A study was conducted to determine the effect of supplementing the diet of breeder hens with a shortchain fatty acid (SCFA) premix, containing 509 g fatty acid salts/kg of which 285 g were calcium butyrate, on their eggshell characteristics and the hatching percentage of the eggs. One thousand six hundred 66-week old White Bovans laying breeder hens were used in this experiment. They were housed in eight identical pens, each containing 200 birds, and four pens were used per treatment. The SCFA premix was included at 1000 mg/kg in the treatment diet, and fed for a period of nine weeks. Responses were compared with an unsupplemented treatment. Supplementation started when the hens were 66 weeks old. From day 75 eggs were collected for the next seven weeks and the occurrence of cracked, dirty and misshapen eggs was recorded, and the hatching percentage of the eggs was determined. Eggshell strength was lower in eggs from the control (1.76 ± 0.05) than from the treatment group (2.07 ± 0.03). The percentage of eggs produced by the control group (68.6 ± 0.08) was significantly lower than that by the supplemented group (71.5 ± 0.15). Percentage of dirty, cracked and misshapen eggs, and the hatchability percentage of the control group (1.15 ± 0.03, 3.44 ± 0.05, 6.27 ± 0.03 and 88.93 ± 0.06, respectively) were also significantly lower than in the group receiving SCFA (0.47 ± 0.03, 2.21 ± 0.03, 3.81 ± 0.03 and 93.36 ± 0.05, respectively). It was concluded that dietary supplementation of SCFA to layer breeder hens from 66 weeks of age onwards improved eggshell strength, reduced the percentage of dirty, cracked and misshapen eggs and increased the hatching percentage of the eggs. The positive responses were suggested to be largely due to the butyrate in the SCFA. _______________________________________________________________________________________

The study was conducted on 197 milk dairy cattle randomly selected from 950 breeding dairy cattle. These animals were monitored immediately after delivery and blood count and serum BHBA analyzes were performed weekly for the first 8 weeks. According to the results of the BHBA obtained, all animals in the study were divided into three groups as follows; a) Control Group "C"; serum BHBA levels below 1.2 mmol/l during the study b) Subclinical Ketosis Group "SK"; serum BHBA levels between 1.2 and 2.9 mmol/l c) Clinical Ketosis Group "CK"; serum BHBA levels were above 2.9 mmol/l. All performance parameters such as milk yield and reproductive efficacy obtained from the herd management program (Dairy Plan, Gea / Germany). TLS, LS, NS, MS levels were found to be higher in the SK and CK compared to the C. Especially, a strong positive interaction between TLS and blood BHBA level was determined (P <0,000). In addition, the incidence of mastitis, metritis and coexistence of these two infections was significantly higher in the SK and CK than in the C (p <0,013). Furthermore, the rate of culling was significantly higher in the SK and CK than C and it was also observed that this ratio increased in parallel with the severity of the ketosis (p <0.008). These findings show that hematologic parameters change significantly in animals that have undergone clinical or subclinical ketosis and that susceptibility to significant infectious diseases during the periparturient period such as mastitis and metritis increases and as a result, the rate of culling increases.