotesangasa, Supaporn Isriyodom, Nitat Gongruttananun สื่อสิ่งพิมพ์:pdf AbstractRaised in individual cages under the same farm condition with free access to feed and water and under the 15L:9D lighting programme from 18 weeks of age onwards, the reproductive performance and egg component of the native and commercial laying hens were compared. At the onset of lay, the native hen had an average age of 152.8 d, 1.51 kg body weight and weight of first egg 28.9 g compared with the commercial laying hen which had an average age of 129.3 d, 1.42 kg body weight and weight of first egg 33.4 g. Hen-day egg production of the native hen was, at all time, lower than that of the commercial laying hen; with their peak production of 38.0 and 75.5%, respectively (P<0.05). Cumulative egg production of 91.6 eggs/hen/year of the native was much lower than that of 242.9 eggs/hen/year of the commercial (P<0.05). Average feed consumption values during laying period (20-72 weeks of age) of the native and commercial laying hens were about 81 and 100 g/hen/day, respectively (P<0.05). Feed conversion ratio, during the same period, of the native ranged from 5.3-176.8 whereas those of the commercial ranged from 2.4-3.7 (P<0.05). Average egg weight of the native was always lower than that of the commercial (P<0.05). Results obtained from the egg component study of the two breeds showed that yolk, albumen and shell weights of the native hen were 14.21, 25.45 and 4.52 g/egg and of the commercial hen were 14.64, 37.24 and 5.42 g/egg, respectively (P<0.05). The evidence that the albumen and shell portions of the native were much lower than those of the commercial whereas the yolk portion was not much different, suggested that the lower egg weight of the native was mainly contributed to its lower oviduct function. |
หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Effects of Water Deprivation during the Prelaying Period on Eggshell Quality, Wet Droppings and Blood Physiology in Laying Hens) ผู้เขียน:ดร.นิรัตน์ กองรัตนานันท์, รองศาสตราจารย์, Ratana Chotesangasa สื่อสิ่งพิมพ์:pdf AbstractThe influence of water deprivation at the onset of lay on subsequent eggshell quality, fecal moisture content and blood physiology was investigated in ISA Brown pullets. Kidney and bone appearances were also determined at the end of the study. The pullets were randomly divided into 3 groups; control, dehydrated, and dehydrated+NH4Cl groups. The birds in the control group were provided a layer diet with water at all times. At 20 weeks of age, drinking water supply in the dehydrated and dehydrated+NH4Cl groups was removed completely for 48 hours whereas feed was available at all times. Thereafter, the water was provided until the end of the trial. The birds in the dehydrated+NH4Cl group were fed on the control diet added with ammonium chloride (NH4Cl) at a level of 1% throughout the rehydration phase. Water deprivation for 2 days at the onset of lay did not affect eggshell quality throughout the experimental period. An incidence of poor eggshell was observed in the dehydrated+NH4Cl group as evidenced by reduced shell weight and shell thickness at 24 weeks of age (P<0.05). During the 2 days of dehydration, fecal moisture contents were significantly reduced for the birds in the two groups of dehydration. However, the excreta moisture of the birds in these groups increased rapidly as the drinking water was returned and significantly greater than that of the control birds by 6 hours of water replenishment. On Week 8 of rehydration, the increase of the manure moisture was observed again for the dehydrated+NH4Cl hens when compared with the control birds (P<0.05). Interruption of available drinking water increased hematocrit values for the two groups of dehydration during 48 hours of water deprival. Hematocrit values of the hens in these groups, however, were rapidly decreased as the water was reintroduced and significantly reduced on Week 8 of rehydration for the dehydrated hens fed with the acidified diet. Water deprivation was associated with increases in the concentration of sodium in plasma whereas plasma pH was inconsistent and varied among the experimental groups. Decreased humerus weight was observed in the dehydrated+NH4Cl hens necropsied at the end of the study. |