No abstract

Chee is 1 of 4 important native chicken breed in Thailand. Genetic selection can be used to improve growth and carcass performance. The objective of this study was to compare growth and carcass performance of native chickens (Chee) with a population selected for economic traits (Chee KKU12) and natural selection (Chee N). Two hundred Chee KKU12 and Chee N chickens were divided into 5 replicates, 20 chickens per replication. Record growth and carcass quality for data analysis. The results showed that at 12 weeks of age, Chee KKU12 chickens (1,279.484 g) had a higher body weight than did Chee N chickens (1,180.212 g). The averages daily weight gain at 4-6, 6-8, and 0-12 weeks of age of Chee KKU12 chicken (17.861,19.230, and 14.843 grams) was higher than Chee N chickens (16.284, 17.497, and 13.668 g) (P<0.05). The carcass quality with mixed gender showed that Chee KKU12 chickens had higher breast (20.859%) and abdominal fat (0.659%) than Chee N chicken (19.585% and 0.217%, respectively) (P<0.05), but Chee KKU12 chicken thigh (17.007%) was significantly lower than Chee N chickens (18.627%). Regression analysis revealed that the selection of Chee KKU12 chickens for gain in weight will result in better carcass composition including wing (0.074 g), breast (0.089 g), and drumstick (0.134 g), while Chee N chicken had better thigh (0.189 g) when selected for high growth performance (P<0.05). It was concluded that chicken population selected for economic traits has a better growth performance in open housing conditions than naturally selected chickens.

No abstract

The purpose of this research was to study effects of climate changes on milk yield and milk composition of Holstein crossbred . This study uses data recording total milk production per farm each day and milk composition (from 2013-2017): fat percentage (% Fat), protein percentage (% Pro), solid not fat percentage (% SNF) and total solid percentage (% TS) from 79 farmers in Mahasarakham Province, Thailand. The temperature and humidity data were obtained from records of meteorological center. Using temperature and relative humidity for calculate temperature humidity index (THI). The effects of THI on milk yield and milk composition were assessed by procedure REG using SAS. The study indicated that, the weather was hot and humid. The temperature ranged from 20.88 -33.01 ° C. and average humidity was 72.59%. The highest THI (82.07) was in May. The relationship between THI and milk yield was negatively related. The slope value was -0.099, it meaning that when the THI value increased by 1 unit the milk yield decreased by 0.099 kg / cow / day. The THI group for effect of THI on milk yield and milk composition was set 4 groups (THI 1 = THI ≤70, THI 2 = 74 ≤THI <70, THI 3 = 78 ≤THI <74, THI 4 = THI> 78). The highest THI effect on low milk yield. In contrast, low THI (THI 1 and THI 2) effect on high milk yields. The climate change, temperature and humidity increase effects on milk production of dairy cows to decrease.

The objectives of the research were to determine the association of Dopamine Receptor D2 type (DRD2) and Vasoactive Intestinal Peptide (VIP) on egg production in 281 high egg strain of Pradu Hangdum Chiangmai chickens (HPHC). PCR-RFLP protocols were used to identify polymorphisms of both genes. The frequencies of TT, TC and CC genotypes of DRD2 were 0.05, 0.40, and 0.55, respectively. The frequencies of T and C alleles of DRD2 were 0.25 and 0.75, respectively. Regarding VIP, the frequencies of II, ID and DD genotypes were 0.59, 0.28, and 0.13, respectively. The frequencies of I and D alleles of VIP were 0.73 and 0.27, respectively. The association of DRD2 polymorphism were detected on egg number at 360 days (EN360) and egg per month (EM) (P<0.05). The chickens carrying the CC genotype had higher EN360 and EM (189.82 eggs and 15.81 eggs) and the ones carrying the TC (180.98 eggs and 15.08 eggs) and the TT genotype (176.38 eggs and 14.69 eggs) was non-significant. The VIP polymorphism were associated on egg number at 270 days (EN270), EN360 and EM (P<0.01). The DD genotype had higher EN270, EN360 and EM when compared to the ID and II genotypes. The DRD2 and VIP genes were moderate polymorphism and their alleles could be the potential genetic markers for chickens' selection to improve egg number.