The effect of altrenogest treatment timing and artificial lighting on hastening of ovulation in barren mares

Background: The mares are seasonally polyestrous animals that regular ovulatory cycles of mares occur together withincreasing day length. Exposure of mares to an artificial photoperiod is the most common and predictable technique thatit is used to develop follicular activity early in the year. Follicle activity is minimal in mares during two winter months ofJanuary and February in Northern Hemisphere. The main objective of this study was to investigate efficacy of artificiallighting and timing of altrenogest treatment for hastening the ovulation in Thoroughbred mares.Materials, Methods & Results: One hundred and six Thoroughbred mares had different follicle sizes ( 35 mm folicle size), and pregnancies were determined at 14, 28 and 50th daypostovulation. Statisticaly, mean and standard deviations and general linear model procedure was performed on Minitab 17,and Anova was used to analysis of variance. The averages of the major variations were compared with the Tukey’s multiplecomparison test. The factors effecting to pregnancy rate was analyzed by Chi-square test. Correlations were comparedwith the Pearson correlation test. The effect of initial months on the size of follicle diameter was found to be significant(P = 0.037). Artificial lighting had no effect on the initial follicle diameter (P = 0.919). The initial follicle diameter (P =0.001)...

The effect of altrenogest treatment timing and artificial lighting on hastening of ovulation in barren mares

Background: The mares are seasonally polyestrous animals that regular ovulatory cycles of mares occur together withincreasing day length. Exposure of mares to an artificial photoperiod is the most common and predictable technique thatit is used to develop follicular activity early in the year. Follicle activity is minimal in mares during two winter months ofJanuary and February in Northern Hemisphere. The main objective of this study was to investigate efficacy of artificiallighting and timing of altrenogest treatment for hastening the ovulation in Thoroughbred mares.Materials, Methods & Results: One hundred and six Thoroughbred mares had different follicle sizes (< 30 mm) wasevaluated under four groups. Mares undergoing only reproductive examination were control group Group I (n = 18). Themares has less than 30 mm in diameter folicle applied oral altrenogest (0.044 mg / bw, for 10 days) were grouped according to the month of application: Group II [February; n = 16], Group III [March; n = 57] and Group IV [April; n = 15].Ultrasonographical examinations performed at the day of admission and repeated twice a week for 15 days. Naturel matingwas planned considering to uterine edema (> 35 mm folicle size), and pregnancies were determined at 14, 28 and 50th daypostovulation. Statisticaly, mean and standard deviations and general linear model procedure was performed on Minitab 17,and Anova was used to analysis of variance. The averages of the major variations were compared with the Tukeys multiplecomparison test. The factors effecting to pregnancy rate was analyzed by Chi-square test. Correlations were comparedwith the Pearson correlation test. The effect of initial months on the size of follicle diameter was found to be significant(P = 0.037). Artificial lighting had no effect on the initial follicle diameter (P = 0.919). The initial follicle diameter (P =0.001)...(AU)

REPRODUCTIVE CHARACTERISTICS OF JAPANESE QUAILS (Coturnix coturnix japonica) HATCHED FROM EGGS INCUBATED UNDER DIFFERENT LIGHT COLORS

Objetivou-se avaliar o efeito de diferentes cores de luz durante a incubação dos ovos sobre os parâmetros reprodutivos de codornas japonesas machos e fêmeas. Um total de 1776 ovos foi incubado em quatro condições de iluminação, 24 horas por dia, durante todo o período de incubação: LED branca, LED verde, LED vermelha e escuro (controle). O delineamento experimental foi o de blocos ao acaso (época de incubação) com quatro tratamentos e seis repetições de duas gaiolas cada. Após a eclosão, as aves foram alojadas em gaiolas de cria com 18 aves cada até os 35 dias de idade, quando foram sexadas e transferidas para gaiolas de produção para avaliação dos parâmetros reprodutivos. Após o início da postura, o número de ovos de cada gaiola foi registrado diariamente e os valores foram utilizados para obter a idade das fêmeas ao primeiro ovo e aos 80% de postura. Aos 35 e aos 60 dias de idade um casal de aves de cada gaiola foi eutanasiado para avaliação anatômica e histológica das gônadas. Até os 60 dias de idade, duas fêmeas de cada gaiola foram pesadas a cada três dias para a determinação da curva de crescimento. Após os 60 dias, os ovos de cada gaiola foram coletados para avaliação da qualidade externa e interna. Aos 70, 74 e 78 dias de idade, coletas de sêmen foram realizadas para avaliação da qualidade seminal. Em seguida, os machos foram transferidos para gaiolas contendo 9 fêmeas para o teste de fertilidade. A eclodibilidade foi maior (P<0,05) nos ovos incubados no escuro e sob a LED vermelha. A idade de máximo crescimento foi maior (P<0,05) nas aves provenientes de ovos incubados no escuro e sob a LED branca. Não houve diferença (P>0,05) das cores de luz na incubação sobre as características anatômicas e histológicas dos testículos, com exceção do diâmetro dos túbulos seminíferos, que foi maior (P=0,06) no escuro e na LED branca. Não houve efeito (P>0,05) das diferentes cores de luz na incubação sobre os índices produtivos e qualidade dos ovos das aves adultas. Também não houve efeito (P>0,05) sobre a qualidade espermática, exceto na motilidade espermática, cujos valores foram maiores (P<0,05) nas aves provenientes de ovos incubados nas diferentes cores de luz. Porém, essa diferença não foi suficiente (P>0,05) para influenciar a fertilidade das aves. Conclui-se que a incubação dos ovos de codornas sob lâmpadas LED branca, vermelha e verde, nas condições que foram estudadas, não influencia as características reprodutivas das codornas na fase de produção.

