ABSTRACT:This study was conducted to compare the effect of source of methionine (Met) in broken ricesoybean diet on performance, blood biochemistry, and fermentation characteristics in weaned pigs. Forty-eight male crossbreed pigs (BW 11 ± 0.1 kg) were randomly allocated to three groups with four replications in a completely randomized design. The experimental diets were: (1) basal diet without methionine (Control; total sulfur amino acids (TSAA) 0.60%); (2) basal diet supplemented with dl-methionine (DLM) (TSAA 0.76%); and (3) basal diet supplemented with dl-2-hydroxy-4-(methylthio) butanoic acid (LMA) (TSAA 0.76%). Supplementation with DLM and LMA improved growth performance of piglets and decreased blood urea nitrogen and increased serum albumin (P < 0.01). The population of Lactobacillus spp. in the caecum was decreased by both DLM and LMA supplementation (P < 0.05). Succinic acid concentration in the caecum of pigs fed the DLM diet was greater than that of LMA group (P < 0.05). It can be concluded that LMA can be used as a good source of Met (88% bioefficacy, weight/weight) in broken rice-soybean diet, although the serum albumin and fermentation characteristics (succinic acid) in the gastrointestinal tract were different.

This study was conducted to compare the effects of DL-2-hydroxy-4-[methylthio] butanoic acid (HMB) and DLmethionine (DLM) on egg production performance and egg quality of laying hens. Two hundred and eighty-eight commercial laying hens were assigned to 3 dietary treatment groups and fed the experimental diets from 34 to 46 weeks of age. The bioefficacy of HMB relative to DL-methionine (DLM) was set at 88% (weight/weight), therefore 0.115% of HMB and 0.101% of DLM were added to a basal diet. DLM and HMB supplementation increased body weight, feed intake, hen-day egg production, egg weight, FCR and egg mass (P＜0.01). These supplementations also increased yolk and albumen weight (g/egg) (P＜0.01), while DLM slightly decreased albumen weight (% of egg). Consequently, Haugh unit was poor by DLM supplementation but did not by HMB supplementation (P＜0.05). DLM supplementation significantly increased fat content in egg (g/egg and % of egg), though level of estradiol in blood was elevated by HMB supplementation. In conclusion, HMB supplementation (as 88% bioefficacy of DLM) can be used as an effective methionine source. However, mechanism of protein and fat synthesis and/or degradation of laying hens may be differed when different form of methionine is supplied.

These results indicate that there is a rapid postpartum resumption of follicular activity in both heavy- and light-strain cows, but that there is an earlier emergence of dominant follicles and ovulation in the former. Differences in luteal function, in terms of lower dioestrus progesterone concentrations and an earlier onset of luteolysis, in heavy- than light-strain cows might be sufficient to impair the fertility of the former.

These results confirm that H cows have poorer first-service conception rates than L cows, but do not support an hypothesis that there are major differences between these strains of Holstein-Friesian dairy cows in the rate of restoration in the hypothalamo-pituitary axis. However, in anoestrous cows, differences between strains in the endogenous release of LH maybe related to an earlier onset of oestrous cycles in H animals.

A study was conducted in Thailand with the aim of evaluating compensatory growth of emaciated cattle fed on ad libitum total mixed rations (TMR) under smallholder feedlot management. Two farms were identified where 121 cattle of various degrees of emaciation were bought for fattening trial. Cattle were grouped according to the degree of emaciation within respective pens and were fed on same type of feed throughout the feeding period. Feed intake was estimated on daily basis and was noted to be low during the start of the feeding trial but gradually increased in an increased rate up to the end of feeding period. The cattle with low weights and body condition scores at the beginning of feeding trial gained more weights than their counterparts which started with high body weights and high body condition scores. There was a significant (P < 0.01) difference between treatments in both weight gains and body condition scores. Final weight gains for bulls in a mixed pen under same feedlot environment were also significantly (P < 0.01) different. A positive linear correlation (r = 0.54) was also observed between weight gains of cattle and feed intake. It was concluded that degree of emaciation, feed intake, breed difference and sex significantly influenced compensatory growth.