When a male pig from line of true-breeding (homozygous) black solid-hooved pigs was crossed to female breed red cloven-hooved their several progeny all looked alike?

When a male pig from a line of true-breeding (homozygous) black solid-hooved pigs was crossed to a female breed of red cloven-hooved, all their progeny looked alike because the male pig was homozygous for both dominant alleles (B/B, S/S) and the female pig was homozygous for both recessive alleles (b/b, s/s).

According to Mendelian inheritance principles, when a homozygous dominant individual is crossed with a homozygous recessive individual, all F1 offspring will be heterozygous (Bb, Ss) and will express the dominant phenotype. In this case, all the progeny will be black solid-hooved, which is the dominant phenotype for both coat color (black) and hoof type (solid).