ที่มา:วิทยาสารเกษตรศาสตร์ สาขา วิทยาศาสตร์

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

Abstract

The 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.

Article Info

Agriculture and Natural Resources -- formerly Kasetsart Journal (Natural Science), Volume 039, Issue 2, Apr 05 - Jun 05, Page 226 - 234 |  PDF |  Page

ที่มา:วิทยาสารเกษตรศาสตร์ สาขา วิทยาศาสตร์

หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Effects of Red Light Illumination on Productivity, Fertility, Hatchability and Energy Effi ciency of Thai Indigenous Hens)

ผู้เขียน:ดร.นิรัตน์ กองรัตนานันท์, รองศาสตราจารย์, Pannapat Guntapa

สื่อสิ่งพิมพ์:pdf

Abstract

This study was conducted to determine the effects of red light exposure on the productivity, fertility and hatching characteristics in Thai native hens (Gallus domesticus). A total of 120 birds aged 18 wk were housed in an open-sided shed and exposed to one of the following lighting treatments: 1) natural daylight supplemented with fl uorescent light (Control), 2) natural daylight supplemented with red light (NR) and 3) red light as the sole light source (R). The red light was produced by light- emitting diodes. All treatments were provided with a daily light:dark photoperiod of 16:8 hr over a 28-week egg-laying period, and there were four replicate pens of 10 hens for each treatment. Photostimulation of the light sources was initiated at age 18 wk and any subsequent effects on the live performance and reproductive traits were observed during the experimental period. Feed and water were available at all times. Body weights, feed consumption and mortality rates were similar among the treatment groups. The age at fi rst egg of the NR birds (130.7 d) was comparable to that of the R birds (129.2 d) which was signifi cantly less than that of the control hens (134.7 d). During the fi rst week of the laying period, R hens produced more eggs than did hens in the control treatment (P < 0.05), whereas the NR birds exhibited an intermediate value between those groups. At 2 wk after photostimulation, the serum estradiol concentration was signifi cantly higher for hens in the R treatment compared to those of the control and NR treatments. The hematocrit values of the birds in the R treatment tended to be lower than those of the other two treatments in some periods of the study. During the lighting period from weeks 6 to 8, a signifi cantly improved feed conversion ratio was observed in the R and NR treatments compared to that of the control treatment. No signifi cant differences in egg weight, egg and eggshell quality or any parameters of hatching occurred between the R and control groups. The weights of the ovary, pituitary gland, spleen and the abdominal fat were similar for all light treatments. It was concluded that photostimulation by red light resulted in an acceleration of sexual development in Thai native hens compared to hens exposed to full-spectrum lighting; however, live performance, egg production, egg and eggshell quality, and fertility were not affected whatever the light treatment. The light-emitting diode lighting regimens could be benefi cial for energy conservation and the reduction of rearing costs in laying hens.

Article Info

Agriculture and Natural Resources -- formerly Kasetsart Journal (Natural Science), Volume 046, Issue 1, Jan 12 - Feb 12, Page 51 - 63 |  PDF |  Page