Effects of the Alpha S1-Casein Genotype on Milk Yield and Milk Composition of Balkan Goat in Montenegro

Abstract

The objective of this study was to investigate genetic polymorphism of the alpha S1 casein gene and its association with milk production parameters (milk yield and milk composition) of indigenous Balkan goat breed reared in Montenegro. Two genetic variants (A and F) and three genotypes AA, AF and FF of alpha S1-casein have been identified. The analysis showed a prevalence of strong A allele (0.626) compared to the weak F allele (0.374), while the frequencies of genotypes were 0.398, 0.456 and 0.146 respectively. The effect of genotype of alpha S1 casein on the total milk yield, length of lactation and daily milk yield was not significant (p>0.05), while it is significantly influenced to the milk composition parameters. Goats with AA genotype of alpha S1 casein had significantly higher (p<0.001) average content of protein (3.54%) than AF and FF genotype (3.40% and 3.33%). The same genotypes order were for fat content and solid non-fat content (AA>AF>FF) with significant differences (p<0.05) of AA genotype in comparison to AF and FF. Genetic characterization of the alpha S1-casein gene contributes to the knowledge of the genetic structure of Balkan goat breed in Montenegro. These results could be important for establishing of the concept of conservation and sustainable use of this indigenous goat breed, as well as for selection scheme and breeding program.

A QUALITATIVE AND QUANTITATIVE ANALYSIS OF EXTRACTIVES FROM THE SPECIES Trifolium pratense L. IN THREE DIFFERENT SOLVENTS

“…The blood samples were maintained at -20⁰ C until used for DNA extraction. DNA extraction was performed using DNA isolation kit (ZYMO research, USA) according to manufacturer's instructions, while phenolchloroform standard protocol used for some samples (Marković et al, 2018). The quality of DNA was checked by Nano-Vue Spectrophotometer taking ratio of optical density (OD) value at 260 and 280 nm.…”

Analysis of the Genetic Structure of Slovak White Shorthaired Goat breed using CSN1S1 gene

“…The EE, FF, and AE, genotypes were observed in only 0.03 each (Anghel et al, 2019). The most common genotype in the Balkan goat breed was A*F: 0.456 (A* = A, B and C) and the less frequent was genotype FF:0.146 (Marković et al, 2018). The most common genotypes in Jamunapari were AA: 0.274 followed by BE and BC with frequencies of 0.163 each.…”

“…Italian breed Garganica has the Original scientific paper DOI: /10.5513/JCEA01/24.4.4010 GAŠPER et al: Analysis of the Genetic Structure of Slovak White Shorthaired Goat breed using... most frequent allele A, followed by F and B (Santillo et al, 2022). Montenegro population of Balkan breed shows, that genotype group A* consists of A, B and C alleles and has frequencies of 0.626 and allele F: 0.374 (Marković et al, 2018). In the Carpathian breed was observed the prevalence of alleles A (0.35) and B (0.40), whereas the occurrence of allele E was only 0.07 and F: 0.18 (Anghel et al, 2019).…”

Review: Genetic and protein variants of milk caseins in goats

“…The α-S1-casein strong variants produced around 3.6 g/L per allele, medium variants produced 1.1–1.6 g/L per allele, weak variants produced 0.45–0.6 g/L per allele, and null variants resulted in absence of the α-S1-casein in milk ( Grosclaude et al, 1987 ; Grosclaude and Martin, 1997 ; Martin et al, 1999 ). Strong variants with high content of α-S1-casein are most desired in dairy production since they are associated with lower pH values, better coagulation properties, faster curdling rate and greater gel firmness, which contribute largely to high yield and quality of cheese, even if the rennet coagulation time was longer ( Ambrosoli et al, 1988 ; Pirisi et al, 1994 ; Clark and Sherbon, 2000 ; Schmidely et al, 2002 ; Zullo et al, 2005 ; Caravaca et al, 2011 ; Devold et al, 2011 ; Cebo et al, 2012 ; Vacca et al, 2014 ; Johansson et al, 2015 ; Marković et al, 2018 ). Since the casein content in milk also affects the size of casein micelles and the amount and composition of milk fatty acids, cheese made from milk with strong α-S1-variants has a better structure and taste with less typical goat flavor than cheese produced from intermediate or weak variants ( Delacroix Buchet et al, 1996 ).…”

“…Goat milk that lacks α-S1-casein has a higher pH value and a low content of chemical components like total solids, protein, casein, Nitrogen, fat, and Phosphorus compared to milk with strong α-S1-casein variants ( Ambrosoli et al, 1988 ; Pirisi et al, 1994 ; Clark and Sherbon, 2000 ; Devold et al, 2011 ; Johansson et al, 2015 ; Marković et al, 2018 ). In addition, milk containing α-S1-casein null variants is characterized by large casein micelles with weak gel firmness and long coagulation time ( Devold et al, 2011 ; Johansson et al, 2015 ).…”