The comparisons of non-linear models to describe the growth performance of Lori-Bakhtiari sheep.

BACKGROUND: The study of growth traits is of interest to many animal scientists, regardless of specialization, due to the economic importance of growth rate, mature weight and other related traits. OBJECTIVE: This study aimed to compare six non-linear models for describing the growth of Lori-Bakhtiari sheep. METHODS: In order to collect weight data, 85 lambs (41 males and 44 females) were reared from birth to 140 days of age, and their growth patterns were recorded by measuring their body weight at 10-day intervals. Various mathematical functions, including the negative exponential, Brody, Gompertz, Logistic, Morgan-Mercer-Flodin (MMF) and Weibull, were used to model the relationship between body weight records and age. RESULTS: The results showed that the MMF and Gompertz models provided the best fit to the body weight data, whereas the negative exponential model exhibited the worst fit. In all models, the asymptotic weight of male lambs was higher than females. The research also revealed differences in growth patterns between male and female lambs. Overall, females had a lower absolute growth rate than males, but they reached their peak growth at an earlier period, and their growth rate declined faster. CONCLUSIONS: The differences in growth patterns between males and females indicate the importance of analysing male and female data separately when describing growth. As a result, Gompertz model can be recommended to Lori-Bakhtiari female and male lamb breeders to determine more accurate growth traits. In addition, it should be considered that feeding male and female lambs separately according to absolute growth rate values may increase growth performance.

Identification of hub genes associated with somatic cell score in dairy cow.

CONTEXT: Somatic cell count (SCC) is used as an indicator of udder health. The log transformation of SCC is called somatic cell score (SCS). AIM: Several QTL and genes have been identified that are associated with SCS. This study aimed to identify the most important genes associated with SCS. METHODS: This study compiled 168 genes that were reported to be significantly linked to SCS. Pathway analysis and network analysis were used to identify hub genes. KEY RESULTS: Pathway analysis of these genes identified 73 gene ontology (GO) terms associated with SCS. These GO terms are associated with molecular function, biological processes, and cellular components, and the identified pathways are directly or indirectly linked with the immune system. In this study, a gene network was constructed, and from this network, the 17 hub genes (CD4, CXCL8, TLR4, STAT1, TLR2, CXCL9, CCR2, IGF1, LEP, SPP1, GH1, GHR, VWF, TNFSF11, IL10RA, NOD2, and PDGFRB) associated to SCS were identified. The subnetwork analysis yielded 10 clusters, with cluster 1 containing all identified hub genes (except for the VWF gene). CONCLUSION: Most hub genes and pathways identified in our study were mainly involved in inflammatory and cytokine responses. IMPLICATIONS: Result obtained in current study provides knowledge of the genetic basis and biological mechanisms controlling SCS. Therefore, the identified hub genes may be regarded as the main gene for the genomic selection of mastitis resistance.

Comparing the effects of intravenous injection and intranasal atomisation of detomidine in sheep.

BACKGROUND: Detomidine is an α-2 agonist sedative drug which reduces the release of norepinephrine in nerves. Administering this drug through intranasal (IN) route could cause direct transmission to the central nervous system. Therefore, IN administration of detomidine would decrease the side effects and the onset of sedation. OBJECTIVES: In this study, IN administration of detomidine in sheep through an atomiser was compared to its IV administration. METHODS: Fifteen mature female sheep with an approximate weight of 49.53 ± 1.72 kg were used. They were randomly divided into three groups: (1) atomising 10 µg/kg (IND10 ); (2) IV 10 µg/kg (IVD) and (3) atomising 30 µg/kg (IND30 ). Following administration, vital signs, electrocardiographic components, sedative score and biochemistry profile were measured after 15, 30 and 60 min, which were compared with the baseline measures. RESULTS: Bradycardia and the percentage of reduction from the baseline value in the respiratory rate were lower in the IND10 group compared to those in the IVD group. There was no significant difference in terms of the temperature and blood oxygen saturation (SpO2 ) among all the groups (p > 0.05). The level of cortisol declined in all the groups, and in the IND30 (60 min), it was significantly different with the baseline value. The level of glucose increased in all the groups compared to the baseline, which was not significant. Insulin concentration was reduced in all the groups, and in the IND30 group, it changed significantly 60 min after the drug administration. Sedation onset time was faster in the IV group. However, sedation scores between the two administration methods were not different, and only a dose-dependent increase was found in the sedation score in the atomisation group. CONCLUSIONS: Our findings revealed that IN atomisation of detomidine triggers similar sedation as its IV administration, which could be used as an alternative method.