The objective of this study was to evaluate the effect of different colors of light during the incubation of eggs on the reproductive parameters of male and female Japanese quails. A total of 1776 eggs were incubated in four lighting conditions, 24 hours a day, during the entire incubation period: white LED, green LED, red LED and dark (control). The experimental design was a randomized block (incubation time) with four treatments of six replicates of two cages each. After hatching, the birds were housed in brood cages with 18 birds each until 35 days of age, when they were sexed and transferred to production cages for evaluation of reproductive parameters. After the start of laying, the number of eggs in each cage was recorded daily and the values were used to obtain the age of the females at the first egg and at 80% of laying. At 35 and 60 days of age a couple of birds from each cage were euthanized for anatomical and histological evaluation of the gonads. Until 60 days of age, two females from each cage were weighed every three days to determine the growth curve. After 60 days, eggs from each cage were collected to assess external and internal quality. At 70, 74 and 78 days of age, semen collections were performed to evaluate seminal quality. Then, the males were transferred to cages containing 9 females for the fertility test. The hatchability was higher (P <0.05) in eggs incubated in the dark and under the red LED. The age of maximum growth was higher (P <0.05) in birds from eggs incubated in the dark and under the white LED. There was no difference (P> 0.05) in the light colors during incubation on the anatomical and histological characteristics of the testicles, except for the diameter of the seminiferous tubules, which was greater (P = 0.06) in the dark and in the white LED. There was no effect (P> 0.05) of the different colors of light in the incubation on the productive index and egg quality of adult birds. There was also no effect (P> 0.05) on sperm quality, except for sperm motility, which values were higher (P <0.05) in birds from eggs incubated in different colors of light. However, this difference was not sufficient (P> 0.05) to influence the birds' fertility. It is concluded that the incubation of quail eggs under white, red and green LED lamps, under the studied conditions, does not influence the reproductive characteristics of quails in the production phase.

The use of light-emitting diodes (LED) in commercial layer production

Artificial lighting is one of the most powerful management tools available to commercial layer producers. Artificial light allows anticipating or delaying the beginning of lay, improving egg production, and optimizing feed efficiency. This study aimed at comparing the performance of commercial layers submitted to lighting using different LED colors or conventional incandescent lamps. The study was carried out in a layer house divided in isolated environments in order to prevent any influenced from the neighboring treatments. In total, 360 Isa Brown layers, with an initial age of 56 weeks, were used. The following light sources were used: blue LED, yellow LED, green LED, red LED, white LED, and 40W incandescent light. Birds in all treatment were submitted to a 17-h continuous lighting program, and were fed a corn and soybean meal-based diet. A completely randomized experimental design with subplots was applied, with 24 treatments (six light sources and four periods) of three replicates. Egg production (%) was significantly different (p<0.05) among treatments, with the best results obtained with red LED, white LED, and incandescent light sources. Egg weight, feed intake, and internal egg quality (albumen height, specific gravity, and Haugh units) were not influenced (p>0.05) by light source. It was concluded that the replacement of incandescent light bulbs by white and red LEDs does not cause any negative effect on the egg production of commercial layers.(AU)

The use of light-emitting diodes (LED) in commercial layer production

Artificial lighting is one of the most powerful management tools available to commercial layer producers. Artificial light allows anticipating or delaying the beginning of lay, improving egg production, and optimizing feed efficiency. This study aimed at comparing the performance of commercial layers submitted to lighting using different LED colors or conventional incandescent lamps. The study was carried out in a layer house divided in isolated environments in order to prevent any influenced from the neighboring treatments. In total, 360 Isa Brown layers, with an initial age of 56 weeks, were used. The following light sources were used: blue LED, yellow LED, green LED, red LED, white LED, and 40W incandescent light. Birds in all treatment were submitted to a 17-h continuous lighting program, and were fed a corn and soybean meal-based diet. A completely randomized experimental design with subplots was applied, with 24 treatments (six light sources and four periods) of three replicates. Egg production (%) was significantly different (p 0.05) among treatments, with the best results obtained with red LED, white LED, and incandescent light sources. Egg weight, feed intake, and internal egg quality (albumen height, specific gravity, and Haugh units) were not influenced (p>0.05) by light source. It was concluded that the replacement of incandescent light bulbs by white and red LEDs does not cause any negative effect on the egg production of commercial layers.